Outcomes of Ureteroscopy vs Mini-Percutaneous Nephrolithotomy for Pediatric Upper Urinary Tract Calculi: Comparative Nonrandomized Outcomes from Two Tertiary Endourology Referral Centers

Mini-versus standard percutaneous nephrolithotomy in pediatric population: A randomized controlled trial

INTRODUCTION

Mini PCNL has gained popularity in adult patients due to reduction in the complication rate with comparable stone free rate. There is paucity of level 1 evidence regarding the benefit of mini PCNL in the pediatric group.

OBJECTIVE

We performed a randomised study to compare mini PCNL (mPCNL) with standard PCNL (sPCNL) for the management of renal calculi in patients less than 18 years of age in terms of safety, efficacy, and stone-free rate (SFR).

MATERIALS AND METHODS

A randomised controlled trial was performed on 50 children who underwent PCNL from June 2015 to March 2021, who were divided into two groups. Group I had 25 patients managed with mPCNL (sheath size 16.5 Fr) and Group II had 25 patients who underwent sPCNL (sheath size 26 Fr). Primary outcomes including stone free rates (SFR) and hemoglobin drop and secondary outcomes like operative time, complications, pain score, need of analgesia, incidence of nephrostomy site leak, hospital stay in days were compared between the two groups.

RESULTS

The mean age of patients in groups I and II was 9.4 ± 2.6 and 10.4 ± 2.26 years, respectively (p = 0.15). The mean stone sizes in both groups I and II were 18.6 ± 2.56 and 20.2 ± 3.58 mm, respectively (p > 0.05). The stone free rate for group I was 88% and for group II, 92% (p = 0.64). The average drop in hemoglobin was higher in group II compared to group I (1.1 ± 0.31 g/dl and 1.7 ± 0.23 g/dl respectively; p < 0.0001), however the mean blood transfusion rate was not significantly different in both groups. The operating time was shorter in group II compared to group I (p-value - 0.0030). The pain scores were lesser for the group I. Grade I complications were higher in group II as compared to group I (p-0.047); however, grade II complications were comparable in both groups. The mean hospital stay was not significantly different in both groups.

DISCUSSION

This study confirms the role of mini PCNL in pediatric patients with renal stones. The stone clearance rate of mini PCNL is equivalent to standard PCNL, with lesser blood loss and postoperative complications, however with longer operative time during mPCNL. The small number of the participants in both arms is a limitation of this study and may also reflect fewer children with urolithiasis being treated surgically even in a tertiary care referral centre.

CONCLUSIONS

Mini-PCNL offers equivalent stone free outcome with lower complications rate compared to the standard PCNL for all types of renal stones.

Paediatric percutaneous nephrolithotomy (P-PCNL) reporting checklist

OBJECTIVE

To develop a reporting checklist that serves to improve and standardise reporting in studies pertaining to paediatric percutaneous nephrolithotomy (PCNL).

METHODS

Based on findings from systematic review of literature, a draft list of items was formulated. By process of review and revisions, a finalised version was established and consensus achieved.

RESULTS

The finalised version of the checklist covers four main sections, which include the following areas: study details, pre-operative, operative and post-operative information. There are 18 further sub-items. Recommendations deemed to be of high importance to include are highlighted in bold.

CONCLUSION

This practical tool can aid clinicians and researchers when undertaking and reviewing studies on paediatric PCNL. This is highly relevant given the current heterogeneity that exists as well as debate in best practice patterns.

Ambulatory Minimally Invasive Endoscopic Combined Intrarenal Surgery in Management of Large Impacted Proximal Ureteral Calculi: A Feasibility Study at a Tertiary Referral Center

Aim: To conduct a comparative, nonrandomized study to assess the feasibility of mini-Endoscopic Combined Intrarenal Surgery (ECIRS) using supine Mini-percutaneous nephrolithotomy (PCNL) access (16F) in Galdakao-Modified Supine Valdivia position for managing proximal large-volume impacted ureteral calculi as ambulatory day-care surgery vis-a-vis standalone ureteroscopy (URS) with push-back PCNL, if needed. The primary aim was to study the outcomes and stone-free rates (SFRs). Secondary aim was to compare the intraoperative and short-term postoperative complications. Materials and Methods: Data of 60 patients undergoing ECIRS (Group 1) from January 2016 to December 2019 were collected prospectively in a nonrandomized fashion from a single center after Ethics Committee approval. A matched-paired analysis was performed with retrospectively collated data of 60 patients undergoing standard URS/pushback PCNL (Group 2) using analysis of variance, Fisher's exact test, and Chi-square test. p < 0.05 was considered statistically significant. Outcomes and Results: Group 1 patients had a significantly shorter procedure time vs Group 2 (42.1 ± 11.2 minutes vs 52.1 ± 13.7 minutes; p < 0.001). Group 1 (59/60) patients had an overall single stage SFR of 98.3%, which was significantly higher than single-stage SFR of 83% in Group 2 (50/60) (p < 0.002). Group 2 patients had a higher incidence of fever (10 vs 4, p = 0.01). However, there were no cases of sepsis in either group. Rest of the complications were comparable for both, as the need for ancillary procedures was significantly higher in Group 2 (10% vs 1.7%, p < 0.001). Patients were discharged on the same day in both groups. Conclusions: The findings of our study suggest that, in large and impacted proximal ureteric stones, combined minimally invasive endoscopic approach offers the best option to render the patient stone free by a single intervention. With better intra- and postoperative outcomes and safety profile, Mini-ECIRS may be considered as an ambulatory procedure in this setting.

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.

Paediatric kidney stone surgery: state-of-the-art review

While urolithiasis in children is rare, the global incidence is rising, and the volume of minimally invasive surgeries being performed reflects this. There have been many developments in the technology, which have supported the advancement of these interventions. However, innovation of this kind has also resulted in wide-ranging practice patterns and debate regarding how they should be best implemented. This is in addition to the extra challenges faced when treating stone disease in children where the patient population often has a higher number of comorbidities and for example, the need to avoid risk such as ionising exposure is higher. The overall result is a number of challenges and controversies surrounding many facets of paediatric stone surgery such as imaging choice, follow-up and different treatment options, for example, medical expulsive therapy, shockwave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy. This article provides an overview of the current status of paediatric stone surgery and discussion on the key topics of debate.

Role of Pediatric Ureteral Access Sheath and Outcomes Related to Flexible Ureteroscopy and Laser Stone Fragmentation: A Systematic Review of Literature

Context

Flexible ureteroscopy and laser lithotripsy (FURSL) represent a good treatment option for pediatric urolithiasis. Scarce evidence is available about the safety and efficacy of the concomitant use of a ureteral access sheath (UAS) in the setting of pediatric ureteroscopy (URS).

Objective

To acquire all the available evidence on UAS usage in pediatric FURSL, focusing on intra- and postoperative complications and stone-free rates (SFRs).

Evidence acquisition

We performed a systematic literature research using PubMed/MEDLINE, Embase, and Scopus databases. The inclusion criteria were cohorts of pediatric patients <18 yr old, submitted to URS for FURSL, reporting on more than ten cases of UAS placement. The primary outcomes were prestenting rates, operating time, ureteric stent placement rates after surgery, rates and grades of complications, ureteral injuries, and overall SFR. A total of 22 articles were selected.

Evidence synthesis

In total, 26 intraoperative and 130 postoperative complications following URS with UAS placement were reported (1.8% and 9.18% of the overall procedures, respectively). According to the Clavien-Dindo classification, 32 were classified as Clavien I, 29 as Clavien II, 43 as Clavien I or II, six as Clavien III, and one as Clavien IV. Twenty-one cases of ureteral injuries (1.59%) were noted in the whole cohort; most of them were ureteral perforation or extravasation, and were treated with a temporary indwelling ureteric stent. The overall SFR after a single URS procedure was 76.92%; after at least a second procedure, it was 84.9%.

Conclusions

FURSL is a safe and effective treatment option for pediatric urolithiasis. UAS use was associated with a low rate of ureteric injuries, mostly treated and resolved with a temporary indwelling ureteric stent.

Patient summary

We performed a systematic literature research on the utilization of a UAS during ureteroscopy for stone treatment in pediatric patients. We assessed the outcomes related to the rates of intra- and postoperative complications and the rates of efficacy of the procedure in the clearance of stones. The evidence shows a low rate and grade of complications associated with UAS placement and good stone-free outcomes. A ureteric injury may occur in 1.6% of cases, but it is usually managed and resolved with a temporary indwelling ureteric stent.

Mini-Percutaneous Nephrolithotomy With an Endoscopic Surgical Monitoring System for the Management of Renal Stones: A Retrospective Evaluation

Purpose

To compare the outcomes and postoperative quality of life of patients with renal calculi who underwent standard percutaneous nephrolithotomy (sPNL), mini-invasive percutaneous nephrolithotomy (mPNL) or mPNL with an endoscopic surgical monitoring system (ESMS) using a retrospective clinical trial.

Methods

Eighty-six adult patients with renal stones who were treated with sPNL were retrospectively compared to ninety-two patients who were treated with mPNL between July 2014 and December 2017. Next, further studies were retrospectively conducted using a matched paired method. The ninety-two patients treated with mPNL were divided into two groups based on whether the endoscopic surgical monitoring system (ESMS) was used (ESMS-mPNL vs. non-ESMS-mPNL). The ESMS used strain gauge transducers to measure the inflow and outflow of irrigation solution. Bleeding and fluid absorption during endoscopic surgery could be accurately calculated by computer program in ESMS.

Results

The fluoroscopy time, complication rate, stone-free status and clinically insignificant residual fragment (CIRF) rate were not significantly different between the two groups (sPNL vs. mPNL). The mPNL group had a significantly longer operation time than the sPNL group, and the mPNL group exhibited a markedly reduced 12-h postoperative visual analogue pain scale (VAS) score, mean hospitalization time, and return to work time, had slightly reduced haemoglobin loss, and underwent more tubeless operations. Moreover, among the 92 patients who underwent mPNL, the operation time (P = 0.090), complication rate (P = 0.996), stone-free status (P = 0.731), CIRF rates (P = 0.125) and number of tubeless operations (P = 0.760) were not significantly different between the two subgroups (non-ESMS-mPNL vs. ESMS-mPNL); however, the patients in the ESMS-mPNL group had significantly longer irrigation times than those in the non-ESMS-mPNL subgroup, along with marked reductions in irrigation fluid, blood loss, haemoglobin loss, 12 h postoperative VAS score, mean hospitalization time, and return to work time.

Conclusions

mPNL is less painful than sPNL in patients undergoing treatment for 20–40 mm renal stones. Similar stone-free rates were achieved by the two procedures, but mPNL was superior to sPNL in terms of blood loss, discomfort, hospitalization time and return to work time. We think that ESMS-mPNL is less painful for patients and more efficacious than non-ESMS-mPNL, and ESMS-mPNL achieves a stone-free rate that is similar to non-ESMS-mPNL in patients receiving treatment for 20–40 mm kidney stones.

External validation of efficacy and reliability of different retrograde intrarenal surgery (RIRS) scoring systems for pediatric nephrolithiasis

INTRODUCTION

Retrograde Intrarenal Surgery (RIRS) is one of minimally invasive procedures for pediatric upper urinary stones. However, a RIRS predictive system for children to evaluate postoperative stone free rate (SFR) is still unavailable.

OBJECTIVE

The aim of this study is to validate the efficacy and reliability of different RIRS scoring systems for children.

STUDY DESIGN

We collected clinical data of 137 pediatric patients treated with RIRS in our center between 2014 and 2021. All the predictors were acquired by preoperative non-contrast CT or CT urography. Receiver Operative Curve (ROC) and Area Under Curve (AUC) were showed to compare the predictive power of different models.

RESULTS

A total of 162 RIRS procedures were performed for these 137 pediatric patients. Median surgical duration, irrigation volume and hospitalization were 30 (20, 40) min, 500 (300, 1000) ml and 6 (4, 7) days, respectively. Overall SFR and complication rate was 79.6% (129/162) and 29.2% (40/137), respectively. Significant difference was detected between non-stone free group and stone free group in terms of stone complexity (p < 0.001), cumulative stone sizes [2.3 (2.0, 3.5) cm vs. 1.5 (1.0, 2.0) cm, p < 0.001], RUS groups (p < 0.001), S-ReSC groups (p < 0.001) and RIRS nomogram score [10 (8, 12) vs. 23 (18, 25), p < 0.001]. Among them, RIRS nomogram presented with the maximum AUC values in comparison with the other two systems (RUS: 0.944 vs. 0.874, p = 0.001; S-ReSC: 0.944 vs. 0.808, p < 0.001).

DISCUSSION

We reported the largest sample size of pediatric patients treated with RIRS in our center. Similar with previous studies, RIRS is an efficacious and safe option for pediatric patients. RIRS nomogram showed the best predictive outcome due to the inclusion of multiple parameters, but an innovative predictive system based on pediatric clinical data is warranted in the future.

CONCLUSION

Among the three scoring systems, RIRS nomogram showed the most optimal predictive power of postoperative SFR for pediatric patients.

Ureteroscopy for stone disease in the paediatric population: lessons learned and outcomes in a Nordic setting

Introduction:

Paediatric stone disease is rare in the Nordic communities. Still, the condition can require surgical intervention in the form of ureteroscopy (URS). Here, we report outcomes achieved at a regional (tertiary) centre.

Patients and methods:

Retrospective analysis was performed of consecutive patients (<18 years of age) undergoing URS for stone disease between 2010 and 2021. Outcomes of interest included stone-free rate (SFR) determined using a definition of no residual fragments ⩾ 3 mm on imaging and complications classified according to Clavien–Dindo system.

Results:

In total, 23 patients underwent 47 URS procedures for a total of 31 stone episodes. Mean age was 9 (range 1–17) years and male-to-female ratio was 6:17. Overall, 35% had at least one medical comorbidity. Ultrasound determined preoperative stone status in 87%. Mean largest index and cumulative stone sizes were 9 (range 3–40) and 12 (range 3–40) mm, respectively. Overall, 32% had multiple stones. Lower pole was the commonest stone location (39%). No patients underwent elective pre-operative stenting. Ureteral access sheaths were not used in any cases. Access to upper urinary tract at first procedure was successful in 94%. Initial and final SFR was 61% and 90%, respectively. No intra-operative complications were recorded. Overall post-operative complication rate was 17.5%. Urinary tract infection (CD II) was the commonest adverse event (12.5%).

Conclusion:

Paediatric URS can be delivered in the setting of a regional centre without compromising outcomes. This includes when carried out by adult endourologists, without routine pre-stenting and omitting use of ureteric access sheath.

The characteristics and influencing factors of fever in postoperative patients undergoing percutaneous nephrolithotomy: A retrospective analysis

Percutaneous nephrolithotomy (PCNL) is commonly used for the treatment of upper urinary calculi in clinical setting, and fever is a common complication after PCNL. It is necessary to evaluate the risk factors of fever in patients undergoing PCNL, to provide insights into the management of PCNL.Patients who underwent PCNL in our hospital from January 2018 to August 2020 were included. The clinical data of postoperative fever and no fever patients were collected and assessed. Logistic regression analyses were conducted to analyze the risk factors for fever in patients undergoing PCNL.A total of 276 patients undergoing PCNL were included, the incidence of postoperative fever for patients undergoing PCNL was 19.39%. No significant differences in the gender, body mass index, alcohol drinking, smoking, hypertension, hyperlipidemia, intraoperative blood infusion, length of hospital stay between fever patients, and no fever patients were found (all P > .05). There were significant differences in the age, diabetes, size of stones, duration of surgery between fever patients, and no fever patients (all P < .05). Age ≥60 years (odds ratio [OR] 2.143, 95% confidence interval [CI] 1.101∼3.264), diabetes (OR 2.218, 95% CI 1.176∼4.642), size of stone ≥2 cm (OR 1.428, 95%CI 1.104∼2.055), duration of surgery ≥100 minutes (OR 1.334, 95% CI 1.015∼1.923) were the risk factors for fever in patients with PCNL (all P < .05). Escherichia coli (48.44%), Staphylococcus aureus (18.75%), and Candida albicans (10.93%) were the top 3 pathogenic bacteria of urine culture.Fever is one of the common complications after PCNL. Patients with high-risk factors should be given full attentions and take corresponding preventive measures targeted on risks.

External Validation of Two Predictive Models for Postoperative Fever After Retrograde Intrarenal Surgery in Pediatric Patients

Objective: The aim of this study is to validate the efficacy and reliability of two predictive models for postoperative fever after retrograde intrarenal surgery (RIRS) in pediatric patients Materials and Methods: A total of 124 children who were treated with RIRS between August 2014 and August 2020 in our center were included. All the predictors were obtained by preoperative routine examinations. Receiver operative curve (ROC) and area under curve (AUC) were showed to compare the predictive power of the two models. Results: One hundred twenty-four children included of 94 boys and 30 girls, with median ages of 2.1 (1.3, 7.0) years and median body mass index of 17.3 (15.6, 20.6) kg/m². The total points of the two nomograms were 81.0 (67.3, 90.3) and 45.5 (20.4, 94.0). Eventually, 21 children (16.9%) suffered from postoperative fever. With the exception of C-reactive protein values (25.0 mg/L vs 5.0 mg/L, p = 0.015), irrigation volumes (800 mL vs 500 mL, p = 0.01), and total points of the two predictive models (Nomogram 1: 88.0 vs 76.0, p < 0.001; Nomogram 2: 76.0 vs 39.0, p = 0.016), there was no statistical difference detected between the fever and nonfever groups. ROCs showed that Nomogram 1 presented with better predictive accuracy and efficacy with excellent AUC values of 0.805 in comparison with Nomogram 2 (0.805 vs 0.664, p = 0.025). Conclusion: We reported a sample of 124 children undergoing RIRS with a final stone-free rate of 87.1%. Twenty-one pediatric patients (16.9%) suffered from postoperative fever. Nomogram 1 presented with better predictive power for postoperative fever after RIRS in pediatric patients.

Role of Mini-Percutaneous Nephrolithotomy in the Management of Pediatric Stone Disease: A Systematic Review of Literature

Introduction: Kidney stone disease in the pediatric setting is rare, but the incidence is rising. Mini-percutaneous nephrolithotomy (mPCNL) is one of the newer surgical interventions to have been developed in recent decades. The aim of this study was to carry out a systematic review (SR) to formally evaluate the safety and efficacy of pediatric mPCNL, which was defined as PCNLs using tract size between 15F and 20F. Methods: An SR was carried out in accordance with Cochrane guidelines and A MeaSurement Tool to Assess systematic Reviews (AMSTAR) checklist. Original studies reporting on outcomes of mPCNL with 20 or more patients (aged ≤18 years) were included. Results: Eight studies were finally identified, which satisfied our predefined criteria. This included two randomized trials and six cohort studies. A total of 384 patients with a weighted mean age of 7.5 years (range: 0.5-18 years) and a male:female ratio of 3:2 underwent mPCNL. The weighted mean stone size was 1.2 cm (range: 0.8-3.5 cm). The weighted mean operative time and length of hospital stay were 76.8 minutes (range: 20-120 minutes) and 4.6 days (range: 1-33 days), respectively. The most common location(s) of stones were lower pole (57%) and renal pelvis (24.3%). The weighted mean initial and overall stone-free rates were 87.9% (range: 76%-97.5%) and 97% (range: 91.3%-100%), respectively. None of the cases required intraoperative conversion to standard PCNL. Complications occurred in 19% (n = 73) of patients. The weighted mean transfusion rate reported across studies was 3.3% (range: 0%-10.3%). Conclusions: mPCNL is safe and effective in the pediatric population. Further randomized studies will help determine its formal role in pediatric endourology and help guideline recommendations accordingly.