Holmium:YAG laser ureteroscopic lithotripsy for ureteric calculi in children: predictive factors for complications and success

Safety and feasability of ureteroscopy for pediatric stone, in children under 5 Years (SFUPA 5): A French multicentric study

INTRODUCTION

Ureteroscopy (URS) can be proposed as first-line therapy for the management of pelvic stones from 10 to 20 mm and for lower ureteric stones in children. However, little is known about the success and the morbidity of URS in young children. Ureteroscopic treatment may present matters in young children because of the small size of the pediatric kidney and the small size of the collecting system.

OBJECTIVE

To assess safety and efficacy of URS for the treatment of urinary stones in children aged of 5 years or less.

STUDY DESIGN

After the institutional ethical board approval was obtained, we conducted a retrospective, analytic, multicentric study that included all URS performed between January 2016 and April 2022 in children aged of 5 years or less. In this non-comparative case series, anonymized pooled data were collected from 7 tertiary care centers of pediatric patients. Endpoints were the one-session SFR at 3 months and per and postoperatives complications. Descriptive statistics were applied to describe the cohort.

RESULTS

Eighty-three patients were included. For them, 96 procedures were performed at the median age of 3.5 years (IQR: 0.8-5) and median weight of 14 Kg (6.3-23). Median stone size was 13 mm (4-45). There were 65 (67 %) renal stones treated with flexible URS, most of which were in the renal pelvis (30 %) and in the lower calix (33 %). A ureteral access sheath was used in 91 % procedures. Preoperative ureteral stent was placed in 52 (54 %) of patients. None of patients had ureteral dilatation. The single-session SFR was 67.4 % (56.3 and 89.2 % for flexible URS and semi-rigid URS respectively) and children require 1.4 procedures to achieve complete stone clearance. The overall complication rate was 18.7 %, most of them were minor (Clavien I-II). Intraoperative perirenal extravasation (Clavien IIIb) due to forniceal rupture was documented in 6.2 % of cases, related to an increased intrapelvic pressure (IPP) performed in a closed pelvicalyceal system.

DISCUSSION

Pediatric urologists should be aware of forniceal rupture based on the presence of extravasation of contrast during endourological procedures especially when they have difficulties to reach lower caliceal stone in small patient.

CONCLUSION

URS in patients aged of 5 years or less, is a complex minimally invasive procedure with reasonable efficacy and low morbidity. Intrarenal stones treated by RIRS in young children carries the risk of additional procedures to complete stone clearance.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Comparing the efficacy of extracorporeal shock wave lithotripsy and ureteroscopic lithotripsy in the treatment of proximal ureteral stones in children: A retrospective study

OBJECTIVES

Ureteroscopic lithotripsy and extracorporeal shock wave lithotripsy methods are commonly used in the treatment of proximal ureteral stones. There are no adequate studies showing which method is more effective in children. In our study, we aimed to evaluate and compare the efficacy of two treatment methods, commonly used for proximal ureteral stones in children.

METHODS

A total of 78 patients who underwent ureteroscopic lithotripsy (n = 38) and extracorporeal shock wave lithotripsy (n = 40) due to stones located in the proximal ureter between 2010 and 2021 were included in the study. Demographic data, clinical characteristics, and treatment outcomes were retrospectively analyzed. Kolmogorov-Smirnov, Chi-square, and Mann-Whitney U tests were used for statistical analysis.

RESULTS

There was no statistical difference between the demographic characteristics of the groups, except for the mean age values (p = 0.008). A statistically significant difference was found in favor of the extracorporeal shock wave lithotripsy group in terms of stone-free rates after the first intervention, complication rates requiring intervention, re-intervention rates, and the average number of anesthesia sessions per patient until stone-free status (p = 0.043, p = 0.009, p = 0.017, and p < 0.001, respectively).

CONCLUSIONS

The results of this retrospective study suggest that extracorporeal shock wave lithotripsy is the primary treatment option for single, non-complicated proximal ureteral stones.

Comparison and Evaluation of Outcomes of Ureteroscopy and Stone Laser Fragmentation in Extremes of Age Groups (≤10 Years and ≥80 Years of Age): A Retrospective Comparative Analysis of over 15 Years from 2 Tertiary European Centres

AIM

To assess and compare the outcomes associated with ureteroscopy and laser fragmentation (URSL) for extremes of age group (≤10 and ≥80 years).

METHODS

Retrospective consecutive data were collected from two European centres for all paediatric patients ≤10 undergoing URSL over a 15-year period (group 1). It was compared to consecutive data for all patients ≥80 years (group 2). Data were collected for patient demographics, stone characteristics, operative details, and clinical outcomes.

RESULTS

A total of 168 patients had 201 URSL procedures during this time (74 and 94 patients in groups 1 and 2 respectively). The mean age and stone sizes were 6.1 years and 85 years, and 9.7 mm and 13 mm for groups 1 and 2 respectively. While the SFR was slightly higher in group 2 (92.5% versus 87.8%, p = 0.301), post-operative stent rate was also significantly higher in the geriatric population (75.9% versus 41.2%, p = 0.0001). There was also no significant difference in pre-operative stenting (p = 0.886), ureteric access sheath use (UAS) (p = 0.220) and post-operative complications. Group 1 had an intervention rate of 1.3/patient as compared to 1.1/patient in group 2. The overall complications were 7.2% and 15.3% in groups 1 and 2 respectively (0.069), with 1 Clavien IV complication related to post-operative sepsis and brief ICU admission in group 2.

CONCLUSION

The paediatric population had a marginally higher incidence of repeat procedure, but the overall SFR and complications were similar, and post-operative stent insertion rates were much better compared to geriatric patients. URSL is a safe procedure in the extremes of age groups with no difference in the overall outcomes between the two groups.

Preliminary experience in endoscopic section of posterior urethral valves using the Holmium: YAG laser

INTRODUCTION

Refinements in endoscopic instrumentation, the widespread popularization of endourology and the minimal invasiveness of endoscopic approaches have led to evolving interest in expanding applications for their use and now include incision of posterior urethral valves (PUV). We aimed to report our paediatric experience of PUV incision with Holmium:YAG laser updating of the endoscopic technique, how we set parameters for the laser energy and provide some tips and tricks to increase the likelihood of completing treatment.

METHODS

A monocentric, prospective, continuous series of boys with PUV were treated endoscopically using a Holmium: YAG laser (1.2 J, 20 Hz, 800 μs). Feasibility was evaluated using operative time in minutes, spontaneous normal micturition after bladder catheter removal, and the duration of bladder catheterization in days in the absence of satisfactory micturition. Peri-operative complications were recorded. A VCUG was performed at 6 weeks postoperatively to exclude residual valves.

RESULTS

Since September 2018, 18 children with PUV were included. The median age at the time of endoscopic laser incision was 12 days (1 day-5 years). The median operative duration was 28 min (17-35). The urinary catheter was systematically removed on the first postoperative day. There were no intraoperative or anaesthesia-related complications. More specifically, no urethral injuries and no bleeding were recorded. No incomplete VUP incision was found on follow-up VCUG, and no endoscopic revision was necessary thus far, with a median follow-up of 44 months (6 months-60 months).

DISCUSSION

The use of the Holmium: YAG laser introduces new perspectives in the treatment of PUV. Its mechanism of action is considered a photothermic effect with a vapourization effect. The laser energy released by the Holmium: YAG source has a short tissue penetration distance and is strongly absorbed in an aqueous environment and therefore limits thermal tissue damage and favours early tissue re-epithelialization, reducing the risk of urethral stricture and decreasing postoperative oedema. The use of the laser in "incision" mode is the setting that most solicits the capacities of the laser (high energy, high frequency, and long pulse). The use of laser energy has the advantage of allowing tissue vapourization while ensuring maximal haemostasis and the possibility of introducing the laser fibre through the working channels of small, 6-Fr paediatric endoscopes.

CONCLUSION

In our experience, endoscopic PUV incision using the Holmium: YAG laser appears to be a safe and efficient technique.

Retrospective Analysis of the Risk Factors and Drug Resistance of Pathogenic Bacteria in Systemic Inflammatory Response Syndrome After Ureteroscopic Holmium Laser Lithotripsy for Impacted Ureteral Calculi

Objective

To investigate the risk factors, pathogen distribution, and drug resistance of systemic inflammatory response syndrome (SIRS) after holmium laser ureteroscopic lithotripsy for impacted ureteral calculi (HLULIUC).

Patients and Methods

The clinical data of 293 patients with HLULIUC in our hospital from October 2017 to February 2021 were retrospectively collected, including age, BMI, stone size, operation time, urine routine, urine culture, basic illness, complete blood count, liver and kidney function, etc. Patients were divided into SIRS and non-SIRS groups according to whether they had SIRS or not. Then the differences in clinical data, blood and urine bacterial culture results, and drug resistance between the two groups were analyzed.

Results

The incidence of SIRS after HLULIUC was 17.75%. Logistic regression analysis showed that the risk factors of SIRS after HLULIUC include ureteral calculi≥1cm (OR=2.839, 95% CI=1.341–5.647, P=0.021), long operation time (OR=4.534, 95% CI=2.597–12.751, P=0.017), diabetes mellitus (OR=3.137, 95% CI=1.142–7.319, P=0.012), increased preoperative C-reactive protein (OR=1.864, 95% CI=1.05–4.347, P=0.032), and positive urine leukocytes (OR=3.514, 95% CI=1.7237–9.734, P=0.007) and culture (OR=6.034, 95% CI=3.097–15.751, P<0.001) before operation. The main pathogens causing SIRS after HLULIUC were Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis, and Pseudomonas aeruginosa. The pathogenic bacteria are sensitive to drugs including piperacillin/tazobactam, meropenem, tigecycline, teicoplanin, vancomycin, and imipenem. The resistance rates to quinolones (such as levofloxacin) and to the second- and third-generations of cephalosporins were as high as 52.94%–90.19%.

Conclusion

Ureteral calculi≥1cm, long operation time, diabetes, increased C-reactive protein, and preoperative positive urine leukocytes and culture are independent risk factors of SIRS after HLULIUC. Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis, and Pseudomonas aeruginosa are the main pathogenic bacteria for SIRS after HLULIUC. The pathogenic bacteria are sensitive to drugs, including piperacillin/tazobactam, meropenem, tigecycline, teicoplanin, vancomycin, and imipenem.

The clinical efficacy of novel vacuum suction ureteroscopic lithotripsy in the treatment of upper ureteral calculi

OBJECTIVE

To investigate the clinical efficacy of a novel vacuum suction ureteroscopic approach in the treatment of upper ureteral calculi and to compare it with traditional rigid and flexible ureteroscopic approaches.

SUBJECTS AND METHODS

A total of 160 patients with impacted upper ureteral calculi were included in this study. 50 patients underwent rigid ureteroscopic lithotripsy, 54 patients underwent flexible ureteroscopic lithotripsy, and 56 patients underwent vacuum suction ureteroscopic lithotripsy. The operative time, length of hospitalization, stone-free rate, the incidence of postoperative complications, and total treatment cost were compared among the three groups. Subgroup analysis was performed based on the stone diameter over and below 1.5 cm.

RESULTS

All operations were performed successfully, and there were no cases converted to open surgery. Compared with the other 2 groups, the vacuum suction ureteroscopy group had a higher stone-free rate at 3-5 days (90.0% vs. 61.9% vs. 55.6%, P < 0.05) and 1 month (96.4% vs. 77.7% vs. 74.0%, P < 0.05) postoperatively. In subgroup analysis, the stone-free rate of the vacuum suction ureteroscopy group was significantly higher when the stone diameter was > 1.5 cm at 1 month postoperatively (P < 0.05) compared with that in the other 2 groups; however, there were no differences in postoperative complications. (P > 0.05).

CONCLUSION

The novel vacuum suction ureteroscopic lithotripsy has significantly improved the stone-free rate especially in complicated cases, compared with that in rigid and flexible approaches; however, the complication and cost were not increased.

Extracorporeal Shockwave Lithotripsy for Cystine Stones in Children: An Observational, Retrospective, Single-Center Analysis

Purpose: Cystinuria is a genetic disorder characterized by a defective reabsorption of cystine and dibasic amino acids leading to development of urinary tract calculi from childhood onward. Cystine lithiasis is known to be resistant to fragmentation. The aim was to evaluate our long-term experience with extracorporeal shockwave lithotripsy (ESWL) used as first-line urological treatment to treat cystine stones in children. Methods: We retrospectively reviewed the charts of all children who underwent ESWL for cystine stone. We assessed the 3-month stone-free rate, according to age, younger (group 1) or older (group 2) than 2 years old. Results: Between 2003 and 2016, 15 patients with a median (IQR) age at first treatment of 48 (15-108) months underwent ESWL in monotherapy. Median age was, respectively, 15 and 108 months in each group. The median (IQR) stone burden was 2,620 (1,202-8,265) mm³ in group I and 4,588 (2,039-5,427) mm³ in group II (p = 0.96). Eleven patients had bilateral calculi. ESWL was repeated on average 2.4 times, with a maximum of 4 for patients of group I, and 4.8 times, with a maximum of 9 for group II (p > 0.05). ESWL in monotherapy was significantly more efficient to reach stone-free status for children under 2 years of age: 83% vs. 6.2% (p = 0.040). The median (IQR) follow-up of the study was 69 (42-111) months. Conclusion: ESWL appears as a valid urological option for the treatment of cystine stones, in young children. Even if cystine stones are known to be resistant to fragmentation, we report 83% of stone-free status at 3 months with ESWL used in monotherapy in children under 2 years old with cystinuria. In older children, the success rate is too low to recommend ESWL as a first line approach.

Imaging modalities and treatment of paediatric upper tract urolithiasis: A systematic review and update on behalf of the EAU urolithiasis guidelines panel

BACKGROUND

Prompt diagnosis and treatment of paediatric urolithiasis are required to avoid long term sequelae of renal damage.

OBJECTIVE

To systematically review the literature regarding the diagnostic imaging modalities and treatment approaches for paediatric urolithiasis.

STUDY DESIGN

PubMed, Science Direct, Scopus and Web of Science were systematically searched from January 1980-January 2019. 76 full-text articles were included.

RESULTS

Ultrasound and Kidney-Ureter-Bladder radiography are the baseline diagnostic examinations. Non-contrast Computed Tomography (CT) is the second line choice with high sensitivity (97-100%) and specificity (96-100%). Magnetic Resonance Urography accounts only for 2% of pediatric stone imaging studies. Expectant management for single, asymptomatic lower pole renal stones is an acceptable initial approach, especially in patients with non-struvite, non-cystine stones<7 mm. Limited studies exist on medical expulsive therapy as off-label treatment. Extracorporeal shock wave lithotripsy (SWL) is the first-line treatment with overall stone free rates (SFRs) of 70-90%, retreatment rates 4-50% and complication rates up to 15%. Semi-rigid ureteroscopy is effective with SFRs of 81-98%, re-treatment rates of 6.3-10% and complication rates of 1.9-23%. Flexible ureteroscopy has shown SFRs of 76-100%, retreatment rates of 0-19% and complication rates of 0-28%. SFRs after first and second-look percutaneous nephrolithotomy (PNL) are 70.1-97.3% and 84.6-97.5%, respectively with an overall complication rate of 20%. Open surgery is seldom used, while laparoscopy is effective for stones refractory to SWL and PNL. Limited data exist for robot-assisted management.

CONCLUSIONS

In the initial assessment of paediatric urolithiasis, US is recommended as first imaging modality, while non-contrast CT is the second option. SWL is recommended as first line treatment for renal stones <20 mm and for ureteral stones<10 mm. Ureteroscopy is a feasible alternative both for ureteral stones not amenable to SWL as well as for renal stones <20 mm (using flexible). PNL is recommended for renal stones >20 mm.

Ureteroscopic lithotripsy for ureteral stones in children using holmium: yag laser energy: results of a multicentric survey

BACKGROUND

Holmium:YAG (Ho:YAG) laser lithotripsy has broadened the indications for ureteroscopic stone managements in adults, but few evidence are currently available in the pediatric population.

OBJECTIVE

This article aimed to assess the outcome of Ho:YAG laser lithotripsy during retrograde ureteroscopic management of ureteral stones in different locations in children.

STUDY DESIGN

The medical records of 149 patients (71 boys and 78 girls; median age 9.2 years) treated with Ho:YAG laser ureteroscopic lithotripsy in five international pediatric urology units over the last 5 years were retrospectively reviewed. Exclusion criteria included patients with renal calculi and/or with a history of ipsilateral stricture, renal failure, active urinary tract infection, or coagulation disorder.

RESULTS

Stones were treated with dusting technique in all cases. The median stone size was 10.3 mm (range 5-17). Stones were located in the distal ureter in 77 cases (51.7%), in the middle ureter in 23 cases (15.4%), and in the proximal ureter in 49 cases (32.9%). The median operative time was 29.8 min (range 20-95). Intra-operative complications included five bleedings (3.3%) and seven stone retropulsions (4.7%). Overall stone-free rate was 97.3%. Overall postoperative complications rate was 4.0% and included two cases of stent migration (1.3%) (Clavien II) and four residual stone fragments (2.7%) that were successfully treated using the same technique (Clavien IIIb). On multivariate analysis, re-operation rate was significantly dependent on the proximal stone location and presence of residual fragments >2 mm (P = 0.001).

DISCUSSION

This study is one of the largest pediatric series among those published until now. The study series reported a shorter operative time, a higher success rate, and a lower postoperative complications rate compared with previous series. A limitation of this study is that stone-free rates may be somewhat inaccurate using ultrasonography and plain X-ray compared with computed tomography (CT); the study's 97.3% success rate may be overestimated because no CT scan was done postoperatively to check the stone-free rate. Other limitations of this article include its retrospective nature, the multi-institutional participation, and the heterogeneous patient collective.

CONCLUSION

The Ho:YAG laser ureteroscopic lithotripsy seems to be an excellent first-line treatment for children with ureteral stones, independently from primary location and size. However, patients with proximal ureteral stones and residual fragments >2 mm reported a higher risk to require a secondary procedure to become stone-free. Combination of techniques as well as appropriate endourologic tools are key points for the success of the procedure regardless of stones' size and location.

A study on the clinical application of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones below L4 level

Purpose

The purpose of the study was to evaluate the efficacy and safety of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones (≥ 1.5 cm) below L4 level.

Methods

We recruited 122 patients with large ureteral stones below L4 level at our hospital from December 2014 to June 2017. The patients were randomly divided into the study and control groups. Multiple operative and perioperative parameters were compared between the two groups.

Results

The study group had shorter operation time, less cases of postoperative fever, lower serum levels of PCT, IL-6 and BET within 24 h after surgery, as well as less number of cases receiving secondary surgery than the control group. Moreover, the former had a significantly higher stone clearance rate than the latter (P < 0.05; t-test or χ² test).

Conclusions

The patented perfusion and suctioning platform and ureteral access sheath are safe and effective in treating large ureteral stones (≥ 1.5 cm) below L4 level.

Cr2+: CdSe passively Q-switched Ho: YAG laser

We first demonstrate the laser performance of a Cr²⁺:CdSe passively Q-switched (PQS) 2.09 μm Ho: YAG laser resonantly pumped by a thulium-doped fiber laser. The maximum output pulse energy of 1.766 mJ, corresponding to a repetition frequency of 685 Hz, was obtained with a pulse duration of 15.4 ns. The pulse peak power was 114.7 kW, while the PQS efficiency was 21.45% against the continuous-wave output. The laser wavelength in the PQS operation was precisely measured to be 2090.2 nm.

High-slope-efficiency 2.06 μm Ho: YLF laser in-band pumped by a fiber-coupled broadband diode

We first demonstrate the laser performance of a compact 2.06 μm Ho: YLF laser resonantly pumped by a broadband fiber-coupled diode. In continuous-wave (CW) operation, maximum output power of 1.63 W, corresponding to a slope efficiency of 89.2%, was obtained with a near diffraction-limited beam quality. In actively Q-switched operation, maximum pulse energy of 1.1 mJ was achieved at the repetition frequency of 100 Hz. The minimum pulse duration was 43 ns. The performance in both the CW and Q-switched regimes indicates that the current fiber-coupled diode in-band pumped Ho: YLF laser has great potential in certain conditions that require several watts of output power or several millijoules of short pulse energy.

Ureteroscopic lithotripsy in Trendelenburg position for proximal ureteral calculi: a prospective, randomized, comparative study

PURPOSE

We conducted a prospective, randomized, comparative study to compare the clinical outcome between the Trendelenburg position ureteroscopic lithotripsy (tURSL) and the conventional position ureteroscopic lithotripsy (cURSL) for the management of single proximal ureteral stone.

METHODS

From January 2012 to September 2013, consecutive patients with single proximal ureteral calculi less than 2 cm and planned for ureteroscopic lithotripsy at our institution were enrolled in this study. The eligible patients were randomized into cURSL group and tURSL group according to sequence of random numbers generated by computer. In tURSL group, patients were turned into a Trendelenburg lithotomy position with head down 30° while the conventional lithotomy position was applied in cURSL group. URSL was performed using a 6/7.5F semi-rigid ureteroscope with holmium laser. When retropulsion occurred, the stones fragments were followed by semi-rigid ureteroscope up to the renal collecting system. The Olympus P5 flexible ureteroscope was used if there was any suspicion of stone migration into lower calices or incomplete stone fragmentation by semi-rigid ureteroscope. Patients' demographics between the two groups, perioperative course, clinical outcome and complication rates were compared. Data were analyzed using Chi-square test, Fisher's exact test or Student's t test. Binary logistic regression analysis was applied to estimate the effects of surgical position and stone size on stone migration.

RESULTS

A total of 355 cases were finally analyzed in this study (176 in cURSL group and 179 in tURSL group). The mean operative time was significantly prolonged in cURSL group than in tURSL group, while the stone-free rate (SFR) at 4 weeks was significantly higher in tURSL group. A statistically significant difference was found in stone migration rate between the two groups (26.7 vs. 43.6 %, P = 0.001). In the stone migration subsetting, less stones fragments were found to migrate into lower calices in tURSL stone migration subgroup (P = 0.000). Also, the flexible ureteroscope utilization as well as the operative time was significantly decreased in tURSL stone migration subgroup (25.5 vs. 72.3 %, P = 0.000), (44.96 ± 11.0 min vs. 59.17 ± 9.2 min, P = 0.000) with higher SFR after retrograde intrarenal surgery (RIRS) (96.2 vs. 74.5 %, P = 0.000).

CONCLUSION

The tURSL was safe and highly efficacious for the management of proximal ureteral calculus, especially in nonobese patient. Even with important stone migration risk, it rendered higher SFR and less operative time compared with cURSL. Moreover, less utilization of flexible ureteroscope and decreased deflection time in tURSL could potentially reduce the medical cost.