Endoscopic Transpapillary Laser Lithotripsy Using FREDDY (Frequency Doubled Double Pulsed Nd:YAG Laser) Technology for Difficult Common Bile Duct Stones

Abstract

Background: Laser lithotripsy of common bile duct (CBD) stones has become a commonly accepted endoscopic treatment for giant or impacted stones with direct endoscopic control. The Frequency-Doubled Double pulse Nd:YAG (FREDDY) laser is a newly short-pulsed, double-frequency, solid-state laser with 532 and 1063 nm which was designed for fragmentation of urinary stone. Its mechanism of action is through the generation of plasma bubble, which generates a mechanical shockwave responsible for stone fragmentation without thermal tissue injury. Aim: The aim of our study was to estimate the effectiveness as well as the safety of this new technology in patients with difficult CBD stones not amenable for conventional maneuvers such as sphincterotomy and mechanical lithotripsy. Method: Fifteen patients (male/female=7/8, mean age: 67.8 yrs) with large or impacted CBD stones were treated by the endoscopic retrograde route using a FREDDY laser (Laser U100, World of Medicine AG, Berlin, Germany) under fluoroscopic control. The laser fiber was inserted into a balloon extraction catheter for centralization into the dilated CBD. The mean stone number was 2.3 (1-5), and mean diameter of largest stone was 26 mm (15-33 mm). Results: Laser-induced stone fragmentation could be achieved in 14 out of 15 patients (93%) without direct visual control. The mean session of endoscopic procedure was 2.3 ± 1.2. After its fragmentation, mechanical lithotripsy was added for complete removal of stones in the 3 cases. Minor complications were noted in 2 patients (acute pancreatitis, transient hemobilia), but major complication did not. Laser probe was broken in the 2 cases. Conclusion: Laser lithotripsy using FREDDY technology without direct visual control was found to be a effective and safe technique in patients with difficult CBD stones not removed by mechanical lithotripsy.