Safety and efficacy of delayed-release diameter reduction in constructing physician-modified endografts for complex...

Physician-modified endografts (PMEGs) remain an option to treat complex aortic aneurysms with fenestrated endovascular aortic repair (FEVAR) if they are unsuitable for commercial endografts or open surgery. FEVAR traditionally involves uniform diameter reduction for graft alignment and target vessel cannulation, after which diameter reduction is released before the delivery of bridging stent grafts. We describe the results of an advanced PMEG design using nonuniform constraints to mold the graft to the inner shape of the visceral aorta with delayed-release diameter reduction. This method allows for sequential vessel cannulation and thus sequential stent graft delivery without the need to have all targets concurrently cannulated.

Patients were treated with PMEG-FEVAR under a physician-sponsored investigational device exemption trial (NCT06501872, IDE#G240122, including lead-in cohort) from 2015 to 2025 at one institution. Cook Zenith Alpha Thoracic endografts (proximal/distal components/extensions) were modified with reinforced fenestrations and diameter reduced posteriorly with 5-0 chromic suture at the perivisceral portion to just 1 mm smaller than the aortic diameter at each Z-stent level. Intraoperatively, grafts were aligned, unsheathed completely, and diameter reduction ties were left intact with the graft achieving near apposition of the aortic wall at each level. The first target vessel is cannulated, and a bridging stent graft is placed; the graft is then released from the delivery mechanism. Then, in a sequential fashion, target vessels were cannulated through each fenestration and bridged with a stent graft one at a time via small-bore contralateral percutaneous groin access. The diameter reduction sutures are left intact and expected to dissolve over the following 14 days. We analyzed Society for Vascular Surgery-prescribed 30-day and 1-year reporting standards on safety and effectiveness for complex aortic endografting.

Inclusion criteria were met by 203 patients who underwent PMEG-FEVAR (mean age, 75.3 years; 71% male; 94% White) for juxtarenal (25%), pararenal (42%), extent IV (13%), or extent II/III/V (20%) thoracoabdominal aortic aneurysms. The mean aneurysm diameter was 59.9 mm and target vessels included celiac (83%), superior mesenteric (98%), right renal (96%), and left renal (94%) arteries. Target vessel cannulation and delivery of bridging stent grafts was achieved in 100% of vessels. There were no intraoperative deaths. Safety and effectiveness outcomes include a 30-day mortality rate of 2.5%, access site complication rate of 5.4%, and no limb ischemia; at 1 year, outcomes included 0.9% paraplegia, 1.8% paraparesis, 6.7% target vessel instability, 7.6% aneurysm-related reintervention, 7.8% all-cause mortality, 1.5% aneurysm-related mortality, and no open conversions.

Delayed-release diameter reduction molds PMEGs to the aortic anatomy, which allows for sequential target vessel cannulation and stent graft delivery without compromising safety or effectiveness. This technique avoids multiple concurrent wires in target vessels, allowing for smaller contralateral sheath access and less risk to target vessels intraoperatively.