Endograft limb occlusion and stenosis after ANCURE endovascular abdominal aneurysm repair.

OBJECTIVE

The purpose of this study was to define the incidence and treatment of endograft limb stenosis or occlusion (endograft limb dysfunction [ELD]) in a single center with the ANCURE unsupported bifurcated or aortouniiliac endograft by using intraoperative completion angiography and postoperative color duplex ultrasound scanning (CDU).

METHODS

Sixty-seven endografts (58 bifurcated, 9 uniiliac) were implanted between February 1996 and July 2000. Intraoperative completion aortography was performed in every patient. Postoperative assessment of the endograft consisted of CDU and computed tomography scanning and kidney, ureter and bladder radiographs within 7 days of implantation, at 3 and 6 months after the operation, and every 6 months thereafter.

RESULTS

At the time of endograft implantation, widely patent normal-appearing endograft limbs were revealed by means of the initial completion angiogram in 58 of 67 patients (group 1). ELD subsequently developed in seven of these 58 patients (13.4%). The results of the completion angiogram were not normal in the remaining nine patients (group 2), leading to the deployment of a self-expanding stent within the endograft limbs. The results of subsequent angiography were normal. No ELD has occurred in any patient in group 2 to date. The primary assisted patency rate at 30 months was 88% +/- 5.2% for group 1 versus 100% +/- 0% for group 2 (P = not significant, Log-rank test). Postoperative ELD occurred in seven patients (10.4%). Endovascular graft thrombosis occurred in three patients (3 endograft limbs). In each case, an endovascular approach was attempted; however, the guidewire would not traverse the occluded endovascular graft limb. Revascularization was accomplished by means of femorofemoral bypass grafting. Endovascular graft stenosis occurred in four patients (4 endograft limbs). Three patients with bifurcated endografts and limb stenosis who had no symptoms diagnosed by means of CDU were successfully treated by means of balloon angioplasty with self-expanding stent implantation, and the endograft limbs remained patent at 3, 5, and 26 months follow-up. The remaining patient who had an aortouniiliac endograft with recurrent severe stenoses underwent endograft explantation and aortobifemoral bypass grafting. The overall incidence of ELD during or after endovascular abdominal aortic aneurysm repair was 23.8% (16 of 67 patients).

CONCLUSION

Unsupported endografts are at risk for developing ELD. The use of stents for limb support at the time of the initial endograft implantation may prevent subsequent ELD and bears further study. Endograft limb occlusion usually presents with acute severe ischemic symptoms, and the failure of operative thrombectomy necessitates femorofemoral artery bypass grafting. Endograft limb stenosis is identified by means of CDU surveillance in the postoperative period. Prompt treatment with percutaneous transluminal angioplasty/stent yields satisfactory primary assisted patency. Intraoperative intravenous ultrasound scanning, oblique angiograms, pressure gradients, and completion angiography may be necessary to detect and treat ELD.