A new management for limb graft occlusion after endovascular aneurysm repair adding a vollmar ring stripper: the unclogging technique.

BACKGROUND

Lower extremity ischemia for limb thrombosis is a well-known adverse event after endovascular abdominal aortic aneurysm repair (EVAR), ranging from 2.6-7.4%. We report our experience in the management of graft limb occlusion that occurred in patients who underwent EVAR in our institution. In cases in which balloon catheter thrombectomy is not useful or is risky, it is important to take into consideration the use of a Vollmar ring stripper (Aesculap, San Jose, CA) to avoid dislodging or disrupting the sealing zones. This technique has taken from thromboendarterectomy the principle of detaching plaque from adventitia and transformed it in a less traumatic way for dissecting thromboses from endografts.

METHODS

Between September 1999 and December 2011, 608 patients underwent EVAR in our institution. In cases of severe claudication or critical ischemia, we tried to remove the thrombus using mild Fogarty balloon traction; in cases of progressive and old stratification, we added the Vollmar ring stripper. After recanalization, if there was a stenosis, an angioplasty was performed and in most patients an adequately size Cheatham platinum stent was positioned. If the endovascular approach failed, bypass procedures were considered.

RESULTS

In 608 patients over a mean follow-up time of 72 months, there were 23 cases of limb thrombosis. Fifteen of the 23 limb occlusions were identified within 6 months after aneurysm repair. The mean time to occlusion was 8.2 ± 4.3 months (range: 20 days-25 months). Presenting symptoms were mild to moderate claudication (Rutherford classification I) in 3 patients (13%), medium severe claudication (Rutherford classification IIA) in 18 patients (78.3%), and paresthesia and rest pain (Rutherford classification IIB) in 2 patients (8.7%; 1 of those patients had a loss of motor function). Four (17.4%) were stable during follow-up, and in 1 of these cases we tried thrombolysis without thrombosis resolution. In 13 (56.5%) cases, we performed balloon catheter thrombectomy with a LeMaitre over the wire embolectomy catheter (LeMaitre Vascular, Burlington, MA). In 8 of 13 (61.5%) patients with certain thrombosis characteristics, we decided to add to the balloon catheter a Vollmar ring stripper for mechanical catheter thrombectomy. In all 13 thrombectomy cases, blood flow was restored through the limb with the endograft itself. There were no episodes of graft dislocation, disruption of the sealing zones, or recurrences. In 5 (21.7%) cases, a femorofemoral crossover was performed, and in 1 (4.3%) case, an axillofemoral bypass was performed. During the follow-up period, 2 of the 5 femorofemoral crossovers closed after 6 and 8 months, respectively.

CONCLUSIONS

This unclogging technique, alone or associated with Vollmar ring stripper, proves to be simple, safe, and effective in the treatment of graft limb occlusion. Additional research will help confirm the role of Vollmar ring stripper.