CHICAGO – A novel bifurcated covered stent graft limb that uses an off-the-shelf graft can treat large common iliac aneurysms, while preserving good pelvic blood flow.
The alternative endovascular approach has been performed on 15 patients since April 2011, with a success rate of 100%. Bilateral stent grafts were placed in four patients.
The all-male cohort has been able to maintain appropriate exercise tolerance and remains free from erectile dysfunction, pelvic ischemia, buttock claudication, and paralysis.
"These people do well," extremely well, Dr. Patrick Kelly said at the annual meeting of the Midwestern Vascular Surgical Society*.
Several iliac branch grafts are currently under investigation, including the Cook Zenith Branch iliac endovascular graft. They promise to preserve flow to the internal iliac artery and thus reduce the potential for ischemic sequelae resulting from iliac embolization. Depending on patient anatomy, however, the internal iliac may become jailed upon deployment of the main body graft, said Dr. Kelly of Sanford Health, Sioux Falls, S.D. The fenestrated systems are also limited by bridging stent technology and the relatively short bridging stent.
His alternative modified bifurcated limb divides the common iliac flow into the internal and external iliac arteries, while excluding the common iliac artery aneurysm.
"The pros are that it uses an off the shelf [graft], should be able to handle virtually any anatomy, can be used to treat either existing EVAR [endovascular aneurysm repair] or previous open repairs, and has multiple off-ramps, so you don’t jail yourself," he said. "The cons: It requires arm access – although I’m not sure that’s a con – and it requires three stents."
The bifurcated limb is created by sewing an 8-mm and 10-mm covered stent graft to the distal end of a standard 16 x 20 x 82-mm stent graft limb. The distal ends of both the 8-mm and 10-mm grafts are left free, allowing flexibility and easier selection of the internal iliac artery, he said.
Once the graft is resheathed using a spiral wire technique, a traditional infrarenal abdominal aneurysm repair is performed. In order to exclude the common iliac aneurysm, the graft is oriented with the 8-mm limb toward the internal iliac and with the distal end of the 8-mm limb being deployed 2-3 cm above the origin of the internal iliac artery. The internal iliac artery is selected from an arm approach, through the 8-mm limb of the bifurcated stent graft limb.
Angiograms are performed and a 3-cm covered, self-expanding bridge stent graft is deployed. The 10-mm limb is used to extend the graft into the external iliac, thus completing exclusion of the common iliac aneurysm, while preserving both the internal and external iliac arteries, Dr. Kelly said.
Thus far, occlusion of the external iliac artery has been reported in one patient, and there were no recurring endoleaks. There was a type-3 endoleak between the main body and bridging stent that was visible on diagnostic angiography, but it resolved after being reballooned and patent flow was established upon completion angiography, Dr. Kelly explained. There was also a retrograde fill that was fixed 1 year postoperatively by extending the limb to obtain a healthy seal.
The average patient age was 65.4 years (range, 46-87 years); fluoroscopy time, 46 minutes (range, 29-91 minutes); and average length of stay 3.1 days (range, 1-9 days).
This compares with an average hospital stay of 4-7 days for the tried-and-true method of open aneurysm repair, which has bleeding rates of 30% or more, colonic ischemia in 20%-30%, and paraplegia in 2%-3%, Dr. Kelly noted.
Dr. Rebecca Kelso of the Cleveland Clinic, who comoderated the session, was enthusiastic about the novel approach.
"The potential for it is quite significant, because the other main competitive device he mentioned that’s on the market still has anatomic limitations for use," she said in an interview. "So if he has something that can be used in any patient, no matter what the circumstances, well then that has significant implications for being available commercially for everyone."
Fellow moderator Dr. Patrick J. Geraghty of Washington University, St. Louis, remarked that while the approach uses a standardized graft, it is somewhat tailored since the length and the diameter of the Bivon grafts extending into the external and internal iliac arteries can be chosen separately. That said, the one-size-fits-all approach is particularly appealing because it could simplify treatment planning and reduce treatment delays.
"If you have a patient who is symptomatic and you have an off-the-shelf component, you could potentially treat them within the next 24 hours," he said in an interview. "The current turnaround time for the fenestrated system is about a month or so, so it would shorten treatment delays and might lead to a broader application of the technology."