The outcome of late open conversion after endovascular abdominal aortic repair.

Background: Endovascular abdominal aneurysm repair (EVAR) offers a less invasive approach to treating abdominal aortic aneurysms (AAA) compared to open repair. However, EVAR is associated with higher rates of reintervention. This study investigates the early and mid-term outcomes of patients who underwent late open conversion including aneurysmorrhaphy after EVAR at our institution.

Methods: We conducted a retrospective cohort study of 29 patients who underwent late open conversion for AAA dilatation after EVAR between April 2015 and March 2022 at Chiba University Hospital. Surgical strategies included an artificial graft replacement for Type Ia endoleak (EL), Type III EL from stent graft main body, ruptured cases, and aneurysmorrhaphy with branch ligation for Type II EL.

Results: The average time from EVAR to open conversion was 4.1 ± 2.3 years. There have been no reported cases of in-hospital mortality to date. Aneurysmorrhaphy demonstrated shorter operative times (239 ± 65 min) and lower red blood cell transfusion volumes (2.7 ± 4.2 units) compared to graft replacement. Postoperative complications included spinal cord ischemia in one patient and three patients requiring reintervention due to persistent or new ELs, who underwent angiography. The seven-year all-cause mortality rate was 78.5%. Among cases that underwent aneurysmorrhaphy, postoperative computed tomography scans showed a reduction in the maximum aortic diameter from 65 ± 6 mm preoperatively to 42 ± 10 mm postoperatively and 36 ± 11 mm at follow-up.

Conclusions: Late open conversion including aneurysmorrhaphy after EVAR appears to be safe and effective, with no in-hospital mortality and low complication rates. Careful preoperative planning and appropriate surgical techniques are essential for optimizing outcomes.