Effect of iliac tortuosity on outcomes after iliac branch procedures

To report a two-centers evaluation of the effects of iliac axis tortuosity on iliac branch device (IBD) results.

From 2015 to 2021, all IBD procedures performed at two European centers were analyzed retrospectively. The preoperative pelvic tortuosity index (PTI), external tortuosity index (ETI), and double iliac sign (DIS) were assessed for each iliac axis submitted to IBD. The primary endpoints were technical success, early and mid-term IBD complications (occlusion, stenosis, endoleaks [ELs]) and reinterventions, and the association with the PTI, ETI, and DIS. The 30-day mortality, survival, freedom from complications and freedom from reinterventions (FFR) were the secondary endpoints.

During the study period, 224 patients had undergone 256 IBD procedures for 165 (64.5%) aortoiliac aneurysms, 44 (17.2%) isolated iliac aneurysms, 11 (4.3%) abdominal aortic aneurysms with a short iliac landing zone, and 36 (14.1%) type Ib ELs. IBD was planned with endovascular aortic aneurysm repair for 158 (61.7%), fenestrated/branched endovascular aortic aneurysm repair for 45 (7.6%), and isolated for 53 (20.7%) cases. Technical success and 30-day mortality were 99.2% (254 of 256) and 0.9% (2 of 224), respectively. A PTI >1.4, an ETI >1.7, and the DIS were tested to identify the risk factors for the endpoints. No ELs and 9 (3.5%) IBD occlusions, requiring five reinterventions (2%), had occurred within 30 days. No association with the PTI, ETI, or DIS was identified; IBD oversizing of ≥25% on the external iliac artery was independently related to occlusion (odds ratio, 4.3; 95% confidence interval [CI], 1-18.1; P = .045). The mean follow-up was 31 ± 27 months, with 11 IBD occlusions, 14 ELs, and 21 reinterventions. At 1, 3, and 5 years of follow-up survival, IBD patency, and FFR were 95%, 89%, and 80%; 93%, 91%, and 90%; and 93%, 89%, and 83%, respectively. The risk factors for overall complications (n = 34; 13.3%) and reinterventions (n = 26; 10.2%) were an ETI >1.7 (P = .037 and P = .019), a PTI >1.4 (P = .016 and P = .012), and a type Ib EL as the indication (P = .025 and P = .001), respectively. Cox regression confirmed PTI >1.4 as an independent predictor of overall complications and reinterventions (hazard ratio [HR], 2.3; 95% CI, 1.1-4.4; P = .018; and HR, 3 95% CI, 1.3-6.8; P = .018, respectively) and ETI >1.7 as an independent risk factor for ELs (HR 6; 95% CI, 2.1-17.5; P = .001). The freedom from complications and FFR were significantly lower with a PTI >1.4 at 3 years (73% vs 92% [log-rank P = .01] and 77% vs 93% [log-rank P = .001], respectively).

We found IBDs to be safe and effective in the treatment of aortoiliac aneurysms. Early complications are uncommon and related to endograft oversizing rather than anatomic characteristics in the present study. Iliac tortuosity is a risk factor for overall complications and reinterventions, in particular for IBD-related ELs.