Infrared laser sealing of porcine vascular tissues using a 1,470nm diode laser: Preliminary in vivo studies

Introduction: Infrared (IR) lasers are being explored as an alternative to radiofrequency (RF) and ultrasonic (US) devices for rapid hemostasis with minimal collateral zones of thermal damage and tissue necrosis. Previously, a 1,470nm IR laser sealed and cut ex vivo porcine renal arteries of 1-8mm diameter in 2seconds, yielding burst pressures greater than 1,200mmHg and thermal coagulation zones less than 3mm. This preliminary study describes in vivo testing of a handheld laser probe in a porcine model. Methods: A handheld prototype with vessel/tissue clasping mechanism was tested on 73 blood vessels less than 6mm diameter using 1,470nm laser power of 35W for 1-5seconds. Device power settings, irradiation time, tissue type, vessel diameter, and histology sample number were recorded for each procedure. The probe was evaluated for hemostasis after sealing isolated and bundled arteriole/venous (A/V) vasculature of porcine abdomen and hind leg. Sealed vessel samples were collected for histological analysis of lateral thermal damage. Results: Hemostasis was achieved in 57 of 73 seals (78%). The probe consistently sealed vasculature in small bowel mesentery, mesometrium, and gastrosplenic and epiploic regions. Seal performance was less consistent on hind leg vasculature including saphenous arteries/bundles and femoral and iliac arteries. Collagen denaturation averaged 1.6±0.9mm in eight samples excised for histologic examination. Conclusions: A handheld laser probe sealed porcine vessels, in vivo. Further probe development and laser parameter optimization is necessary before infrared lasers may be evaluated as an alternative to RF and US vessel sealing devices.