Microembolization during endovascular and conventional aneurysm repair

Purpose: Endovascular aneurysm repair has been advocated as a ''minimally invasive'' alternative to conventional aneurysm surgery. However, because of manipulation within the aneurysm sac, endovascular techniques may result in massive microembolization. Methods: In this study lower limb microemboli were quantified in 29 patients undergoing conventional (11 straight and 7 bifurcated grafts) and endovascular aneurysm repair (8 aortoiliac, 1 straight, and 2 bifurcated grafts) by insonation of the superficial femoral artery with a 2 MHz Doppler probe. Emboli were detected as high-intensity, short-duration signals on the background Doppler trace. Differentiation of gaseous emboli from particulate emboli was achieved by calculation of the sample volume length (emboli velocityxduration=sample volume length) for each embolus (N=4927). Previous experiments had determined that a sample volume length <1.4 cm represented particulate embolization. Results: The number of gaseous, particulate, and total emboli were significantly greater in the endovascular group compared with the conventional group (P <0.05). Conclusions: These data demonstrate that peripheral microembolization is significantly higher during endovascular aneurysm repair than during conventional surgery. Methods to reduce embolization must be developed before endovascular aortic surgery is widely adopted.