Michael O. Murphy

Access for Endovascular Aneurysm Repair

Despite advancement in stent-graft technology, access-related problems continue to occur during endovascular repair of aortic aneurysms. Various techniques have been adopted to overcome difficult access situations, however. To survey these developments in arterial access, we performed a systematic literature review from 1994 through 2005 to identify relevant articles pertaining to endovascular access techniques and complications. Excessive iliac tortuosity, circumferential vessel wall calcification, significant occlusive disease, and small caliber vessels account for the majority of access problems, most of which are readily apparent with adequate baseline imaging. Even with careful preoperative assessment, however, some access problems may not be foreseen; nonetheless, the majority can be overcome using todays array of ancillary procedures, such as an iliac conduit, a brachiofemoral wire, or arterial reconstruction. Alternatively, other approach routes, such as the common carotid artery or direct aortic access, may be used to facilitate endovascular aneurysm repair.

Colonic epithelial apoptosis during conventional and endoluminal aortic surgery.

This study characterized the initial modes of colonic mucosal injury during aneurysm surgery and correlated these with proinflammatory cytokine release into the colonic and systemic circulations.

In Vivo Attenuation of Myointimal Hyperplasia Using Transforming Growth Factor-Beta3 in an Interposition Graft Model

Purpose: To examine if transforming growth factor-beta3 (TGFβ3) can attenuate the development of para-anastomotic myointimal hyperplasia in an animal model of small-diameter vascular graft failure. Methods: Under general anesthesia, 10 adult goats underwent bilateral polyurethane interposition graft insertion in the carotid position. Following completion of the anastomoses, each artery received adventitial infiltration of 50 ng of TGFβ3 around the anastomoses; a placebo was administered to the other side. Postoperatively, each animal received 150 mg of aspirin daily. The arteries were explanted, half at 6 weeks and the remaining 5 at 3 months, for histological examination. Results: Vessel wall thickness surrounding the anastomosis was reduced by 37% in TGFβ3-treated arteries compared to placebo at 6 weeks and 3 months, principally due to reduced smooth muscle cell proliferation. There was decreased overall luminal loss on angiography. Total collagen content was not significantly different between TGFβ3 and placebo sides. Further analysis for the subendothelial matrix component collagen type VIII showed decreased levels on the treated side. Total elastin content was reduced on the TGFβ3-treated side. Conclusion: Direct single-dose subadventitial infiltration of TGFβ3 following insertion of an interposition graft reduces SMC proliferation and elastin content. It would appear that TGFβ3 holds promise as a prophylaxis against the development of myointimal hyperplasia, the predominant cause of graft failure in peripheral bypass surgery.