Outcomes of Complex Endovascular Treatment of Post-Dissection Aneurysms.

Objective: Reports of endovascular treatment of chronic post-dissection aneurysms are limited to high volumes centres, posing questions about generalisability.

Methods: All endovascular repairs of intact pararenal and thoraco-abdominal aneurysms in the Vascular Quality Initiative from 2014 to 2021 were studied, and peri-operative and long term outcomes were compared between repairs of degenerative and post-dissection aneurysms. Peri-operative outcomes were compared using mixed effects logistic regression, and long term outcomes using Medicare linkage.

Results: There were 123 patients who completed treatment for post-dissection aneurysms and 3 635 for degenerative aneurysms, with 36% of post-dissection repairs and 6.7% of degenerative repairs performed in a staged fashion (p < .001). The majority (84%) of post-dissection aneurysms were extensive thoraco-abdominal aneurysms (TAAAs: Crawford Type 1, 2, 3, 5), compared with 22% of degenerative aneurysms (p < .001). Physician modified endografts were the primary repair type for post-dissection (73%), while commercially available fenestrated grafts were the dominant repair for degenerative (48%). The first stage of staged procedures was associated with a 2.8% peri-operative mortality rate, 5.1% spinal cord ischaemia, and 8.9% thoraco-abdominal life altering events (the composite of peri-operative death, stroke, permanent spinal cord ischaemia, and dialysis). Th final stage procedure and fluoroscopy times were similar, but technical success was lower in post-dissection repairs (75% vs. 83%, p = .018), both due to issues with the main endograft or bridging vessels (11% vs. 6.6%, p = .055), and types 1and 3 endoleak at completion (17% vs. 10%, p = .035). In addition, high volume surgeons had two fold higher odds of technical success than their low volume counterparts. Adjusted peri-operative outcomes were similar between pathology types, including when comparisons were restricted to extensive TAAAs. Crude and adjusted three year survival were similar, but three year re-interventions were significantly higher following post-dissection repairs (p < .001).

Conclusion: Complex endovascular repair of chronic post-dissection aneurysms is feasible but is associated with high rates of re-interventions and non-trivial rates of lack of technical success. More data are needed to evaluate the long term durability of these procedures, and the utility of centralising these complex procedures.