Comparison between prone and supine nephrolithotomy in pediatric population: a double center experience

An updated systematic review and meta-analysis on the efficacy of supine versus prone position for pediatric PCNL

BACKGROUND

The incidence of pediatric kidney stones is increasing with recurrence rates ranging from 35 to 50%. Supine percutaneous nephrolithotomy (PCNL) presents a viable alternative to the conventional prone position, offering specific benefits but also posing certain risks.

OBJECTIVE

To update a previously published systematic review and meta-analysis comparing the efficacy of PCNL in the supine versus prone positions in children.

METHODS

A systematic search of Web of Science, Cochrane Library, PubMed, and Embase was conducted to identify eligible studies. Two authors independently screened the literature and extracted data. The meta-analysis was performed using StataMP 17. The study was prospectively registered in PROSPERO (ID: CRD42024545145). The sensitivity and subgroup analyses explored sources of heterogeneity, and publication bias was assessed with a funnel plot. The study adhered to PRISMA guidelines and the Cochrane Handbook.

RESULTS

This study included a total of nine studies, comprising five randomized controlled trials and four case-control studies, with 614 patients in total. Compared with the prone position group, the supine position group demonstrated significant advantages in terms of operative time (WMD = - 15.43, 95% CI: - 22.18 to - 8.69, P = 0.0001), hospital stay (WMD = - 0.77, 95% CI: - 1.12 to - 0.42, P = 0.0001), overall complication rate (OR = 0.46, 95% CI: 0.42-0.99, P = 0.046), and hemoglobin decrease (WMD = - 0.22, 95% CI: - 0.40 to - 0.05, P = 0.013). However, no significant differences were observed between the two groups in stone clearance rate, high-grade complication rate, or radiation exposure time. Subgroup analysis revealed that in studies published after 2024, cases of small stones (< 2 cm), and older children (> 9 years), the supine position group had fewer low-grade complications. Additionally, in the supine PCNL group with ultrasound or endoscopy-assisted puncture, radiation exposure time was significantly reduced.

CONCLUSION

This study shows that supine position PCNL in children is superior to the prone position in terms of operative time, hospital stay, complication rate, and hemoglobin decrease, with no significant difference in stone clearance, high-grade complications, or radiation exposure. The subgroup analysis found that supine position resulted in fewer low-grade complications in studies published after 2024, small stones, and older children. It also significantly reduced radiation exposure with ultrasound or endoscopy-assisted puncture, suggesting that supine position is a safer and more effective option.

Flank-free modified supine vs. prone position for pediatric nephrolithotripsy: an updated systematic review and meta-analysis

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is widely performed as the preferred treatment for kidney stones larger than 20 mm in pediatric patients, with current research focusing on comparing outcomes between prone and supine positions to determine optimal procedural positioning. Therefore, the aim of this study is to compare the efficacy of prone versus supine positioning in pediatric PCNL, providing clarity on this critical aspect of the procedure to guide clinical decision-making.

METHODS

We conducted a systematic review in PubMed, Embase, Scopus, Cochrane, Web of Science and Google Scholar. We included studies that compared PCNL in prone vs supine positions for pediatric patients. Our primary outcome was stone-free rate (SFR). Secondary outcomes included operative time, length of hospital stay and overall complications rate. The statistical analysis was performed using Review Manager 5.4.

RESULTS

We retrieved 8 articles, with 269 patients in the prone group and 223 patients in the supine group. The mean age of all patients was 7.92 years old. Our findings presented no statistically significant difference in SFR between the two positions (OR 0.67; CI95 0.38, 1.18; p = 0.17; I2 = 0%). Additionally, we noted a significant reduction in operative time in the supine position group (MD 13.75; CI95 4.35, 23.15; p = 0.004; I2 = 84%). At the same time, the length of hospital stay after the procedure was lower in supine group (MD 0.61; CI95 0.34, 0.88; p < 0.0001; I2 = 21%). No difference was observed regarding the total complication rate (OR 1.47; CI95 0.88, 2.47; p = 0.15; I2 = 0%).

CONCLUSION

Our meta-analysis suggests that PCNL performed in the prone position is equivalent to supine PCNL in terms of SFR. However, mainly in the RCT studies, we could observe benefits of the supine position in comparison of prone position in terms of lower operative time, as well as a reduced postoperative hospital stay.

Renal Access in Pediatric Supine Miniaturized Percutaneous Nephrolithotomy: Comparative Evaluation of Ultrasound-Fluoroscopy Combined and Biplanar (0°-90°) Fluoroscopic Techniques

Introduction: Ultrasound (US)-guided puncture has the benefits of avoiding radiation and limiting the risk of visceral injury. We aimed to evaluate the results of two different renal access techniques during pediatric supine mini percutaneous nephrolithotomy (smPCNL) in a comparative manner. Patients and Methods: Data obtained from pediatric patients undergoing smPCNL by single surgeon between September 2021 and 2023 were reviewed retrospectively. Children were divided into two groups namely; biplanar 0°-90° fluoroscopy (Group-F) and US-fluoroscopy combined (Group-C). In all cases, preoperative, operative, and postoperative findings were recorded. Success was defined as the determination of either no (complete stone-free status) or < 4 mm residual fragments (CIRF) on US and X-ray (postoperative 3rd month) images. Complications were evaluated according to modified Clavien-Dindo classification. Results: Data of 54 patients with a mean age of 8.6 years (Group-F = 30, Group-C = 24) are reviewed. In addition to the similar success rates in both groups (Group-F = 86.7% Group-C = 87.5% p = 0.928), similar minor complications were noted in the majority of the cases. No child required transfusion and/or angioembolization. Although the fluoroscopy and operation time were lower in Group-C, the difference was not statistically significant. Conclusion: US-fluoroscopy combined access technique can be applied with similar success and complication rates in pediatric smPCNL. Ultimately, as experience is gained, this technique may lower radiation exposure, although this was not observed in the current study.

Supine versus prone pediatric percutaneous nephrolithotomy: A systematic review and meta-analysis

Percutaneous nephrolithotomy (PCNL) is the treatment of choice for pediatric nephrolithiasis more than 20 mm. Prone position was the preferred position for decades. Recently, supine position has gained more interest. This meta-analysis aims to evaluate the safety and efficacy of PCNL in supine versus prone position in pediatric population. A systematic search of PubMed, Scopus, Web of Science, and Cochrane Library was performed till 28 February 2024. The study included comparative studies comparing both positions in children that were written in English. A total of three randomized studies and three retrospective studies were included with a total number of 290 patients. Cochrane risk-of-bias tool for randomized trials was used for quality assessment, while Newcastle-Ottawa scale was used for non-randomized controlled trials. The meta-analysis was conducted using Review Manager software. Numerical data were analyzed using standardized mean difference (SMD), while the risk ratio was used for analysis of categorical data. Fixed or random effects models were used according to heterogeneity. There were statistically insignificant differences between both groups for stone-free rate (RR 1.08, 95% CI [0.98-1.18], p = 0.11) and overall complications (RR 0.93, 95% CI [0.59-1.47], p = 0.76). Operation time was significantly shorter in supine group (SMD -0.99, 95% CI [-1.67 to -0.30], p = 0.005). Therefore, comparable efficacy and safety outcomes were proved between both supine and prone positions for PCNL in pediatrics.

Comparison of Two Centers' Experience in Pediatric Supine and Prone Miniaturized Percutaneous Nephrolithotomy with Propensity Match Analysis

Introduction: Percutaneous nephrolithotomy (PNL) is the treatment of choice in children with complex and large stones. With the experience gained from adult practice, supine PNL is increasingly performed in children as well. We aimed to evaluate the comparative results of prone and supine mini-PNL (m-PNL) performed for large/complex stones in children. Patients and Methods: The study included children who underwent supine and prone m-PNL at two centers between September 2019 and 2022. Patients were divided into two groups with a 1:1 ratio to index supine m-PNL and prone m-PNL cases for the size, number, location of the stones, degree of hydronephrosis, and age. Operative related parameters, success, and complication rates are being discussed on a procedure-based manner. Results: Forty-two patients (21 supine and 21 prone) were included. The mean age was 9.6 ± 4 years and mean stone size was 28.8 ± 13.6 mm. Regarding the operative data, the mean duration of procedure time was 65.7 ± 17.8 minutes in supine group, whereas 86.9 ± 19.0 minutes in prone group (p = 0.001). Fluoroscopy time was shorter in supine group (p = 0.027). Tubeless PNL was performed in 11 cases of prone group (52%), whereas this number was 18 (86.7%) in supine group (p = 0.019). Stone-free rates were similar in both groups (supine m-PNL: 90.5%, prone m-PNL: 85.7%, p = 0.634). Complications were minor in nature in most of the cases of both groups, which resolved with supportive measures in a short period of time. However, there was a statistically significant difference regarding the location and number accesses between two groups (p = 0.008). Simultaneous flexible ureterorenoscopy was performed in eight patients in the supine PNL group (<0.001). Conclusions: Our current findings and the highly limited data reported in the literature indicate that as an established minimal invasive treatment alternative m-PNL procedure in supine position can also be performed with similar success and complication rates in pediatric population.

A comparative analysis of the efficacy and safety of mini-percutaneous nephrolithotomy performed in the supine and prone positions for the treatment of pediatric kidney stones: a single-center experience

Mini-percutaneous nephrolithotomy (MPCNL), which has a smaller tract size (14-20 Fr) than conventional percutaneous nephrolithotomy, has been shown to be safe and effective in pediatric patients with large and complex upper urinary tract stones. This study aimed to compare the efficacy and safety of MPCNL between the supine and prone positions in a pediatric population. The data of pediatric patients who underwent MPCNL at our center between January 2010 and March 2023 were retrospectively analyzed. According to the surgical position, the patients were divided into the prone (Group P) and supine (Group S) groups. In both groups, dilatation was performed using 14-18 Fr metallic dilators. The two groups were compared in terms of perioperative data, postoperative stone-free rates (SFRs), and complications. There were 36 (59%) patients in Group P and 25 (41%) patients in Group S. Stones were mostly located in the pelvis (49.2%) and second most frequently in the lower pole (27.9%). Fluoroscopy time was shorter in Group S but did not statistically significantly differ compared to Group P (p = 0.181). However, operation time was statistically significantly shorter in Group S (73.8 ± 35 vs. 99.8 ± 37.4 min, p = 0.008). Although there was no significant difference, relatively higher SFR were detected in Group S (88% vs. 83%, p = 0.725). Endoscopic combined intrarenal surgery (ECIRS) was performed on six (24%) patients in Group S, and the SFR was 100% among these patients. There was no significant difference between the two groups in terms of the presence of complications (16.7% vs. 16%, p = 0.945). Both supine and prone MPCNL appear to be safe and effective in the pediatric age group, with similar stone-free and complication rates. In the supine procedure, the operation time is shortened compared to the prone. In addition, simultaneous retrograde access has the potential to increase the overall success rate of surgery.

The role of mini-PCNL as primary approach for the treatment of pediatric kidney stones in a high-income country. Ten-year single-center report

PURPOSE

To describe our experience in the use of percutaneous nephrolithotomy (PCNL) as a primary treatment for paediatric kidney stones and to highlight its benefits.

METHODS

The design was retrospective and observational. All the children treated for kidney stones from 2011 to 2021 were included. The population was divided into Group A (PCNL) and Group B (retrograde intrarenal surgery, RIRS). The outcomes were stone-free rate (SFR), the rate of procedures per patient, the rate of failure and the rate of complications.

RESULTS

Twenty-eight patients with 33 kidney units were included. Eighteen of them (64%) were males. The median age was 10 (IQR 6.8-13) years. Forty-seven procedures were performed. Twenty-four of them (51%) were mini-PCNL. Group A included 17 patients (61%). Group A presented a higher SFR (p = 0.007) and a lower number of procedures (p < 0.001). RIRS failed in five cases (45%) because of non-compliant ureter. Two urinary tract infections (UTI) were reported after PCNL and four UTIs after RIRS (p = 0.121). No major complications were reported.

CONCLUSION

Mini-PCNL should be suggested as a primary approach for pediatric kidney stones. This technique presented a better effectiveness with a reduced number of procedures when compared to RIRS.