Is Hypogastric Artery Embolization during Endovascular Aortoiliac Aneurysm Repair (EVAR) Innocuous and Useful?

Introduction

We hypothesized that the coverage of the hypogastric artery with a stent-graft causes an occlusion of the artery in its proximal segment, allowing collateral network formation in distal segments of the artery. In contrast, hypogastric embolisation may cause the formation of microthrombi that tend to disseminate leading to embolic occlusion of secondary branches and collaterals. This phenomenon worsens pelvic ischemia.

To answer this question we compared two groups of patients with aortoiliac aneurysms treated with or without coil embolization to assess 1) The occurrence and evolution of buttock ischemia and 2) the effect on endoleak.

Materials/Methods

Between October 1995 and January 2007, 147 out of 598 EVAR patients (24.6%) required occlusion of one or both hypogastric arteries. 101 were available for over one year of follow-up. Group A included 76 patients (75%) who underwent coil embolization before EVAR and group B 25 patients (25%) who had their hypogastric artery covered by the sole limb of the stent.

Patient demographics, aneurysm characteristics, operative details, immediate and long term clinical outcomes, and CT-scan evaluation were stored prospectively in a specific data base and analyzed retrospectively.

Results

They were 96 males (95%). Mean age was 72.1±9.5 years. One month postoperatively, 51 patients (50.0%) suffered from buttock claudication. After six months, 34 patients were still disabled (34%), 32 in Group A (42%) and 2 in Group B (8%) (p=0.001). Post-operative sexual dysfunction occurred in 19 (19.6%) without statistical difference between the two groups.

Type 2 endoleaks occurred in 12 patients (16.0%) in group A and 4 patients (16.0%) in group B (p=1). Endoleak from the hypogastric artery occurred in one patient in each group.

Univariate analysis showed that predictive factors of long term (over six months) buttock claudication were embolization (p<0.001), younger age (p<0.03), coronary disease (p=0.06) and left ventricular dysfunction (p<0.01). The logistic regression analysis showed that buttock claudication was independently associated with embolization OR=9.1[95%CI=1.9-44] and left ventricular dysfunction OR=4.1[95%CI=1.3-12.7].

Conclusions

Coil embolization of hypogastric artery during EVAR is not an innocuous procedure and may not reduce the rate of type II endoleak.

Keywords: Abdominal aortic aneurysm, Hypogastric embolization, Endovascular procedure, Buttock claudication