Comparison of Physician-Modified Fenestrated/Branched Stent-Grafts and Hybrid Visceral Debranching Plus Stent-Graft Placement for Complex Thoracoabdominal Aortic Aneurysm Repair

Abstract

Purpose: To evaluate the immediate postoperative and midterm outcomes of complex thoracoabdominal aortic aneurysm (TAAA) treatment with fenestrated/branched physician-modified endovascular grafts (PMEGs) or open debranching of the visceral aorta with bypass graft revascularization plus endovascular aneurysm exclusion (hybrid repair). Materials and Methods: A retrospective analysis was conducted of 88 patients (mean age 70.0±10.6 years; 73 men) with complex TAAAs who underwent treatment with PMEGs (60, 68%) or a hybrid technique (28, 32%) between 2016 and 2019. The mean aneurysm diameter was 64.5±11.7 mm, and 37 patients (42%) were symptomatic. The Zenith TX2 and Ankura were the main stent-grafts used in the PMEG group. The hybrid technique involved visceral debranching with extra-anatomical bypass graft revascularization and subsequent stent-graft deployment (1- or 2-stage procedure). Results: In the PMEG group, 35 patients received modified stent-grafts with 4 fenestrations, 8 patients had 4 branches per device, and 17 patients had combinations (50 fenestrations and 18 branches) that successfully revascularized 228 of the 240 targets (95%). In the 28 hybrid cases, all 110 target vessels were successfully revascularized with bypass grafts. The overall 30-day mortality was 3.4% (2 PMEG and 1 hybrid), and the early rate of target vessel stenosis/occlusion was 3.3% (5 in PMEG group and 6 in the hybrid repair group). The 30-day morbidity was mainly attributed to pulmonary complications (15%), lower limb ischemia (8%), or spinal cord ischemia with paraplegia (6%). Eleven patients (13%) had deteriorated renal function with a >30% decrease in the glomerular filtration rate. The mean follow-up was 22.3±4.9 months, and mortality was 4.5% (3.3% in the PMEG group vs 7.1% in the hybrid repair group). Conclusion: PMEGs and hybrid techniques seem to be feasible treatment options for aortic aneurysms necessitating visceral vessel revascularization. PMEGs may have a lower morbidity than the hybrid technique, which nonetheless remains an important option available for complex aortic aneurysms.

Commentary: Physician-Modified Fenestrated/Branched EVAR and Hybrid Techniques for Acute Thoracoabdominal Aortic Pathologies: Inequality When Comparing Alternative Options With Different Philosophies Does Not Equal Lower Quality

“…Notably, acute renal failure and mesenteric ischemia presented more commonly in the hybrid group (2.6% vs 18% and 3% vs 23%, respectively). 6 This was also true in the study by Yang et al 1 (renal deterioration 25%, dialysis on discharge 21%) but surprisingly not related to increased mortality even though preoperative renal impairment was high (17.9%), a known risk factor for postoperative major adverse events. 7 The authors also achieved 24-month cumulative survival rates of 96.7% and 92% for the f/bPMEG and hybrid repair groups, respectively, 1 and this fact should not be ignored.…”

“…Whereas significant differences favoring f/bPMEGs over hybrid reconstructions were seen relative to operative technique and efficiency (duration of operation, blood loss, shock, acute renal failure requiring dialysis, renal and pulmonary complications, and lengths of intensive care and hospital stays), these did not translate into differences in early or late mortality rates. 1 Notably, low 30-day mortality was reported for the f/bPMEG and hybrid repair groups (3.3% and 3.6%, respectively) despite the high rate of symptomatic or contained rupture cases (42%). Similar excellent 30-day mortality outcomes for f/bPMEGs have also been obtained from dedicated teams in high-volume centers (5.1%, 2 5.5%, 3 3.7% in the most recent period, 4 and 4.9% 5 ) having gained initial experience much earlier (2007,2007,2009, and 2010, respectively) than the present authors (2016), 1 highlighting the substantial learning curve effect and also the ability of the Chinese authors to replicate the usual methods of device construction and delivery system preparation.…”

“…1 Notably, low 30-day mortality was reported for the f/bPMEG and hybrid repair groups (3.3% and 3.6%, respectively) despite the high rate of symptomatic or contained rupture cases (42%). Similar excellent 30-day mortality outcomes for f/bPMEGs have also been obtained from dedicated teams in high-volume centers (5.1%, 2 5.5%, 3 3.7% in the most recent period, 4 and 4.9% 5 ) having gained initial experience much earlier (2007,2007,2009, and 2010, respectively) than the present authors (2016), 1 highlighting the substantial learning curve effect and also the ability of the Chinese authors to replicate the usual methods of device construction and delivery system preparation. Like Yang et al, 1 innovative physicians who are capable of performing complicated procedures (f/bPMEGs or hybrid techniques) for aortic disease can give the patient a better chance of surviving this morbid and potentially lethal disease in the acute setting (urgent repair of a large aneurysm, rapid sac expansion, impending or contained rupture), without always taking into consideration alternative techniques (eg, offthe-shelf stent-grafts that fit many different anatomies).…”

“…However, the most clinically significant difference shown was in terms of late aortic reinterventions for type II and III endoleaks, with the PMEG cases having 3.5 times the incidence of reinterventions as hybrid cases. 1 This underlines not only the unproven long-term durability of f/bPMEG therapy but also the possible learning curve of the authors in the modification technique. The use of more fenestrations than branches in TAAAs could be another explanation for the high incidence of type III endoleaks.…”

“…In the October 2020 issue of the JEVT, Yang et al 1 have reported valuable research comparing fenestrated/branched physician-modified endovascular grafts (f/bPMEGs) to hybrid open debranching of the visceral aorta with bypass graft revascularization plus endovascular aneurysm exclusion (EVAR) for the treatment of complex thoracoabdominal aortic aneurysms (TAAAs), mainly symptomatic and in high-risk patients. Based on the current absence of published large clinical trials providing the necessary supporting evidence for both techniques, such comparative studies, although retrospective, are meaningful until reliable and more applicable "off-the-shelf" stent-grafts are universally available in the marketplace.…”