Midterm Outcomes of the Fenestrated Anaconda Stent Graft for Complex Aortic Aneurysm Repair: A Large, Single Centre, Retrospective Study

The aim of this study was to evaluate the short and midterm outcomes of the Anaconda fenestrated stent graft for the treatment of complex abdominal and thoraco-abdominal aneurysms. This was a retrospective study in a single academic centre. All patients consecutively treated with a fenestrated Anaconda device between January 2019 and May 2024 were included. Outcomes analysed included technical success (TS), procedure related death, occurrence of major adverse events (MAEs) and target vessel instability (TVI), type Ia endoleak (T1aEL), abdominal aortic aneurysm (AAA) related re-interventions, sac changes, and death. Two hundred and ten patients were treated with the Anaconda stent graft. The mean AAA diameter was 60.4 ± 9.4 mm, with a mean of 3.9 ± 0.6 fenestrations per patient for a total of 816 target vessels (TVs). TS was 96.2% (202/210), MAEs occurred in 6.2% of patients (13/210), and procedure related mortality was 2.9% (6/210). The mean follow up was 24.0 ± 18.3 months. AAA related re-intervention was necessary in 18.6% of patients. Primary and secondary TV patency at follow up were 97.1% (24/816) and 98.0% (16/816), respectively. Freedom from TVI at one, three, and five years was 95.5% (95% confidence interval [CI] 93.9 - 97.1%), 92.5% (95% CI 90.2 - 94.8%), and 91.7% (95% CI 89.0 - 94.4%), respectively. No T1aEL was observed during follow up. Estimated freedom from sac enlargement at one, three, and four years was 96.9% (95% CI 94.3 - 99.6%), 88.4% (95% CI 82.6 - 94.3%), and 82.8% (95% CI 74.1 - 91.6%), respectively. Estimated overall survival at one, three, and five years was 92.2% (95% CI 88.6 - 95.9%), 80.0% (95% CI 73.3 - 86.8%), and 71.6% (95% CI 62.1 - 81.0%), respectively, with one case (0.5%) of late aortic related death. Endovascular repair of complex abdominal or thoraco-abdominal aneurysms using the fenestrated Anaconda stent graft is safe and effective with a high TS and low procedure related mortality rate. The midterm results appear satisfactory in terms of sac evolution, with a low TVI rate. The need for re-intervention is acceptable and justifies the need for meticulous imaging follow up.