IMPACT OF AORTIC ROOT REPLACEMENT VS CONSERVATIVE REPAIR ON OUTCOMES OF SURGICALLY TREATED ACUTE TYPE A AORTIC DISSECTION

Objective: Optimal treatment of the aortic root in acute type A aortic dissection (ATAAD) is debated, partially due to the difficulty in producing randomized clinical trials. In this study we compared outcomes of root-conservative repair (RCR) vs aortic root replacement (ARR) and performed a counterfactual analysis of causation to estimate their impact on long-term outcomes. Methods: From January 2000 to July 2021 494 ATAAD were surgically treated at our institution. Among these, 296 received RCR, 198 ARR. Pre-operative characteristics, short- and long-term outcomes were compared. Counterfactual analysis estimated the causal treatment effect of ARR vs RCR on time to death and time to reintervention. Results: In the ARR group patients were younger (61.7±11.2 vs 67.8±11.5 years, p<0.01) and showed higher rates of moderate to severe AR (47.5% vs 18.2%, p<0.01). Short-term outcomes did not differ except for bleeding requiring reopening, which occurred more in the ARR group (18.2 vs 10.2%, p=0.01). There was no statistically significant difference in terms of 10-year survival and freedom from reintervention. The results of causal effect analysis, however, showed that time-to-death was increased by 7 months and time-to-reintervention by 17 months in the ARR group, though this didn’t reach statistical significance. Conclusions: ARR and RCR showed comparable outcomes. Survival and freedom from reintervention, however, might be increased by root replacement.