Systematic review and meta-analysis of elective and urgent late open conversion after failed endovascular aneurysm repair

Background: In this study, we systematically reviewed late open conversions after failed endovascular aneurysm repair (EVAR), assessed the methodologic quality of the included studies, and performed a meta-analysis on the 30-day mortality rates for urgent and elective late conversions.

Methods: Electronic databases were systematically searched for studies published up to June 2018 that focused on late open conversion of failed EVAR (ie, >30 days after the initial EVAR), reported the primary outcome of 30-day mortality rate, and distinguished the 30-day mortality rate between urgent and elective late conversions. Two independent reviewers assessed the methodologic quality of the included studies with the Methodological Index for Non-Randomized Studies. Data on baseline demographics, indication for conversion, surgical approach, and early and late mortality rates were recorded. Reported data correspond to the average or range of the means reported in the individual studies. A random-effects model was used to pool 30-day mortality rates for urgent and elective late conversion.

Results: There were 27 retrospective studies with a total of 791 patients available for analysis, with 617 elective and 174 urgent late conversions. The methodologic quality was mostly poor (median, 6; interquartile range, 5-7). The mean time from primary EVAR to conversion was 35.1 months (95% confidence interval [CI], 30.4-39.8 months). The most commonly explanted endografts were Excluder (W. L. Gore & Associates, Flagstaff, Ariz) in 16.2%, Talent (Medtronic, Minneapolis, Minn) in 14.5%, and AneuRx (Medtronic) in 13.7%. Nineteen other types of endografts were used in 43.3%; the type of endograft was not reported in 12.3%. A transperitoneal approach was used in a mean 74.0% of conversions (95% CI, 70.9%-77.0%), and complete endograft explantation was performed in 478 (60.4%) patients (95% CI, 57.0%-63.8%). The complication rate was 36.7% (95% CI, 27.0%-46.4%). Temporary or permanent hemodialysis after conversion was required in 3.9% of patients (95% CI, 2.6%-5.2%). The pooled estimate for the 30-day mortality rate was 2.8% (95% CI, 1.5%-4.0%; P = .726) for elective late conversions and 28.1% (95% CI, 18.9%-37.3%; P < .001) for urgent late conversions.

Conclusions: Type I endoleak and rupture are the most common indications for, respectively, elective and urgent conversions. A 10 times higher 30-day mortality rate was observed for patients treated with late open conversion in an urgent vs elective setting. The 30-day mortality rate of elective late open conversions is almost comparable to that of primary elective open abdominal aortic aneurysm repair procedures. For the interpretation of the outcomes of the review, however, the methodologic quality of the available literature should be considered.