ENHANCED OCCLUSION OF VESSELS COMBINING RETRIEVABLE, DETACHABLE COILSAS DIFFERENTIAL ELECTRODES WITH PERCUTANEOUS, INTRAVASCULAR RADIOFREQUENCY ELECTROCOAGULATION - AN EXPERIMENTAL-STUDY

RATIONALE AND OBJECTIVES. The authors evaluate the feasibility to acce lerate occlusion of high-velocity flow vessels by a combination of tra nscutaneous coil placement and application of radiofrequency current. METHODS. Piglets (n = 8) were anesthetized and acutely instrumented vi a cutdowns in both carotid and one brachial arteries, Two identical cy lindrically shaped coils (length, 3 mm; outer diameter, 2.4 mm; inner diameter, 1.4 mm) were mounted on titanium-nickel core wire and placed via 3-French Nylon catheters in both iliac arteries, The coils were k ept connected to the delivery wire, which is isolated from the surroun ding tissue by the catheter, The first-placed system served as control , the contralateral coil was connected to a radiofrequency generator c losing electrical circuit via an external indifferent electrode, Angio grams via the brachial artery demonstrated the adequate placement of t he coils and the status of the iliac arteries without and with current application, In 6 of the 8 cases, 25 watts of radiofrequency current were applied repeatedly over 10 seconds to the coil on one side at 4-m inute intervals until occlusion was demonstrated, In 2 of 8 cases, 25 watts were applied continuously over 30 seconds, The coils were detach ed from the wire and the catheters removed, Additional angiograms were performed after 5, 15, 45, and 60 minutes to show the patency of the control setting. RESULTS. Complete occlusion was achieved in all cases after a maximum of three consecutive applications of current for 10 s econds, The control remained patent for a minimum of 45 minutes, On gr oss and histologic examination the arteries on both sides remained int act, Disruption and charring occurred only after continuous applicatio n of current over 30 seconds. CONCLUSIONS. It is feasible to use detac hable coils in conjunction with high-frequency electrocoagulation to p romote coil fixation and accelerate occlusion of vessels with high blo od flow.