CASE 1072 Published on 14.08.2001

Distal limb migration after endovascular AAA stent-grafting treated by percutaneous covered stent placement.

Section

Interventional radiology

Case Type

Clinical Cases

Authors

L Bouchard, X Kos, P Otal, F Joffre, H Rousseau

Patient

73 years, male

Categories
No Area of Interest ; Imaging Technique CT, CT
Clinical History
73 years-old male treated for AAA by endovascular stent grafting presented for a left limb claudication at 18 months follow-up. Color Doppler ultrasound, CT-scan and angiography were performed
Imaging Findings
A 73 years-old man with many cardiovascular risk factors successfully treated for a 60 mm abdominal aortic aneurysm (AAA) by endovascular bifurcated stent-grafting (Vanguard I, Boston Scientific) presented for a left-sided claudication at 18-month follow-up. A color Doppler sonogram revealed a revascularization of the AAA, which was confirmed by CT-scan and aortography. This was due to a distal migration of the left iliac graft branch in the aneurysmal sac. Initially, a 15 mm overlap between the iliac branch and the main device was allowed. This mid-term complication was successfully percutaneously treated by a 12 mm by 60 mm stent-graft (Passager, Meadox) via a left femoral percutaneous approach. Control aortogram demonstrated a patent left iliac branch with complete AAA exclusion. To date (3 and a half year CT-scan follow-up) the AAA remains completely excluded with a stable 60 mm diameter but with a longitudinal retraction with secondary iliac branch tortuosity.
Discussion
Endovascular stent-grafting for AAA is not infrequently associated with complications. Some of these complications can be dramatic like peroperative displacement of the entire stent-graft or visceral artery covering and thrombosis. Other are self-limited like femoral access site hematoma, fever or distal embolization. Technical failure is defined as incomplete AAA exclusion secondary to leakage which is classified as follows: Endoleak Type 1 is an incomplete proximal or distal sealing; Type 2 is a retrograde blood flow to the aneurysm via patent arteries, the lumbar arteries per example; Type 3, as in our case, is a sealing problem between two parts of the device; Type 4 is related to the porosity of the graft material. Type 3 endoleaks can be explained by AAA retraction after complete exclusion. The lack of compliance between stent-graft and aortoiliac anatomy after exclusion probably explains iliac dislocation. This risk can be minimized by sufficient overlapping of connections and good proximal and distal neck covering. Vanguard stent-grafts are supported, bifurcated, self expandable devices, made of a frame of Nitinol covered by a thin Dacron graft material and had undergone extensive transformation since their inception and are now at the third generation. A first generation Vanguard stent-graft was implanted in our patient. This model is now clearly associated with high incidence of late graft failure, including fabric erosion, limb dislocation and thrombosis. An improved model (third generation Vanguard III) was developed to address these problems but since its introduction in European trials, some Vanguard I and II have been found to have separation of the upper two stent rows from the body of the device and as the Vanguard III was not specifically addressed for this problem, its use has been put on hold. This case stresses the importance of stent-graft follow-up as mid and long-term complications can occur and also the role of endovascular techniques as an alternative to surgical treatment.
Differential Diagnosis List
Type 3 endoleak secondary to distal iliac limb migration of a bifurcated abdominal aortic stent-graft treated by endovascular means.
Final Diagnosis
Type 3 endoleak secondary to distal iliac limb migration of a bifurcated abdominal aortic stent-graft treated by endovascular means.
Case information
URL: https://www.eurorad.org/case/1072
DOI: 10.1594/EURORAD/CASE.1072
ISSN: 1563-4086

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