The use of branched endovascular devices requires the bridging of the target vessels with covered stents for excluding successfully aortic aneurysms. While the stent-graft designs and the procedural steps have been standardized over the years, covered stents are often used off-label and the materials choices are left to implanting physician preference and personal experience. At present, only few studies have been published evaluating the different types of covered stent used during complex aortic procedures. The aim of this study is to present the short and midterm results of a new self-expanding covered stented mated with off-the-shelf and custom-made branched endografts.
A physician-initiated, multicenter, ambispective, observational registry of patients undergoing aortic procedures employing the use of the Bard Covera Plus covered self-expandable stents (Tempe, Arizona, USA) was designed (ClinicalTrials.gov Identifier: NCT04598802) to evaluate the peri-operative and short-, mid- and long-term outcomes of the covered stents for the treatment of atherosclerotic aorto-iliac aneurysm in combination with a branched endograft. The preoperative risk factors and the outcomes were classified according to the new SVS reporting standards.
Two hundred seventy-seven patients (median age, 76 years; 79% males) in 24 centers underwent endovascular aneurysm exclusion with a Bard Covera Plus covered stent combined with a branched endograft. The demographics of the cohort are listed in Table I. A total of 694 target vessels were treated, of which 144 celiac trunks (CT), 185 superior mesenteric arteries (SMA), 301 renal arteries (RA), 53 hypogastric arteries (HA), three common hepatic arteries, two inferior mesenteric arteries, one splenic artery, three common iliac arteries and two external iliac arteries. Vessel's characteristics and procedural details are shown in Table II. The Covera stent were used with an off-the-shelf graft in 543 cases and a custom-made graft in 149 cases. Five hundred thirty-seven grafts were from Cook (Bloomington, IN, USA), 153 from JOTEC® (Jotec GmbH®, Hechingen, Germany) and 2 from GORE® (W. L. Gore and Associates, Flagstaff, AZ, USA). The median operative time was 271 minutes, median dose area product (DAP) was 278 Gycm2, median contrast medium used was 200 ml and the median fluoroscopy time was 81 minutes. A final cone beam computed tomography angiography (CTA) was used in 144 vessels (21%). Six hundred twenty-two vessels (90%) were branched from an upper extremity access and 72 (10%) from a femoral access. Thirty-seven percent of implanted stent were post-dilated and 301 adjunctive stents (43%) were deployed, of which 115 (38%) proximal, 63 (21%) intrastent and 123 (41%) distal.
Perioperative technical bridging success was 98%. The reported causes of technical failure were two cases of endoleak I/III, one case of vessel occlusion and four cases of deployment mechanism failure which required implantation of either a new Covera Plus or a different bridging stent. Eight patients (3%) died in the perioperative period. Follow up was available for 605 vessels (87%) at a median of 23 months. Follow up was performed by CTA for 409 (68%) vessels and by duplex ultrasound for 83 (14%) vessels. Primary patency rates at one year and two years are 98% (334/341) and 97% (249/256), respectively. (Figure 1) A branch instability was reported in 2% of cases : two cases stent angioplasty (CT and SMA) for a type IC endoleak, nine cases of stent occlusion (one CT, one SMA, one RRA and six LRA). Four of the occluded renal arteries were treated by thromboaspiration, three of which successfully.
Forty-seven (8%) patients died during follow up, nine (4%) of which due to aortic-related causes.
The new self-expanding covered Bard Covera Plus stent mated with branched endografts proved to be safe and feasible with high technical procedural success rates. Short- and mid-term follow-up observed low rates of branch instability. Larger follow-up data are needed.