Undoubtedly the most common complication with HA occlusion is buttock claudication (BC), occurring within 2–55 % (on average 25 %) of patients immediately after occlusion. Potential reasons accounting for the wide variations for the incidence of BC include publication bias, patient factors, and differences in procedural technique.

To better evaluate pelvic circulation in a vascular surgery cohort, Iliopoulos et al. examined HA stump pressures in patients undergoing open revascularization for aortoiliac aneurysmal or occlusive disease [23]. They identified the ipsilateral external iliac and femoral circumflex arteries as more crucial to the maintenance of pelvic circulation than the contralateral HA. Indeed Yano et al. reviewed preoperative angiograms in patients developing pelvic ischemia after HA occlusion [4]. They identified a contralateral HA stenosis and absence of ipsilateral circumflex femoral collaterals as two consistent radiographic findings. Similarly Lin et al. identified a stenotic (defined as greater than 50 %) profunda femoral artery in all patients who developed ischemic symptoms after HC occlusion [7].

Several studies support the fact that the immediate symptoms of BC are not permanent, but rather improve and occasionally resolve over time. Karch et al. reported BC improvement in 43 % of patients [3]. In a larger series, Farahmand demonstrated a 33 % incidence in persistent BC at 6 months follow up [13]. This has been shown in other series highlighting resolution or improvement in varying numbers of patients postoperatively [4–6, 9–12, 14, 19].

Intuitively coil embolization of both HAs would be expected to increase the rate of severity of ischemic complications. This phenomenon, however, has not definitively been proven in the literature. Lin et al. demonstrated lower penile-brachial indices in patients undergoing bilateral HA occlusion compared with those undergoing unilateral HA occlusion, but were unable to demonstrate a significant difference in the incidence of pelvic ischemic complications between the two groups [7]. Mehta et al. reviewed outcomes on 32 patients undergoing bilateral HA occlusion in a staged fashion prior to EVAR, noting a similar incidence of BC and ED as that of other series [10]. In contrast, Rayt et al. demonstrated a higher incidence of both BC and ED in patients undergoing bilateral HA occlusion compared to patients undergoing unilateral occlusion [14].

Technical factors also affect the incidence of pelvic ischemic symptoms. Kritpracha et al. examined the effect of the location of coil placement on pelvic ischemic symptoms [8]. In patients whom coils were placed within the main trunk of the HA (termed proximal embolization), rates of BC and ED were lower compared to patients in whom coils were placed into distal branches of the HA (termed distal embolization). This trend was supported by Bratby et al. as well [15]. Other groups favor the use of endovascular embolization plugs over coils, in order to facilitate proximal HA trunk occlusion and minimize inadvertent distal embolization [19]. This technique is only viable in cases of non-aneurysmal HA, otherwise all branches of the HA require coil embolization to successfully exclude flow from a HA aneurysm.

In order to study the effect of timing of HA occlusion on ischemic outcomes, Lee et al. compared a small group of patients undergoing concomitant HA occlusion and EVAR with those undergoing staged (1 week or greater) HA occlusion followed by EVAR [11]. Despite showing the safety in simultaneous embolization and EVAR, the authors demonstrated higher rates of BC in these patients compared to those that underwent staged repair. In contrast, Bratby was unable to demonstrate a statistically significant difference in rates of pelvic ischemia between patients undergoing simultaneous versus staged HA occlusion [15]. Little data exists on recommending the appropriate time (if any) to delay aneurysm repair after HA occlusion. Some groups report a delay of only 1 day prior to EVAR for unilateral HA occlusion, and a delay of 3 months in those undergoing staged bilateral HA occlusions [13].

Erectile dysfunction (ED) has been poorly studied in the setting of HA occlusion, having been evaluated as an endpoint in less than half of the studies reviewed in this chapter. Like BC, ED is reported to occur in varying numbers of patients undergoing HA occlusion (between 2 and 40 % of patients, Table 6.2). Complicating matters is the high frequency (nearly 30 %) of pre-existing sexual dysfunction in this patient population [10]. One study was able to correlate the occurrence of postoperative ED with a decrease in postoperative penile-brachial indices [7]. Fortunately more serious complications, such as ischemic colitis, gluteal necrosis, and spinal cord ischemia occur far less frequently. Combined they comprise less than 2 % of all ischemic complications (Table 6.2).

Recently several groups have challenged the notion that HA embolization is required prior to stent graft coverage to prevent a type II endoleak, highlighting the benefits of decreased radiation eposure, operative time, contrast use, and cost. Papazoglou et al. published their series on 112 patients in which the HA was not embolized prior to coverage with a stent graft [18]. The decision not to preemptively embolize was based upon the presence of an adequate seal zone in the EIA or a small (<5 mm) HA orifice. In fact the total incidence of type II endoleak occurrence (related to the covered HA) was reported at 6.2 %. Half of these resolved during follow up and the remaining did not result in aneurysm sac enlargement and, thus, were observed. Similarly Stokmans et al. published their series of 32 patients undergoing stent graft coverage of the HA without coil embolization [21]. They reported no rates of type II endoleaks related to the covered HA, and similar rates of pelvic ischemia as other groups.

Despite the large of prevalence of BC subsequent to HA occlusion, the severity of BC and its impact on a patient’s quality of life has not been extensively studied to date. Several authors have attempted to grade the disability caused by BC via subjective descriptions such as “severe” or “life-style limiting” [3, 13]. Two studies attempted to quantify the disability associated with BC using telephone interviews, demonstrating inferior scores in patients with BC compared with those without symptoms [5, 9]. In a well-designed review of patients undergoing HA occlusion prior to stent graft coverage, Jean-Baptiste et al. prospectively evaluated patients using a previously validated assessment tool (the Walking Impairment Questionnaire) to quantify the degree of buttock claudication and its subsequent effects on quality of life [22]. They demonstrated lower quality of life scores in patients who develop persistent BC, in comparison to patients who either 1) did not develop BC or 2) had resolution of immediate postoperative BC. Their study was limited by the lack of preoperative quality of life scores.