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.