Quantifying the learning curve of emergent total arch replacement in acute type A aortic dissection

Background: Acute type A aortic dissection with arch involvement is a life-threatening condition, which requires immediate surgical attention. Emergent total arch replacement and root reconstruction is a technically demanding operation with varying outcomes based on surgeon experience. The human factors in total arch replacement in the emergent setting have never been systematically investigated. The ability of surgeons with low volumes to achieve acceptable results in their start-up period is not known. Methods: From January 2013 to December 2016, patients with acute type A aortic dissection who underwent emergent total arch replacement with three surgeons were enrolled. Basic characteristics, procedural and postoperative outcomes were collected. The time of critical surgical steps and operative mortality were calculated using descriptive statistics and cumulative SUM (CUSUM) analysis. Results: A total of 300 patients (age 53.8 +/- 11.5 years, female 63, 21.0%) with acute type A aortic dissection underwent emergent total arch replacement. A total of 219 patients (73.0%) had root reinforcement, 295 patients (98.3%) underwent frozen elephant trunk repair. Mean circulatory arrest and cross-clamp times were 29.8 +/- 9.8 and 112.3 +/- 32.1 min, respectively. The operative mortality was 6.7%, the stroke rate was 4.0%. The mean length of postoperative ICU and hospital stays were 8.4 +/- 10.6 and 18.0 +/- 12.2 days, respectively. By CUSUM depictions, surgeons appeared to have different learning curves with regards to operative time. By CUSUM failure analysis on operative mortality, two newly appointed surgeons in their start-up period stayed in an acceptable range, while one senior surgeon with higher volumes experienced superior outcomes and better performance. Conclusions: Although emergent total arch replacement for acute type A dissection is a complex scenario, surgeons well-trained in adult cardiac surgery are able to achieve acceptable results in their start-up period.