Conformability of GORE Excluder Iliac Branch Endoprosthesis and COOK Zenith Bifurcated Iliac Side Branched Iliac Stent Grafts.

BACKGROUND: Forty percent of the abdominal aortic aneurysms present an extension to the iliac axes. The access to a distal neck requiring an embolization of the internal iliac artery (IIA) may cause buttock claudication, colic ischemia, perineal necrosis, erectile dysfunction, and spinal cord ischemia. The aim of the branched iliac stent grafts is to preserve pelvic vascularization while adapting to the constraints of arterial tortuosity which generate type Ib endoleaks, plications, and limb thromboses. The objective was to analyze and compare the in vivo anatomical conformability of the Gore Excluder® Iliac Branch Endoprosthesis (IBE) and the Zenith Bifurcated Iliac Side® (ZBIS) Cook Iliac Endovascular Device branched stent grafts.

METHODS: This was a monocentric retrospective therapeutic study including 13 IBE and 9 ZBIS stent grafts. Three indices of tortuosity were measured with EndoSize: common iliac artery, pelvic artery index (PAI), and the double iliac sign (DIS). The centerline lengths of the iliac axes and the iliac axis and the IIA were measured by 2 different operators as a blind fashion.

RESULTS: The interoperator correlation of the measurements was r = 0.841 (P < 0.0001). Twenty-two patients had a high iliac tortuosity: PAI ≥ 1.14 (mean PAI 1.43 [1.16-2.09]). The IBE stent graft modified neither the ipsilateral length nor tortuosity of the common iliac axis or the PAI (P ≤ 0.17, P ≤ 0.16, and P ≤ 0.23, respectively). The ZBIS stent graft significantly modified (P ≤ 0.02) the length and the tortuosity measured by the PAI compared with the IBE group (P ≤ 0.02). The use of IBE or ZBIS did not modify the postoperative length of the IIA (P ≤ 0.34). Three patients of the IBE group presented one DIS. Postoperatively, they did not present any DIS without significant modification of the postoperative PAI (P ≤ 0.07).

CONCLUSIONS: In patients with a severe iliac tortuosity, the IBE Gore branched iliac stent graft is more conformable than the ZBIS Cook. IBE, more conformable with the anatomy of the patient, could thus make it possible to decrease the incidence of distal endoleaks without increasing the risk of limb thrombosis related to the anatomical constraints.