4:10 PM Abstract No. 108 - A new percutaneous pneumatic lithotripsy technique for common bile duct gallstones removal

Abstract

Purpose To develop a new technique for percutaneous removal of common bile duct (CBD) gallstones by using a pneumatic lithotripter with a XCOIL encapsulator (XE) and retractor (XR) system. Materials and Methods For in-vitro confirmation, a 6.0mm glass tube was shaped to simulate the cystic duct and CBD of pigs. Human gallstone was placed into the tube. An 11Fr custom balloon introducer sheath (BIS) was positioned close to the gallstone, and then inflated to occlude the proximal tube. An XE and XR system was advanced through the BIS into the tube, to catch the gallstone by pulling XR back into the XE. The stone was restricted within the XE by closing the distal XE end via a string. A 1.0mm lithotripter probe was manually-curved according to the glass tube shape and then advanced into the XE through the BIS, where the gallstone was shocked. Fragments were then extracted from the tube with the XE. Lithotripsy procedures were repeated for 6 times. The shock numbers, the skin-to-skin lithotripsy time and fragment sizes were recorded. For in-vivo validation, via a transcystic approach, human gallstones were positioned into CBDs of three pigs through a 16Fr introducer. Under fluoroscopy, an 11Fr BIS was placed into CBD to break and remove the gallstones with the same procedures as developed from the in-vitro experiment. Pre- and post-cholangiographies were obtained to confirm the successes of the gallstone placement, breaking, and removal. After the experiment, the pigs were euthanized and CBDs were harvested for histology. Results Of the in-vitro experiment, average 9.5±4.2 shocks were required to break gallstones. The average skin-to-skin lithotripsy time was 6'10. All stones were successfully broken, with the average maximal length of the gallstone fragments at 2.1±0.3mm compared to the pre-lithotripsy stone length at 5.3±0.2 mm (p Conclusion The new XCOIL-assisted percutaneous pneumatic lithotripsy is feasible and safe for CBD gallstones breaking and removal, which establishes groundwork for its further clinical application.