A comparison of elective late open surgical conversion after endovascular aneurysm repair versus primary open repair for abdominal aortic aneurysm in a single high-volume center

Background: Late open surgical conversion (LOC) after endovascular aneurysm repair (EVAR) has been considered a high-risk operation. This study compared patient characteristics, procedural details, and short- and long-term outcomes between LOC after EVAR and primary open surgical repair (OSR) in a high-volume center. Methods: This single-center, retrospective, nonrandomized study included all consecutive patients undergoing elective OSR for abdominal aortic aneurysm or LOC after EVAR between January 2012 and May 2024. Exclusion criteria were Crawford extent IV thoracoabdominal, isolated iliac, or mycotic aneurysms, prior stent-graft infection, and aortoenteric fistula; emergency operation for rupture was also excluded. Infrarenal, juxtarenal, and pararenal abdominal aortic aneurysms were included. Primary end points were in-hospital mortality and major perioperative complications such as cardiac events, pulmonary complications, intestinal ischemia, and renal dysfunction according to the Acute Kidney Injury Network (AKIN) criteria. Secondary end points were reintervention and overall survival during follow-up. In contemporary practice, the proximal free-flow, when present and possibly the first covered stent, and the iliac limbs are generally preserved during conversion procedures. Patient demographics, intraoperative variables, and outcomes were compared between the LOC and OSR groups. Propensity score matching (1:2 ratio) was performed using age, smoking status, hypertension, coronary artery disease, diabetes, chronic obstructive pulmonary disease, and aortic diameter. Survival and reintervention-free survival were assessed using Kaplan-Meier analysis. Results: A total of 1266 patients were included (LOC: 87; OSR: 1179), with a mean age of 75.7 ± 6.8 years in the LOC group vs 70.7 ± 7.5 years in the OSR group (P < .001). After propensity score matching, 87 LOC and 174 OSR patients were analyzed. In-hospital mortality did not differ between groups in either the unmatched (0.0% vs 0.7%; P = .44) or matched cohorts (0.0% vs 1.1%; P = .32). Thirty-day reintervention rates were also similar (unmatched: 0.0% vs 2.3%, P = .15; matched: 0.0% vs 1.7%; P = .22). Pulmonary complications were more frequent in LOC patients before matching (6.9% vs 2.3%; P = .01) but comparable after matching (6.9% vs 4.6%; P = .44). AKIN stage 1 renal dysfunction occurred more often in LOC patients in both unmatched and matched cohorts (P < .001 and P = .01, respectively), whereas higher AKIN stages, cardiac events, and bowel ischemia showed no significant differences. At a median follow-up of 68 months, overall survival was significantly lower in LOC patients (unmatched: 56.9 ± 40.4 vs 70.4 ± 34.9 months; P < .001; matched: 56.9 ± 40.4 vs 72.1 ± 40.4 months; P = .01). Reintervention-free survival showed a similar trend. Conclusions: Elective LOC after EVAR can be performed safely in high-volume centers, with perioperative and long-term outcomes comparable to primary OSR. Prospective multicenter studies are needed to confirm these findings and guide best practices. Preservation of the proximal bare-metal stent and initial covered stent may have helped reduce complications.