Randomized Controlled Trial Comparing Three Different Modalities of Lithotrites for Intracorporeal Lithotripsy in Percutaneous Nephrolithotomy

Single-Center Experience with Swiss LithoClast® Trilogy for Kidney Stones

INTRODUCTION

PCNL remains the gold standard for larger kidney stones. Reducing the operating time of PCNL and its complication rate seems to be the next logical step in optimizing this classical technique. To achieve these objectives, some new methods of lithotripsy emerge. We present the data of a single, high-volume, academic center with combined ultrasonic and ballistic lithotripsy in PCNL using the Swiss LithoClast^® Trilogy device.

MATERIALS AND METHODS

We designed a prospective, randomized study including patients who underwent PCNL or miniPerc with lithotripsy using the new EMS Lithoclast Trilogy or EMS Lithoclast Master. The procedure was carried out with all patients in prone position, by the same surgeon. The working channel size was 24 Fr-15.9 Fr. We evaluated the stones' features, operative time, fragmentation time, complications, stone clearance rate and stone-free rate.

RESULTS

Our study included 59 patients, 38 females and 31 males, of an average age of 54.5 years old. The Trilogy group included 28 patients and the comparator included 31 patients. Urine culture was positive in seven cases which required seven days of antibiotics. The mean stone diameter was 35.6 mm with a mean Hounsfield unit (HU) of 710.1. The average number of stones was 2.08 (6 complete staghorn stones and 12 partial staghorn stones). A total of 13 patients presented a JJ stent (46.4%). We found a very significant difference in all the parameters favoring the Trilogy device. The most important result in our opinion is the probe active time, which was almost six times shorter in the Trilogy group. The stone clearance rate was about double in the Trilogy group, leading to shorter overall and intra-renal operating times. The overall complication rate was 17.9% in the Trilogy group and 23% in the Lithoclast Master group. The mean hemoglobin drop was 2.1 g/dL with a mean creatinine rise of 0.26 mg/dL.

CONCLUSIONS

Swiss LithoClast^® Trilogy, a device combining ultrasonic and ballistic energy, is a safe and efficient method of lithotripsy for PCNL, proving statistically significant benefits over its predecesor. It can achieve the goal of reducing complication rates and operative times for PCNL.

Clearance of Metal Particles After Percutaneous Nephrolithotomy with Trilogy Lithotripter

Purpose: To evaluate the clearance of metal particles produced and released in the pelvicaliceal system (PCS) during percutaneous nephrolithotomy (PCNL) with the use of the Swiss Lithoclast^® Trilogy dual-energy (EMS Urology, Nyon, Switzerland) lithotripter. Methods: An experimental in vivo study and a clinical investigation of case series were conducted. An in vivo porcine model with two pigs for lithotripsy (after inserting artificial stones into the collecting system) and two pigs for submucosal injection of metal particles (provided by the manufacturer of Trilogy) was conducted. Porcine kidney histology analysis for metal leftovers was conducted immediately or 2 weeks after the surgery. A prospective observational study design included 10 consecutive patients treated with conventional 30F PCNL or with 22F mini-PCNL technique. Only the patients with the confirmed metal particles in the PCS during the initial PCNL and the need for additional retrograde intrarenal surgery over a period of 2-4 weeks were selected. The presence of metal particles was evaluated during the second endoscopic surgery. Results: The generated metal particles during PCNL and the submucosally injected particles were not found macroscopically 2 weeks postoperatively in porcine models. No pathologic changes such as foreign body granuloma or inflammation were found. Similarly, no metal particles were observed during the second look endoscopy (n = 10). Conclusion: Metal particles observed endoscopically using the Trilogy lithotripter are cleared with no pathologic evidence of tissue damage from the metal particles 2 weeks after the procedure. Thus, the intraoperative release of any particle by the Trilogy lithotripter should not raise any safety concerns.

International Alliance of Urolithiasis (IAU) Guideline on percutaneous nephrolithotomy

The International Alliance of Urolithiasis (IAU) would like to release the latest guideline on percutaneous nephrolithotomy (PCNL) and to provide a clinical framework for surgeons performing PCNLs. These recommendations were collected and appraised from a systematic review and assessment of the literature covering all aspects of PCNLs from the PubMed database between January 1, 1976, and July 31, 2021. Each generated recommendation was graded using a modified GRADE methodology. The quality of the evidence was graded using a classification system modified from the Oxford Center for Evidence-Based Medicine Levels of Evidence. Forty-seven recommendations were summarized and graded, which covered the following issues, indications and contraindications, stone complexity evaluation, preoperative imaging, antibiotic strategy, management of antithrombotic therapy, anesthesia, position, puncture, tracts, dilation, lithotripsy, intraoperative evaluation of residual stones, exit strategy, postoperative imaging and stone-free status evaluation, complications. The present guideline on PCNL was the first in the IAU series of urolithiasis management guidelines. The recommendations, tips and tricks across the PCNL procedures would provide adequate guidance for urologists performing PCNLs to ensure safety and efficiency in PCNLs.

An ex-vivo assessment of a new single probe triple modality (Trilogy) lithotripter

Introduction and objectives

This Swiss LithoClast^® Trilogy lithotrite is a new lithotrite for percutaneous nephrolithotomy (PCNL). It has four modifiable settings; impact, frequency, ultrasound and suction. We aim to determine the optimal device settings for the fastest stone clearance.

Materials and methods

Kidney stone phantoms were made with Begostone in a powder to water ratio (15:3–15:6). Complete stone clearance (seconds) was calculated and impact and frequency were adjusted and repeated N = 3. Intra renal pressure (IRP) was then measured in a porcine kidney model.

Results

Stone phantoms with physical properties similar to struvite were cleared best with 100% impact and frequency of 12 Hz. Both uric acid stone phantoms and calcium phosphate stone phantoms were cleared most efficiently with an impact of 30% and a frequency of 4 Hz. The mean time to clear uric acid stone phantoms was 83 s versus 217 s for calcium phosphate stone phantoms. Similarly, for calcium oxalate stone phantoms, an impact of 30% and a frequency of 4 Hz was associated with the fastest clearance time, mean 204 s. However, the differences between 4, 8 and 12 Hz were not statistically significant. At a suction level of 60% or higher, IRP became negative.

Conclusion

These results indicate that stone phantoms of hard kidney stones are cleared more efficiently at lower impact and frequency settings. With regard to suction, a setting of ≤ 50% appears to be the optimal setting.

Does combined lithotripter show superior stone-success rate than ultrasonic or pneumatic device alone during percutaneous nephrolithotrotomy? A meta-analysis

OBJECTIVES

To compare the stone clearance rate and stone-success rate among lithotripter with ultrasonic lithotripter alone, pneumatic lithotripter alone and combined mechanisms.

METHODS

Up till 2021 May, we conducted a literature search among several widely used database around the world, including Pubmed, Embase (Ovid Version), Medline (Ovid Version) and Cochrane Central Register of Controlled Trials. Only English literature was considered. Pediatric patients were excluded. Reviews and protocols without any published data were excluded. Conference abstracts and articles with unrelated contents were also excluded.

RESULTS

Fifteen articles were included in our final meta-analysis, with 9 RCTs and 6 cohort studies. In Lithoclast combined with ultrasonic device vs pneumatic device subgroup, overall stone-success rate yielded insignificant difference. As for subgroup of Shock Pulse vs pneumatic device, pooled analysis yielded a higher 1-month stone-success rate for Shock Pulse (RR = 1.10, 95% CI: 1.01-1.19). In Lithoclast combined with ultrasonic device vs ultrasonic device subgroup and Cyberwand vs ultrasonic device subgroup, both overall stone-success rate did not differ from one another. We found Lithoclast with ultrasonic device was more efficient in stone clearance rate than pneumatic device (mean difference = 8.23, 95% CI: 4.99-11.47). The same situation was applied to the comparison between Lithoclast with ultrasonic device and ultrasonic device (mean difference = 13.02, 95% CI: 4.57-21.46).

CONCLUSIONS

Combined lithotripter was more efficient in clearing stones than pneumatic or ultrasonic device alone. However, when it came to stone-success rate, no obvious superiority was seen in combined one.

Multi-Institutional Prospective Randomized Control Trial of Novel Intracorporeal Lithotripters: ShockPulse-SE vs Trilogy Trial

Introduction: Currently, there are multiple intracorporeal lithotripters available for use in percutaneous nephrolithotomy (PCNL). This study aimed to evaluate the efficiency of two novel lithotripters: Trilogy and ShockPulse-SE. Materials and Methods: This is a prospective multi-institutional randomized trial comparing outcomes of PCNL using two novel lithotripters between February 2019 and June 2020. The study assessed objective measures of stone clearance time, stone clearance rate, device malfunction, stone-free rates, and complications. Device assessment was provided through immediate postoperative survey by primary surgeons. Results: There were 100 standard PCNLs completed using either a Trilogy or ShockPulse-SE lithotrite. Using quantitative Stone Analysis Software to estimate stone volume, the mean stone volume was calculated at 4.18 ± 4.79 and 3.86 ± 3.43 cm3 for the Trilogy and ShockPulse-SE groups, respectively. Stone clearance rates were found to be 1.22 ± 1.67 and 0.77 ± 0.68 cm3/min for Trilogy vs ShockPulse-SE (p = 0.0542). When comparing Trilogy to ShockPulse-SE in a multivariate analysis, total operative room time (104.4 ± 48.2 minutes vs 121.1 ± 59.2 minutes p = 0.126), rates of secondary procedures (17.65% vs 40.81%, p = 0.005), and device malfunctions (1.96% vs 34.69%, p < 0.001) were less, respectively. There was no difference in final stone-free rates between devices. Conclusion: Both the Trilogy and ShockPulse-SE lithotripters are highly efficient at removing large renal stones. In this study, we noted differences between the two devices including fewer device malfunctions when Trilogy device was utilized. Clinical Trial ID number: NCT03959683.

Therapeutic effects of flexible ureteroscopy alone and in combination with external physical vibration on upper urinary tract calculi: a randomized controlled trial

INTRODUCTION

Upper urinary tract calculus is a common disease of the urinary system.

AIM

To compare the therapeutic effects of flexible ureteroscopy alone and in combination with external physical vibration on upper urinary tract calculi.

MATERIAL AND METHODS

A total of 146 patients were randomly divided into control and experimental groups (n = 73). The control group received flexible ureteroscopy lithotripsy, and the experimental group underwent the same but combined with external physical vibration. The rate of finding stones in the urine on the day after treatment, clearance rate, components of stones, levels of renal function indices blood urea nitrogen (BUN) and serum creatinine (Scr), and incidence of complications were compared. The stone-free rate during 1-year follow-up was analysed by Kaplan-Meier method.

RESULTS

The rate of finding stones in the urine on the day after treatment was higher in the experimental group (100%) than that in the control group (29.73%) (p < 0.05). The clearance rates on the day, at 1 week, and at 2 weeks after treatment in the experimental group were 71.23%, 87.67%, and 95.89%, respectively, which surpassed those of the control group at corresponding time points (p < 0.05). BUN and Scr levels decreased after treatment in both groups, especially in the experimental group (p < 0.05). The stone-free rate during 1-year follow-up in the experimental group (n = 71 (97.26%)) exceeded that of the control group (n = 61 (83.56%)) (p < 0.05).

CONCLUSIONS

External physical vibration combined with flexible ureteroscopy lithotripsy significantly increased the rate of finding stones in the urine the day after treatment, the clearance rate of upper urinary tract calculi, and the ameliorated renal function and reduced the stone re-formation rate.

Efficacy and safety of the EMS Swiss LithoClast® Trilogy for PCNL: results of the European multicentre prospective study on behalf of European Section of UroTechnology

Purpose

PCNL requires a lithotrite to efficiently break stones, and some devices include active suction to remove the fragments. We set out to determine the efficacy and safety of the Swiss LithoClast® Trilogy, in a prospective European multicentre evaluation and compared it to published stone clearance rates for Trilogy based on surface area (68.9 mm²/min) and using the 3D calculated stone volume (526.7 mm³/min).

Methods

Ten European centres participated in this prospective non-randomized study of Trilogy for PCNL. Objective measures of stone clearance rate, device malfunction, complications and stone-free rates were assessed. Each surgeon subjectively evaluated ergonomic and device effectiveness, on a 1–10 scale (10 = extremely ergonomic/effective) and compared to their usual lithotrite on a 1–10 scale (10 = extremely effective).

Results

One hundred and fifty seven PCNLs using Trilogy were included (53% male, 47% female; mean age 55 years, range 13–84 years). Mean stone clearance rate was 65.55 mm²/min or 945 mm³/min based on calculated 3D volume. Stone-free rate on fluoroscopy screening at the end of the procedure was 83%. Feedback for suction effectiveness was 9.0 with 9.1 for combination and 9.0 for overall effectiveness compared to lithotrite used previously. Ergonomic score was 8.1, the least satisfactory element. Complications included 13 (8.2%) Clavien–Dindo Grade II and 2 (1.3%) Grade III. Probe breakage was seen in 9 (5.7%), none required using a different lithotrite.

Conclusions

We have demonstrated that Trilogy is highly effective at stone removal. From a user perspective, the device was perceived by surgeons to be highly effective overall and compared to the most commonly used previous lithotrite, with an excellent safety profile.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Percutaneous Nephrolithotomy

CONTEXT

Although percutaneous nephrolithotomy (PCNL) has been performed for decades and has gone through many refinements, there are still concerns regarding its more widespread utilization because of the long learning curve and the potential risk of severe complications. Many technical details are not included in the guidelines because of their nature and research protocol.

OBJECTIVE

To achieve an expert consensus viewpoint on PCNL indications, preoperative patient preparation, surgical strategy, management and prevention of severe complications, postoperative management, and follow-up.

EVIDENCE ACQUISITION

An international panel of experts from the Urolithiasis Section of the European Association of Urology, International Alliance of Urolithiasis, and other urology associations was enrolled, and a prospectively conducted study, incorporating literature review, discussion on research gaps (RGs), and questionnaires and following data analysis, was performed to reach a consensus on PCNL.

EVIDENCE SYNTHESIS

The expert panel consisted of 36 specialists in PCNL from 20 countries all around the world. A consensus on PCNL was developed. The expert panel was not as large as expected, and the discussion on RGs did not bring in more supportive evidence in the present consensus.

CONCLUSIONS

Adequate preoperative preparation, especially elimination of urinary tract infection prior to PCNL, accurate puncture with guidance of fluoroscopy and/or ultrasonography or a combination, keeping a low intrarenal pressure, and shortening of operation time during PCNL are important technical requirements to ensure safety and efficiency in PCNL.

PATIENT SUMMARY

Percutaneous nephrolithotomy (PCNL) has been a well-established procedure for the management of upper urinary tract stones. However, according to an expert panel consensus, core technical aspects, as well as the urologist's experience, are critical to the safety and effectiveness of PCNL.

Consultation on kidney stones, Copenhagen 2019: lithotripsy in percutaneous nephrolithotomy

PURPOSE

To evaluate the balance between existing evidence and expert opinions on the safety and efficacy of new technological improvements in lithotripsy techniques for percutaneous nephrolithotomy (PCNL).

METHODS

A scoping review approach was applied to search literature in Pubmed, Embase, and Web of Science. Consensus by key opinion leaders was reached at a 2-day meeting entitled "Consultation on Kidney Stones: Aspects of Intracorporeal Lithotripsy" held in Copenhagen, Denmark, in September 2019.

RESULTS

New-generation dual-mode single-probe lithotripsy devices have shown favourable results compared with use of ballistic or ultrasonic lithotripters only. However, ballistic and ultrasonic lithotripters are also highly effective and safe and have been the backbone of PCNL for many years. Compared with standard PCNL, it seems that mini PCNL is associated with fewer bleeding complications and shorter hospital admissions, but also with longer operating room (OR) time and higher intrarenal pressure. Use of laser lithotripsy combined with suction in mini PCNL is a promising alternative that may improve such PCNL by shortening OR times. Furthermore, supine PCNL is a good alternative, especially in cases with complex renal stones and large proximal ureteric stones; in addition, it facilitates endoscopic combined intrarenal surgery (ECIRS).

CONCLUSION

Recent technological improvements in PCNL techniques are promising, but there is a lack of high-level evidence on safety and efficacy. Different techniques suit different types of stones and patients. The evolution of diverse methods has given urologists the possibility of a personalized stone approach, in other words, the right approach for the right patient.

Stone clearance times with mini-percutaneous nephrolithotomy: Comparison of a 1.5 mm ballistic/ultrasonic mini-probe vs. laser

INTRODUCTION

A limitation of mini-percutaneous nephrolithotomy (mPCNL) is the narrow working channel of mini-nephroscopes, typically restricting instrumentation to 5 French (F) or smaller. We evaluated the efficacy of the 1.5 mm Swiss LithoClast ^® Trilogy (Trilogy) rigid probe and compared the results to consecutive cases performed with a 30 W Holmium:YAG (Ho:YAG) laser.

METHODS

A retrospective review of 30 consecutive mPCNL cases using the Trilogy and 30 W Holmium laser was performed. A 12 F MIPS nephroscope with a 16.5 F access sheath and 6.7 F working channel was used for all mPCNL cases. The Trilogy was used with a disposable 1.5 mm × 440 mm probe with dual ultrasonic and ballistic energy. The Ho:YAG laser was used with a 550 micron fibre and a maximum of 30 W. Stone clearance time (SCT) was defined by the total time interval between activation of the lithotripter until insertion of the nephrostomy tube and measured in mm²/minutes. SCT included time for fragment retrieval, equipment adjustments, and rigid and flexible nephroscopy during and after lithotripsy.

RESULTS

Eleven cases using a 1.5 mm Trilogy probe and 16 cases using a Ho:YAG laser met final inclusion criteria. Three cases using the Trilogy were excluded from final analysis due to conversion to alternative energy sources - two of those were upsized to standard PCNL and one was converted to laser. Mean stone diameter and density in the final Trilogy cohort was 26.7 mm and 1193 Hounsfield units (HU). Mean diameter and density in the laser cohort was 25.2 mm and 1049 HU. The mean stone area clearance time for Trilogy was 4.7±1.8 mm²/minute vs. 3.4±0.7 mm²/minute with Ho:YAG laser (p=0.21). For hard stones, defined as density >1000 HU, the Trilogy averaged 3.7±1.6 mm²/minutes, while the laser averaged 3.1±1.3 mm²/minutes (p=0.786). For soft stones, defined as <1000 HU, the Trilogy averaged 8.9±1.0 mm²/minutes compared to the Ho:YAG, which averaged 3.6±1.8mm²/minutes (p=0.019). No device-related complications occurred in either cohort.

CONCLUSIONS

The 1.5 mm mPCNL Trilogy probe was comparable to 30 W Ho:YAG laser for clearing hard stones. The Trilogy performed better than laser on soft stones with a HU density <1000 HU.

Comparison of stone elimination capacity and drilling speed of endoscopic clearance lithotripsy devices

PURPOSE

To investigate the fragmentation capacity, clearance time, and drilling speed of combined ultrasonic with impact dual-energy and single energy ultrasonic lithotripter devices.

METHODS

Stone fragmentation and clearance tests were performed under direct view in an underwater layered hemisphere by four different operators using artificial stones (n = 10/operator). Time for complete clearance was measured. Drilling tests were performed using an underwater setup, consisting of a mounting rack for fixing the lithotripter handpiece with the probe in vertical position and in contact with the stone phantom placed on one side of a balance for defined and constant contact application pressure equivalent to 450 g load. Time until complete perforation or in case of no perforation, the penetration depth after 60 s into the stone sample was recorded. Four devices, one single energy device (SED), one dual-energy dual probe (DEDP), two dual-energy single probe (DESP-1, DESP-2), with different parameters were tested.

RESULTS

Stone fragmentation and clearance speed were significantly faster for dual-energy device DESP-1 compared to all other devices (p < 0.001). Using DESP-1, the clearance time needed was 26.0 ± 5.0 s followed by DESP-2, SED and DEDP requiring 38.4 ± 5.8 s, 40.1 ± 6.3 s and 46.3 ± 11.6 s, respectively. Regarding the drilling speed, DESP-1 was faster compared to all other devices used (p < 0.05). While the drilling speed of DESP-1 was 0.69 ± 0.19 mm/s, compared to 0.49 ± 0.18 mm/s of DESP-2, 0.47 ± 0.09 mm/s of DEDP, and 0.19 ± 0.03 mm/s of SED.

CONCLUSIONS

The dual-energy/single-probe device combining ultrasonic vibrations with electromechanical impact was significantly faster in fragmentation and clearing stone phantoms as well as in drilling speed compared to all other devices.

Initial Clinical Experience with Swiss LithoClast Trilogy During Percutaneous Nephrolithotomy

Introduction and Objective: Current available lithotrites have clinical stone clearance rates averaging 24 to 32 mm²/minute. The objective of this study was to critically evaluate the initial experience with the Swiss LithoClast^® Trilogy lithotrite during percutaneous nephrolithotomy (PCNL). Methods: We prospectively enrolled patients with a minimum of 15 mm of stone in axial diameter at three locations (Indiana University, University of California Davis, and University of California San Diego) scheduled to undergo PCNL for nephrolithiasis over a 60-day trial period. We assessed objective measures of stone clearance time, stone clearance rate, device malfunction, stone-free rate, and complications. Each surgeon also evaluated subjective parameters from each case related to the use of Trilogy on a 1 to 10 scale (10 = extremely effective), and compared it with their usual lithotrite on a 1 to 5 scale (5 = much better). Results: We included 43 patients and had 7 bilateral (16.3%) cases, for a total of 50 renal units. One case was a mini-PCNL. Two cases experienced device malfunctions requiring troubleshooting but no transition to another lithotrite. The mean stone clearance rate was 68.9 mm²/minute. The stone-free rate on postoperative imaging was 67.6% (25 of 37 patients with available imaging). The lowest subjective rating was the ergonomic score of 6.7, and the highest subjective rating was the ease of managing settings score of 9.2. The surgeon impressions of ultrasound (7.3), ballistics (8.1), combination of ultrasound and ballistics (8.7), and suction (8.4) were high. One patient experienced an intraoperative renal pelvis perforation, one patient required a blood transfusion, one patient had a pneumothorax requiring chest tube placement, and one patient had a renal artery pseudoaneurysm requiring endovascular embolization. Conclusions: This multi-institutional study evaluated a new and efficient combination lithotrite that was perceived by surgeons to be highly satisfactory, with an excellent safety and durability profile.

EMS Lithoclast Trilogy™: an effective single-probe dual-energy lithotripter for mini and standard PCNL

PURPOSE

Several energy sources are available to clear stones during PCNL. Required improvements are faster stone clearance, optimized suction and ease of use while maintaining high patient safety standard. EMS LithoClast^® Trilogy, is the first device combining electromagnetic impactor with ultrasonic energy and suction, all-in-one probe. Animal studies and in vitro phantom stone studies have proven safety and efficacy of this device. We aim to study safety and clinical efficacy of Trilogy in our patients.

METHODS

31 patients with renal stones were included. Amplatz sheath sizes/Trilogy probe size was 22-28 Fr/10.2 Fr for standard PNL (n = 20) and 15 Fr./5.7 Fr for mini PNL access (n = 11). Analysis was done with respect to demography, stone characteristics, operation duration (total time and lithotripter activation time), post op Hb drop, clearance rate and adverse events. Stone area/volume was calculated based on CT using 3D doctor. Efficacy was determined by stone volume clearance rate (mm³/min).

RESULTS

Male:female ratio was 6:5 and 16:4 for mini (MPNL)/standard PNL (SPNL). Stone densities were 1229 ± 206 vs. 1168 ± 344 HU (MPNL vs. SPNL). Mean stone volumes were 3776.1 ± 2132 mm³ for MPNL and 7096 ± 6441 for SPNL. Mean stone volume clearance ratios were 370.5 ± 171 mm³/min and 590.7 ± 250mm³/min for MPNL and SPNL, respectively. Hb drop was 1.24 ± 0.64 g/dL (MPNL) and 1.23 ± 0.89gm/dL (SPNL). Total procedure time/lithotripter activation time was 53.4 ± 23.8/14.7 ± 12.4 min for MPNL and 65.2 ± 23.5/12.0 ± 8.9 for SPNL. Immediate post-operative/1 month stone clearance rates were 93%/96% with one clinically insignificant residual fragment (< 3 mm) and no necessity for auxiliary procedures. No device failure occured and three Clavien grade I and one grade II complications were observed.

CONCLUSION

Swiss LithoClast^® Trilogy provides fast stone clearance in standard/mini-PCNL procedures. Ease of use, high tissue safety and optimized suction that avoids fragment blockings are other key features.

Comparative evaluation of tissue damage induced by ultrasound and impact dual-mode endoscopic lithotripsy versus conventional single-mode ultrasound lithotripsy

OBJECTIVE

The aim of our study was to perform comparative investigation of the tissue safety of three different endoscopic lithotripter devices including a new single-probe/dual-energy lithotripter in an in vivo animal model. The Swiss LithoClast Trilogy was compared to the Storz Calcuson and the Swiss LithoClast Vario. The safety test simulated the accidental direct contact between lithotripter probes and the urothelium, which can occur when sliding off a stone or drilling through a calculus during lithotripsy. The safety test included a smallest (1.5 mm) and largest (3.3/3.4 mm) probe diameter per device.

METHODS

Testing was performed in nine pigs (three animals per device). The bladder tissue was exposed to direct lithotripter probe contact at maximum power for 10 s to produce visible tissue lesions. Acute tissue trauma was evaluated using a simplified scoring model describing the expected bladder wall injuries for histological examination. After 7 days, all animals were killed, necropsied and examined post mortem. For between-group comparisons regarding microscopic histopathologic features, a Chi-square test was used. A p value < 0.05 was considered to be statistically significant.

RESULTS

Irrespective of the lithotripter used, no systemic signs of toxicity were observed. Histologically, signs of normal ongoing healing were observed on the bladder mucosa. There were no significant differences in histological findings taking changes of the epithelium (p = 0.360), the leucocyte infiltration (p = 0.123), the vascular congestion (p = 0.929) and the edema (p = 1.0) between the groups into account.

CONCLUSIONS

The results of this study demonstrated a comparable safety between all lithotripsy devices.

Present indications and techniques of percutaneous nephrolithotomy: What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy (PCNL) procedure in terms of indications and evolving techniques, and to identify the advantages and disadvantages of each modality. The data for this review were collected after a thorough PubMed search in core clinical journals in English language. The key words included “PCNL” and “PNL” in combination with “indications”, “techniques”, “review” and “miniaturized PCNL”. Publications relevant to the subject were retrieved and critically reviewed. Current European and American Urology Association Nephrolithiasis Guidelines were included as well. The indications for standard PCNL have been changed through the past decade. Despite evolution of the procedure, innovations and the development of new technical approaches, the indications for miniaturized PCNL have not been standardized yet. There is a need for well-constructed randomized trials to explore the indications, complications and results for each evolving approach. A continuous reduction of tract size is not the only revolution of the last years. There is constant ongoing interest in developing new efficient miniature instruments, intracorporeal lithotripters and sophisticated tract creation methods. We can summarize that, PCNL represents a valuable well-known tool in the field of endourology. We should be open minded to future changes in surgical approaches and technological improvements.