“Preserving pelvic artery perfusion should be a goal during EVAR”

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Early experience with a device that allows the preservation of the hypogastric artery during endovascular treatment of iliac artery aneurysms shows that the endograft is safe and effective, with a high success rate and patency of over 90% at six months. Results with the new Iliac Branch Excluder were presented at the Vascular Annual Meeting (17–20 June, Chicago, USA).

Iliac artery aneurysms are relatively common, with 40% of patients with abdominal aortic aneurysms having an associated iliac artery aneurysm. Hypogastric artery sacrifice with traditional coil and cover techniques can result in buttock claudication, erectile dysfunction, colonic ischaemia and spinal cord injury, said Darren B Schneider, chief of Vascular and Endovascular Surgery, New York-Presbyterian, Weill Cornell Medical Center, New York, USA. “These have significant quality of life ramifications for our patients,” he noted.

A meta-analysis by Lin et al (Semin Vasc Surg 2009) that looked at occlusion of the hypogastric artery showed that buttock claudication occurs in 16–50% of patients after unilateral embolisation and up to 80% after bilateral embolisation. Schneider commented: “This may improve over several months but this is not always the case. Erectile dysfunction occurs in 17% of patients after unilateral occlusion and 24% after bilateral occlusion.”

Schneider spoke about the Gore Excluder Iliac Branch Endoprosthesis (Gore), a device that is intended to be used in endovascular aneurysm repair to preserve perfusion of the hypogastric arteries: “The Iliac Branch Endoprosthesis has been designed to be used as part of a modular system with the existing Excluder endovascular graft. It is the only complete iliac branch system with its own internal iliac component. It is delivered via femoral access, is relatively low-profile, with 16F for the iliac branch component and like the C3 Excluder it is repositionable with a two-stage deployment. The internal iliac component is 12F compatible, and can treat a range of internal iliac diameters from 6.5mm to 13.5mm. The deployment is hub-to-tip because of the direction it is introduced.” The Gore Excluder Iliac Branch Endoprosthesis is currently under investigation in the United States but is commercially available in other countries.

For the deployment of iliac branch component, Schneider explained, the system includes a removable guidewire tube for pre-cannulation of the internal iliac gate. In the first stage of deployment, the limb for the hypogastric artery is deployed; however, the limb that will be implanted into the external iliac artery remains constrained onto the catheter to help with the repositionability of the device. The second deployment is to fully deploy the device. He continued, “One of first steps is to establish cross-femoral through-wire access because the device is introduced over two wires—the aortic and the cross-femoral wires. Once you have performed the initial deployment, over the cross-femoral wire a 12F sheath is advanced around the aortic bifurcation and into the hypogastric artery gate. The hypogastric artery is catheterised, and the internal iliac component is used to extend that limb into the hypogastric artery. The repair is completed with an Excluder abdominal aortic aneurysm device and a bridging component between the Excluder abdominal device and the Excluder iliac branch endoprosthesis.

The study presented at the Vascular Annual Meeting, a prospective, multicentre trial (IBE 12–04) designed to evaluate the safety and effectiveness of the Iliac Branch Excluder for treatment of common iliac artery aneurysms, described the initial six-month results with the device. Schneider emphasised that the results were site reported data and not core lab adjudicated data, which were still being compiled.

In the study, 60 patients with common iliac artery aneurysms or aorto-iliac artery aneurysms were prospectively enrolled at 26 centres in the United States from 2013 to 2014. Additional 12 patients were enrolled in continued access. The primary effectiveness endpoints were freedom from patency and/or endoleak-related reinterventions and freedom from occlusion of device branches. The secondary effectiveness endpoint was freedom from new-onset buttock claudication. Schneider is the national principal investigator of the trial.

All patients underwent placement of a single Iliac Branch Endoprosthesis, and patients with bilateral common iliac artery aneurysms were allowed to be enrolled with prior staged coil embolisation and coverage of the contralateral internal iliac artery. Follow-up is ongoing and will include clinical examination and computed tomography imaging at one month, six months, 12 months, and yearly thereafter for five years.

In total 77 devices were implanted. All but one patient were male and the mean age was 69.3 years. Fifty nine per cent of patients had a unilateral iliac artery aneurysm. In terms of aneurysm size, the average maximum aortic diameter was 4.5cm and the average common iliac artery diameter was 3.89cm. Access was percutaneous in approximately 50% of patients but most patients were treated under general anaesthesia. The procedures took on average 148 minutes.

Technical success was 96.1% (successful deployment and patency of all components and freedom from type I or III endoleak). One patient did not receive the internal iliac component as inadvertently a traditional Excluder device was placed so that patient did not meet the technical success definition. There were two patients with endoleaks, one type Ib and one type III endoleak and there was not documentation at the end of the procedure that those had been eliminated but they were not present at 30 days. Median hospital stay was 1.9 day, and there was no mortality up to six months.

Site-reported 30-day (n=69) results showed no type I or III endoleaks, no migration, three (4.3%) occlusions of the internal iliac component, no claudication on the Iliac Brach Endoprosthesis treatment side and one reintervention but not on the branch device side. At six months (n=55), again no type I or III endoleaks, no migration, no additional internal iliac component occlusions, there was one reported claudiation (non-branch device side but this needs to be confirmed) and one additional reintervention (embolisation of a type II endoleak).

In conclusion, Schneider told delegates, “hypogastric artery sacrifice is not benign and preserving pelvic artery perfusion should be a goal during EVAR”. He added, “Preliminary results of this prospective study demonstrate that treatment of common iliac artery aneurysms with the Gore Iliac Branch Endoprosthesis is technically feasible with high rates of technical success and safety and more than 90% patency at six months. We are waiting for confirmation from final core lab adjudicated results.”

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