Bifurcated drum occluder endograft for treatment of abdominal aortic aneurysm: An experimental study in dogs

PURPOSE: To evaluate a new, low profile, home-made, bifurcated drum occlude r endograft (BDOEG), designed for percutaneous, transcatheter treatment of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: AAA was created in 10 dogs with over-dilated Palmaz stents. To prevent back filling, the lumbar arteries, inferior mesenteric a rtery, and common internal iliac arteries were embolized. The BDOEG was con structed of a drum occluder device and two PTFE endografts. The drum device consisted of a modified Z stent with Dacron stretched across and held with in the ends of the stent, each with two 8 x 6-mm slits through which PTFE e ndografts were delivered. The PTFE endografts were 8 mm in diameter and 9.5 cm in length. Preloaded, the BDOEG was delivered through a 10-F sheath fro m both femoral arteries in a three-step procedure. All 10 animals were trea ted with BDOEG. Aortography was performed immediately, 6 weeks, and 12 week s after stent-graft placement. Five animals were killed at 6 weeks and five were killed at 3 months. Gross and histologic evaluation was performed. RESULTS: The infrarenal aortic diameters and both external iliac arteries r anged from 8.0 mm to 10.3 mm (mean, 9.4 mm +/- 0.6) and from 5.2 mm to 6.8 mm (mean, 5.8 mm +/- 0.5), respectively. Creation of the AAA was successful in all 10 dogs. AAA diameters ranged from 13.7 mm to 15.9 mm (mean, 14.9 m m +/- 0.7). Complete exclusion of the AAA was achieved immediately after BD OEG placement and aneurysms remained excluded without perigraft leak to the time of killing in all 10 animals. There was a high incidence of aortoilia c limb occlusion. Occlusion of 12 aortoiliac limbs (60%) caused by intimal hyperplasia at the distal end of the endografts in iliac arteries developed in nine animals (90%). In six animals (60%), one limb occluded and, in thr ee animals (30%), there was occlusion of both limbs. CONCLUSION: This study suggests a new approach for treatment of AAA. BDOEG use reduces sheath size for endograft delivery and may eliminate the need f or a surgical cut down on femoral arteries. Tapering of the iliac ends of e ndografts to the size of the artery will be needed to prevent distal intima l hyperplasia.