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The aim of this study was to evaluate our early experience with the Corvita endoluminal graft for the treatment of a variety of arterial injuries. Ten patients with arterial pseudoaneurysms (8) or arteriovenous fistulas (2) due to arterial injuries were followed prospectively after undergoing treatment with the endovascular graft. Our results showed that the Corvita low-profile endoluminal graft can be successfully used to treat arterial injuries but that it sometimes requires the placement of additional stents in patients with tortuous or tapering vessels. These grafts are extremely useful for the safe treatment of difficult and high-risk patients. Further improvements in available endovascular grafts and good long-term results will be necessary before considering these grafts the best treatment available for most patients with significant arterial injuries.

Endovascular grafting is a technique that combines the use of intravascular stents and prosthetic grafts to fabricate devices with unique properties. The purpose of this study is to describe the use of endovascular graft technology in the treatment of failed or failing standard aortoiliofemoral reconstructions. Over a 15-month period five patients with limb-threatening ischemia and failed aortofemoral or iliofemoral reconstructions underwent successful placement of six endovascular grafts to revascularize seven severely ischemic lower extremities. Standard thin-walled 6 mm polytetrafluoroethylene grafts and Palmaz balloon-expandable stents were used to fashion each reconstruction. In addition to the primary endovascular grafts, three patients underwent immediate femoropopliteal bypasses to improve distal outflow and one patient had a femorofemoral bypass graft to restore circulation to the contralateral ischemic extremity. The ankle/brachial indices of all patients significantly improved after the procedure (from a mean of 0.32 to a mean of 0.75) and all grafts are patent to date (mean follow-up 10 months). There were no deaths or limb loss in this group of patients. These favorable results indicate that this minimally invasive approach, which permits a new arterial graft to be inserted through a remote access site, is a valuable method for providing unobstructed arterial inflow after aortoiliofemoral graft failure. This procedure may be particularly valuable when there are contraindications to the use of axillary arteries or the thoracic aorta as alternatives to complex reoperative abdominal aortic surgery.

Controversy continues as to whether percutaneous transluminal angioplasty (PTA) or surgical revision is the ideal modality for the treatment of failing grafts. This prompted a histopathologic analysis of failing human vein graft segments subjected to ex vivo balloon dilatation to define variables responsible for the discrepant results. Fifteen vein graft lesions from 14 patients with failing infrainguinal bypasses were recovered after surgical excision. Each graft lesion was focal and uniform in length (2.1 +/- 0.3 cm). Rings sectioned from adjacent regions of each vein graft lesion before and after balloon inflation were processed for histologic study, photomicrography, and image analysis. Angioplasty balloon size was selected on the basis of preoperative arteriograms. Graft lesions were divided into three groups based on lesion thickness and the degree of fibrosis and cellularity seen on sections stained with Masson's trichrome. The luminal area before angioplasty was not significantly different for the three groups (p0.2). Vein grafts with thick intimas (group 1) had significantly less luminal dilatation after angioplasty as compared with less thick intimal lesions (groups 2 and 3; p0.001). Those lesions with varying degrees of cellularity (groups 2 and 3) showed no significant differences in luminal diameter after angioplasty. However, the cellular lesions in group 2 consistently formed multiple intimal flaps that could produce PTA failures even with good luminal restoration. The varying histology of vein graft lesions and associated differences in intimal thickness and cellularity may be responsible for the inconsistent results following PTA. Estimates of wall thickness before angioplasty, particularly in the intimal area, may be helpful in evaluating which lesions might benefit most from PTA.