Thrombus Formation Using Endovenous Lasers

Endovenous laser ablation is a commonly used, effective treatment of the incompetent great saphenous vein (GSV). Despite its efficacy, complications have been observed following the procedure, such as deep vein thrombosis (DVT) and pulmonary embolism (PE). Thermally induced thrombus formed during laser exposure in the vein lumen is a possible precursor to more serious side effects like DVT. Post-procedure thrombus extensions through the saphenofemoral junction (SFJ) have been observed. These experiments were performed to simulate thrombus formation during endovenous laser closure by measuring coagulum formation in in-vitro laser exposures in porcine blood and consequently investigate the role of procedure equipment in thrombus formation. Continuous wave (CW) 810, 940, 980, 1310 and 1470 nm lasers were tested along with microsecond pulsed wave 1064 nm Nd:YAG, 1320 nm Nd:YAG, and 2100 nm THC:YAG lasers. Standard fibers with diameters of 365, 550 and 600 μm as well as two prototype modified tip fibers were tested. The results of this study show that pulsed lasers with high peak power densities form less coagulum. Fiber specifications were found not to influence coagulum formation, and prototype modified tip fibers designed to prevent contact between the fiber tip and the vein wall did not eliminate coagulum formation.