Single-step percutaneous nephrolithotomy (microperc): the initial clinical report

Endoscopic combined intrarenal surgery versus percutaneuos nephrolithotomy for complex pediatric stone disease: A comparative analysis of efficacy and safety

INTRODUCTION

Decision-making for complex pediatric urinary system stone disease is still a challenge for pediatric urologists. The interest in supine percutaneous nephrolithotomy (PCNL) is increasing among centers to achieve high surgical success rates with less morbidity. Despite advanced retrograde intrarenal surgery armamentarium, percutaneous approaches remain the first-line surgical treatment modality for >2 cm and complex renal stones. There are no comparative studies yet in the literature for pediatric endoscopic combined intrarenal surgery (ECIRS) OBJECTIVE: In this study, we aimed to contribute to the literature by evaluating the safety and efficacy of ECIRS by comparing it with PCNL.

STUDY DESIGN

Patients under 18 years of age who underwent PCNL and ECIRS for urinary tract stone disease at our Pediatric Urology department between 2012 and 2024 were included. Preoperative (demographic characteristics, stone characteristics, biochemical parameters), perioperative (duration of surgery, number of accesses, lasing and fluoroscopy times, endoscopic and fluoroscopic stone-free rates) and postoperative (hospital stay, urinary tract infection, complication and radiological stone-free rates) parameters were retrospectively evaluated.

RESULTS

A total of 68 children [28 (41%) girls and 40 (59%) boys] aged 5 (0-17) years were included in the study. ECIRS was performed in 19 (28%), supine in 28 (41%) and prone PCNL in 21 (30%) patients. Age (p = 0.029), Guy's stone score (p < 0.001), S.T.O.N.E. (p < 0.001), and Seoul National University Renal Stone Complexity (S-ReSC) scores (p = 0.001) for preoperative parameters were found to be higher in ECIRS group over both PCNL methods (Summary Table). However, Clinical Research Office of the Endourological Society (CROES) score was seen lower for ECIRS group patients compared to other groups (p = 0.028). Surgery time (in favor of supine over prone PCNL), fluoroscopy time (in favor of ECIRS and Supine PCNL over Prone PCNL), preferred laser type (prone PCNL group was mostly performed with holmium laser, whereas other groups were balanced between Holmium and Thulium Fiber Laser) and exit strategy (the preferred exit strategy was DJ Stent in most of the ECIRS patients, whereas nephrostomy tube was used in some of the PCNL group) showed significant difference among the groups as perioperative parameters (p = 0.042, <0.001, <0.001, <0.001, respectively). Surgery time was lower for supine PCNL compared to prone PCNL. For postoperative parameters, stone-free rates, complication rates and urinary tract infections were similar between the 3 groups, while a difference was detected in terms of length of hospital stay in favor of ECIRS over both supine and prone PCNL (p = 0.006).

DISCUSSION

The current trial suggests that stone-free and complication rates of ECIRS and supine PCNL were similar in the pediatric complex stone patients. Although, the stones in the ECIRS group we found to be more complex. Also, ECIRS was superior to PCNL in terms of fluoroscopy exposure and hospital stay.

CONCLUSION

With the widespread use of new generation ureteral access sheaths and flexible ureterorenoscopes, ECIRS may have an important role in treatment of complex pediatric kidney stones.

A comparative study between one step dilatation and serial dilatation technique in percutaneous nephrolithotomy

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is the first line treatment for treating kidney stones larger than 2 cm size with the advantages of lower morbidity and faster post-operative recovery. Creation of a nephrostomy access is one of the major steps of PCNL. It can be done either by single-step dilatation or by multi-step serial dilatation technique.

OBJECTIVES

To compare the outcome and evaluate the efficacy of percutaneous nephrolithotomy done by single-step versus serial dilatation technique with specific reference to access time, fluoroscopy time, rate of blood transfusion, length of hospital stay (post-op) and complication rate.

METHODS

It was a prospective study with a sample size of 100 where 50 patients underwent one-step dilatation and other 50 patients underwent serial-dilatation technique. These patients were analysed on the basis of their demographic profile, renal access time, total fluoroscopy time for access, post-operative haematuria, duration of post-operative hospital stay and complications after operative procedure. Data was analysed and reported using statistical tools.

RESULTS

Demographic profile of the patients and stone characteristics were equivalent between two groups. Mean access tract dilatation time, mean total fluoroscopy time were significantly less in one of the groups. Requirement of blood transfusion, and post-operative complications rate were not significant between two groups.

CONCLUSION

Both methods are safe and effective for tract dilatation. However, PCNL can be successfully performed by one-step dilatation with the added advantages of lesser time of renal access, lesser radiation exposure. Blood loss and hospital stay after operative procedure were not statistically significant between two groups.

Super-mini PCNL (SMP) with suction versus standard PCNL for the management of renal calculi of 1.5 cm-3 cm: a randomized controlled study from a university teaching hospital

PURPOSE

To assess the safety and efficacy of super-mini PCNL (SMP, 14 Fr) when compared to standard PCNL (sPCNL, 24-30 Fr) in the management of renal calculi of size ranging from 1.5 to 3 cm.

METHODS

From February 2021 to January 2022, a total of 100 patients were randomized to either SMP group or sPCNL group in a 1:1 ratio (50 in each group) using computer-generated simple randomization. Demographic data, stone characteristics, operative times, perioperative complications, blood transfusions, postoperative drop in haemoglobin, postoperative pain, duration of hospital stay and stone-free rates were compared between the two groups.

RESULTS

Mean stone volume (2.41 cm2 vs 2.61 cm2) and stone-free rates (98% vs 94%, p = 0.14) were similar in both the SMP and sPCNL groups, respectively. The SMP group had significantly longer mean operative times (51.62 ± 10.17 min vs 35.6 ± 6.8 min, p = 0.03). Intraoperative calyceal injury (1/50 vs 7/50, p = 0.42) and mean postoperative drop in haemoglobin (0.8 ± 0.7 g/dl vs 1.2 ± 0.81, p = 0.21) were lower in the SMP group, but not statistically significant. SMP group showed significantly lower mean postoperative pain VAS scores (5.4 ± 0.7 vs 5.9 ± 0.9, p = 0.03) and mean duration of hospital stay (28.38 ± 3.6 h vs 39.84 ± 3.7 h, p = 0.0001). Complications up to Clavien grade 2 were comparable, with grade ≥ 3 complications higher in the standard group, but not statistically significant.

CONCLUSION

Super-mini PCNL is equally effective as standard PCNL in treating renal calculi up to 3 cm, with significantly reduced postoperative pain and duration of hospital stay and lower risk of Clavien grade ≥ 3 complications, although with higher operative times.

Comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters: a retrospective study

PURPOSE

To compare the efficacy and safety of micropercutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy (FURS) in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters.

METHODS

This study is a retrospective analysis that combines a review of medical records with an outcomes management database. A total of 163 patients who underwent MPCNL and 137 patients who had FURS were identified between January 2017 and December 2021. Demographic data, operation time, hospitalization time, stone-free rate, and complication rate were collected and analyzed.

RESULTS

Preoperative general data of sex, age, BMI, serum creatinine, time of stone existence, stone hardness, stone diameter, preoperative hydronephrosis, and preoperative infection of the MPCNL group have no statistically significant difference with that of the FURS group. All MPCNL or FURS operations in both groups were successfully completed without any instances of reoperation or conversion to another surgical procedure. Patients who underwent MPCNL had a considerably reduced operation time (49.6 vs. 72.4 min; P<0.001), but a higher duration of hospitalization (9.1 vs. 3.9 days; P<0.001) compared to those who underwent FURS. The stone-free rate in the MPCNL group was superior to that of the FURS group, with a percentage of 90.8% compared to 71.5% (P<0.001). There was no statistically significant disparity in the rate of complications between the two groups (13.5% vs. 15.3%; P = 0.741).

CONCLUSION

Both MPCNL and FURS are viable and secure surgical choices for individuals with solitary upper ureteral calculi measuring 1 to 2 cm. The FURS procedure resulted in a shorter duration of hospitalization compared to MPCNL. However, it had a comparatively lower rate of successfully removing the stones and required a longer duration for the operation.There were no substantial disparities observed in the complication rate between the two groups.FURS is the preferable option for treating uncomplicated upper ureteral calculi, whereas MPCNL is the preferable option for treating complicated upper ureteral calculi.Prior to making treatment options, it is crucial to take into account the expertise of surgeons, the quality of the equipment, and the preferences of the patient.

TRIAL REGISTRATION

No.

Miniaturizing the approach to upper tract renal calculi: Is smaller always better? A narrative review

Newer modalities for treating upper tract urinary stones focus on maintaining and improving outcomes, reducing complications, and optimizing patient care. This narrative review aims to outline novel miniaturized endourological innovations for managing upper tract calculi.

Efficacy and safety of minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of upper urinary tract stones (> 1 cm): a systematic review and meta-analysis of 18 randomized controlled trials

BACKGROUND

The advantages and disadvantages of retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (mPCNL) for treatment of upper urinary tract calculi have not been conclusively determined.

METHODS

In this meta-analysis, We comprehensively evaluated the performance of the two surgical approaches in treatment of upper urinary calculi. We searched the Pubmed, Embase, Cochrane and Web of science databases for randomized controlled trial (RCT) articles on RIRS and mPCNL upto December 2022. Data were extracted by two independent reviewers and subjected to the meta-analysis using the Stata 15.1 software (StataSE, USA).

RESULTS

A total of 18 eligible RCTs involving 1733 patients were included in this study. The meta-analysis revealed that mPCNL of 1-2 cm or 2-3 cm stones had a higher stone clearance rate (RR:1.08, 95%CI (1.03, 1.14), p = 0.002) and shorter operation time (WMD : -10.85 min, 95%CI (-16.76, -4.94), p<0.001). However, it was associated with more hospital stay time (WMD :1.01 day, 95%CI(0.53, 1.5), p<0.001), hemoglobin drops (WMD :0.27 g/dl, 95%CI (0.14, 0.41), p<0.001), blood transfusion rate (RR:5.04, 95%CI(1.62, 15.65), p = 0.005), pain visual analogue score (WMD:0.75, 95%CI (0.04, 1.46), p = 0.037), hospital costs (SMD :-0.97, 95%CI (-1.19, -0.76), p<0.001) and major complications (RR:1.89, 95%CI(1.01, 3.53), p = 0.045).

CONCLUSION

Therefore, in terms of surgical effects and operation time, mPCNL is superior to RIRS, but is inferior with regards to other perioperative parameters. These factors should be fully considered in clinical decision making.

Minipercutaneous Nephrolithotomy in the Management of Large and Complex Renal Calculi in Children: How Effective Is It?

Purpose: To evaluate the efficacy and safety of minipercutaneous nephrolithotomy (PCNL) in the management of large and complex calculi in children. Patients and Methods: From May 2017 to April 2021, a total of 41 pediatric cases were diagnosed with large/complex renal stones (partial-total staghorn) and following a detailed biochemical evaluation and thorough radiological examination (plain abdominal radiograph, urinary ultrasound, noncontrast and/or computed tomography), all cases underwent mini-PCNL procedure for the minimal invasive management of these calculi. Preoperative, intraoperative, and postoperative data were analyzed and reported in detail. Results: A total of 41 procedures were performed in 26 boys and 15 girls (male/female = 1.73). While the age of the kids ranged from 2.5 to 10 years (mean 6.74 ± 2.76), mean size of the stones was 16.28 ± 3.43 mm (range 11-24) with a mean stone density value of 816 HU (range 550-1350). Evaluation of the success rates in terms of complete stone clearance on postoperative day 1 revealed that while 73.2% (30/41), residual fragments have been noted in 11 cases (26.8%). Size of the residual fragments ranged from 2 to 7 mm (mean 4.3). Of those children, 10 cases required flexible ureteroscopy for stone removal, and in 1 case, placement of Double-J was adequate for spontaneous passage. During a 3-month follow-up, the stone-free rate (SFR) increased to 100% without any residual fragment left. Conclusions: Mini-PCNL with holmium laser lithotripsy is an effective and safe treatment alternative in the minimal invasive management of large/complex kidney stones in children with high SFRs.

Single-center experience of micro-perc in the treatment of children with 1.0-2.0 cm sized kidney stones in the Galdakao-modified supine Valdivia position

OBJECTIVE

We aimed to explore the applicability and safety of micro-percutaneous nephrolithotomy (micro-perc) in the treatment of children with kidney stones in the Galdakao-modified supine Valdivia (GMSV) position under the guidance of whole-course ultrasound.

MATERIALS AND METHODS

Patients were aged < 18 years in the GMSV position who underwent micro-perc for kidney stones under ultrasound guidance between August 2020 and May 2022 at our institution were reviewed retrospectively.

RESULTS

A total of 23 patients, 15 males and 8 females, received micro-perc. The average stone size was 1.6 cm (range 1.1-2.0 cm). Among them, 12 patients had left kidney stones, 10 patients had right kidney stones, and 1 patient had bilateral kidney stones. The mean operative time was 55.3 min (range 35-86 min). The mean hospital stay was 2.9 days (range 2-4 days). The mean hemoglobin decrease was 1.7 g/L (range 0.9-3.2 g/L). A total of 17 patients had complete stone clearance at 48 h postoperatively. A total of 22 patients had complete stone clearance at 2 weeks postoperatively.

CONCLUSION

Our results demonstrate that micro-perc under ultrasound guidance is a safe and effective method for the treatment of children with kidney stones in the GMSV position. Further research is warranted to confirm these results.

A meta-analysis: retrograde intrarenal surgery vs. percutaneous nephrolithotomy in children

Backgrounds

The increasing prevalence of pediatric kidney stones worldwide makes minimally invasive lithotripsy like retrograde intrarenal surgery (RIRS) and percutaneous Nephrolithotomy (PCNL) more prevalent. However, their safety and efficacy are controversial. Consequently, a meta-analysis of the comparison between RIRS and PCNL is conducted.

Methods

Clinical trials were selected from PubMed, EMBASE, Scopus, and Cochrane Library databases. The data extraction and study quality assessment were performed by two individuals independently. The data relating to therapeutic effects were extracted and analyzed by Review manager 5.4.

Results

Thirteen studies involving 1,019 patients were included. The micro-PCNL excelled in stone-free rate (P = 0.003), postoperative fever rate (P = 0.02), and Clavien-Dindo II complications (P = 0.05). Notably, the mean age of the micro-PCNL group was younger than other groups (P = 0.0005). The operation time in mini-PCNL was longer than RIRS (P < 0.00001) but with high heterogeneity (I² = 99%). There was no difference in Clavien-Dindo I, II, and III complications between the PCNL and the RIRS, but mini-PCNL showed a higher probability than RIRS in Clavien-Dindo I (P = 0.0008) and II complications (P = 0.007).

Conclusions

Compared with RIRS, micro-PCNL could be a better therapeutic option for kidney stones in children. Of note, more parameters should be analyzed to illustrate the efficacy of different minimally invasive surgeries for pediatric kidney stones due to poor cases in our study.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/#recordDetails, PROSPERO CRD42022323611.

Reliability of nephrolithometric nomograms in patients treated with minimally invasive percutaneous nephrolithotomy: A precision study

Objectives

The study aimed to evaluate quality of nephrolithometric nomograms to predict stone-free rates (SFRs) and complication rates (CRs) in case of minimally invasive percutaneous nephrolithotomy (PNL). In the last decade, nomograms have been introduced to estimate the SFRs and CRs of PNL. However, no data are available regarding their reliability in case of utilization of miniaturized devices. Herein we present a prospective multicentric study to evaluate reliability of Guy's stone score (GSS), the stone size, tract length, obstruction, number of involved calyces, and essence of stone (S.T.O.N.E.) nephrolithometry score and Clinical Research Office of the Endourological Society (CROES) score in patients treated with minimally invasive PNL.

Methods

We evaluated SFRs and CRs of 222 adult patients treated with miniaturized PNL. Patients were considered stone-free if no residual fragments of any size at post-operative unenhanced computed tomography scan. Patients demographics, SFRs, and CRs were reported and analyzed. Performances of nomograms were evaluated with the area under the curve (AUC).

Results

We included 222 patients, the AUCs of GSS, CROES score, and S.T.O.N.E. nephrolithometry score were 0.69 (95% confidence interval [CI] 0.61-0.78), 0.64 (95% CI 0.56-0.73), and 0.62 (95% CI 0.52-0.71), respectively. Regarding SFRs, at multivariate binomial logistic regression, only the GSS had significance with an odds ratio of 0.53 (95% CI 0.31-0.95, p=0.04). We did not find significant correlation with complications, with only a trend for GSS.

Conclusion

This is the first study evaluating nomograms in miniaturized PNL. They still show good reliability; however, our data showed lower performances compared to standard PNL. We emphasize the need of further studies to confirm this trend. A dedicated nomogram for minimally invasive PNL may be necessary.

Super-Mini Percutaneous Nephrolithotomy for Nephrolithiasis: A Systematic Review and Meta-Analysis

We aimed to conduct a systematic review and meta-analysis to summarize the current evidence regarding the role of super-mini percutaneous nephrolithotomy (SMP), which refers to a 7-Fr nephroscope placed through a tract sized 10-14 Fr, in treating renal stones and compare its outcomes with the standard mini-percutaneous nephrolithotomy (PCNL) techniques. A systematic literature search was conducted on the Medline database via PubMed and SCOPUS until May 2022 to retrieve the relevant studies. The titles and abstracts of unique records were screened for eligibility, followed by the full-text screening of potentially eligible abstracts. Data extraction was performed by two independent reviewers. The risk of bias assessment was conducted based on the study design. Open Meta (Analyst) and Review Manager 5.4 were used to perform all analyses. A total of 14 studies (n = 4,323 patients) were included, with two randomized controlled trials, one single-arm trial, and 11 cohort studies. The stone-free rate (SFR) of SMP was 91.4%. The pooled analysis showed no significant difference between SFR in mini-PCNL (mean difference (MD) = 1.03, 95% confidence interval (CI) = (0.99, 1.06), p = 0.12) and flexible ureteroscopy (MD = 0.84, 95% CI = (0.4, 1.76), p = 0.65]. On the other hand, SMP had a better SFR rate when compared with retrograde intrarenal surgery (MD = 1.3, 95% CI = (1.01, 1.66), p = 0.04). The pooled mean operative time of SMP was 49.44 minutes (95% CI = (41, 57.88), p < 0.001), which was longer than mini-PCNL (MD = 1.92, p < 0.001) and shorter than ureteroscopy (MD = -17.17, p < 0.00001). In the SMP group, the postoperative complications included fever (>38°C), pain, and hematuria, with an incidence of 7.6%, 2.3%, and 3.4%, respectively. The mean length of hospital stay after SMP was 2.4 days (95% CI = (2.17, 2.7), p < 0.001). The current evidence suggests that SMP is a safe and effective technique in the management of renal stones in both children and adults.

The treatment option for calyceal diverticulum stones: flexible ureteroscopy lithotripsy (FURL) or all-seeing needle-assisted percutaneous nephrolithotomy (PCNL)?

The purpose of this study was to investigate the effectiveness and safety of flexible ureteroscopy lithotripsy (FURL) and all-seeing needle-assisted percutaneous nephrolithotomy (PCNL) for the treatment of calyceal diverticula (CD) stones. From June 2012 to November 2020, 24 patients, including 14 females and 10 males, with an average age of 45.6 ± 17.4 years were retrospectively reviewed in this study. Among these patients, 14 were treated with FURL, and 10 underwent all-seeing needle-assisted PCNL. The demographic data, perioperative parameters and complications, as well as follow-up data, were recorded. In the FURL group, the ostium of CD was not identified in two patients, and these patients were finally treated with all-seeing needle-assisted PCNL. The stone clearance rate (SCR) was 64.3%, and the mean blood loss was 0.9 ± 0.8 g/dL. The average operation time was 57.5 ± 17.4 min, and the mean hospital stay was 3.5 ± 1.4 days. A complete resolution of CD was observed in five (41.7%) patients over the average follow-up of 10.8 months. In terms of the all-seeing needle-assisted PCNL, the average operation time was 83.5 ± 32.4 min, and the mean hospital stay was 4.38 ± 2.25 days. The SCR reached 91.7%, and the blood loss was 1.7 ± 1.1 g/dL. Nine patients (75%) were observed to have complete CD resolution over an average of 12.2 months of follow-up. All complications were grade I and II in both the groups. CD stones can be treated minimally invasive and effectively by FURL and PCNL. The effect of FURL greatly depends on the location and anatomy of the diverticula. PCNL is more efficient, and its safety was improved with the help of the all-seeing needle assistance.

A prospective, single-centered, cohort study comparing the treatment of renal stones by following PCNL types: Standard, tubeless & totally tubeless

Introduction

Renal stones are a frequent cause of morbidity globally. The number of lumbotomies performed for benign lithiasis has been greatly decreased with the usage of Percutaneous Nephrolithotomy (PCNL). Further development is aimed at reducing tract size, leading to numerous advanced minimally invasive PCNL procedures like mini-PERC, ultra-mini-PERC, and micro-PERC. The aim of this study was to evaluate whether tubeless or totally tubeless PCNL is the safest and most efficient, less morbid management technique for renal stones compared to the standard PCNL with a nephrostomy tube.

Methodology

This is a comparative, prospective, single-centered, cohort study that took place between August 2015 and January 2018 in the Urology department of Benazir Bhutto Hospital in Rawalpindi, Pakistan. 218 patients having single/multiple stones of variable sizes were enrolled in the study. Participants were stratified into three groups; Group A: Standard PCNL treatment; Group B: Tubeless PCNL treatment; Group C Totally Tubeless treatment. Mean operation time (±SD) and stone-free rates were our primary outcomes. The rate of complications during and post-operative complications were our secondary outcomes.

Results

A total of 181 patients were included in our study. A decreasing trend can be seen in mean operation time as we move from Group A to Group C (p = 0.000). The rate of problems during operation in each group was highest (45.8%) in Group A, much lesser problems in Group C (13.3%), and least problems in Group B (8.1%) (p = 0.000). The postoperative complication rate was again the highest in Group A (30.5%), low in Group C (8.3%), and extremely low in Group B (1.6%)

Conclusion

Tubeless PCNL proved to be the safest and most effective when compared to standard and totally tubeless PCNL procedures. It also showed the highest stone-free rates and least ‘unsatisfactory’ results amongst all the groups. Conclusively, it should be performed in routine preferably.

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In terms of safety and efficacy, tubeless PCNL outperformed both regular and completely tubeless PCNL.

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The Tubeless PCNL is much superior than other techniques of PCNL.

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Aftercare and difficulties during surgery are virtually nonexistent with tubeless PCNL.

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Stone-free rates were also the highest and the least “unsatisfactory” across all groups. Finally, it's best if it's done on a regular basis.

Comparative efficacy and safety between Micro-Percutaneous Nephrolithotomy (Micro-PCNL) and retrograde intrarenal surgery (RIRS) for the management of 10–20 mm kidney stones in children: A systematic review and meta-analysis

Objectives

Kidney stone in children is a recurring problem that requires multiple interventions over time. Minimally-invasive approach, such as Extracorporeal Shockwave Lithotripsy (ESWL) is recommended for moderately-sized stones. However, since ESWL is associated with multiple interventions, Micro-Percutaneous Nephrolithotomy (Micro-PCNL) and Retrograde Intrarenal Surgery (RIRS) can also be considered to treat kidney stones in pediatric patients. Both approaches have their respective advantages and disadvantages. In this study, we aimed to compare the efficacy and safety of Micro-PCNL and RIRS in pediatric patients with kidney stones.

Methods

This systematic review and meta-analysis adhered to the PRISMA guideline and Cochrane Handbook of intervention. The included studies were obtained from the PubMed and ScienceDirect databases. The protocol of this review has been registered in PROSPERO (CRD42021265894). The quality of the studies was assessed using the Newcastle-Ottawa Scale, outcomes were analyzed using STATA®16, and certainty of evidence was evaluated using GRADE.

Results

A total of 239 participants were included in this study, divided into the Micro-PCNL (n = 112) and RIRS (n = 127) procedure groups. Statistical analysis revealed a significantly lower requirement of postoperative stenting procedure in Micro-PCNL compared to RIRS (OR 0.09; 95%CI 0.02, 0.47; p < 0.01). However, no significant difference was found in stone-free rate (p = 0.86), operative time (p = 0.09), UTI incidence (p = 0.67), blood transfusion requirement (p = 0.95), and length of stay (p = 0.77).

Conclusion

Micro-PCNL is superior to RIRS in managing pediatric kidney stones,10–20 mm in size based on their comparable SFR and fewer requirements of additional stenting procedures.

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Micro-PCNL had a comparable SFR to RIRS in managing pediatric kidney stones,10–20 mm.

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Micro-PCNL had less requirement of stenting procedure than RIRS in managing pediatric kidney stones,10–20 mm.

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Micro-PCNL is superior to RIRS in managing pediatric kidney stones,10–20 mm.

Paediatric stone management: innovations and standards

PURPOSE OF REVIEW

The aim of this study was to discuss current trends and recent developments in the surgical management of paediatric urolithiasis.

RECENT FINDINGS

Medical expulsive therapy (MET) is considered as an option for the treatment of children with ureter stones. Extracorporeal shockwave lithotripsy (SWL) remains as a first option for majority of kidney stones and upper ureter stones. Advances in endourology have led to increased adoption of retrograde intrarenal surgeries (RIRS) and percutaneous nephrolithotomy (PCNL/mini-PCNL/ultra-mini-PCNL/micro-PCNL).

SUMMARY

Management of paediatric stone disease has developed significantly in the past decade. However, the evidence in the literature remains disproportional to these advances. Well designed multicentric studies are still needed to compare effectiveness and safety of these procedures.

Outcomes of Mini-Percutaneous Nephrolithotomy in Children and Adolescents: A 10-Year Single-Centre Experience From Kuwait

The current study retrospectively reviewed data for all children and adolescents who underwent mini-percutaneous nephrolithotomy (PCNL) at Ibn Sina Hospital and Sabah Al Ahmad Urology Centre in Kuwait over 10 years. Accordingly, the 40 patients underwent mini-PCNL. Among them, 21 patients (52.5%) had varying degrees of hydronephrosis, with mild to moderate severity accounting for nearly half of them, whereas six (15%) had multiple stones. The median operative time was 54.5 (43.3-64) minutes. Moreover, 11 patients needed flexible ureteroscopy (URS) and double-J (DJ) ureteric stent, and one patient required DJ ureteric stent only. None of the cases developed intraoperative bleeding. The median hospital stay of the included patients was three (2.3-4) days. Residual stone was observed in 11 patients (27.5%), with a median size of 3 (2 to 7) mm. The incidence of postoperative complications was 27.5% (n = 11 patients), with three patients experiencing postoperative bleeding (7.5%) and eight patients developing a fever (20%). All patients had mild postoperative pain. However, no leakage, sepsis, or pelvic injury occurred. None of the patients required revision. In conclusion, mini-PCNL was a safe and effective procedure in children and adolescents with renal stones.

Comparison of Ultra-Mini Percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery for Renal Stones: A Systematic Review and Meta-Analysis from the KSER Update Series

Miniaturized percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for renal stones have been developed to overcome the invasive disadvantages of PCNL. We aimed to compare the therapeutic effect and safety of ultra-mini percutaneous nephrolithotomy (UMPCNL) and RIRS for renal stones using an updated systematic review and meta-analysis. We searched clinical trials comparing UMPCNL and RIRS for renal stones using the PubMed, EMBASE, Cochrane Library, and Google Scholar databases up to October 2021. Seven studies were included in the current study. The renal stone size was 10–20 mm in three studies, 10–25 mm in one study, 10–35 mm in two studies, and not specified in one study. The stone-free rate of UMPCNL was higher than that of RIRS (p = 0.02; odds ratio (OR) = 2.01; 95% confidence interval (CI) = 1.12, 3.61). The complication rate showed no significant difference between UMPCNL and RIRS (p = 0.48; OR = 1.20; 95% CI = 0.73, 1.98). Regarding the operative time, UMPCNL was shorter than RIRS (p = 0.005; weighted mean difference (WMD) = −15.63; 95% CI = −26.60, −4.67). The hospital stay of UMPCNL was longer than that of RIRS (p = 0.0004; WMD = 1.48; 95% CI = 0.66, 2.31). UMPCNL showed higher efficacy than RIRS and similar safety to RIRS. UMPCNL may be a useful therapeutic option for moderate-sized renal stones.

Pediatric Stone Surgery: What Is Hot and What Is Not

PURPOSE OF REVIEW

We aim to highlight recent advances in technology and techniques for surgical management of urinary tract calculi in pediatric patients.

RECENT FINDINGS

Percutaneous nephrolithotomy (PCNL) is classically performed in the prone position. The supine PCNL was first attempted to overcome the shortcomings of difficult airway access, patient and surgeon discomfort. The supine PCNL, and subsequent modifications, has been successfully described in the pediatric population. Classically, PCNL has also been classically concluded with obligate placement of a nephrostomy tube and bladder catheter. Recently, tubeless and totally tubeless PCNL reduces pain and duration of hospitalization with satisfactory surgical outcomes in children. Finally, we describe the use of thulium laser technology, which offers improved efficacy in stone treatment and may supplant the current dominant technologies in coming years. Recent advances in pediatric stone surgery include supine PCNL, miniaturized PCNL instrumentation, tubeless procedures, and thulium laser technology.

Super-mini percutaneous nephrolithotomy (SMP) vs retrograde intrarenal surgery (RIRS) in the management of renal calculi ≤ 2 cm: a propensity matched study

OBJECTIVE

To compare the effectiveness and safety of Super-Mini PCNL (SMP) and Retrograde Intrarenal Surgery (RIRS) in the management of renal calculi ≤ 2 cm.

PATIENTS AND METHODS

A prospective, inter-institutional, observational study of patients presenting with renal calculi ≤ 2 cm. Patients underwent either SMP (Group 1) or RIRS (Group 2) and were performed by 2 experienced high-volume surgeons.

RESULTS

Between September 2018 and April 2019, 593 patients underwent PCNL and 239 patients had RIRS in two tertiary centers. Among them, 149 patients were included for the final analysis after propensity-score matching out of which 75 patients underwent SMP in one center and 74 patients underwent RIRS in the other. The stone-free rate (SFR) was statistically significantly higher in Group 1 on POD-1 (98.66% vs. 89.19%; p = 0.015), and was still higher in Group 1 on POD-30 (98.66% vs. 93.24%, p = 0.092) SFR on both POD-1 and POD-30 for lower pole calculi was higher in Group 1 (100 vs. 82.61%, p = 0.047 and 100 vs 92.61% p = 0.171). The mean (SD) operative time was significantly shorter in Group 1 at 36.43 min (14.07) vs 51.15 (17.95) mins (p < 0.0001). The mean hemoglobin drop was significantly less in Group 1 (0.31 vs 0.53 gm%; p = 0.020). There were more Clavien-Dindo complications in Group 2 (p = 0.021). The mean VAS pain score was significantly less in Group 2 at 6 and 12 h postoperatively (2.52 vs 3.67, 1.85 vs 2.40, respectively: p < 0.0001), whereas the mean VAS pain score was significantly less in Group 1 at 24 h postoperatively (0.31 vs 1.01, p < 0.0001). The mean hospital stay was significantly shorter in Group 1 (28.37 vs 45.70 h; p < 0.0001).

CONCLUSION

SMP has significantly lower operative times, complication rates, shorter hospital stay, with higher stone-free rates compared to RIRS. SMP is associated with more early post-operative pain though.

Pediatric Urolithiasis: Current Surgical Strategies and Future Perspectives

New technological innovations and cutting-edge techniques have led to important changes in the surgical management of pediatric urolithiasis. Miniaturized technologies and minimally invasive approaches have been increasingly used in children with urinary stones to minimize surgical complications and improve patient outcomes. Moreover, the new computer technologies of the digital era have been opening new horizons for the preoperative planning and surgical treatment of children with urinary calculi. Three-dimensional modeling reconstructions, virtual, augmented, and mixed reality are rapidly approaching the surgical practice, equipping surgeons with powerful instruments to enhance the real-time intraoperative visualization of normal and pathological structures. The broad range of possibilities offered by these technological innovations in the adult population finds increasing applications in pediatrics, offering a more detailed visualization of small anatomical structures. This review illustrates the most promising techniques and devices to enhance the surgical treatment of pediatric urolithiasis in children, aiming to favor an early adoption and to stimulate more research on this topic.

Minimally invasive surgery for pediatric renal and ureteric stones: A therapeutic update

The incidence of pediatric urolithiasis (PU) is growing worldwide. The corresponding therapeutic methods have become a research hot spot in pediatric urology. PU has the characteristics of abnormal metabolism, easy recurrence, and immature urinary system development, which make its treatment different from that of adults. Pediatric urologists should select the optimal treatment modality to completely remove the stones to prevent recurrence. Currently, the curative treatments of PU include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy, retrograde intrarenal surgery, percutaneous nephrolithotomy (PCNL), laparoscopic, robot-assisted laparoscopic, and open surgery. This review aims to conduct a therapeutic update on the surgical interventions of both pediatric renal and ureteric stones. It accentuates that pediatric surgeons or urologists should bear in mind the pros and cons of various minimally invasive surgical treatments under different conditions. In the future, the treatment of PU will be more refined due to the advancement of technology and the development of surgical instruments. However, a comprehensive understanding of the affected factors should be taken into account by pediatric urologists to select the most beneficial treatment plan for individual children to achieve precise treatment.

Size Distribution of Fragments by High-power Holmium Laser Lithotripsy in MiniPCNL with Suction

PURPOSE OF REVIEW

Data are lacking on distribution of size of fragments created with the laser lithotripsy, stone density, and composition. Dust (< 1 mm) and small fragments (1-3 mm) may be too small to be efficiently removed with forceps compared to larger fragments (> 3 mm). We aim to report the size distribution of fragments formed during holmium laser lithotripsy.

RECENT FINDINGS

One hundred ten patients with renal calculi < 3 cm underwent miniPCNL using ClearPetra sheath (Well Lead Medical Co., China) with controllable irrigation and suction system that minimizes fragment dispersion and maximizes fragment aspiration. Moses holmium laser (Lumenis INC, Israel) was used with predefined laser energy settings for lithotripsy. Proportion of fragment size < 1 mm was 46.36 ± 16.68%, 1-3 mm was 28.18 ± 10.01%, and > 3 mm was 25.19 ± 16.18% for the entire cohort. Complete stone clearance at 48 h was achieved in 77.3% cases. The remaining 22.7% patients had complete clearance at 1-month follow-up CT. In all the stone density, volume, and composition groups, majority of fragments created were either < 1 mm or 1-3 mm. Only 25% fragments were > 3 mm that would get aspirated out through the sheath with suction or could be retrieved with forceps. The combination of a high-power holmium laser and suction would help in complete stone clearance with effective aspiration of smaller stone fragments and dust simultaneously during lasing.

Comparison of Micro-Percutaneous and Mini-Percutaneous Nephrolithotomy in the Treatment of Renal Stones: A Systematic Review and Meta-Analysis

Background: To assess the efficacy and safety of micro-percutaneous nephrolithotomy (Microperc) and mini-percutaneous nephrolithotomy (Miniperc) in the treatment of moderately sized renal stones. Methods: Literature search of PubMed, Web of Science, and Embase was performed prior to January 2021. We used odds ratios (OR) and weighted mean difference (WMD) for dichotomous variables and continuous variables, respectively. Results were pooled using Review Manager version 5.3 software. Results: A total of six studies involving 291 Microperc and 328 Miniperc cases was included. The overall stone-free rate (SFR) of Microperc was 87.29% (254/291), while the SFR of Miniperc was 86.59% (284/328). Microperc was associated with lower hemoglobin drop (WMD: -0.98; P = 0.03) and higher renal colic requiring D-J stent insertion (OR: 3.49; P = 0.01). No significant differences existed between Microperc and Miniperc with respect to SFR (OR: 1.10; P = 0.69), urinary tract infection (OR: 0.38; P = 0.18), operative time (WMD: -5.76; P = 0.62), and hospital stay time (WMD: -1.04; P = 0.07). Conclusions: Our meta-analysis demonstrated that Microperc could produce an SFR that was comparable with that of Miniperc. Microperc was associated with lower hemoglobin drop, while Miniperc was associated with lower renal colic rates. In addition, the operation time and hospital stay time for both these procedures were similar.

Role of Intrarenal Pressure in Modern Day Endourology (Mini-PCNL and Flexible URS): a Systematic Review of Literature

PURPOSE OF REVIEW

To review the latest evidence about intrarenal pressures (IRPs) generated during flexible ureteroscopy (fURS) and mini percutaneous nephrolithotomy (mPCNL) and present tools and techniques to maintain decreased values.

RECENT FINDING

fURS and PCNL constitute the primary means of stone treatment. New flexible ureterorenoscopes with small diameter and miniaturized PCNL instruments achieve optimal stone-free rates (SFRs) while decreasing invasiveness and morbidity. Nevertheless, endourologists must remain cognizant regarding the dangers of increased IRPs to avoid complications. Current research presents essential information for urologists regarding this topic. During fURS, using a ureteral access sheath (UAS), we avoid extremely high IRPs with all irrigation types. During mPCNL, pressure remains low, mainly using the purging effect or a vacuum-assisted sheath. Devices of intraoperative IRP measurement and intelligent pressure control have proven their feasibility, accuracy and efficacy. These will have an increasing role to play in the future management of stone disease.

Comparison of percutaneous nephrolithotomy under epidural anesthesia versus general anesthesia: A randomized prospective study

Introduction:

PCNL has revolutionized the treatment of renal calculi putting almost an end to the era of open stone surgery. The procedure can safely be carried out under general anesthesia (GA) or regional anesthesia viz. spinal anesthesia (SA), epidural anesthesia (EA) or combined spinal and epidural anesthesia (CSE).

Aims and Objectives:

We evaluated the surgical outcome after PCNL in two groups of patients randomly divided to undergo procedure under GA or EA.

Patients and Methods:

Two hundred and thirty patients with American Society of Anesthesiologists (ASA) score <3 were randomly divided into two groups according to the type of anesthesia: i.e. GA (n=110) or EA (n=120). All patients underwent PCNL in prone position. Puncture was done using Bulls eye technique under fluoroscopic guidance and tract dilated using serial dilators up to 24Fr-28 Fr. Demographics, perioperative and postoperative parameters were noted and data analysed.

Results:

The two groups were comparable in terms of mean age, distribution of stone location, and stone burden. The stone free rate was 90.9% in GA group and 89.2% in EA group and the difference was statistically insignificant (P= 0.659). The requirement for auxiliary procedures was similar between the two groups. A significant difference in pain score was seen in favor of EA group during early post-operative period (P< 0.05).

Conclusion:

It seems that PCNL can be performed safely and effectively under regional epidural anesthesia with results comparable to general anesthesia with the added advantage of less immediate postoperative pain and analgesic requirement.

Changes in percutaneous approach to kidney stones in children: A single institute experience over 500 cases

PURPOSE

The aim of this study is to identify the changes in patient age and stone sizes with technological advancement over time.

METHODS

This study was conducted retrospectively with 404 patients (504 renal units) who underwent percutaneous nephrolithotomy (PCNL) between January 1997 and June 2020. Patient characteristics and trends on instrument preferences were investigated.

RESULTS

Median age was 7 (1-18) years. Male to female ratio was 1.48:1 (301/203). Median stone burden was 2 cm² (0.20-25) and median operative time was 90 minutes (20-240). The stone-free rate was 74.6%. Patients were divided into four groups according to the size of the instrument. It was found that the size of sheath used increased significantly with increasing age and stone burden. The micro-PCNL group had the shortest hospitalisation and lowest blood transfusion rate. Chronologically categorised four equal groups were compared to analyse changing patient profiles and trends. Median patient age, stone burden, operation time, sheath size, blood transfusion and complication rates decreased significantly with time. However, the use of tracts smaller than 20F and the number of patients with previous intervention increased significantly.

CONCLUSION

Our study demonstrated that the patient's age and stone size at the time of initial diagnosis decrease over time while miniaturisation techniques increase in paediatric urology.

European Association of Urology and European Society for Paediatric Urology Guidelines on Paediatric Urinary Stone Disease

CONTEXT

Paediatric stone disease is an important clinically entity and management is often challenging. Although it is known that the condition is endemic in some geographic regions of the world, the global incidence is also increasing. Patient age and sex; the number, size, location, and composition of the stone; and the anatomy of the urinary tract are factors that need to be taken into consideration when choosing a treatment modality.

OBJECTIVE

To provide a general insight into the evaluation and management of urolithiasis in the paediatric population in the era of minimally invasive surgery.

EVIDENCE ACQUISITION

A nonsystematic review of the literature on management of paediatric urolithiasis was conducted with the aim of presenting the most suitable treatment modality for different scenarios.

EVIDENCE SYNTHESIS

Because of high recurrence rates, open surgical intervention is not the first option for paediatric stone disease, except for very young patients with very large stones in association with congenital abnormalities. Minimally invasive surgeries have become the first option with the availability of appropriately sized instruments and accumulating experience. Extracorporeal shockwave lithotripsy (SWL) is noninvasive and can be carried out as an outpatient procedure under sedation, and is the initial choice for management of smaller stones. However, for larger stones, SWL has lower stone-free rates and higher retreatment rates, so minimally invasive endourology procedures such as percutaneous nephrolithotomy and retrograde intrarenal surgery are preferred treatment options.

CONCLUSIONS

Contemporary surgical treatment for paediatric urolithiasis typically uses minimally invasive modalities. Open surgery is very rarely indicated.

PATIENT SUMMARY

Cases of urinary stones in children are increasing. Minimally invasive surgery can achieve high stone-free rates with low complication rates. After stone removal, metabolic evaluation is strongly recommended so that medical treatment for any underlying metabolic abnormality can be given. Regular follow-up with imaging such as ultrasound is required because of the high recurrence rates.

Tips and Tricks to Improve Ergonomics, Efficacy, Versatility, and Overcome Limitations of Micro Percutaneous Nephrolithotomy

Percutaneous Nephrolithotomy (PCNL) has evolved over the decades from Standard to Mini to Ultramini PCNL to Micro-perc, with miniaturisation being the dominant theme and supine approach gaining momentum world over.

Aim: In literature, miniaturised PCNL with microperc needle access system has raised concerns of intrarenal pressure and has some limitations with its success for larger stones. Our tips and tricks explain how to overcome these pitfalls by utilising the full construct of the needle system to its maximum potential. These will in turn help make the procedure versatile, precise, ergonomical, and enhance a surgeon's experience with improved outcomes for patients especially in large renal stones.

Materials and Methods: We describe the limitations of microperc needle access as stated in literature and proposals by the co-authors using microperc for miniaturised access on how to overcome the same.

Results: A simplified table describing the limitations and tips and tricks on overcoming these is provided for quick reference.

Conclusion: As Technological advancements and techniques for miniaturised access in urolithiasis improve, we believe our suggestions will help surgeons overcome the quoted limitations of microperc needle access for miniaturised PCNL, making this a versatile, safe and efficacious technique even in large and complex stones. A multi centre trial will be the best way to validate the suggestions proposed in this article.

Trends of percutaneous nephrolithotomy in Saudi Arabia

Objective:

The objective of the study was to present the current practice patterns on percutaneous nephrolithotomy (PCNL) in Saudi Arabia and to compare it with the international patterns and to observe the adherence to the guidelines.

Materials and Methods:

A survey consisting of 28 questions was sent to urologists working in Saudi Arabia using a Google Forms questionnaire. The questioner covered most aspects of performing PCNL starting from preparing the patient till discharging him.

Results:

One hundred and thirty-two replied to the survey. Almost 70.2% performed PCNL and 59.1% of them learned PCNL during residency. The access was obtained by the urologists in 80.3% from the participants, 68.2% of them uses fluoroscopic guidance for the puncture. The majority (80.3%) perform PCNL in the prone position. Nearly 69.7% use the balloon dilators and 16.7% use the Amplatz dilators. For kidney drainage, 60.6% place a nephrostomy tube and a double-J stent (DJ stent) together and 4.5% perform tubeless PCNL (DJ stent only). About 45.5% stated that the introduction of flexible ureteroscopy decreased the rate of doing PCNL for >20%.

Conclusions:

Data obtained from a group of urologists in Saudi Arabia showed that the majority of urologists practicing in Saudi Arabia perform PCNL. They usually learn PCNL during residency. We observe that the majority of urologists attach to the original patterns in PCNL, i.e., they predominantly prefer the prone position and use fluoroscopy to gain the PCNL access. Furthermore, the data showed that new trends in PCNL did not gain a lot of momentum as few practices miniaturized PCNL and tubeless PCNL. The majority use balloon dilators and combined ultrasonic/pneumatic lithotripters. The complication rate encountered by the participants is concomitance with the published international figures. The introduction of flexible ureteroscopy highly decreased the rate of doing PCNL for most urologists.

Microperc with Self-Assembled Fr 4.85 Visual Needle and Ureteral Access Sheath

BACKGROUND

Micropercutaneous nephrolithotomy (microperc) is the least invasive among percutaneous nephrolithotripsy (PCNL) procedures. Although microperc has a high stone-free rate and certain advantages over other methods, modifications may be needed to improve the technique. We describe our experience performing microperc using a self-assembled visual needle and ureteral access sheath (UAS).

METHODS

Between June 2016 and April 2019, the data of 30 patients with kidney stones undergoing microperc with our self-assembled 4.8 Fr visual needle combined with a UAS was retrospectively analyzed. Patients were placed in an obilique spine lithotomy position.

RESULTS

Two cases were excluded: one due to conversion to mini PCNL and the other required flexible ureteroscopy during microperc. The remaining 28 cases included 18 men and 10 women, age 38.4 ± 7.5 years, stone size 1.7 ± 0.4 cm, and stone density on CT 969 ± 233 HU. Operative time was 47 ± 9.9 minutes, visual analogue scale score of tract pain on postoperative day 1 was 2.5 ± 1.0, hemoglobin decrease was 6.4 ± 1.0 g/L, and hospital stay was 3.1 ± 0.8 days. There was 1 case of fever and urinary infection, 2 cases of hematuria, and 1 case of flank pain. All symptoms resolved after conservative or antibiotic treatment. On postoperative day 1, 12 (42.9%) caseswere stone-free. The stone-free rates at postoperative month 1 and 3 were 92.9% (26/28) and 100% (28/28), respectively.

CONCLUSIONS

Our self-assembled visual needle and UAS instrument is effective for microperc. Use of the UAS may improve the operative outcome.

Precision Stone Surgery: Current Status of Miniaturized Percutaneous Nephrolithotomy

PURPOSE OF REVIEW

Innovations in lasers and surgical technology have led to a renewed interest in the miniaturization of percutaneous nephrolithotomy (PCNL). We review the different approaches and evidence on the efficacy of mini-PCNL.

RECENT FINDINGS

Mini-PCNL encompasses a range of techniques using tract sizes from 4.8 to 22 F to treat renal stones. The most common device uses irrigation to passively extract stones out of the sheath. Super-mini-PCNL incorporates active suction. Ultra- and micro-techniques reduce the tract to smaller diameters. Laser fragmentation is the main lithotripsy modality. Studies demonstrate an association with reduced complications, hospital stay, and increased tubeless rate. Drawbacks include longer operative times while stone-free rates for larger stones may be sub-optimal. Mini-PCNL has advantages of less trauma and the avoidance of nephrostomy tubes. Ambulatory surgery is feasible in select patients. Advances in laser lithotripsy and active suction have the potential to improve stone clearance and treat larger stones.

From "feeling" to "seeing": modification of the percutaneous peritoneal dialysis catheter insertion with an optical puncture system

PURPOSE

Blind insertion limits the application of percutaneous peritoneal dialysis (PD) catheter placement. In this study, we first described the use of an optical puncture system in the PD catheter insertion, and investigated the feasibility and advantages of this modified technique.

METHODS

This retrospective study included 65 patients with chronic kidney disease stage 5 (CKD5) who received ultrasound-guided percutaneous PD catheter insertion with or without optical puncture system assistance between June 2018 and July 2019. The patients' characteristics as well as the surgical outcomes and complications were compared between the modified group and the routine percutaneous insertion group.

RESULTS

Twenty-five patients underwent optical puncture system assistant insertion, whereas 40 patients received routine percutaneous insertion. More patients had previous abdominal surgical histories in the modified group than those in the routine group (24.0% vs. 5.0%, p = 0.047). The time of accessing to the abdominal cavity was significantly shorter in the modified group (median [IQR]; 1.1 min [0.8-1.3] vs. 5.0 min [4.0-6.0]; p < 0.001). Meanwhile, the time of the whole procedure was also significantly shorter in the modified group (median [IQR]; 26.0 min [25.0-29.0] vs. 33.0 min [29.0-35.0]; p < 0.001). None of the patient in the modified group, while two patients (5.0%) in the routine group converted to open procedure. There were no significant differences in the short and long postoperative complications between the two groups.

CONCLUSIONS

The operation of ultrasound-guided PD catheter placement with the optical puncture system is easy, safe, fast and accurate, whereby the PD catheter can be implanted percutaneously and visually under local anesthesia with minimal procedure-related complications. The visible puncture of the optical puncture system may facilitate ultrasound-guided percutaneous PD catheter insertion in patients with obesity and previous abdominal surgeries.

A systematic review and meta-analysis of minimally invasive vs. standard percutaneous nephrolithotomy in the surgical management of renal stones

The present study aimed to assess current evidence on the effectiveness and safety of minimally invasive vs. standard percutaneous nephrolithotomy (PCNL) in the management of renal stones. A systematic search of electronic databases, which included PubMed, EMBASE and the Cochrane Library up to May 2019 was performed. Using Review Manager statistical software (version 5.3), primary outcomes, including stone-free rates (SFRs), were evaluated. Meanwhile, analysis was also performed to compare secondary outcomes, such as peri- and postoperative complications and operative data. Fourteen studies involving 1,611 patients with renal stones were analyzed based on the inclusion criteria. On the basis of the present analysis, mini percutaneous nephrolithotomy (MPCNL) was proven to have non-inferior clinical efficacy with respect to the SFR compared with PCNL [odds ratio (OR)=1.10; 95% confidence interval (CI), 0.84-1.44; P=0.48]. In addition, the meta-analysis showed that MPCNL had a significantly lower hemoglobin decrease [mean difference (MD)=-0.68; 95% CI, -1.05 to -0.31; P=0.0003] and fewer blood transfusions (OR=0.36; 95% CI, 0.18-0.71; P=0.003) compared with PCNL. Moreover, the MPCNL group had a shorter inpatient stay (MD=-0.81; 95% CI, -1.55 to -0.08; P=0.03) compared with the PCNL group. However, the overall evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with PCNL. The present meta-analysis indicates that MPCNL is an effective method for treating renal stones. Compared with PCNL, MPCNL not only has similarly high SFRs but is also associated with less blood loss, fewer blood transfusions, more favorable recovery time and shorter inpatient stays. However, the findings of the present study should be further confirmed by well-designed prospective randomized controlled trials with a larger patient series.

Classification and standardized reporting of percutaneous nephrolithotomy (PCNL): International Alliance of Urolithiasis (IAU) Consensus Statements

BACKGROUND

The aim of this study was to reach a consensus in the classification and standardized reporting for the different types of PCNLs.

METHODS

The RAND/UCLA appropriateness methodology was used to reach a consensus. Thirty-two statements were formulated reviewing the literature on guidelines and consensus on PCNLs, and included procedure specific details, outcome measurements and a classification for PCNLs. Experts were invited to two rounds of input, the first enabled independent modifications of the proposed statements and provided the option to add statements. The second round facilitated scoring of all statements. Each statement was discussed in the third round to decide which statements to include. Any suggestion or disagreement was debated and discussed to reach a consensual agreement.

RESULTS

Twenty-five recommendations were identified to provide standardized reporting of procedure and outcomes. Consensual scoring above 80% were strongly agreed upon by the panel. The top treatment related outcomes were size of sheath used (99.1%) and position for PCNL (93.5%). The highest ranked Outcome Measures included definition of postoperative hospital length of stay (94.4%) and estimated blood loss (93.5%).

CONCLUSIONS

The consensus statements will be useful to clarify operative technique, in the design of clinical trials and standardized reporting, and presentation of results to compare outcomes of different types of PCNLs.

Micro-Ureteroscopy as a Treatment of Renal Pelvis Lithiasis in Young Children

Aim: Miniaturization of endoscopic instruments has allowed to improve the efficacy of kidney stone treatment in young children. Aim of the study is to evaluate the usefulness of microureteroscopy with 4.85F sheath in the treatment of renal stones in children. M&M: We present 4 cases of microureteroscopy in 3 younger than 3 years patients with renal pelvic stones. Lithiasis was unilateral in 2 female patients and bilateral in 1 male patient. Microureteroscopy was performed using a MicroPerc set 4.85F sheath, without placing a safety guide or dilating the meatus in 3 procedures. The lithotripter system used was Ho:YAG Laser with 200-μm fiber in all cases. Results: Mean operating time was 100 ± 16 min. There were no intraoperative complications. In all procedures, complete pulverization of the lithiasis was achieved, except in the coraliform lithiasis in which 5 mm residual lithiasis remained in the lower calyx. All patients were discharged 24 h after the intervention. Conclusion: Microureteroscopy can be considered a new alternative for treatment of selected cases of renal pelvic stones in infants and children.

Comparison of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy for Kidney Stones: A Meta-Analysis

BACKGROUND

Advances in micro-percutaneous nephrolithotomy (PCNL) for kidney stones have made it an alternative approach to the retrograde intrarenal surgery (RIRS) approach. Nevertheless, the superiority of micro-PCNL over RIRS is still under debate. The results are controversial.

OBJECTIVES

The purpose of this study was to systematically evaluate the clinical results in patients presenting with kidney stones treated with micro-PCNL or RIRS.

METHODS

A literature search was done for electronic databases to identify researches that compared micro-PCNL and RIRS till December 2019. The clinical outcome included complications, stone-free rates (SFRs), hemoglobin reduction, length of hospital stay, and operative time.

RESULTS

Five articles were included in our study. The pooled results revealed no statistical difference in the rate of complications (OR = 0.99, 95% CI = 0.57-1.74, p = 0.99), length of hospital stay (MD = -0.29, 95% CI = -0.82 to 0.24, p = 0.28), and operative time (MD = -6.63, 95% CI = -27.34 to 14.08, p = 0.53) between the 2 groups. However, significant difference was present in hemoglobin reduction (MD = -0.43, 95% CI = -0.55 to 0.30, p < 0.001) and the SFRs (OR = 0.59, 95% CI = 0.36-0.98, p = 0.04) when comparing RIRS with micro-PCNL.

CONCLUSIONS

Compared with micro-PCNL to treat kidney stones, RIRS is associated with better stone clearance and bearing higher hemoglobin loss. As the advantages of both technologies have been shown in some fields, the continuation of well-designed clinical trials may be necessary.

Lasers for stone treatment: how safe are they?

PURPOSE OF REVIEW

To update laser lithotripsy advances in regard to new laser types and technologies as well as review contemporary laser safety concerns.

RECENT FINDINGS

The high prevalence of urolithiasis and the continuing miniaturization of scopes has encouraged the growth of laser lithotripsy technology. The holmium:yttrium-aluminum-garnet (Ho:YAG) laser has been used for over 20 years in endourology and has been extensively studied. Holmium laser power output is affected by a number of factors, including pulse energy, pulse frequency, and pulse width. Several recent experimental studies suggest that the new dual-phase Moses 'pulse modulation' technology, introduced in high-power laser machines, carries a potential to increase stone ablation efficiency and decrease stone retropulsion. A newly introduced thulium fiber laser (TFL) has been adapted to a very small laser fiber size and is able to generate very low pulse energy and very high pulse frequency. Both of these technologies promise to play a larger role in laser lithotripsy in the near future. However, more experimental and clinical studies are needed to expand on these early experimental findings. Even though laser lithotripsy is considered safe, precautions should be taken to avoid harmful or even catastrophic adverse events to the patient or the operating room staff.

SUMMARY

The Ho:YAG laser remains the clinical gold standard for laser lithotripsy for over the last two decades. High-power Ho:YAG laser machines with Moses technology have the potential to decrease stone retropulsion and enhance efficiency of laser ablation. The new TFL has a potential to compete with and perhaps even replace the Ho:YAG laser for laser lithotripsy. Safety precautions should be taken into consideration during laser lithotripsy.

Super-mini percutaneous nephrolithotomy (PCNL) vs standard PCNL for the management of renal calculi of <2 cm: a randomised controlled study

OBJECTIVE

To compare the effectiveness and safety of standard percutaneous nephrolithotomy (sPCNL) and super-mini PCNL (SMP).

PATIENTS AND METHODS

A total of 150 patients presenting with renal calculi of <2 cm were randomised to either sPCNL (Group 1) or SMP (Group 2). Randomisation was based on centralised computer-generated numbers. Variables studied included: stone-free rates (SFRs), operative time, intra- and postoperative complications, postoperative pain score, analgesic requirement, and hospital stay. Statistical analysis was performed using a t-test or Mann-Whitney U-test for continuous variables and chi-squared test or Fisher's exact test for categorical variables.

RESULTS

Between September 2018 and April 2019, 75 patients were included in each group. The SFRs of the groups were similar (97.33 vs 98.66%, P = 0.56). The mean (sd) operative time was significantly longer in Group 2, at 36.40 (14.07) vs 23.12 (11.96) min (P < 0.001). The mean (sd) decrease in haemoglobin was significantly less in Group 2, at 3.0 (4.9) vs 7.5 (6.5) g/L (P < 0.001). The mean (sd) pain score at 24 h was significantly lower in Group 2, at 0.3 (0.46) vs 0.75 (0.53) (P < 0.001). The mean (sd) analgesic requirement was significantly less in Group 2, at 67 (22.49) vs 91.5 (30.56) mg tramadol (P < 0.001). The mean (sd) hospital stay was significantly less in Group 2, at 28.38 (3.6) vs 39.84 (3.7) h (P < 0.001).

CONCLUSIONS

SMP is equally as effective as sPCNL for managing renal calculi of <2 cm, with improved safety. Although SMP is associated with a longer operative time, it has a significantly lower incidence of bleeding and postoperative pain, and a shorter hospital stay.

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.

Minimally invasive percutaneous nephrolithotomy (PCNL): Techniques and outcomes

Minimally invasive percutaneous nephrolithotomy (PCNL) was introduced to decrease the morbidity of the standard PCNL (sPCNL). Thereafter, many modifications and techniques have been presented with the introduction of different miniaturized PCNL (mPCNL) techniques, such as micro-PCNL and ultra-mini-PCNL (UMP). As of present, none of the techniques has displaced the sPCNL. Nonetheless, mini-PCNL has continuously widening indications and has been proposed to have significant advantages over sPCNL. In the current review, each technique is presented while discussing the advantages and disadvantages of each approach. A comprehensive review of the current literature has been performed. Articles related to the topic were retrieved and critically analyzed. Less peri-operative bleeding and shorter hospital stay were the most important advantages advocated for mini-PCNL. Although the performance of mini-PCNL is safe, the utilization of micro-PCNL and UMP should be done with caution.

Comparison of intrarenal pelvic pressure and postoperative fever between standard- and mini-tract percutaneous nephrolithotomy: a systematic review and meta-analysis of randomized controlled trials

Background

High intrarenal pelvic pressure (IPP) induces systemic absorption of irrigation fluid containing bacteria or endotoxins, which is associated with postoperative fever (POF) and even urosepsis. The emphasis of this meta-analysis lies in comparison of IPP and POF between mini-tract percutaneous nephrolithotomy (MPCNL) and standard-tract percutaneous nephrolithotomy (SPCNL).

Methods

Eligible randomized controlled trials (RCTs) were identified from electronic databases from inception to November 2019. Studies selection, quality assessment, data extraction and analysis were accomplished by two independent reviewers using Cochrane Collaboration’s tools.

Results

Patients in the MPCNL group experienced higher IPP compared to SPCNL group [mean difference (MD): 8.31, 95% confidence interval (CI): 3.67–12.96, P=0.0005] with highly between-study heterogeneity (P=0.001, I²=85%). Notably, the IPP was higher in MPCNL group in different stages of the procedure including introduction, fragmentation and end. However, only two trials were available for pooled analysis. Additionally, the risk of POF in MPCNL was 2.43 times higher than that in SPCNL [odds ratio (OR): 2.43, 95% CI: 1.39–4.27, P=0.002] with no significant between-study heterogeneity (P=0.83, I²=0%). The two procedures was comparable on stone-free rate (SFR) (OR: 1.06, 95% CI: 0.61–1.86, P=0.83) and operation time (MD: 5.69, 95% CI: −4.54 to 15.91, P=0.28).

Conclusions

Current evidence indicates that MPCNL is an effective alternative to SPCNL with comparable SFR. IPP and POF is significantly higher during MPCNL compared to SPCNL. Intraoperative detection of IPP is of great significance for ensuring safety and reducing postoperative complications, especially for patients with MPCNL and the duration of stone fragmentation. Further large well-designed trials are warranted to confirm our findings.

Management of staghorn stones in special situations

Staghorn stones have always been a challenge for urologists, especially in some special situations, such as horseshoe kidney, ectopic kidney, paediatric kidney, and solitary kidney. The treatment of these staghorn stones must be aggressive because they can lead to renal function loss and serious complications. The gold-standard management for staghorn stones is surgical treatment with the aim of clearing the stones and preserving renal function. Treatment methods for staghorn stones have developed rapidly, such as extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy and laparoscopy and open surgery. Whether the standard procedures for staghorn stones can also apply to these stones in special situations is still not agreed upon. The decision should be made individually according to the circumstances of the patient. In this review, we evaluates the previous studies and comments on the management of staghorn stones under special situations in the hope of guiding the optimal choice for urologists.

Minimally invasive versus standard endoscopic combined intrarenal surgery for renal stones: a retrospective pilot study analysis

PURPOSE

The effect of combining miniaturization with endoscopic combined intrarenal surgery (ECIRS) is unclear. Thus, we compared the treatment outcomes between minimally invasive ECIRS (mini-ECIRS) using 16.5 Fr percutaneous access sheath and standard ECIRS using 24 Fr access sheath for renal stones MATERIALS AND METHODS: We retrospectively analyzed consecutive patients who underwent single session mini or standard-ECIRS in the modified Valdivia position for renal stones between April 2009 and May 2016. To adjust for patient characteristics, 77 pairs were matched using preoperative parameters including age, sex, history of febrile urinary tract infection (UTI), stone surface area, number of involved calyces, and staghorn calculi.

RESULTS

The stone free rate (SFR) was similar between mini and standard ECIRS according to non-contrast computed tomography (61.1% vs. 52.0%, p = 0.388). The rate of perioperative complications exceeding grade 2 based on the Clavien-Dindo classification was similar in both groups (19.5% vs. 26.0%, p = 0.442). Severe complications exceeding grade 3 were also similar in both groups (2.6% vs. 3.9%, p > 0.99). Two cases of septic shock were noted in each group. Although there was no difference regarding bleeding-related complications (2.6% vs. 6.5%, p = 0.442), pseudoaneurysm or blood transfusion was not observed in the mini-ECIRS group. Pain visual analog scale values in the perioperative period were lower in the mini-ECIRS group (1.34 ± 1.08 vs. 1.69 ± 1.23, p = 0.062).

CONCLUSIONS

This study demonstrated that, compared to standard ECIRS, mini-ECIRS maintained SFR without increasing perioperative complications, tended to reduce postoperative pain and had a potential to reduce bleeding-related complications. This report suggests the advantages of ECIRS miniaturization for renal stones.

Optical puncture combined with balloon dilation PCNL vs. conventional puncture dilation PCNL for kidney stones without hydronephrosis: a retrospective study

Background

Accurate puncture and dilation of the target kidney calices for percutaneous nephrolithotomy (PCNL) can be difficult. This study aimed to investigate the advantages of PCNL using optical puncture (i.e. the puncture is visualized on a screen as seen through the needle) combined with balloon dilation vs. conventional puncture methods.

Methods

This was a retrospective study of 58 consecutive patients with kidney stones without hydronephrosis and treated at the Minimally Invasive Urology Center of Zhejiang Provincial People’s Hospital between 10/2016 and 12/2017. Twenty-one patients underwent optical puncture combined with balloon dilation PCNL. Thirty-seven patients underwent conventional puncture instrument dilation PCNL (controls). Success rate, tubeless rate, blood loss, pain, and complications were compared between the two groups.

Results

The one-time puncture success rate (95.2% [20/21] vs. 67.6% [25/37], P = 0.02) and the postoperative tubeless rate (81.0% [17/21] vs. 54.1% [20/37], P = 0.04) were higher in the optical puncture group compared with controls. The average postoperative hemoglobin reduction was smaller (1.13 ± 0.63 vs. 1.56 ± 0.59 g/dL, P = 0.01), the postoperative VAS score was lower (1.6 ± 0.9 vs. 2.5 ± 1.2, P = 0.004), the rate of postoperative analgesic use was lower (14.3% [3/21] vs. 40.5% [15/37], P = 0.04), and the postoperative mean hospitalization days was shorter (3.7 ± 0.9 vs. 4.4 ± 0.8, P = 0.005) in the optical puncture group vs. controls. There was no case of urinary sepsis, blood transfusion, perirenal hematoma, pleural injury, and visceral organ damage.

Conclusions

Optical puncture combined with balloon dilation PCNL could be associated with good therapeutic effect and low frequency of complications for the treatment of kidney stones without hydronephrosis.