Assessment of fenestrated Anaconda stent graft design by numerical simulation: Results of a European prospective multicenter study.

OBJECTIVE: A crucial step in designing fenestrated stent grafts for treatment of complex aortic abdominal aneurysms is the accurate positioning of the fenestrations. The deployment of a fenestrated stent graft prototype in a patient-specific rigid aortic model can be used for design verification in vitro, but is time and human resources consuming. Numerical simulation (NS) of fenestrated stent graft deployment using the finite element analysis has recently been developed; the aim of this study was to compare the accuracy of fenestration positioning by NS and in vitro. METHODS: All consecutive cases of complex aortic abdominal aneurysm treated with the Fenestrated Anaconda (Terumo Aortic) in six European centers were included in a prospective, observational study. To compare fenestration positioning, the distance from the center of the fenestration to the proximal end of the stent graft (L) and the angular distance from the 0° position (C) were measured and compared between in vitro testing (L1, C1) and NS (L2, C2). The primary hypothesis was that ΔL (|L2 - L1|) and ΔC (|C2 - C1|) would be 2.5 or less mm in more than 80% of the cases. The duration of both processes was also compared. RESULTS: Between May 2018 and January 2019, 50 patients with complex aortic abdominal aneurysms received a fenestrated stent graft with a total of 176 fenestrations. The ΔL and ΔC was 2.5 mm or less for 173 (98%) and 174 (99%) fenestrations, respectively. The NS process duration was significantly shorter than the in vitro (2.1 days [range, 1.0-5.2 days] vs 20.6 days [range, 9-82 days]; P < .001). CONCLUSIONS: Positioning of fenestrations using NS is as accurate as in vitro and could significantly decrease delivery time of fenestrated stent grafts.

Assessment of Pull-out Forces in TEVAR and ANACONDA FEVAR Combination and Early Clinical Results: Creation of a Proximal Landing Zone for FEVAR in Patients with Extent I and Extent IV TAAAs.

BACKGROUND: Although recent data on the treatment of thoracoabdominal aortic aneurysms (TAAAs) are promising, in some cases, the paravisceral segment of the aorta may not be suitable for a branched endograft due to space restrictions. A combination of a fenestrated aneurysm repair (FEVAR) with a thoracic aneurysm repair (TEVAR) may represent a feasible treatment option. The current investigation was performed to assess the stability of a fenestrated Anaconda device implanted into a set of thoracic endografts from different manufacturers. We then assessed our clinical results with the FEVAR/TEVAR combination. METHODS: Pull-out forces were measured in vitro after docking a fenestrated Anaconda graft within the distal end of different TEVAR devices. Anaconda devices were implanted in 28- or 30-mm thoracic tube grafts (oversizing of at least 2 mm: 13.3-21.4; minimum overlap of 15 mm). Continuously increasing longitudinal pull forces of up to 100 N were applied on an Instron Tensile Tester. Initial break point and damage to the endografts were documented. Clinical results of patients treated with such an FEVAR/TEVAR combination at our institution are presented as a second part of this study. RESULTS: Median pull-out forces ranged from 2.38 N to 55.0 N. The highest stability was achieved with 34-mm Anaconda devices in 28-mm thoracic tube grafts. Grafts with either thinner Dacron material or those featuring a polytetrafluorethylene membrane seemed especially vulnerable to punctures and tears caused by the downward-looking hooks of the Anaconda device. Between April 1, 2013 and December 31, 2018, in 28 of 172 patients treated with a fenestrated Anaconda device, prior implantation of a thoracic tube graft was necessary to create a sufficient proximal landing zone. In 25 cases (89.3%), the aneurysm was successfully treated. Although the 30-day reintervention rate in this subgroup was relatively high at 28.6%, none of these was due to a failure of the FEVAR/TEVAR combination. Upon an average follow-up of 15 months, no failure of the graft connection and no type III endoleak due to membrane damage were observed. CONCLUSIONS: The combination of a thoracic tube graft and a fenestrated Anaconda device is a viable option for the treatment of patients with Extent I or IV TAAAs with no adequate landing zone above the celiac trunk. Although pull-out testing has shown good stability with most assessed grafts, the thoracic devices with thicker Dacron membranes seemed to be especially suitable.

Successful percutaneous access for endovascular aneurysm repair is significantly cheaper than femoral cutdown in a prospective randomized trial.

OBJECTIVE: Because of its minimally invasive nature, percutaneous femoral access for endovascular aneurysm repair (pEVAR) is currently undergoing rapid popularization. Compared with surgical cutdown for femoral access (cEVAR), it offers the advantage of faster recovery after surgery as well as a reduction in wound complications. Despite proposed advantages, the method is largely considered uneconomical because of its reliance on costly closure devices. METHODS: There were 50 patients undergoing EVAR who were enrolled in this randomized prospective single-center trial. Each patient randomly received percutaneous access in one groin and surgical access in the other. The primary end points were access duration and cost. Secondary end points were wound complications and the postoperative pain levels. RESULTS: Surgery was performed per protocol in 44 patients. Mean access times for pEVAR and cEVAR were 11.5 ± 3.4 minutes and 24.8 ± 12.1 minutes (P < .001), respectively. Total access costs were €559.65 ± €112.69 for pEVAR and €674.85 ± €289.55 for cEVAR (P = .016). Eight complications in six patients were attributed to cutdown, none to pEVAR (P = .02). The percutaneously accessed groin was significantly less painful at day 1 and day 5 after surgery (P < .001). An intention-to-treat analysis (N = 50 patients) included six cases of pEVAR conversion due to technical failure in three patients (6%) and change of the operative strategy in another three patients (eg, aortouni-iliac stent graft followed by crossover bypass). The intention-to-treat analysis showed shorter mean overall access time for pEVAR (pEVAR, 14.65 ± 10.20 minutes; cEVAR, 25.12 ± 11.77 minutes; P < .001) and no cost difference between the two methods (pEVAR, €651.29 ± €313.49; cEVAR, €625.53 ± €238.29; P = .65). CONCLUSIONS: Our data confirm proposed potential benefits attributable to the minimally invasive nature of pEVAR while demonstrating cost-effectiveness despite the additional cost of closure devices. Taking into account pEVAR failures still does not increase pEVAR costs over cEVAR. Further considering reduced postoperative pain and wound complications, the technique deserves consideration in suitable patients.

High-degree atrioventricular block in patients with preexisting bundle branch block or bundle branch block occurring during transcatheter aortic valve implantation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has become the standard therapy for high-risk and non-operable patients with severe aortic stenosis. However, the procedure involves several adverse effects, such as rhythm and conduction disturbances. Patients with postprocedural left bundle branch block may have an increased mortality risk, whereas patients with preprocedural right bundle branch block display a higher rate of postinterventional bradyarrhythmias. OBJECTIVE: The purpose of this study was to investigate the occurrence of high-degree atrioventricular block (AVB) in patients with preexisting bundle branch block (BBB) or BBB occurring during TAVI. METHODS: In this prospective single-center study, 50 consecutive patients undergoing TAVI with the Medtronic CoreValve Revalving System were included. Of these patients, 17 with preexisting BBB or BBB occurring during TAVI received a primary prophylactic permanent DDD pacemaker, programmed to the SafeR-mode and featuring dual-channel event counters as well as stored intracardiac electrograms. Pacemaker readouts and intracardiac electrograms were analyzed for the occurrence of high-degree AVB. RESULTS: Ten of 17 patients (58.8%) with preexisting BBB or BBB occurring during TAVI developed episodes of high-degree AVB that were immediately terminated due to switch into DDD backup pacing. In 5 of the cases (29.4%), the first documented episode of high-degree AVB occurred after hospital discharge. Mean follow-up period was 578.1 ± 294.9 days. CONCLUSION: Development of high-degree AVB is a common complication in patients with preexisting BBB or BBB occurring during TAVI. Accordingly, intensified monitoring might be reasonable, especially in patients treated with the self-expandable Medtronic CoreValve Revalving System.