Development of an innovative intrarenal pressure regulation system for mini-PCNL: A preliminary study

Miniaturized percutaneous nephrolithotomy (mini-PCNL) requires saline irrigation at high-pressures to maintain visual clarity. However, this may raise the intrarenal pelvic pressures (IRPs) beyond a safe range and may result in a higher complication rate. The aim of this study was to make and validate an automated pressure saline irrigation system to regulate IRPs during mini-PCNL.

A ureteric catheter was connected to an urodynamic machine and the minimum, maximum, and average IRPs reached during a standard 15 Fr mini-PCNL were measured in ten cases. Next, an intrarenal pressure regulation system (IPRS) was conceptualized, designed, patented, and constructed. IPRS was then tested on a mannequin model using the routine instruments. Lastly, the IPRS was evaluated on - five cases of 15 Fr mini-PCNL. The mean maximum IRP as recorded in the baseline data was set as the maximum permissible pressure on IPRS. The efficacy of IPRS was assessed by measuring the IRP, recorded in parallel, on both the IPRS and the urodynamic machine at various stages of the procedure.

The mean maximum IRP reached during baseline evaluation was 25 cm of water which was set as the maximum permissible limit of the IPRS. Evaluation of the IRPS on mannequin models and validation clinical cases showed that IPRS measured the IRP accurately and prevented the pressure surge above the set limits Overall, higher IRPs were recorded during stone pulverization as compared to the other surgical steps.

The current IPRS is the first of its kind open platform, portable, automated pressure saline irrigation system. It precisely monitors and controls the IRP and has the potential to reduce the irrigation pressure-related complications.