Objectives: This study aims at apprehending the learning curve of an operator trained in a high-volume aortic center for fenestrated and/or branched endovascular aortic repairs (F/B-EVAR).
Methods: Consecutive elective patients treated with custom-made F/B-EVAR for abdominal or thoraco-abdominal aortic aneurysms (TAAAs) from January 2013 and March 2020 were retrospectively included. Groups were defined whether the procedure was performed by an experienced operator (operator 1, group 1), an operator at his initial experience (operator 2, group 2) or by the operator 2 under the supervision of the operator 1 (group 3). All data were recorded according to the SVS reporting standards. The primary composite endpoint including technical failure, early death and/or any major adverse event (MAE) was analyzed in a multivariable model. The learning curve of the operator 2 was assessed using a cumulative sum analysis (CUSUM) providing the relationship between MAE or death and case experience (acceptable and unacceptable event rates were 12.5% and 20%, respectively).
Results: Overall, 437 patients were included (240 in group 1, 173 in group 2, 24 in group 3). Median age was 69 [63-77] (male, 93%; n=385). There were significantly more extended TAAAs (extent I, II, III and V) in group 1 (n=68 (28%) vs 19 (11%) in group 2; p<.001). Total operating time was lower in group 2 (150 min (120-200) vs 180 min (159-225) (p <.001), but no difference was found in other procedural metrics. The technical success rate was 94.6% in group 1 and 94.2 % in group 2 (p=.874). The 30-day mortality and/or MAE rates in juxta/pararenal aneurysms or type IV TAAAs were 8.1% in group 1 and 9.7% in group 2 (p=.612), while 10.3% (group 1) and zero (group 2) for extended TAAAs (p=.339). By multivariate analysis, the operator’s experience was not predictive for the composite criterion (p= .557); only affected by preoperative chronic kidney disease (odds ratio (OR)=2.32; 95%CI[1.2-4.39]; p=.011) and intraoperative unplanned additional procedure (OR=3.11; 95%CI[1.64-5.80]; p<.001). The median follow-up was 14 months [11.0-20.0] in group 2 and 45 months [23.0-59.0] in group 1 (p <.001). Patients of group 1 were less likely to experience an aorta-related secondary intervention (HR= 0.24; 95%CI[0.07-0.91]; p=.035). The CUSUM plots highlighted satisfactory results from the beginning of the experience, outcomes were constantly inferior to the target event rate (Fig1).
Conclusions: This study demonstrates favourable outcomes in patients treated by F/B-EVAR performed by a young operator trained in a high-volume aortic center from the beginning of his autonomy.
