FLASHLAMP EXITED PULSED DYE-LASER AND ELECTROHYDRAULIC LITHOTRIPSY - IN-VITRO STUDY ON TISSUE EFFECTS

In Vitro Study on Tissue Effects. Intracorporal lithotripsy has gather ed momentum in the management of gallstone disease due to the increasi ng sophistication of technical equipment for the percutaneous, as well as the retrograde-endoscopic route. Laser-induced shock wave lithotri psy (LISL) and electrohydraulic lithotripsy (EHL) have proved feasible by allowing reliable fragmentation of biliary calculi. Evaluation of therapeutic risks, e.g., effects of accidental irradiation of the gall bladder wall, has been performed in small sample sizes only. We invest igated the effects of LISL and EHL on multiple sets of human and porci ne gallbladders under in vitro conditions. Gallbladders were freshly h arvested, mounted, and immersed in different mediums (normal saline, b lood, bile). They were swiftly exposed to LISL (Pulsolith(TM)) and EHL (Lithotron EL 23(TM) under differing experimental conditions (energy setting, pulse mode, exposition time, medium, probe pressure) and subj ected to standard procedures for morphometric evaluation (Bioquant(TM) ). Tissue effects were described by the depth (d) and width (w) of the catered lesions, as well as the extension of the damage in the surrou nding tissue (s). Serial cuts of the exposed areas yielded 894 section s for morphometric analysis. Multivariate analysis of variance (MANOVA ) revealed a significant effect of laser energy (p [d] < 0. 002, p[w] < 0.05, p[s] < 0. 05), medium (p[d] < 0.03, p[w] < 0.001, p[s] < 0.04) , and exposition time (p[d] < 0.001, p[s] < 0.001) on the degree of ti ssue lesion. Similar effects were observed after EHL for spark energy (p[d] < 0.02, p[w] < 0.02), pulse mode (p[d] < 0.001, p[w] < 0.05, p[s ] < 0.001), medium (p[d] < 0.05), and probe pressure (p[d] < 0.001, p[ s] < 0.05). Tissue damage was significantly more pronounced after EHL than after LISL at comparable system settings. We conclude that tissue damage during intracorporal lithotripsy in the clinical situation can be assessed from in vitro experiences. By doing so, we feel that LISL may be safer than EHL in the therapeutic approach to gallstone diseas e.