Mini-percutaneous cystolithotripsy (mPCCL) versus transurethral cystolithotripsy (TUC) in pre-school children: Prospective comparative non-randomized outcomes over 8 years.

Introduction: Bladder stones in children can often be challenging to manage. We present our experience of minimally invasive percutaneous cystolithotripsy using 'mini-perc' instruments in the treatment of the bladder stones in pre-school children. The study also compares the outcomes of mini-percutaneous cystolithotripsy (mPCCL) and transurethral cystolithotripsy (TUC).

Objective: We hypothesized that mPCCL is a new minimally invasive technique with comparable outcomes to TUC.

Study Design: After parental consent and institutional review board approval, consecutive pre-school children with bladder stones were included from January 2011-December 2018. We shifted from the TUC to mPCCL in 2014, with mPCCL introduced as a new technique. Outcomes including stone free rate (SFR) and complication rates were compared for patients aged between 1 and 5 years of age who underwent mPCCL or TUC.

Results: A total of 31 patients (16 patients in Group 1 (mPCCL) and 15 patients in Group 2 (TUC) underwent the procedure. The mean age, stone size and operative times were 2.4 ± 0.96 years and 3.8 ± 0.77 years; 1.86 ± 0.65 cm and 1.34 ± 0.52 cm; and 33.5 ± 8.42 min and 38.2 ± 6.76 min for groups 1 and 2 respectively. While there were no intra or post-operative complications in group 1, in group 2 one patient required conversion to mPCCL due to difficulty in fragment removal per urethra and one with residual fragment needed repeat cystoscopy and fragment removal (Clavien IIIb). All patients in both groups were discharged the following day after catheter removal and remained stone free at 1- and 6-month follow-up.

Discussion: Our study shows good outcomes in managing bladder stones with the use of both TUC and mPCCL. We shifted from the former to mPCCL in 2014 during which there was an overlap of both these techniques, while mPCCL was being introduced. Subsequently, all stones have been managed with mPCCL without the need to revert back to TUC. In Group 1, we performed mPCCL, where the puncture was performed under ultrasound-guidance and fragment retrieval was accomplished with the vacuum-cleaner effect through the operating sheath. Complete stone clearance was achieved in all cases with no complications or need for secondary procedures. Limitations of our study include small sample size, single-centre experience, and lack of randomization. Further prospective randomized multicenter studies may be required to validate our results.

Conclusion: The technique of percutaneous suprapubic cystolithotripsy using mini-nephroscope is an alternate to transurethral cystolithotripsy. While both these techniques are suitable for smaller bladder stones, PCCL may be considered as the preferred management option of especially large bladder calculus in preschool children.