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Marom R, Dau JJ, Ghani KR, Hall TL, Roberts WW. Assessing renal tissue temperature changes and perfusion effects during laser activation in an in vivo porcine model. World J Urol 2024; 42:197. [PMID: 38530484 DOI: 10.1007/s00345-024-04896-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 02/21/2024] [Indexed: 03/28/2024] Open
Abstract
INTRODUCTION High fluid temperatures have been seen in both in vitro and in vivo studies with laser lithotripsy, yet the thermal distribution within the renal parenchyma has not been well characterized. Additionally, the heat-sink effect of vascular perfusion remains uncertain. Our objectives were twofold: first, to measure renal tissue temperatures in response to laser activation in a calyx, and second, to assess the effect of vascular perfusion on renal tissue temperatures. METHODS Ureteroscopy was performed in three porcine subjects with a prototype ureteroscope containing a temperature sensor at its tip. A needle with four thermocouples was introduced percutaneously into a kidney with ultrasound guidance to allow temperature measurement in the renal medulla and cortex. Three trials of laser activation (40W) for 60 s were conducted with an irrigation rate of 8 ml/min at room temperature in each subject. After euthanasia, three trials were repeated without vascular perfusion in each subject. RESULTS Substantial temperature elevation was observed in the renal medulla with thermal dose in two of nine trials exceeding threshold for tissue injury. The temperature decay time (t½) of the non-perfused trials was longer than in the perfused trials. The ratio of t½ between them was greater in the cortex than the medulla. CONCLUSION High-power laser settings (40W) can induce potentially injurious temperatures in the in vivo porcine kidney, particularly in the medullary region adjacent to the collecting system. Additionally, the influence of vascular perfusion in mitigating thermal risk in this susceptible area appears to be limited.
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Affiliation(s)
- Ron Marom
- Department of Urology, University of Michigan, 4432 Medical Science I, 1301 Catherine Street, Ann Arbor, MI, 48109-5330, USA.
| | - Julie J Dau
- Department of Urology, University of Michigan, 4432 Medical Science I, 1301 Catherine Street, Ann Arbor, MI, 48109-5330, USA
| | - Khurshid R Ghani
- Department of Urology, University of Michigan, 4432 Medical Science I, 1301 Catherine Street, Ann Arbor, MI, 48109-5330, USA
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - William W Roberts
- Department of Urology, University of Michigan, 4432 Medical Science I, 1301 Catherine Street, Ann Arbor, MI, 48109-5330, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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Best SL. Ho:YAG laser and dusting-high power vs low power: there is no difference. World J Urol 2024; 42:96. [PMID: 38386126 DOI: 10.1007/s00345-024-04788-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/10/2024] [Indexed: 02/23/2024] Open
Abstract
The introduction of the Ho:YAG laser 3 decades ago revolutionized the endoscopic treatment of urolithiasis. Since then, a variety of innovations have continued to evolve these devices, including the development of high-power lasers capable of high-frequency lithotripsy. The clinical utility of high-frequency lithotripsy, however, has not necessarily lived up to the potential suggested by in vitro studies. A review of the relevant literature, confirming strong similarities between the outcomes associated with high and lower power laser lithotripsy, follows.
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Affiliation(s)
- Sara L Best
- Department of Urology, School of Medicine and Public Health, University of Wisconsin, 1685 Highland Ave MFCB 3rd Floor, Madison, WI, 53705, USA.
- Litholink Corporation, Laboratory Corporation of America Holdings, Chicago, IL, USA.
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Mishra A, Medairos R, Chen J, Soto-Palou F, Antonelli J, Preminger GM, Lipkin ME, Zhong P. Exploring optimal settings for safe and effective thulium fibre laser lithotripsy in a kidney model. BJU Int 2024; 133:223-230. [PMID: 37942684 PMCID: PMC10947524 DOI: 10.1111/bju.16218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
OBJECTIVES To explore the optimal laser settings and treatment strategies for thulium fibre laser (TFL) lithotripsy, namely, those with the highest treatment efficiency, lowest thermal injury risk, and shortest procedure time. MATERIALS AND METHODS An in vitro kidney model was used to assess the efficacy of TFL lithotripsy in the upper calyx. Stone ablation experiments were performed on BegoStone phantoms at different combinations of pulse energy (EP ) and frequency (F) to determine the optimal settings. Temperature changes and thermal injury risks were monitored using embedded thermocouples. Experiments were also performed on calcium oxalate monohydrate (COM) stones to validate the optimal settings. RESULTS High EP /low F settings demonstrated superior treatment efficiency compared to low EP /high F settings using the same power. Specifically, 0.8 J/12 Hz was the optimal setting, resulting in a twofold increase in treatment efficiency, a 39% reduction in energy expenditure per unit of ablated stone mass, a 35% reduction in residual fragments, and a 36% reduction in total procedure time compared to the 0.2 J/50 Hz setting for COM stones. Thermal injury risk assessment indicated that 10 W power settings with high EP /low F combinations remained below the threshold for tissue injury, while higher power settings (>10 W) consistently exceeded the safety threshold. CONCLUSIONS Our findings suggest that high EP /low F settings, such as 0.8 J/12 Hz, are optimal for TFL lithotripsy in the treatment of COM stones. These settings demonstrated significantly improved treatment efficiency with reduced residual fragments compared to conventional settings while keeping the thermal dose below the injury threshold. This study highlights the importance of using the high EP /low F combination with low power settings, which maximizes treatment efficiency and minimizes potential thermal injury. Further studies are warranted to determine the optimal settings for TFL for treating kidney stones with different compositions.
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Affiliation(s)
- Arpit Mishra
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina
| | - Robert Medairos
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Junqin Chen
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina
| | - Francois Soto-Palou
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Jodi Antonelli
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Glenn M. Preminger
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Michael E. Lipkin
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - Pei Zhong
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina
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He Z, Xun Y, Wang S. Evaluation of a novel circulation system for ureteroscopic laser lithotripsy in vitro. World J Urol 2024; 42:62. [PMID: 38285266 DOI: 10.1007/s00345-023-04705-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 11/01/2023] [Indexed: 01/30/2024] Open
Abstract
PURPOSE To evaluate the cooling effect and other advantages of a novel circulation system for ureteroscopic holmium laser lithotripsy (URSL) in a standardized in vitro model. MATERIALS AND METHODS The novel circulation system was assembled by connecting a 4Fr ureteral catheter and a filter. Trails were divided into a new URSL group and a conventional URSL group. First, different power settings (18-30 W) of the holmium laser and irrigation flow rates (20-50 mL/min) were used to evaluate the thermal effect on the lithotripsy site of all groups. Then, renal pelvic temperature and pressure were assessed during URSL at a power of 1.5 J/20 Hz and irrigation flow rates of (20-50 mL/min). Finally, the whole process of lithotripsy was performed at 1.5 J/20 Hz (operator duty cycle ODC: 50%) with an irrigation flow rate of 30 mL/min. The time required for lithotripsy, visual field clarity, and stone migration were observed. RESULTS Temperature of the lithotripsy point was significantly lower in the new URSL group than in the conventional group (P < 0.05) with irrigation rates (20, 30 mL/min). The renal pelvic pressure of the new group was significantly lower than that of the conventional group in which intrarenal hypertension developed at an irrigation rate of 50 ml/min. The new group had better visual clarity and lesser stone upward migration when lithotripsy was performed at 1.5 J/20 Hz and 30 ml/min. CONCLUSION The novel circulation system is more effective in reducing the thermal effects of URSL, pelvic pressure, stone upward migration, and improving the visual clarity of the operative field.
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Affiliation(s)
- Zonghai He
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, Hubei, People's Republic of China
- Department of Urology, Hospital of Kunming Medical University, Kunming, People's Republic of China
| | - Yang Xun
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, Hubei, People's Republic of China.
| | - Shaogang Wang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, Hubei, People's Republic of China.
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Tonyali S, von Bargen MF, Ozkan A, Gratzke C, Miernik A. The heat is on: the impact of excessive temperature increments on complications of laser treatment for ureteral and renal stones. World J Urol 2023; 41:3853-3865. [PMID: 38010538 PMCID: PMC10693507 DOI: 10.1007/s00345-023-04652-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 09/21/2023] [Indexed: 11/29/2023] Open
Abstract
OBJECTIVE Technological advancements in the field of urology have led to a paradigm shift in the management of urolithiasis towards minimally invasive endourological interventions, namely ureteroscopy and percutaneous nephrolithotomy. However, concerns regarding the potential for thermal injury during laser lithotripsy have arisen, as studies have indicated that the threshold for cellular thermal injury (43 °C) can be exceeded, even with conventional low-power laser settings. This review aims to identify the factors that contribute to temperature increments during laser treatment using current laser systems and evaluate their impact on patient outcomes. MATERIALS AND METHODS To select studies for inclusion, a search was performed on online databases including PubMed and Google Scholar. Keywords such as 'temperature' or 'heat' were combined with 'lithotripsy', 'nephrolithotomy', 'ureteroscopy', or 'retrograde intrarenal surgery', both individually and in various combinations. RESULTS Various strategies have been proposed to mitigate temperature rise, such as reducing laser energy or frequency, shortening the duration of laser activation, increasing the irrigation fluid flow rate, and using room temperature or chilled water for irrigation. It is important to note that higher irrigation fluid flow rates should be approached cautiously due to potential increases in intrarenal pressure and associated infectious complications. The utilization of a ureteral access sheath (UAS) may offer benefits by facilitating irrigation fluid outflow, thereby reducing intrapelvic pressure and intrarenal fluid temperature. CONCLUSION Achieving a balance between laser power, duration of laser activation, and irrigation fluid rate and temperature appears to be crucial for urologists to minimize excessive temperature rise.
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Affiliation(s)
- Senol Tonyali
- Department of Urology, Faculty of Medicine, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg, Germany.
| | - Maximilian Ferry von Bargen
- Department of Urology, Faculty of Medicine, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Arif Ozkan
- Department of Urology, Koc University Hospital, Istanbul, Turkey
| | - Christian Gratzke
- Department of Urology, Faculty of Medicine, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Faculty of Medicine, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg, Germany
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Solano C, Corrales M, Panthier F, Candela L, Doizi S, Traxer O. Navigating urolithiasis treatment: assessing the practicality and performance of thulium fiber laser, holmium YAG, and thulium YAG in real-world scenarios. World J Urol 2023; 41:2627-2636. [PMID: 37468656 DOI: 10.1007/s00345-023-04487-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 06/07/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND The management of urolithiasis has undergone significant advancements with the introduction of pulsed lasers, particularly the holmium:yttrium-aluminum-garnet (Ho:YAG) laser, which is currently considered the gold standard in endourology. However, the Ho:YAG laser has certain limitations, such as the inability to support small laser fibers (150 μm) and the requirement of a heavy water cooling system, making it challenging to transfer between operating rooms. These limitations have led to the emergence of new laser technologies, including the thulium fiber laser (TFL) and the thulium:yttrium-aluminum-garnet laser (Tm:YAG), as potential alternatives to the Ho:YAG laser. METHODS In this review, we aimed to evaluate the effectiveness and safety of TFL, Ho:YAG, and Tm:YAG lasers in real-life scenarios by comparing clinical trial data with laboratory findings. A literature review was conducted, and relevant in vitro studies and clinical trials until March 2023 were analyzed. RESULTS The findings indicate that TFL has demonstrated high ablation efficiency for stones of any composition, size, and location, superior the capabilities of Ho:YAG lasers. TFL has shown superior dusting and fragmentation abilities, lower retropulsion, and increased patient safety. The laser parameters, such as ablation efficiency, speed, operative time, dust quality, retropulsion, visibility, temperature safety, and stone-free rate, were compared between laboratory studies and clinical outcomes. CONCLUSION Although the number of studies on TFL is limited, the available evidence suggests that TFL represents a significant advancement in laser technology for lithotripsy. However, further research is needed to fully explore the implications and limitations of TFL and Tm:YAG lasers.
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Affiliation(s)
- Catalina Solano
- GRC n20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France
- Department of Endourology, Uroclin S.A.S, Medellín, Colombia
| | - Mariela Corrales
- GRC n20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France
| | - Frederic Panthier
- GRC n20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France
| | - Luigi Candela
- GRC n20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France
- Division of Experimental Oncology/Unit of Urology, URI-Urological Research Institute IRCCS Ospedale San Raffaele, Milan, Italy
| | - Steeve Doizi
- GRC n20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France
| | - Olivier Traxer
- GRC n20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université, 75020, Paris, France.
- Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université, 4 Rue de la Chine, 75020, Paris, France.
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Panthier F, Pauchard F, Traxer O. Retrograde intra renal surgery and safety: pressure and temperature. A systematic review. Curr Opin Urol 2023; 33:308-317. [PMID: 37140545 DOI: 10.1097/mou.0000000000001102] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
PURPOSE OF REVIEW Retrograde intra renal surgery (RIRS) with laser lithotripsy represents the gold-standard to treat renal stones up to 20 mm. Controlling intraoperative parameters such as intrarenal pressure (IRP) and temperature (IRT) is mandatory to avoid complications. This article reviews advances in IRP and IRT over the last 2 years. RECENT FINDINGS We conducted a PubMed/Embase search and reviewed publications that include temperature and pressure during RIRS. Thirty-four articles have been published which met the inclusion criteria. Regarding IRP, a consensus has emerged to control IRP during RIRS, in order to avoid (barotraumatic and septic) complications. Several monitoring devices are under evaluation but none of them are clinically approved for RIRS. Ureteral access sheath, low irrigation pressure and occupied working channel help to maintain a low IRP. Robotic systems and suction devices would improve IRP intraoperative management and monitoring. IRT determinants are the irrigation flow and laser settings. Low power settings(<20 W) with minimal irrigation flow (5-10 ml/min) are sufficient to maintain low IRT and allows continuous laser activation. SUMMARY Recent evidence suggests that IRP and IRT are closely related. IRP depends on inflow and outflow rates. Continuous monitoring would help to avoid surgical and infectious complications. IRT depends on the laser settings and the irrigation flow.
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Affiliation(s)
- Frédéric Panthier
- GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université
- Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université
- PIMM, UMR 8006 CNRS-Arts et Métiers ParisTech, Paris, France
- Progressive Endourological Association for Research and Leading Solutions (PEARLS)
| | - Felipe Pauchard
- Progressive Endourological Association for Research and Leading Solutions (PEARLS)
- Urology Department, Hospital Naval Almirante Nef, Viña del Mar, Chile
| | - Olivier Traxer
- GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, Sorbonne Université
- Service d'Urologie, Assistance-Publique Hôpitaux de Paris, Hôpital Tenon, Sorbonne Université
- Progressive Endourological Association for Research and Leading Solutions (PEARLS)
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Huettenbrink C, Schaldach J, Hitzl W, Shamlou A, Ell J, Pahernik S. Different ureteral access sheaths sizes for retrograde intrarenal surgery. World J Urol 2023; 41:1913-1919. [PMID: 37222780 DOI: 10.1007/s00345-023-04423-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 04/27/2023] [Indexed: 05/25/2023] Open
Abstract
PURPOSE There is a trend toward miniaturization in endourological stone therapy. Good visibility, intrarenal pressures and temperature control should be ensured by ureteral sheaths. In the context of the present study, 10/12 Charr. sheaths and 12/14 Charr. sheaths for flexible ureterorenoscopy were investigated regarding stone-free rate, complication rate and efficacy for laser lithotripsy. METHODS From January 2020 to January 2022, 100 patients each with kidney stone up to 1.5 cm in diameter were included in the study. Use of a 12/14 Charr. vs. 10/12 Charr. ureteral sheath for flexible ureterorenoscopy was compared. Perioperative data, stone size, volume and density, laser energy, laser duration, stone-free rates and complications based on Clavien-Dindo classification were retrospectively analyzed. RESULTS For both groups of ureteral access sheaths, there were no differences in median surgery duration (10/12 Charr: 29 min (7-105 min) vs. 12/14 Charr: 34 min (9-95 min); p = 0.33), overall complication rate (p = 0.61) and hospitalization (p = 0.155). There were no differences in stone-free rates (97.9% vs. 92.7%, p = 0.37). Laser lithotripsy duration usingholmium laser was 1.9 min (0.1-10.8 min) vs. 3.8 min (0.2-20.7 min) (p < 0.01) and applied laser energy was 3.1 J (0.15 J-10.29 J) vs. 6.8 J (1.07 J-26.77 J) (p < 0.01) for 12/14 Charr. sheaths and 10/12 Charr. sheaths, respectively. CONCLUSION In terms of stone-free rates, there are no differences between the 10/12 and 12/14 Charr. ureteral access sheaths. The laser duration and energy was increased with 10/12 Charr. sheaths without showing increased risk for clinical complications like trauma or inflammation.
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Affiliation(s)
- Clemens Huettenbrink
- Department of Urology, Nuremberg General Hospital, Paracelsus Medical University, Prof. Ernst-Nathan Strasse 1, 90419, Nuremberg, Germany.
| | - Julia Schaldach
- Department of Urology, Nuremberg General Hospital, Paracelsus Medical University, Prof. Ernst-Nathan Strasse 1, 90419, Nuremberg, Germany
| | - Wolfgang Hitzl
- Research and Innovation Management (RIM), Biostatistics and Publication of Clinical Trial Studies Paracelsus Medical University, Salzburg, Austria
- Department of Ophthalmology and Optometry, Paracelsus Medical University Salzburg, Salzburg, Austria
- Research Program Experimental Ophthalmology and Glaucoma Research, Paracelsus, Medical University Salzburg, Salzburg, Austria
| | - Aida Shamlou
- Department of Urology, Nuremberg General Hospital, Paracelsus Medical University, Prof. Ernst-Nathan Strasse 1, 90419, Nuremberg, Germany
| | - Jascha Ell
- Department of Urology, Nuremberg General Hospital, Paracelsus Medical University, Prof. Ernst-Nathan Strasse 1, 90419, Nuremberg, Germany
| | - Sascha Pahernik
- Department of Urology, Nuremberg General Hospital, Paracelsus Medical University, Prof. Ernst-Nathan Strasse 1, 90419, Nuremberg, Germany
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Wu Z, Wei J, Sun C, Huangfu Q, Wang B, Huang G, Qi K, Jiang Z, Zhu W, Wen J. Temperature changes of renal calyx during high-power flexible ureteroscopic Moses holmium laser lithotripsy: a case analysis study. Int Urol Nephrol 2023:10.1007/s11255-023-03611-3. [PMID: 37145376 DOI: 10.1007/s11255-023-03611-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/21/2023] [Indexed: 05/06/2023]
Abstract
PURPOSE The risk of thermal damage increases with the introduction of high-power lasers during holmium laser lithotripsy. This study aimed to quantitatively evaluate the temperature change of renal calyx in the human body and the 3D printed model during high-power flexible ureteroscopic holmium laser lithotripsy and map out the temperature curve. METHODS The temperature was continuously measured by a medical temperature sensor secured to a flexible ureteroscope. Between December 2021 and December 2022, willing patients with kidney stones undergoing flexible ureteroscopic holmium laser lithotripsy were enrolled. High frequency and high-power settings (24 W, 80 Hz/0.3 J and 32 W, 80 Hz/0.4 J) were performed for each patient with room temperature (25 °C) irrigation. In the 3D printed model, we studied more holmium laser settings (24 W, 80 Hz/0.3 J, 32 W, 80 Hz/0.4 J and 40 W, 80 Hz/0.4 J) with warmed (37 °C) and room temperature (25 °C) irrigation. RESULTS Twenty-two patients were enrolled in our study. With 30 ml/min or 60 ml/min irrigation, the local temperature of the renal calyx did not reach 43 °C in any patient under 25 °C irrigation after 60 s laser activation. There were similar temperature changes in the 3D printed model with the human body under the irrigation of 25 °C. Under the irrigation of 37 °C, the temperature rise slowed down, but the temperature in the renal calyces was close to or even exceeded the 43 °C at the setting of 32 W, 30 ml/min and 40 W, 30 ml/min after continuing laser activation. CONCLUSION In the irrigation of 60 ml/min, the temperature in the renal calyces can still be maintained within a safe range after continuous activation of a holmium laser up to 40 W. However, continuous activation of 32 W or higher power holmium laser in the renal calyces for more than 60 s in the limited irrigation of 30 ml/min can cause excessive local temperature, in such situation room temperature perfusion at 25 ℃ may be a relatively safer option.
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Affiliation(s)
- Zhiyue Wu
- Department of Urology, School of Medicine, The Fourth Affiliated Hospital, Zhejiang University, Yiwu, Zhejiang, China
| | - Jingchao Wei
- Department of Urology, School of Medicine, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chengfang Sun
- Department of Urology, School of Medicine, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qi Huangfu
- Department of Urology, School of Medicine, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Bohan Wang
- Department of Urology, School of Medicine, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Guangyi Huang
- Department of Urology, School of Medicine, The Fourth Affiliated Hospital, Zhejiang University, Yiwu, Zhejiang, China
| | - Kai Qi
- Department of Urology, School of Medicine, The Fourth Affiliated Hospital, Zhejiang University, Yiwu, Zhejiang, China
| | - Zeping Jiang
- Department of Urology, School of Medicine, The Fourth Affiliated Hospital, Zhejiang University, Yiwu, Zhejiang, China
| | - Wuan Zhu
- Department of Urology, School of Medicine, The Fourth Affiliated Hospital, Zhejiang University, Yiwu, Zhejiang, China
| | - Jiaming Wen
- Department of Urology, School of Medicine, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China.
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Assessing critical temperature dose areas in the kidney by magnetic resonance imaging thermometry in an ex vivo Holmium:YAG laser lithotripsy model. World J Urol 2023; 41:543-549. [PMID: 36543945 PMCID: PMC9947089 DOI: 10.1007/s00345-022-04255-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
PURPOSE We aimed to assess critical temperature areas in the kidney parenchyma using magnetic resonance thermometry (MRT) in an ex vivo Holmium:YAG laser lithotripsy model. METHODS Thermal effects of Ho:YAG laser irradiation of 14 W and 30 W were investigated in the calyx and renal pelvis of an ex vivo kidney with different laser application times (tL) followed by a delay time (tD) of tL/tD = 5/5 s, 5/10 s, 10/5 s, 10/10 s, and 20/0 s, with irrigation rates of 10, 30, 50, 70, and 100 ml/min. Using MRT, the size of the area was determined in which the thermal dose as measured by the Cumulative Equivalent Minutes (CEM43) method exceeded a value of 120 min. RESULTS In the calyx, CEM43 never exceeded 120 min for flow rates ≥ 70 ml/min at 14 W, and longer tL (10 s vs. 5 s) lead to exponentially lower thermal affection of tissue (3.6 vs. 21.9 mm2). Similarly at 30 W and ≥ 70 ml/min CEM43 was below 120 min. Interestingly, at irrigation rates of 10 ml/min, tL = 10 s and tD = 10 s CEM43 were observed > 120 min in an area of 84.4 mm2 and 49.1 mm2 at tD = 5 s. Here, tL = 5 s revealed relevant thermal affection of 29.1 mm2 at 10 ml/min. CONCLUSION We demonstrate that critical temperature dose areas in the kidney parenchyma were associated with high laser power and application times, a low irrigation rate, and anatomical volume of the targeted calyx.
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Louters MM, Kim HJ, Dau JJ, Hall TL, Ghani KR, Roberts WW. Characterization of Fluid Dynamics and Temperature Profiles During Ureteroscopy with Laser Activation in a Model Ureter. J Endourol 2022; 36:1593-1598. [PMID: 35904397 DOI: 10.1089/end.2022.0275] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Introduction: Ureteral thermal injury has been reported in patients following ureteroscopy with laser lithotripsy due to overheating of fluid within the ureter. Proper understanding of this risk necessitates knowing the volume of fluid available to absorb laser energy. This can be approximated as the volume of fluid that mixes during laser activation, since energy transfer through fluid is dominated by convection. Objectives of this study were to determine the volume of fluid that mixes during laser activation at different irrigation rates and to characterize the temporal/spatial temperature distribution in a model ureter. Methods: The model ureter consisted of a plastic tube-160 mm length and 5.3 mm inner diameter. Irrigation was first applied with clear, then dyed, deionized water at rates from 8 to 40 mL/min. The laser was activated at 20 W (0.5 J/40 Hz). The distances the dyed fluid propagated were measured and volumes calculated. Temperatures were recorded from six thermocouples-five embedded within the tube and one affixed to the ureteroscope. Thermal dose was calculated using the Dewey and Sapareto methodology. Results: The volume of total fluid mixing in the model ureter was ≤1.26 ± 0.10 cm3, consistent with a sharp temperature increase after laser activation from -5 to 25 mm from the ureteroscope tip. With irrigation rates ≤12 mL/min, calculated thermal dose within the model ureter exceeded the threshold of tissue injury and extended greater distances along the ureter with lower irrigation rates. Conclusion: The volume of total fluid mixing within the model ureter was found to be small thus conferring a greater risk of ureteral thermal injury. A thermocouple positioned near the tip of the ureteroscope reasonably approximates temperature in front of the ureteroscope. Until temperature sensors are incorporated into ureteroscopic systems, laser power settings should be carefully selected to minimize risk of ureteral thermal injury.
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Affiliation(s)
- Marne M Louters
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Hyung Joon Kim
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Julie J Dau
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Khurshid R Ghani
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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Dau JJ, Hall TL, Matzger AJ, Louters MM, Khajeh NR, Ghani KR, Roberts WW. Laser Heating of Fluid With and Without Stone Ablation: In Vitro Assessment. J Endourol 2022; 36:1607-1612. [PMID: 35904398 DOI: 10.1089/end.2022.0199] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Introduction: Laser lithotripsy can cause excessive heating of fluid within the collecting system and lead to tissue damage. To better understand this effect, it is important to determine the percentage of applied laser energy that is converted to heat and the percentage used for stone ablation. Our objective was to calculate the percentage of laser energy used for stone ablation based on the difference in fluid temperature measured in an in vitro model when the laser was activated without and with stone ablation. Methods: Flat BegoStone disks (15:5) were submerged in 10 mL of deionized water at the bottom of a vacuum evacuated double-walled glass Dewar. A Moses 200 D/F/L laser fiber was positioned above the surface of the stone at a distance of 3.5 mm for control (no stone ablation) or 0.5 mm for experimental (ablation) trials. The laser was activated and scanned at 3 mm/second across the stone in a preprogrammed pattern for 30 seconds at 2.5 W (0.5 J × 5 Hz) for both short-pulse (SP) and Moses distance (MD) modes. Temperature of the fluid was recorded using two thermocouples once per second. Results: Control trials produced no stone ablation, while experimental trials produced a staccato groove in the stone surface, simulating efficient lithotripsy. The mean temperature increase for SP was 1.08°C ± 0.04°C for control trials and 0.98°C ± 0.03°C for experimental trials, yielding a mean temperature difference of 0.10°C ± 0.06°C (p = 0.0005). With MD, the mean temperature increase for control trials was 1.03°C ± 0.01°C and for experimental trials 0.99°C ± 0.06°C, yielding a smaller mean temperature difference of 0.04°C ± 0.06°C (p = 0.09). Conclusions: Even under conditions of energy-efficient stone ablation, the majority of applied laser energy (91%-96%) was converted to heat.
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Affiliation(s)
- Julie J Dau
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Adam J Matzger
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Marne M Louters
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Nikta R Khajeh
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Khurshid R Ghani
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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13
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Hong Y, Wang H, Xu Q, Chen L, Huang X, Xiong L. Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application. BMC Urol 2022; 22:144. [PMID: 36071397 PMCID: PMC9450233 DOI: 10.1186/s12894-022-01061-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/28/2022] [Indexed: 11/25/2022] Open
Abstract
Background To assess the outcome of the mini-track, mini-nephroscopy, mini ultrasonic probe percutaneous nephrolithotomy for upper ureteral and kidney stones. Methods We collected data of 53 patients (55 kidney units) who underwent mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy between September 2020 and March 2021. The study included single and upper ureteral stones from 12 kidneys, multiple stones from 28 kidneys, and staghorn stones from 15 kidneys. Results The mean operative duration was 50.6 min, ranging from 15 to 200 min, whereas the mean lithotripsy and stone removal time was 17.2 min (3–45 min). Moreover, the mean postoperative length of stay was 4.0 days (1–7 days). Besides, the stone-free rate (SFR) of discharge was 89.1% (49/55). The mean hemoglobin drop was 15.3 mg/dL, ranging 1–32 mg/dL. Out of the total cases, only 4 of them displayed minor complications. The outcomes of < 40 mm versus ≥ 40 mm calculi were compared by performing subgroup analysis. The results demonstrated a longer operation duration (65.2 vs. 40.2 min), higher complication rate (13.0% vs. 3.3%), and lower SFR in the ≥ 40 mm calculi subgroup. Conclusions In summary, mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy is an effective and safe method to treat patients with upper ureteral and kidney calculi. This is especially significant for the stone size of 20–40 mm, demonstrating excellent SFR and a lower complication rate.
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Affiliation(s)
- Yang Hong
- The Department of Urology, Peking University People's Hospital, 11# Xizhimen Nandajie Street, XiCheng District, Beijing, 100034, China.,Peking University Applied Lithotripsy Institute, Beijing, China
| | - Huanrui Wang
- The Department of Urology, Peking University People's Hospital, 11# Xizhimen Nandajie Street, XiCheng District, Beijing, 100034, China.,Peking University Applied Lithotripsy Institute, Beijing, China
| | - Qingquan Xu
- The Department of Urology, Peking University People's Hospital, 11# Xizhimen Nandajie Street, XiCheng District, Beijing, 100034, China.,Peking University Applied Lithotripsy Institute, Beijing, China
| | - Liang Chen
- The Department of Urology, Peking University People's Hospital, 11# Xizhimen Nandajie Street, XiCheng District, Beijing, 100034, China.,Peking University Applied Lithotripsy Institute, Beijing, China
| | - Xiaobo Huang
- The Department of Urology, Peking University People's Hospital, 11# Xizhimen Nandajie Street, XiCheng District, Beijing, 100034, China. .,Peking University Applied Lithotripsy Institute, Beijing, China.
| | - Liulin Xiong
- The Department of Urology, Peking University People's Hospital, 11# Xizhimen Nandajie Street, XiCheng District, Beijing, 100034, China. .,Peking University Applied Lithotripsy Institute, Beijing, China.
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14
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Peteinaris A, Pagonis K, Vagionis A, Adamou C, Tsaturyan A, Ballesta Martínez B, Karpetas G, Farsari E, Liatsikos E, Kallidonis P. What is the impact of pulse modulation technology, laser settings and intraoperative irrigation conditions on the irrigation fluid temperature during flexible ureteroscopy? An in vivo experiment using artificial stones. World J Urol 2022; 40:1853-1858. [PMID: 35366109 DOI: 10.1007/s00345-022-04002-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/18/2022] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To investigate the effect of different combinations of laser power settings and irrigation conditions using the pulse modulation technology of Quanta™ on irrigation fluid temperature (IFT) during FURS (flexible ureteroscopy) on an in-vivo porcine model with artificial stones. MATERIALS AND METHODS A female pig was used. Following the insertion of artificial stones (Begostone™, BEGO USA, Lincoln, RI), a K-type thermocouple was fixed to the created percutaneous access tract. Real-time recordings of IFT during FURS were performed without UAS (ureteral access sheath), with 10/12 UAS, 12/14 UAS and 14/16 UAS. Stone fragmentation was achieved using Quanta Litho Cyber Ho 150 W™ (Samarate, Italy). The IFT was recorded for 30 s, during laser activation, with power settings of 20, 40, 60, 75 and 100 W under both manual pump and gravity irrigation. RESULTS The IFT rise above 54 °C was recorded above a power of 40 W when gravity irrigation was used. The use of UAS prolonged the time for IFT to reach high values, although high power settings increase IFT within seconds from the laser activation. Under pump irrigation, only the 100 W power setting without the use of UAS resulted in dangerous IFT after approximately 10 s. CONCLUSION The high-power Ho:YAG laser can cause a damaging thermal effect to the kidney exceeding the threshold of 54 °C, under gravity irrigation. Lower power settings (up to 40 W) can be used with safety. According to our experiment, when using high power settings, the use of UAS and manual pump irrigation, is the safest combination regarding renal thermal damage.
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Affiliation(s)
| | | | | | | | | | | | - Georgios Karpetas
- Department of Anesthesiology and ICU, University of Patras, Patras, Greece
| | - Ergina Farsari
- Department of Chemical Engineering, University of Patras, 26504, Patras, Greece
| | - Evangelos Liatsikos
- Department of Urology, University of Patras, Patras, Greece.,Institute for Urology and Reproductive Health, Sechenov University, Moscow, Russia.,Medical University of Vienna, Vienna, Austria
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15
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MOSES™ pulse modulation technology versus conventional pulse delivery technology: the effect on irrigation fluid temperature during flexible ureteroscopy. Urolithiasis 2022; 50:613-618. [PMID: 35771241 DOI: 10.1007/s00240-022-01342-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 06/05/2022] [Indexed: 10/17/2022]
Abstract
To compare the effect of MOSES™ modulation technology to conventional pulse delivery technology on the irrigation fluid temperature (IFT) under different irrigation conditions during flexible ureteroscopy (FURS) in a live-anesthetized porcine model. For this experiment was used one female pig. A percutaneous access was obtained and a 30Fr sheath was placed inside the upper calyceal system. A thermocouple was inserted through the sheath to the upper calyx to record the effect on IFT during FURS. A Lumenis 120H Ho:YAG laser was used and the IFT was recorded during laser activation for 30 s at a laser power of 20 W, 40 W and 60 W under gravity and manual pump irrigation using MOSES™ and conventional pulse delivery technology. In the highest power settings the maximum IFT was achieved in 18 s under gravity irrigation (66.4 °C). It seems that there is no significant difference on IFT between MOSES and conventional mode on the IFT under different irrigation conditions during FURS at 20 W, 40 W and 60 W power settings. Furthermore, our results indicate that under manual pumping even high-power settings (40 W, 60 W) can be performed with safety. In the in vivo model, the MOSES™ pulse delivery technology does not have a significant difference in the maximal IFT in comparison to conventional pulse delivery technology during FURS in the same power settings. Manual pumping should be used to keep the IFT within safe limits.
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16
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Yamashita S, Inoue T, Kohjimoto Y, Hara I. Comprehensive endoscopic management of impacted ureteral stones: Literature review and expert opinions. Int J Urol 2022; 29:799-806. [PMID: 35475562 DOI: 10.1111/iju.14908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 04/10/2022] [Indexed: 11/30/2022]
Abstract
Treatment of urolithiasis, a benign disease, requires high efficacy and safety. Endoscopic treatment of impacted ureteral stones remains a challenging procedure for urologists, despite recent remarkable advances in surgical technology in treatment of urolithiasis. The success rate of endoscopic treatment in patients with impacted stones is reported to be lower than that in patients with nonimpacted stones. Moreover, the presence of stone impaction is associated with high rates of intraoperative and postoperative complications. The best management for patients with impacted ureteral stones should therefore be devised based on the latest knowledge and techniques. The present review focuses on the preoperative prediction of stone impaction, the safest and most effective endoscopic surgical procedures, and the most appropriate management for postoperative ureteral strictures. We overview comprehensive endoscopic management for impacted ureteral stones based on literature review and expert opinions.
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Affiliation(s)
| | - Takaaki Inoue
- Department of Urology, Hara Genitourinary Hospital, Kobe, Japan.,Department of Urology, Kobe University, Kobe, Japan
| | - Yasuo Kohjimoto
- Department of Urology, Wakayama Medical University, Wakayama, Japan
| | - Isao Hara
- Department of Urology, Wakayama Medical University, Wakayama, Japan
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17
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Rice P, Somani BK, Nagele U, Herrmann TRW, Tokas T. Generated temperatures and thermal laser damage during upper tract endourological procedures using the holmium: yttrium-aluminum-garnet (Ho:YAG) laser: a systematic review of experimental studies. World J Urol 2022; 40:1981-1992. [PMID: 35355103 DOI: 10.1007/s00345-022-03992-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/14/2022] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To perform a review on the latest evidence related to generated temperatures during Ho:YAG laser use, and present different tools to maintain decreased values, and minimize complication rates during endourological procedures. METHODS We performed a literature search using PubMed, Scopus, EMBASE, and Cochrane Central Register of Controlled Trials-CENTRAL, restricted to original English-written articles, including animal, artificial model, and human studies. Different keywords were URS, RIRS, ureteroscopy, percutaneous, PCNL, and laser. RESULTS Thermal dose (t43) is an acceptable tool to assess possible thermal damage using the generated temperature and the time of laser exposure. A t43 value of more than 120 min leads to a high risk of thermal tissue injury and at temperatures higher than 43 °C Ho:YAG laser use becomes hazardous due to an exponentially increased cytotoxic effect. Using open continuous flow, or chilled irrigation, temperatures remain lower than 45 °C. By utilizing high-power (> 40 W) or shorter laser pulse, temperatures rise above the accepted threshold, but adding a ureteral access sheath (UAS) helps to maintain acceptable values. CONCLUSIONS Open irrigation systems, chilled irrigation, UASs, laser power < 40 W, and shorter on/off laser activation intervals help to keep intrarenal temperatures at accepted values during URS and PCNL.
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Affiliation(s)
- Patrick Rice
- Department of Urology, University Hospital Southampton NHS Trust, Southampton, UK
| | - Bhaskar Kumar Somani
- Department of Urology, University Hospital Southampton NHS Trust, Southampton, UK
| | - Udo Nagele
- Department of Urology and Andrology, General Hospital Hall i.T., Milser Str. 10, 6060, Hall in Tirol, Austria
- Training and Research in Urological Surgery and Technology (T.R.U.S.T.)-Group, Hall in Tirol, Austria
| | - Thomas R W Herrmann
- Training and Research in Urological Surgery and Technology (T.R.U.S.T.)-Group, Hall in Tirol, Austria
- Department of Urology, Kantonspital Frauenfeld, Spital Thurgau AG, Frauenfeld, Switzerland
| | - Theodoros Tokas
- Department of Urology and Andrology, General Hospital Hall i.T., Milser Str. 10, 6060, Hall in Tirol, Austria.
- Training and Research in Urological Surgery and Technology (T.R.U.S.T.)-Group, Hall in Tirol, Austria.
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18
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Laser operator duty cycle effect on temperature and thermal dose: in-vitro study. World J Urol 2022; 40:1575-1580. [DOI: 10.1007/s00345-022-03967-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/14/2022] [Indexed: 11/26/2022] Open
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19
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Impact of Magnetic-Pulse and Chemical-Thermal Treatment on Alloyed Steels’ Surface Layer. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12010469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The relevant problem is searching for up-to-date methods to improve tools and machine parts’ performance due to the hardening of surface layers. This article shows that, after the magnetic-pulse treatment of bearing steel Cr15, its surface microhardness was increased by 40–50% compared to baseline. In this case, the depth of the hardened layer was 0.08–0.1 mm. The magnetic-pulse processing of hard alloys reduces the coefficient of microhardness variation from 0.13 to 0.06. A decrease in the coefficient of variation of wear resistance from 0.48 to 0.27 indicates the increased stability of physical and mechanical properties. The nitriding of alloy steels was accelerated 10-fold that of traditional gas upon receipt of the hardened layer depth of 0.3–0.5 mm. As a result, the surface hardness was increased to 12.7 GPa. Boriding in the nano-dispersed powder was accelerated 2–3-fold compared to existing technologies while ensuring surface hardness up to 21–23 GPa with a boride layer thickness of up to 0.073 mm. Experimental data showed that the cutting tool equipped with inserts from WC92Co8 and WC79TiC15 has a resistance relative to the untreated WC92Co8 higher by 183% and WC85TiC6Co9—than 200%. Depending on alloy steel, nitriding allowed us to raise wear resistance by 120–177%, boriding—by 180–340%, and magneto-pulse treatment—by more than 183–200%.
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20
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Dorantes-Carrillo LA, Basulto-Martínez M, Suárez-Ibarrola R, Heinze A, Proietti S, Flores-Tapia JP, Esqueda-Mendoza A, Giusti G. Retrograde Intrarenal Surgery Versus Miniaturized Percutaneous Nephrolithotomy for Kidney Stones >1cm: A Systematic Review and Meta-analysis of Randomized Trials. Eur Urol Focus 2022; 8:259-270. [PMID: 33627307 DOI: 10.1016/j.euf.2021.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/19/2021] [Accepted: 02/09/2021] [Indexed: 12/16/2022]
Abstract
CONTEXT Although miniaturized percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) are both options for treating >1cm kidney stones, controversies exist on whether one is more effective and safer than the other. OBJECTIVE To systematically appraise randomized trials comparing the effectiveness and safety of mPCNL and RIRS for treating >1cm kidney stones. EVIDENCE ACQUISITION A systematic search on PubMed/Medline, Web of Science, Embase, and ClinicalTrials.gov was conducted in August 2020 following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). Randomized trials comparing mPCNL and RIRS for >1cm kidney stones, and reporting stone-free rate (SFR), hemoglobin drop, transfusion rate, length of hospital stay (LOS), and/or complications, were included. EVIDENCE SYNTHESIS Eight studies compared mPCNL and RIRS, but one was not included due to its high risk of bias. SFR was higher for mPCNL (RR: 1.06 [95% coefficient interval {CI}, 1.01-1.10], p=0.008). Hemoglobin drop was higher for mPCNL (mean difference [MD]: 0.35 [95% CI, 0.05-0.65] g/dl, p=0.02); however, transfusion rates were similar (p=0.44). Complication rate was similar between mPCNL and RIRS (p=0.39), and the LOS was higher for mPCNL (MD: 1.11 [95% CI, 0.06-2.16] d, p=0.04). A subgroup analysis of lower pole stones showed that SFR was higher for mPCNL (RR: 1.09 [95% CI, 1.00-1.19], p=0.05). CONCLUSIONS Both approaches are effective and safe. Among these approaches, mPCNL has a higher SFR than RIRS for overall >1cm renal and lower pole stones, but longer LOS, and a higher hemoglobin drop that does not translate into higher transfusion rates. Complications are comparable. PATIENT SUMMARY Randomized trials have evaluated whether miniaturized percutaneous nephrolithotomy (mPCNL) or retrograde intrarenal surgery is more effective and safer for treating >1cm stones. After comparing the stone-free rate, hemoglobin drop, transfusion rate, length of hospital stay, and complications between both the approaches, mPCNL was found to be slightly more effective, but both were equally safe.
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Affiliation(s)
| | - Mario Basulto-Martínez
- European Training Center in Endourology, Department of Urology, IRCCS San Raffaele Hospital, Milan, Italy; Department of Urology, Hospital Regional de Alta Especialidad de la Península de Yucatán, Merida, Mexico.
| | - Rodrigo Suárez-Ibarrola
- Department of Urology, Faculty of Medicine, University of Freiburg Medical Centre, Freiburg, Germany
| | | | - Silvia Proietti
- European Training Center in Endourology, Department of Urology, IRCCS San Raffaele Hospital, Milan, Italy
| | - Juan Pablo Flores-Tapia
- Division of Nephrology, Urology and Transplant Surgery, Hospital Regional de Alta Especialidad de la Península de Yucatán, Merida, Mexico
| | - Antonio Esqueda-Mendoza
- Department of Urology, Hospital Regional de Alta Especialidad de la Península de Yucatán, Merida, Mexico
| | - Guido Giusti
- European Training Center in Endourology, Department of Urology, IRCCS San Raffaele Hospital, Milan, Italy
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Kraft L, Petzold R, Suarez-Ibarrola R, Miernik A. In vitro fragmentation performance of a novel, pulsed Thulium solid-state laser compared to a Thulium fibre laser and standard Ho:YAG laser. Lasers Med Sci 2021; 37:2071-2078. [PMID: 34905141 PMCID: PMC8971152 DOI: 10.1007/s10103-021-03495-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 12/08/2021] [Indexed: 11/30/2022]
Abstract
The aim of this work was to compare the fragmentation efficiency of a novel, pulsed Thulium solid-state laser (p-Tm:YAG) to that of a chopped Thulium fibre laser (TFL) and a pulsed Holmium solid-state laser (Ho:YAG). During the fragmentation process, we used a silicone mould to fixate the hemispherical stone models under water in a jar filled with room-temperature water. Each laser device registered the total energy applied to the stone model to determine fragmentation efficiency. Our study examined laser settings with single pulse energies ranging from 0.6 to 6 J and pulse frequencies ranging from 5 to 15 Hz. Similar laser settings were applied to explicitly compare the fragmentation efficiency of all three devices. We experimented with additional laser settings to see which of the three devices would perform best. The fragmentation performance of the three laser devices differed statistically significantly (p < 0.05). The average total energy required to fragment the stone model was 345.96 J for Ho:YAG, 372.43 J for p-Tm:YAG and 483.90 J for TFL. To fragment the stone models, both Ho:YAG and p-Tm:YAG needed similar total energy (p = 0.97). TFL’s fragmentation efficiency is significantly lower than that of Ho:YAG and p-Tm:YAG. Furthermore, we found the novel p-Tm:YAG’s fragmentation efficiency to closely resemble that of Ho:YAG. The fragmentation efficiency is thought to be influenced by the pulse duration. TFL’s shortest possible pulse duration was considerably longer than that of Ho:YAG and p-Tm:YAG, resulting in Ho:YAG and p-Tm:YAG exhibiting better fragmenting efficiency.
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Affiliation(s)
- Lea Kraft
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Ralf Petzold
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Rodrigo Suarez-Ibarrola
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Hugstetter Str. 55, 79106, Freiburg, Germany.
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22
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Dau JJ, Rezakahn Khajeh N, Hall TL, Roberts WW. Chilled irrigation for control of temperature elevation during ureteroscopic laser lithotripsy: in vivo porcine model. J Endourol 2021; 36:403-409. [PMID: 34569294 DOI: 10.1089/end.2021.0537] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION Multiple studies have shown significant heating of fluid within the urinary collecting system with high-power laser settings. Elevated fluid temperatures may cause thermal injury and tissue damage unless appropriately mitigated. A previous in vitro study demonstrated that chilled (4 °C) irrigation slowed temperature rise, decreased plateau temperature, and lowered thermal dose during laser activation with high-power settings. We sought to evaluate the thermal effects of chilled, room temperature, and warmed irrigation during ureteroscopy with laser activation in an in vivo porcine model. MATERIALS AND METHODS Seven female Yorkshire cross pigs (45-55 kg) were anesthetized and positioned supine. Retrograde ureteroscopy was performed with a thermocouple affixed 5 mm from the distal end of the ureteroscope. In two pigs a holmium:YAG laser was activated for 60 seconds at irrigation rates of 8 ml/min, 12 ml/min, and 15 ml/min with chilled, room temperature, or warmed irrigation. In five pigs core body temperature was recorded for one hour with or without continuous chilled irrigation at 15 ml/min. RESULTS At irrigation rates ≥ 12 ml/min, temperature curves appeared uniformly offset, warmed > room temperature > chilled irrigation. The threshold of thermal tissue injury was reached during laser activation for all irrigation temperatures at 8 ml/min. The threshold was not reached with chilled irrigation at 12 ml/min or 15 ml/min, or with room temperature irrigation at 15 ml/min. The threshold was exceeded at all irrigation rates with warmed irrigation. There was no significant change in core body temperature after delivering chilled irrigation at 15 ml/min compared with no irrigation for 60 minutes. CONCLUSION Irrigation with chilled saline solution during ureteroscopic laser lithotripsy slows temperature rise, lowers peak temperature, and lengthens the time to thermal injury compared to irrigation with room temperature or warmed saline solutions. Core body temperature was not significantly impacted by chilled irrigation.
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Affiliation(s)
- Julie J Dau
- University of Michigan, 1259, Urology, 4432 Medical Sciences Bldg I, 1301 Catherine St, Ann Arbor, Michigan, United States, 48109-1382;
| | | | - Timothy L Hall
- University of Michigan, Biomedical Engineering, 2200 Bonisteel Blvd, Ann Arbor, Michigan, United States, 48109;
| | - William W Roberts
- University of Michigan, Urology, 3879 Taubman Center, 1500 East Medical Center Dr,, Ann Arbor, Michigan, United States, 48109-5330.,University of Michigan, Biomedical Engineering, Ann Arbor, Michigan, United States;
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Hein S, Petzold R, Suarez-Ibarrola R, Schoenthaler M, Gratzke C, Miernik A. Thermal effects of thulium: YAG laser treatment of the prostate-an in vitro study. World J Urol 2021; 40:161-167. [PMID: 34476596 PMCID: PMC8813676 DOI: 10.1007/s00345-021-03805-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 08/04/2021] [Indexed: 01/10/2023] Open
Abstract
PURPOSE To objectively determine whether there is potential thermal tissue damage during Tm:YAG laser-based LUTS treatment. METHODS Our experimental model was comprised of a prostatic resection trainer placed in a 37 °C water bath. In a hollowed-out central area simulating the urethral lumen, we placed a RigiFib 800 fibre, irrigation inflow regulated with a digital pump, and a type K thermocouple. A second thermocouple was inserted 0.5/1 cm adjacently and protected with an aluminum barrier to prevent it from urethral fluid. We investigated continuous and intermittent 120 W and 80 W laser application with various irrigation rates in eight measurement sessions lasting up to 14 min. Thermal measurements were recorded continuously and in real-time using MatLab. All experiments were repeated five times to balance out variations. RESULTS Continuous laser application at 120 W and 125 ml/min caused a urethral ∆T of ~ 15 K and a parenchymal temperature increase of up to 7 K. With 50 ml/min irrigation, a urethral and parenchymal ∆T of 30 K and 15 K were reached, respectively. Subsequently and in absence of laser application, prostatic parenchyma needed over 16 min to reach baseline body temperature. At 80 W lower temperature increases were reached compared to similar irrigation but higher power. CONCLUSIONS We showed that potentially harming temperatures can be reached, especially during high laser power and low irrigation. The heat generation can also be conveyed to the prostate parenchyma and deeper structures, potentially affecting the neurovascular bundles. Further clinical studies with intracorporal temperature measurement are necessary to further investigate this potentially harming surgical adverse effect.
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Affiliation(s)
- Simon Hein
- Department of Urology, Division of Urotechnology, Medical Centre, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany
| | - Ralf Petzold
- Department of Urology, Division of Urotechnology, Medical Centre, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany
| | - Rodrigo Suarez-Ibarrola
- Department of Urology, Division of Urotechnology, Medical Centre, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany
| | - Martin Schoenthaler
- Department of Urology, Division of Urotechnology, Medical Centre, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany
| | - Christian Gratzke
- Department of Urology, Division of Urotechnology, Medical Centre, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Division of Urotechnology, Medical Centre, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany
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Rezakahn Khajeh N, Hall TL, Ghani KR, Roberts WW. Pelvicalyceal Volume and Fluid Temperature Elevation During Laser Lithotripsy. J Endourol 2021; 36:22-28. [PMID: 34254838 DOI: 10.1089/end.2021.0383] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND While high-power laser systems facilitate successful ureteroscopic treatment of larger and more complex stones, they can substantially elevate collecting system fluid temperatures with potential thermal injury of adjacent tissue. The volume of fluid in which laser activation occurs is an important factor when assessing temperature elevation. The aim of this study was to measure fluid temperature elevation and calculate thermal dose from laser activation in fluid-filled glass bulbs simulating varying calyx/pelvis volumes. MATERIALS AND METHODS Glass bulbs of volumes 0.5, 2.8, 4.0, 7.0, 21.0, and 60.8 ml were submerged in a 16 L tank of 37˚C deionized water. A 230-µm laser fiber extending 5mm from the tip of a ureteroscope was positioned in the center of each glass bulb. Irrigation with 0, 8, 15, and 40 ml/min of room temperature DI water was applied. Once steady state temperature was achieved, a Ho:YAG laser was activated for 60 seconds at 40W (0.5J x 80Hz, SP). Temperature was measured from a thermocouple affixed to the external tip of the ureteroscope. Thermal dose was calculated using the Dewey and Sapareto t43 methodology. RESULTS The extent of temperature elevation and thermal dose from laser activation were inversely related to the volume of fluid in each model and the irrigation rate. The time to threshold of thermal injury was only 3 seconds for the smallest model (0.5ml) without irrigation but was not reached in the largest model (60.8ml) regardless of irrigation rate. Irrigation delivered at 40 ml/min maintained safe temperatures below the threshold of tissue injury in all models with 1 minute of continuous laser activation. CONCLUSIONS The volume of fluid in which laser activation occurs is an important factor in determining the extent of temperature elevation. Smaller volumes receive greater thermal dose and reach threshold of tissue injury more rapidly than larger volumes.
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Affiliation(s)
- Nikta Rezakahn Khajeh
- University of Michigan, 1259, Urology, 4432 Med Sci I, 1301 Catherine St., Ann Arbor, Michigan, United States, 48109-1382;
| | - Timothy L Hall
- University of Michigan, Biomedical Engineering, 2200 Bonisteel Blvd, Ann Arbor, Michigan, United States, 48109;
| | - Khurshid R Ghani
- University of Michigan, Urology, 3448 Riverbend Drive, Ann Arbor, Michigan, United States, 48105.,University of Michigan, 1259, Ann Arbor, Michigan, United States, 48109-1382;
| | - William W Roberts
- University of Michigan, Urology, 3879 Taubman Center, 1500 East Medical Center Dr,, Ann Arbor, Michigan, United States, 48109-5330.,University of Michigan, Biomedical Engineering, Ann Arbor, Michigan, United States;
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25
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Aldoukhi AH, Dau JJ, Majdalany SE, Hall TL, Ghani KR, Hollingsworth JM, Ambani SN, Dauw CA, Roberts WW. Patterns of Laser Activation During Ureteroscopic Lithotripsy: Effects on Caliceal Fluid Temperature and Thermal Dose. J Endourol 2021; 35:1217-1222. [PMID: 33397188 DOI: 10.1089/end.2020.1067] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Introduction: Characterizing patterns of laser activation is important for assessing thermal dose during laser lithotripsy. The objective of this study was twofold: first, to quantify the range of operator duty cycle (ODC) and pedal activation time during clinical laser lithotripsy procedures, and second, to determine thermal dose in an in vitro caliceal model when 1200 J of energy was applied with different patterns of 50% ODC for 60 seconds. Methods: Data from laser logs of ureteroscopy cases performed over a 3-month period were used to calculate ODC (lasing time/lithotripsy time). Temporal and rolling 1-minute average power tracings were generated for each case. In vitro experiments were conducted using a 21 mm diameter glass bulb in a 37°C water bath, simulating a renal calix. A LithoVue ureteroscope with attached thermocouple was inserted and 8 mL/min irrigation was delivered with a 242 μm laser fiber within the working channel. In total, 1200 J of laser energy was applied in five different patterns at 20 W average power for 60 seconds. Thermal dose was calculated using the Sapareto and Dewey t43 method. Results: A total of 63 clinical cases were included in the analysis. Mean ODC was 32% overall and 63% during the 1-minute of greatest energy delivery. Mean time of pedal activation was 3.6 seconds. In vitro studies revealed longer pedal activation times produced higher peak temperature and thermal dose. Thermal injury threshold was reached in 9 seconds when 40 W was applied at 50% ODC with laser activation patterns of 30 seconds on/off and 15 seconds on/off. Conclusion: ODC was quantified from clinical laser lithotripsy cases: 32% overall and 63% during 1-minute of peak power. Time of pedal activation is an important factor contributing to fluid heating and thermal dose. Awareness of these concepts is necessary to reduce risk of thermal injury during laser lithotripsy procedures.
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Affiliation(s)
- Ali H Aldoukhi
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - Julie J Dau
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - Sami E Majdalany
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Khurshid R Ghani
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | | | - Sapan N Ambani
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - Casey A Dauw
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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26
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Laserlithotripsie. Urolithiasis 2021. [DOI: 10.1007/978-3-662-62454-8_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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[Innovative laser technologies in the treatment of urolithiasis : A change to more gentle methods with increased patient safety]. Urologe A 2020; 60:19-26. [PMID: 33315134 DOI: 10.1007/s00120-020-01409-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2020] [Indexed: 10/22/2022]
Abstract
Management of urolithiasis has undergone fundamental changes with the introduction of extracorporeal shock wave lithotripsy (ESWL) and percutaneous and ureterorenoscopic techniques in the 1980s. Since then, these minimally invasive techniques have been continuously optimized and specific laser techniques for stone disintegration have emerged. Besides the established holmium laser, other types of lasers are also emerging. Especially the thulium fiber laser is the subject of promising research due to its variable adjustment options. In terms of patient safety, both holmium and thulium techniques seem to be similar . While serious direct physical lesions are rare, there is increasing evidence of clinically relevant secondary thermal injury due to increased temperatures in the upper urinary tract during treatment. Our research group has recently demonstrated in both in vitro and in vivo (porcine animal model) experiments that monitoring the fluorescence spectra of calculi allows precise target differentiation between stone, tissue, and endoscope components. Consequently, pulse emissions were only emitted when stone material was detected. We believe that target monitoring will minimize the risk of laser-induced urothelial damage and decrease energy release into the upper urinary tract allowing adequate temperature management.
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28
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Petzold R, Suarez-Ibarrola R, Miernik A. Temperature Assessment of a Novel Pulsed Thulium Solid-State Laser Compared with a Holmium:Yttrium-Aluminum-Garnet Laser. J Endourol 2020; 35:853-859. [PMID: 33191783 DOI: 10.1089/end.2020.0803] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Purpose: To compare a novel Thulium laser device with the commonly used Holmium:Yttrium-Aluminum-Garnet (Ho:YAG) laser in terms of the in vitro temperatures generated. Methods: Our study investigated and compared an evaluation model of a solid-state Thulium laser with a Medilas H Solvo 35 Holmium laser device, both by Dornier (Dornier MedTech Laser GmbH, Wessling, Germany). Our in vitro model consisted of a 20 mL test tube placed in a 37°C water bath. Constant irrigation was set at 50 mL/minute with a Reglo Z Digital pump (Cole Parmer, Chicago, IL). Four hundred micrometers of Dornier laser fibers were used. The temperature was measured with a type K thermocouple and a real-time data logger from Pico (PICO Technology, Cambridgeshire, United Kingdom). Power settings between 2 and 30 W were investigated. Each measurement lasted 120 seconds and was repeated five times. The data were evaluated by MATLAB® (The Mathworks, Inc., Natick, MA). Results: The resulting temperatures were directly proportional to the power supplied. When comparing Holmium with Thulium, we observed maximum deviations of ≤0.82 K in temperatures at 120 seconds. The highest investigated laser power of 30 W yielded maximum temperatures differing by 6.7 K from the initial value. Out of the five comparisons, Thulium showed marginally yet significantly lower end temperatures in four cases and slightly lower cumulative equivalent minutes at 43°C (CEM43) values in three cases. Conclusion: The Thulium laser resembles the Holmium device in the temperatures generated during in vitro application. An increase in laser power, thus, leads to equivalent increases in temperature that are largely independent of frequency, pulse duration, and single pulse energy. Pulsed Thulium:Yttrium-Aluminum-Garnet (Tm:YAG), Ho:YAG, and Thulium fiber laser seem to share a similar risk profile for patients in terms of temperature development. Intrarenal power outputs exceeding 10 W during clinical application should be compensated by ensuring sufficient irrigation.
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Affiliation(s)
- Ralf Petzold
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Freiburg, Germany
| | - Rodrigo Suarez-Ibarrola
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Freiburg, Germany
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29
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Dau JJ, Hall TL, Maxwell AD, Ghani KR, Roberts WW. Effect of Chilled Irrigation on Caliceal Fluid Temperature and Time to Thermal Injury Threshold During Laser Lithotripsy: In Vitro Model. J Endourol 2020; 35:700-705. [PMID: 33176475 DOI: 10.1089/end.2020.0896] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Introduction: High-power lasers (100-120 W) have widely expanded the available settings for laser lithotripsy and facilitated tailoring of treatment for individual cases. Previous in vitro and in vivo studies have demonstrated that a toxic thermal dose to tissue can result from treatment within a renal calix. The objective of this in vitro study was to compare thermal dose and time with tissue injury threshold when using chilled (CH) irrigation and room temperature (RT) irrigation. Materials and Methods: A glass tube attached to a 19 mm diameter bulb simulating a renal calix was placed in a 37°C water bath. A 242 μm laser fiber was passed through a ureteroscope with its tip in the center of the glass bulb. A wire thermocouple was placed 3 mm proximal to the ureteroscope tip to measure caliceal fluid temperature. RT at 19°C or CH at 1°C irrigation was delivered at 0, 8, 12, 15, or 40 mL/minute. The laser was activated at 0.5 J × 80 Hz (40 W) for 60 seconds. Thermal dose was calculated using the Sapareto and Dewey t43 methodology with thermal dose = 120 equivalent minutes considered the threshold for thermal tissue injury. Results: At each irrigation rate, CH irrigation produced a lower starting temperature, a lower plateau temperature, and less thermal dose compared with RT irrigation. The threshold of thermal injury was reached after 13 seconds of laser activation without irrigation. With 12 mL/minute irrigation, the threshold was reached in 46 seconds with RT irrigation but was not reached with CH irrigation. Conclusion: As higher power laser lithotripsy techniques become further refined, methods to mitigate and control thermal dose are necessary to enhance efficiency. CH irrigation slows temperature rise, decreases plateau temperature, and lowers thermal dose during high-power laser lithotripsy.
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Affiliation(s)
- Julie J Dau
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - Timothy L Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Adam D Maxwell
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Khurshid R Ghani
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology and University of Michigan, Ann Arbor, Michigan, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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30
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Chung JH, Baek M, Park SS, Han DH. The Feasibility of Pop-Dusting Using High-Power Laser (2 J × 50 Hz) in Retrograde Intrarenal Surgery for Renal Stones: Retrospective Single-Center Experience. J Endourol 2020; 35:279-284. [PMID: 33081518 DOI: 10.1089/end.2020.0585] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Objective: Recently, retrograde intrarenal surgery (RIRS) using laser lithotripsy has become popular. However, the optimal laser energy setting for pop-dusting has not been established. In this study, we report our experiences of RIRS using the high-power (up to 100 W) pop-dusting (HPPD) technique. Methods: This study retrospectively assessed 82 cases with RIRS using HPPD. Patients who underwent abdominal CT or mercaptoacetyltriglycine (MAG3) diuretic renal scan at 3 months postoperatively were included in this study. Patient and stone characteristics and perioperative and postoperative outcomes were evaluated. Results: The average number of renal stones was 3.67 ± 4.11, and the average length of the largest stones was 13.30 ± 6.41 mm. The mean Hounsfield units was 959.99 ± 384.73. The operation time was 58.10 ± 26.67 minutes. The mean HPPD time was 11.93 ± 9.48 minutes, with settings of 1.97 ± 0.25 J and 48.78 ± 3.29 Hz. The stone-free rate was 89%. The mean hospital stay was 1.68 ± 1.29 days. Pelvicaliceal and ureter injuries were observed in 9.8% and 32.9% of the study population, respectively. However, there was no transfusion, subcapsular hematoma, persistent urinary leakage, ureteral or infundibular stricture, or renal functional deterioration. There was transient postoperative fever in 12.2% of the study population. Conclusions: HPPD could be performed safely during RIRS for renal stones without significant complications such as collecting system injury or bleeding. High-power laser mode (up to 100 W) can be a safe and effective choice for pop-dusting during RIRS, especially for large and hard stones.
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Affiliation(s)
- Jae Hoon Chung
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Minki Baek
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sang Soo Park
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Deok Hyun Han
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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31
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Lildal SK, Andreassen KH, Baard J, Brehmer M, Bultitude M, Eriksson Y, Ghani KR, Jung H, Kamphuis G, Kronenberg P, Turney B, Traxer O, Ulvik Ø, Osther PJS. Consultation on kidney stones, Copenhagen 2019: aspects of intracorporeal lithotripsy in flexible ureterorenoscopy. World J Urol 2020; 39:1673-1682. [PMID: 33067728 PMCID: PMC8217045 DOI: 10.1007/s00345-020-03481-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 10/01/2020] [Indexed: 12/20/2022] Open
Abstract
Purpose To summarize current knowledge on intracorporeal laser lithotripsy in flexible ureterorenoscopy (fURS), regarding basics of laser lithotripsy, technical aspects, stone clearance, lithotripsy strategies, laser technologies, endoscopes, and safety. Methods A scoping review approach was applied to search literature in PubMed, EMBASE, and Web of Science. Consensus was reached through discussions at the Consultation on Kidney Stones held in September 2019 in Copenhagen, Denmark. Results and conclusions Lasers are widely used for lithotripsy during fURS. The Holmium laser is still the predominant technology, and specific settings for dusting and fragmenting have evolved, which has expanded the role of fURS in stone management. Pulse modulation can increase stone ablation efficacy, possibly by minimizing stone retropulsion. Thulium fibre laser was recently introduced, and this technology may improve laser lithotripsy efficiency. Small fibres give better irrigation, accessibility, and efficiency. To achieve optimal results, laser settings should be adjusted for the individual stone. There is no consensus whether the fragmentation and basketing strategy is preferable to the dusting strategy for increasing stone-free rate. On the contrary, different stone scenarios call for different lithotripsy approaches. Furthermore, for large stone burdens, all laser settings and lithotripsy strategies must be applied to achieve optimal results. Technology for removing dust from the kidney should be in focus in future research and development. Safety concerns about fURS laser lithotripsy include high intrarenal pressures and temperatures, and measures to reduce both those aspects must be taken to avoid complications. Technology to control these parameters should be targeted in further studies.
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Affiliation(s)
| | - Kim Hovgaard Andreassen
- Department of Urology, Herlev-Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Joyce Baard
- Department of Urology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Marianne Brehmer
- Department of Surgery and Urology, Danderyd University Hospital, Stockholm, Sweden
- Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden
| | - Matthew Bultitude
- Urology Centre and Stone Unit, Guy's and St. Thomas' NHS Foundation Trust, London, UK
| | - Ylva Eriksson
- Department of Surgery and Urology, Danderyd University Hospital, Stockholm, Sweden
- Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden
| | - Khurshid R Ghani
- Department of Urology, University of Michigan, Ann Arbor, MI, USA
| | - Helene Jung
- Department of Urology, Urological Research Center, Lillebaelt Hospital, University of Southern Denmark, Vejle, Denmark
| | - Guido Kamphuis
- Department of Urology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Peter Kronenberg
- Department of Urology, Hospital CUF Descobertas, Lisbon, Portugal
| | - Ben Turney
- Department of Urology, Churchill Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
| | | | - Øyvind Ulvik
- Department of Urology, Haukeland University Hospital, Bergen, Norway
| | - Palle Jörn Sloth Osther
- Department of Urology, Urological Research Center, Lillebaelt Hospital, University of Southern Denmark, Vejle, Denmark.
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Schlager D, Schulte A, Schütz J, Brandenburg A, Schell C, Lamrini S, Vogel M, Teichmann HO, Miernik A. Laser-guided real-time automatic target identification for endoscopic stone lithotripsy: a two-arm in vivo porcine comparison study. World J Urol 2020; 39:2719-2726. [PMID: 32960325 PMCID: PMC8332575 DOI: 10.1007/s00345-020-03452-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022] Open
Abstract
Introduction and objective Thermal injuries associated with Holmium laser lithotripsy of the urinary tract are an underestimated problem in stone therapy. Surgical precision relies exclusively on visual target identification when applying laser energy for stone disintegration. This study evaluates a laser system that enables target identification automatically during bladder stone lithotripsy, URS, and PCNL in a porcine animal model. Methods Holmium laser lithotripsy was performed on two domestic pigs by an experienced endourology surgeon in vivo. Human stone fragments (4–6 mm) were inserted in both ureters, renal pelvises, and bladders. Ho:YAG laser lithotripsy was conducted as a two-arm comparison study, evaluating the target identification system against common lithotripsy. We assessed the ureters’ lesions according to PULS and the other locations descriptively. Post-mortem nephroureterectomy and cystectomy specimens were examined by a pathologist. Results The sufficient disintegration of stone samples was achieved in both setups. Endoscopic examination revealed numerous lesions in the urinary tract after the commercial Holmium laser system. The extent of lesions with the feedback system was semi-quantitatively and qualitatively lower. The energy applied was significantly less, with a mean reduction of more than 30% (URS 27.1%, PCNL 52.2%, bladder stone lithotripsy 17.1%). Pathology examination revealed only superficial lesions in both animals. There was no evidence of organ perforation in either study arm. Conclusions Our study provides proof-of-concept for a laser system enabling automatic real-time target identification during lithotripsy on human urinary stones. Further studies in humans are necessary, and to objectively quantify this new system’s advantages, investigations involving a large number of cases are mandatory. Electronic supplementary material The online version of this article (10.1007/s00345-020-03452-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel Schlager
- Department of Urology, Faculty of Medicine, Medical Center - University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
| | - Antonia Schulte
- Department of Urology, Faculty of Medicine, Medical Center - University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Jan Schütz
- Fraunhofer Institute for Physical Measurement Techniques IPM, Heidenhofstrasse 8, 79110, Freiburg, Germany
| | - Albrecht Brandenburg
- Fraunhofer Institute for Physical Measurement Techniques IPM, Heidenhofstrasse 8, 79110, Freiburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center - University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Samir Lamrini
- LISA Laser Products GmbH, Albert-Einstein-Straße 4, 37191, Katlenburg-Lindau, Germany
| | - Markus Vogel
- LISA Laser Products GmbH, Albert-Einstein-Straße 4, 37191, Katlenburg-Lindau, Germany
| | | | - Arkadiusz Miernik
- Department of Urology, Faculty of Medicine, Medical Center - University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
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Petzold R, Miernik A, Suarez-Ibarrola R. In Vitro Dusting Performance of a New Solid State Thulium Laser Compared to Holmium Laser Lithotripsy. J Endourol 2020; 35:221-225. [PMID: 32799650 DOI: 10.1089/end.2020.0525] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose: To examine the dusting performance of a novel solid state Thulium laser device compared to a standard holmium:yttrium-aluminum-garnet (Ho:YAG) device. Methods: This study compares a Dornier Medilas H Solvo 35 with an evaluation model of a pulsed solid state thulium:yttrium-aluminum-garnet (Tm:YAG) laser (Dornier MedTech Laser GmbH, Wessling, Germany). The in vitro model consisted of a mold with irrigated water at 37°C. For 2-9 minutes, laser fibers were guided by an xy-plotter in spirals over BegoStones. Stone mass was measured before and after laser application. Comparisons to Ho:YAG and further Tm:YAG investigations were performed. Results: Identical settings with similar pulse durations yielded a significant 14% advantage for Ho:YAG in slow fiber speeds and a tendency toward 15% higher efficiency of Tm:YAG in fast fiber speeds. Increased pulse duration in Tm:YAG led significantly to 32%-54% higher ablation rates in comparison to Tm:YAG in both setups. Ablated mass loss range is 102-1107 mg for slow fiber speeds and 22-528 mg for fast speeds. Mass loss is proportional to pulse energy, frequency, and pulse duration, whereas pulse energy defines the penetration depth into the model stones. Frequency characterizes the ablation homogeneity and possible working speeds. Conclusion: Tm:YAG is significantly more efficient when longer pulse durations are used. Identical settings revealed a strong connection to fiber movement speeds. In addition, the Tm:YAG device enables a broader range of settings with the possibility of minimal pulse energy of 100 mJ for low retropulsion and fine dusting with possible frequencies ≤200 Hz.
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Affiliation(s)
- Ralf Petzold
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Freiburg, Germany
| | - Rodrigo Suarez-Ibarrola
- Department of Urology, Faculty of Medicine, University of Freiburg-Medical Centre, Freiburg, Germany
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Noureldin YA, Farsari E, Ntasiotis P, Adamou C, Vagionis A, Vrettos T, Liatsikos EN, Kallidonis P. Effects of irrigation parameters and access sheath size on the intra-renal temperature during flexible ureteroscopy with a high-power laser. World J Urol 2020; 39:1257-1262. [PMID: 32556675 DOI: 10.1007/s00345-020-03287-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 05/28/2020] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES To investigate the effect of different laser power settings on intra-renal temperature (IRT) under different irrigation conditions during flexible ureteroscopy (FURS) in a live-anesthetized porcine model. METHODS Following ethics approval, 2 female pigs weighing ~ 28 kg were used. Under general anesthesia, a percutaneous access was obtained to fix a K-type thermocouple inside the pelvi-calyceal system for real-time recording of IRT during FURS without UAS, UAS-10/12, UAS-12/14, and UAS-14/16F. A high-power holmium laser was used and the IRT was recorded during laser activation for up to 60 s at a laser power of 20 W, 40 W, and 60 W under gravity irrigation and manual pump irrigation. RESULTS Under gravity irrigation, FURS without UAS was associated with hazardous IRT at a laser power as low as 20 W for as short as 20 s of laser activation. The IRT was rendered borderline when UAS was used. This UAS buffering effect disappeared with the use of higher laser-power settings (40 W and 60 W) with the maximal IRT exceeding 60 °C. Moreover, laser activation at 60 W was associated with very rapid increase in IRT within few seconds. Under pump irrigation, laser activation at the highest power setting (60 W) for 60 s was associated with a safe IRT, even without the use of UAS. The maximal IRT was below 45 °C. CONCLUSION The use of high-power Ho:YAG laser carries potentially harmful thermal effect when used under gravity irrigation, even when large-diameter UAS is used. High-power settings (> 40 W) require high irrigation flow. The use of UAS is advisable to reduce the IRT and balance any intra-renal pressure increase.
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Affiliation(s)
- Yasser A Noureldin
- Department of Urology, University of Patras, Patras, Greece.,Department of Urology, Benha Faculty of Medicine, Benha University, Benha, Egypt
| | - Ergina Farsari
- Department of Chemical Engineering, University of Patras, Patras, Greece
| | | | | | | | - Theofanis Vrettos
- Department of Anesthesiology and ICU, University of Patras, Patras, Greece
| | - Evangelos N Liatsikos
- Department of Urology, University of Patras, Patras, Greece. .,Department of Urology, Medical University of Vienna, Vienna, Austria.
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Taratkin M, Laukhtina E, Singla N, Kozlov V, Abdusalamov A, Ali S, Gabdullina S, Alekseeva T, Enikeev D. Temperature changes during laser lithotripsy with Ho:YAG laser and novel Tm-fiber laser: a comparative in-vitro study. World J Urol 2020; 38:3261-3266. [PMID: 32078706 DOI: 10.1007/s00345-020-03122-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
AIM The aim of this study was to compare the thermal effects of Ho:YAG and Tm-fiber lasers during lithotripsy in an in-vitro model via real-time temperature measurement. METHODS We compared a Ho:YAG laser (pav up to 100 W, Lumenis, Yokneam, Israel) and a superpulse Tm-fiber laser (SP TFL, pav up to 40 W, NTO IRE-Polus, Fryazino, Russia), both equipped with 200 µm bare-ended fibers. The following settings were used: 0.2 J, 40 Hz (nominal pav 8 W). Power meter FieldMaxII-TO (Coherent, Santa Clara, CA, USA) was used to verify output laser power (pav). Each laser was fired for 60 s in two setups: (1) thermos-insulated (quasi-adiabatic) cuvette; (2) actively irrigated setup with precise flow control (irrigation rates 0, 10, 35 mL/min). RESULTS Power measurements performed before the test revealed a 10% power drop in Ho:YAG (up to 7.2 ± 0.1 W) and 6.25% power drop in SP TFL (up to 7.5 ± 0.1). At the second step of our experiment, irrigation reduced the respective temperatures in the same manner for both lasers (e.g., at 35 mL/s SP TFL - 1.9 °C; for Ho:YAG laser - 2.8 °C at 60 s). CONCLUSION SP TFL and Ho:YAG lasers are not different in terms of volume-averaged temperature increase when the same settings are used in both lasers. Local temperature rises may fluctuate to some degree and differ for the two lasers due to varying jet streaming caused by non-uniform heating of the aqueous medium by laser light.
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Affiliation(s)
- Mark Taratkin
- Institute for Urology and Reproductive Health, Sechenov University, 2/1 Bolshaya Pirogovskaya St., Moscow, 119991, Russia.
| | - Ekaterina Laukhtina
- Institute for Urology and Reproductive Health, Sechenov University, 2/1 Bolshaya Pirogovskaya St., Moscow, 119991, Russia
| | | | - Vasily Kozlov
- Department of Public Health and Healthcare Organization, Sechenov University, Moscow, Russia
| | - Abdusalam Abdusalamov
- Institute for Urology and Reproductive Health, Sechenov University, 2/1 Bolshaya Pirogovskaya St., Moscow, 119991, Russia
| | - Stanislav Ali
- Institute for Urology and Reproductive Health, Sechenov University, 2/1 Bolshaya Pirogovskaya St., Moscow, 119991, Russia
| | - Svetlana Gabdullina
- Institute of Linguistics and Intercultural Communication, Sechenov University, Moscow, Russia
| | - Tatyana Alekseeva
- Institute for Urology and Reproductive Health, Sechenov University, 2/1 Bolshaya Pirogovskaya St., Moscow, 119991, Russia
| | - Dmitry Enikeev
- Institute for Urology and Reproductive Health, Sechenov University, 2/1 Bolshaya Pirogovskaya St., Moscow, 119991, Russia
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Aldoukhi AH, Black KM, Hall TL, Ghani KR, Maxwell AD, MacConaghy B, Roberts WW. Defining Thermally Safe Laser Lithotripsy Power and Irrigation Parameters: In Vitro Model. J Endourol 2020; 34:76-81. [DOI: 10.1089/end.2019.0499] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Ali H. Aldoukhi
- Division of Endourology, Department of Urology, University of Michigan, Ann Arbor, Michigan
| | - Kristian M. Black
- Division of Endourology, Department of Urology, University of Michigan, Ann Arbor, Michigan
| | - Timothy L. Hall
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
| | - Khurshid R. Ghani
- Division of Endourology, Department of Urology, University of Michigan, Ann Arbor, Michigan
| | - Adam D. Maxwell
- Department of Urology, University of Washington School of Medicine, Seattle, Washington
| | - Brian MacConaghy
- Applied Physics Laboratory, University of Washington, Seattle, Washington
| | - William W. Roberts
- Division of Endourology, Department of Urology, University of Michigan, Ann Arbor, Michigan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
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Peng Y, Liu M, Ming S, Yu W, Li L, Lu C, Fang Z, Wang Z, Dong H, Shen R, Xie F, Gao X, Gao X. Safety of a Novel Thulium Fiber Laser for Lithotripsy: An In Vitro Study on the Thermal Effect and Its Impact Factor. J Endourol 2019; 34:88-92. [PMID: 31608659 DOI: 10.1089/end.2019.0426] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction: To investigate the thermal effect on the water by a novel thulium fiber laser (TFL) designed for lithotripsy and evaluate the safety of this laser for clinical use. Materials and Methods: An in vitro experimental setup was constructed. A test tube filled with saline was immersed in an electric water bath, and a TFL fiber and a thermal probe were inserted into it. Saline was irrigated into the tube and pumped out synchronously at the same speed by two pumps, respectively, to maintain convection when needed. Then, continuous TFL firing of different power settings was imposed to saline in the tube for 60 seconds, on the conditions of different irrigation rates. The temperature was recorded every 5 seconds during the whole trial, and each trial was repeated five times. Safety threshold of temperature increase (STTI) was determined comparing with the deemed safe temperature of 43°C in vivo. Results: On condition of 0 mL/min irrigation rate, STTI was 6.5°C, and water temperature increase (WTI) caused by ≥15 W settings surpassed STTI after 20 seconds of laser firing; on condition of 15 mL/min irrigation rate, only WTI caused by the highest 30 W power setting surpassed STTI after 45 seconds of laser firing. When irrigation rate was added up to 25 and 50 mL/min, WTIs caused by all power settings were below STTIs in a 60-second experiment. High frequency and low pulse energy combinations caused a slightly higher WTI compared with low frequency and high pulse energy, given a constant power and irrigation rate. Conclusion: Power setting and irrigation rate collaboratively play a critical role in WTI during TFL lithotripsy, and it is safe to use TFL referring to the thermal effect as long as there is moderate irrigation, while TFL power should be lowered enough when irrigation is ceased.
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Affiliation(s)
- Yonghan Peng
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Min Liu
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Shaoxiong Ming
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Weixing Yu
- Department of Urology, Shaoxing Shangyu People's Hospital, Zhejiang, China
| | - Ling Li
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Chaoyue Lu
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Ziyu Fang
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Zeyu Wang
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Hao Dong
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Rong Shen
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Fei Xie
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Xiaomin Gao
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
| | - Xiaofeng Gao
- Department of Urology, Shanghai Changhai Hospital, Shanghai, China
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[Role of pressure and temperature in ureterorenoscopy and percutaneous nephrolitholapaxy : Pressure and temperature changes during stone treatment]. Urologe A 2019; 58:1289-1297. [PMID: 31501985 DOI: 10.1007/s00120-019-01034-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Ureterorenoscopy and percutaneous nephrolitholapaxy are minimally invasive procedures and are the standard procedures for the treatment of kidney stones and ureteral calculi. To achieve an adequate view, in both methods an optimal and sufficient irrigation flow is necessary. The intrarenal pressure is influenced by the irrigation pressure and irrigation volume and has to be controlled. Pathologically elevated intrarenal pressure can lead to irreversible damage of the kidneys. Lasers are frequently used for stone fragmentation. It has been shown in studies that the laser energy can lead to an increase in the temperature and that thermal effects can also damage the kidneys. This article provides the surgeon with an overview about the effects of temperature and pressure changes during ureterorenoscopy and percutaneous nephrolitholapaxy and how damages can be avoided.
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