Twenty-two Year Multicentre Experience of Late Open Conversions after Endovascular Abdominal Aneurysm Repair

Objective: The aim was to report indications, technical aspects, and outcomes of a multicentre experience of late open conversions (LOCs) after endovascular abdominal aneurysm repair (EVAR), in order to identify risk factors which may influence early morbidity and mortality rates, and long term survival.

Methods: Ten vascular centres retrospectively reviewed all patients requiring LOC (≥30 days from initial EVAR, undergoing total or partial endograft explantation) from 1996 to 2017. Baseline characteristics, endograft data, indications, procedural details, post-operative outcomes, and follow up data were reviewed and analysed.

Results: Included patients totalled 232 (90.1% males, mean age 74.3 ± 7.9 years). The number of LOC per year significantly increased during the study period, reaching 22 in 2017 (correlation r = 0.867, p < .0001). Reasons for LOC were 80.2% endoleak (186/232), 15.5% endograft infection (36/232), and 9.9% endograft thrombosis (23/232). Sixty-nine patients (29.7%) were operated on urgently; rupture was present in 18.5% (43/232). Eighty-nine patients (38.4%) underwent endovascular re-interventions prior to LOC. The proximal aortic cross clamp site was infrarenal in 40.5% (94/232), suprarenal in 25.4% (59/232), supracoeliac in 32.8% (76/232), and thoracic in 1.3% (3/232). Endograft explantation was total in 164/232 patients (70.7%), and partial in the remaining 68/232 (29.3%). The overall 30 day mortality was 11.2% (26/232). Early mortality was significantly higher for patients operated on urgently (26.1% vs. 4.9%, p < .001). Suprarenal clamping (odds ratio (OR) 2.34, 95% CI 1.12-4.88) and pre-existing renal insufficiency (OR 2.11, 95% CI 1.03-4.31) were independent risk factors for post-operative renal failure on multivariable analysis. Median follow up was 24.1 months (IQR 4.4-60.6). The estimated overall one and five year survival rates were 79.7% and 58.6%, respectively. Survival estimates were significantly lower for patients with endograft infection (83.8% vs. 59% at one year, 65.2% vs. 28.9% at five years; log rank p = .005), as well as for urgent patients (87.2% vs. 62.1% at one year, 65.1% vs. 43.7% at five years; log rank p < .0001).

Conclusion: The annual number of LOC increased over time. LOCs performed urgently or for endograft infection are associated with poor survival. Infrarenal aortic clamping has lower post-operative complication rates.