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.

The incidence and natural history of type I and II endoleak: a 5-year follow-up assessment with color duplex ultrasound scan.

PURPOSE: The purpose of this study was the demonstration of the value of color duplex ultrasound (CDU) scanning in the detection of type I endoleak (T1EL) and type II endoleak (T2EL), the correlation of Doppler scan waveform pattern to endoleak persistence or seal, and the description of the natural history of endoleak. METHODS: The study was a retrospective review of 83 patients who underwent periodic CDU scan and computed tomographic (CT) scan surveillance of the endograft and aneurysm sac after insertion of an aortic endograft for abdominal aortic aneurysm (AAA). Forty-one patients (49%) with an endoleak at anytime in the follow-up period form the basis of this report. RESULTS: T1EL was detected in all five patients with CDU and CT scans. T2EL was detected in 36 patients with CDU scan as compared with 18 patients with CT scan. With CT scan, endoleak was not detected when CDU scan showed no endoleak. Conversely, all CT scan--detected endoleaks were found with CDU scanning. The T2EL source artery was identified with CT scan in seven patients, whereas the source was identified in all 36 patients with CDU scan. Endoleak source did not correlate with outcome (seal or persistence). However, a to/fro Doppler scan waveform pattern was associated with spontaneous T2EL seal in seven of 12 patients, and a monophasic or biphasic waveform was associated with endoleak persistence in 14 of 17 patients (P =.023, with chi(2) test). Thirteen of 36 T2ELs underwent spontaneous seal by 6.2 +/- 2.8 months. T2ELs without increasing AAA diameter were observed. Eight patients with persistent T2EL present for more than 12 months did not undergo treatment. However, two patients underwent T2EL obliteration with coils because of AAA sac enlargement. T1EL of the distal attachment site was the initial endoleak identified in five patients, but seven patients harboring T2ELs had subsequent T1ELs develop. For the entire 83 patients, the combined T1EL and T2EL prevalence rate was 20% of patients at a 6-month follow-up period, but this rate increased to 50% after 24 months. The incidence rate of newly detected endoleaks and of spontaneous sealing was 24.4% at 12 months and 12.5% in longer-term follow-up period. CONCLUSION: CDU scan is effective in the identification of the type of endoleak, the delineation of the vessel involved, and the hemodynamic information not available with any other testing method. Endoleaks have a dynamic natural history characterized by a variable onset with changing branch vessel involvement and spectral flow patterns. Periodic long-term endograft surveillance with CDU scanning is necessary for following existing endoleaks and for detecting new ones. Corroboration of these findings in larger multicenter prospective trials will be needed to determine whether CDU scan analysis of endoleaks would be predictive of long-term success in endovascular AAA repair.