Factors associated with perioperative mortality after late open conversion for failed endovascular aortic repair.

Introduction: The aim of this study was to perform a systematic review about the clinical and technical aspects of late open conversion for failed endovascular aortic repair (EVAR) of abdominal aortic aneurysms (AAA), and to investigate if the need for suprarenal aortic cross clamping, graft infection, urgent procedures, endoleaks and aortic rupture were associated with an increase of 30-days (perioperative) mortality.

Evidence acquisition: A literature search was conducted on PubMed using the words "open conversion endovascular" on December 29^th, 2021. Studies included randomized controlled trials, cohort studies, and case series of patients submitted to open conversion that were performed at least 1 month after the initial EVAR for AAA, reporting about 30-days mortality after surgery. A meta-analysis was performed to explore the association of suprarenal aortic cross clamping, graft infection, urgent procedures, endoleaks and aortic rupture with 30-days postoperative mortality using log odds ratios (ORs), with STATA/MP 17.0 (Stata Corp. 2021, LLC). Two-sided P values less than 0.05 were considered statistically significant.

Evidence synthesis: The search retrieved 985 results on PubMed from 1994 to 2021. Among them, 40 papers were included in the study for the systematic review, and 5 of them for the meta-analysis. A total of 2297 patients from 1992 to 2020 were submitted to open conversion after a median of 40.4 months from the initial EVAR. Endoleak was the most frequent cause of open conversion (76.3%). Perioperative mortality was 23.5% for urgent and 5.3% for elective conversions. At meta-analysis, urgent procedures and aortic rupture were both associated with higher perioperative mortality (OR 5.27, 95% CI 2.90-9.57 and OR 5.61, 95% CI 3.09-10.19 respectively). Similarly, patients with infections and who needed suprarenal aortic clamping were at higher risk of 30-days postoperative death (OR 3.74, 95% CI 1.96-7.13) and OR 2.23, 95% CI 1.24-4.02), while the presence of a preoperative endoleaks was not associated with a higher 30-days mortality.

Conclusions: Late open conversion after EVAR of AAA is burdened by a perioperative mortality rate of 23.5% for urgent and 5.3% for elective cases. Urgent treatment, presence of aortic rupture or infection, and the need for suprarenal aortic cross clamping were associated with increased perioperative mortality, while the presence of an endoleak did not affect perioperative mortality.