Enhanced occlusion of vessels combining retrievable, detachable coils as differential electrodes with percutaneous,...

The authors evaluate the feasibility to accelerate occlusion of high-velocity flow vessels by a combination of transcutaneous coil placement and application of radiofrequency current.

Piglets (n = 8) were anesthetized and acutely instrumented via cutdowns in both carotid and one brachial arteries. Two identical cylindrically 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 kept connected to the delivery wire, which is isolated from the surrounding tissue by the catheter. The first-placed system served as control, the contralateral coil was connected to a radiofrequency generator closing electrical circuit via an external indifferent electrode. Angiograms via the brachial artery demonstrated the adequate placement of the 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-minute intervals until occlusion was demonstrated. In 2 of 8 cases. 25 watts were applied continuously over 30 seconds. The coils were detached from the wire the catheters removed. Additional angiograms were performed after 5, 15, 45, and 60 minutes to show the patency of the control setting.

Complete occlusion was achieved in all cases after a maximum of three consecutive applications of current for 10 seconds. The control remained patent for a minimum of 45 minutes. On gross and histologic examination the arteries on both sides remained intact. Disruption and charring occurred only after continuous application of current over 30 seconds.

It is feasible to use detachable coils in conjunction with high-frequency electrocoagulation to promote coil fixation and accelerate occlusion of vessels with high blood flow.