Surgical management and outcomes of type A dissection-the Mayo Clinic experience

Abstract

Background: Type A aortic dissection (TAAD) is a complex cardiovascular disease that is associated with high perioperative morbidity and mortality. The most effective approach is still being debated-such as the best cannulation technique, and conservative versus extensive initial surgery. We reviewed our experience over the last 20 years and examined for variables that correlated with observed outcomes.

Methods: All patients who underwent TAAD repair were reviewed. Chi-Square tests, Fisher Exact tests and Wilcoxon tests were performed where appropriate. Survival and freedom from reoperations were analyzed with the Kaplan-Meier actuarial method.

Results: Acute TAAD was associated with a higher incidence of permanent stroke (P=0.010), renal failure (P=0.025), prolonged mechanical ventilator support (P=0.004), higher operative mortality (P=0.039) and higher 30-day mortality (P=0.003) compared to chronic TAAD. There was a trend towards higher risk for transient neurologic events among patients who were reoperated on (P=0.057). Extensive proximal repair led to longer perfusion and cross clamp times (P<0.001) and the need for temporary mechanical support post-operatively (P=0.011). More patients that had extensive distal repair underwent circulatory arrest (P=0.009) with no significant differences in the incidence of peri-operative complications, early, middle and long-term survival compared to the conservative management group. Overall survival in our series was 66.73% and 46.30% at 5 and 10 years respectively (median survival time: 9.38 years). There was a significant improvement in operative mortality (P=0.002) and 30-day mortality (P=0.033) in the second decade of our study.

Discussion: TAAD is a complex disease with several options for its surgical management. Each technique has its own advantages and complications and surgical management should be individualized depending on the clinical presentation. We propose our present approach to maximize benefits in both the short and long term.

Keywords: Ascending aorta dissection; DeBakey I dissection; arterial cannulation; root management; surgical repair; type A dissection.

Figure 1

Survival curves. (A) Line graph of the annual census for TAAD patients in the last 20 years; (B) overall survival of TAAD patients in our series; (C) Kaplan-Meier survival curve comparing acute and chronic TAAD; (D) survival curve comparing first time surgery patients versus reoperation patients, with reoperation considered as time dependent variable; (E) Kaplan-Meier survival curve comparing conservative versus definitive root management during the initial surgery for TAAD; (F) Kaplan-Meier survival curve comparing conservative versus extensive extent of distal repair during the initial surgery for TAAD. CI, confidence interval.

Figure 2

Proposed surgical management for type A aortic dissection. (A) Aortic valve resuspension using pledgeted mono-filament suture; (B) conservative root management by placing a felt sandwich in between the dissected layers of the root followed by tacking suture; (C,D) distal repair showing hemiarch procedure with application of felt sandwich between the dissected layers; (E,F) suggested surgical management of DeBakey type I dissection, which includes ascending aorta replacement, total arch reconstruction with antegrade deployment of frozen elephant trunk into the descending aorta.