Late surgical conversions after abdominal endovascular aortic repair: underlying mechanisms, clinical results and strategies for prevention.

Objectives: Our goal was to report our results of late surgical conversion after endovascular aneurysm repair (EVAR).

Methods: Variables analysed included baseline data, preinterventional anatomy, type of endovascular intervention, indications for conversion, operative technique, postoperative complications and follow-up survival rate.

Results: Between April 2011 and May 2018, 16 patients with late complications after EVAR underwent open surgical conversion at our institution. The mean age was 73.6 [standard deviation (SD) 8.9] years. There were 3 (18.8%) female patients. In 15 patients, the indication for primary EVAR was abdominal aortic aneurysm, and in 1 patient, chronic abdominal aortic dissection. Five patients underwent secondary EVAR service interventions for endoleak treatment between the index EVAR and the final secondary surgical conversion. Thirteen patients underwent surgery in an elective setting and 3 patients underwent emergency surgery. The mean time from EVAR to open surgical conversion was 6.31 (SD 4.0) years (range 1.2-16.0 years). The most common indication for conversion was endoleak formation (n = 12, 75%), followed by 3 cases of aortic rupture (1 patient with primary type 1 endoleak) and 2 cases of stent graft infection-1 with and 1 without an aortoduodenal fistula. One patient died during emergency open surgery of cardiopulmonary instability. Three patients developed postoperative renal dysfunction with recovery of their renal function before discharge. The in-hospital mortality rate was 12.5%. The median follow-up was 16.5 months (interquartile range 21 months). Freedom from death and aortic reintervention was 100%, respectively. After careful review of the index computed tomography scans for EVAR, the majority of failures could have been anticipated due to trade-offs with regard to length, diameter, morphology, shape and angulation of the proximal and/or distal landing zone.

Conclusions: Despite being a challenging operation, late surgical conversion after EVAR yields excellent results with regard to outcome and freedom from the need for further aortic interventions. An anticipative strategy adhering to current recommendations for using or refraining from using EVAR in patients with anatomical challenges will help reduce the need for secondary surgical conversions and keep them to minimum.