Bell-bottom aortoiliac endografts: an alternative that preserves pelvic blood flow

Dilated common iliac arteries that complicate aortic aneurysm stent grafting usually have been managed with endograft extension across the iliac artery bifurcation with internal iliac artery (IIA) occlusion. We studied 25 patients with significant common iliac artery (CIA) dilation treated with two methods: endograft extension across the iliac bifurcation or a new approach with a flared cuff within the CIA that preserves the IIA.

Of 86 patients with abdominal aortic aneurysm (AAA) who underwent bifurcated endovascular stent grafting (ESG), 25 (29.1%) had at least one dilated CIA. Two treatment groups had different methods of management of iliac artery dilation. Group 1 underwent ESG with straight extension across the iliac bifurcation and IIA coil embolization before the ESG procedure (n = 2) or simultaneously with ESG (n = 8). Group 2 underwent ESG with flared distal cuff (AneuRx, Medtronic AVE, Santa Rosa, Calif) contained within the CIA, the so-called "bell-bottom" procedure, thus preserving the IIA (n = 15). Iliac artery dimensions, operating room time, fluoroscopy time, and postoperative complications were prospectively gathered.

Two women and 23 men had mean diameters of AAA of 56.6 mm (range, 38 to 98 mm) and of CIA of 21.4 mm (range, 15 to 48 mm). The diameters of CIA treated with device extension into external iliac artery after IIA coil embolization in group 1 and with the bell-bottom procedure in group 2 were not different (mean CIA diameter, 19.9 mm; range, 15 to 26 mm; and mean, 19.1 mm; range, 15 to 24 mm; respectively). However, significantly lower operating room and catheter procedure times were found in group 2 compared with group 1 (137 versus 192 minutes; 58 versus 106 minutes; P =.02 and.02, respectively). No periprocedural type I endoleaks were found in either group. Nine patients in group 2 also had a second contralateral CIA aneurysm, and five patients (mean CIA diameter, 33.0 mm; range, 22 to 48 mm) underwent treatment with extension across the iliac artery bifurcation and IIA occlusion. Use of the bell-bottom procedure on the other side allowed preservation of one IIA. Four cases (mean diameter, 19.3 mm) also underwent contralateral bell-bottom procedure. Two of these group 2 patients had complications, with severe buttock claudication in one and distal embolism necessitating limb salvage bypass after preoperative coil embolization of the IIA in another.

Significant CIA ectasia or small aneurysm is often associated with AAA. In such cases, the bell-bottom procedure that preserves IIA circulation is a new alternative to the common practice of placement of endograft extensions across the iliac artery bifurcation in patients with at least one CIA diameter of less than 26 mm. Additional benefits include reduced total procedure time. Early technical success appears to justify continued use. However, long-term evaluation is necessary to determine durability because the risk of rupture as the result of potential expansion of the excluded iliac artery or late failure is unknown.