Improved Bladder Stone Fragmentation with a Newly Designed Net: Studies in ex Vivo Porcine Model

We have designed and made a net to secure bladder stones that will facilitate their fragmentation. Ex vivo porcine bladders were used for experimental trials with artificial calculi fragmented with electrohydraulic and ultrasonic lithotripters with and without the net. The duration and number of electrohydraulic shocks were significantly reduced with the net: mean of 2 v 11 minutes; 17 v 59 shocks. The duration of ultrasonic lithotripsy also was reduced significantly with the net: 2 v 13 minutes. The net facilitates stone fragmentation by acting as a sieve to retain large particles for further fragmentation while letting smaller particles pass through. It also increases efficiency by holding the stone fragments closer and surrounding the lithotripter probe, where they absorb the shock wave or energy maximally. In addition, the net may reduce bladder injury by keeping stones and fragments and the lithotripter probe away from the mucosa.