Interinstitutional analysis of the outcome after surgery for type A aortic dissection

Purpose: To evaluate the impact of individual institutions on the outcome after surgery for Stanford type A aortic dissection (TAAD). Methods: This is an observational, multicenter, retrospective cohort study including 3902 patients who underwent surgery for TAAD at 18 university and non-university hospitals. Results: Logistic regression showed that four hospitals had increased risk of in-hospital mortality, while two hospitals were associated with decreased risk of in-hospital mortality. Risk-adjusted in-hospital mortality rates were lower in four hospitals and higher in other four hospitals compared to the overall in-hospital mortality rate (17.7%). Participating hospitals were classified as overperforming or underperforming if their risk-adjusted in-hospital mortality rate was lower or higher than the in-hospital mortality rate of the overall series, respectively. Propensity score matching yielded 1729 pairs of patients operated at over- or underperforming hospitals. Overperforming hospitals had a significantly lower in-hospital mortality (12.8% vs. 22.2%, p < 0.0001) along with decreased rate of stroke and/or global brain ischemia (16.5% vs. 19.9%, p = 0.009) compared to underperforming hospitals. Aggregate data meta-regression of the results of participating hospitals showed that hospital volume was inversely associated with in-hospital mortality (p = 0.043). Hospitals with an annual volume of less than 15 cases had an increased risk of in-hospital mortality (adjusted OR, 1.345, 95% CI 1.126-1.607). Conclusion: The present findings indicate that there are significant differences between hospitals in terms of early outcome after surgery for TAAD. Low hospital volume may be a determinant of poor outcome of TAAD. Trial registration: ClinicalTrials.gov Identifier: NCT04831073.