Semi-closed-circuit vacuum-assisted mini percutaneous cystolithotomy (vamPCL) in the pediatric population: Initial experience of a novel technique in native and augmented bladders.

Introduction: Bladder stones (BS) in children are a rare condition and represent 1-5 % of all urinary tract stones. With advances in miniaturized endoscopes and intracorporeal lithotripters, percutaneous cystolithotomy has been demonstrated to be an effective, safe and quick technique, despite the longer operative time. This limitation may be overcome by a semi-closed-circuit vacuum-assisted technology (vamPCL), characterized by a continuous inflow and a suction-controlled outflow (ClearPetra®).

Objectives: To assess the safety and efficacy of a vamPCL characterized by continuous inflow and suction-controlled outflow to treat bladder stones in pediatric patients with native or augmented bladder.

Study design: From January 2021 up to December 2023, we prospectively collected variables on consecutive vamPCL procedures (Fig.) The stone-free rate (SFR) was defined as absence of stones or residual fragment <5 mm diagnosed with ultrasound.

Results: Six patients with a median age of 139 months (55-212) were recruited for the study. Three patients (50 %) with the initial diagnosis of extrophy-epispadia complex had an augmented bladder, whereas of the remaining three (50 %) with an initial diagnosis of anorectal malformation two had an augmented bladder. All patients had a Mitrofanoff conduit opening on the right flank, except for one (16 %) with umbilical access. The mean cumulative stone size was 24 mm ± 14,2. The mean operating time was 78,3 min ± 14,7. One procedure was interrupted after 90 min due to the overall size (>50 mm). Stone removal was achieved only via suction in all cases. All vamPCL procedures were completed without intraoperative complications. Fever for 24 h (1/6; 16 %) was the only post-operative complication. The mean stay of the suprapubic catheter was 3.4 days ± 1,5 and of the trans-Mitrofanoff catheter was 9.3 days ± 4,5. The SFR was confirmed in all the cases with US performed after 2 months. Only one male patient (16 %) had recurrent stones after 8 months and he is waiting for second surgery. Mean follow-up was 7.2 months ± 9,4.

Discussion: In the present study we demonstrated that vamPCL is safe and feasible in selected cases especially in those with augmented bladder. To our knowledge, this manuscript is the first to present the use of the ClearPetra® for the treatment of bladder stones.

Conclusions: To our knowledge, this manuscript is the first to present the use of the ClearPetra® for the treatment of bladder stones. The vamPCL seems to be sustainable, safe and feasible for bladder stones treatment in selected children.