Outcomes of Frozen Elephant Trunk for Type A Acute Aortic Dissection: A Nationwide, Population Based Study

Type A acute aortic dissection (TAAAD) is associated with a high risk of surgical mortality despite early diagnosis and treatment. The optimal extent of aortic arch repair for primary TAAAD remains unclear. This study aimed to investigate the outcomes of the frozen elephant trunk (FET) procedure compared with non-FET procedures in patients with primary TAAAD.

This retrospective cohort study included patients who had undergone open TAAAD repair in Taiwan at any time between 1 January 2011 and 31 December 2020. Relevant data were collected from Taiwan's National Health Insurance Research Database. The primary outcome of interest was in hospital mortality. Late surgical outcomes, including overall survival and re-operation, were evaluated from hospital discharge until outcome occurrence, death, or database conclusion (31 December 2020).

Five thousand seven hundred sixty-nine patients were divided into FET and non-FET groups. Subsequently, these groups were subjected to 1:1 (n = 1 225) propensity score matching. The in hospital mortality rate was statistically significantly higher in the FET group than in the non-FET group (22.4% vs. 18.0%, respectively; odds ratio 1.31, 95% confidence interval [CI] 1.07 - 1.60). The FET group exhibited a statistically significantly elevated rate of post-discharge all cause mortality (hazard ratio [HR] 1.20, 95% CI 1.03 - 1.39). The rate of re-operation after open aortic repair was statistically significantly lower in the FET group than in the non-FET group (0.7% vs. 3.0%, respectively; subdistribution HR 0.24, 95% CI 0.11 - 0.55). However, no statistically significant between group difference was observed in the rate of re-operation after any other aortic surgery. Surgical volume for TAAAD correlated with in hospital mortality; this correlation was stronger in the non-FET group than in the FET group.

Patients who underwent FET for TAAAD had higher risks of in hospital mortality and post-operative complications compared with those who received non-FET procedures.