Percutaneous ablation of gallstones.

The purpose of this study was to determine if gallstones could be safely and effectively ablated in the pig using a proprietary percutaneous rotor-tipped catheter, the Kensey-Nash Lithotrite (KNL). All gallstones in a single human gallbladder were defined as a gallstone set. Human gallstone sets not meeting current treatment criteria for extracorporeal shock wave lithotripsy (ESWL) were placed in the gallbladder (GB) of male pigs (N = 8; 80-100 kg). A percutaneous transhepatic guide wire was put into the GB and the abdomen closed. The KNL was then introduced under fluoroscopy using the Seldinger technique and activated. Gallstone ablation was monitored by tactile and auditory feedback to the operator and by fluoroscopy. Once completed the device was withdrawn, the GB irrigated, and the 9F sheath removed. Animals were sacrificed immediately (Group 1, N = 4) and at 28 +/- 5 days (Group 2, N = 4). Gallstones were ablated in 26 +/- 8 min. No pig had significant hemorrhage, GB perforation, or pancreatitis. One acute animal had stone fragments greater than 2 mm in the gallbladder. No other animals had any fragments greater than 1 mm present in the GB, cystic duct, common duct, ampulla, or duodenum. Histologic examination of the GB showed acute hemorrhagic mucosal injury in Group 1 and extensive mucosal regeneration with some stone fragment granulomata and mural fibrosis in Group 2. We conclude that percutaneous gallstone ablation with the KNL is safe and effective in this short-term pig model and appears to be a safe procedure for gallstone ablation. Long-term safety and effectiveness remain to be demonstrated. This device should be useful for treatment of symptomatic gallstones in patients not treatable by ESWL.