Acute type A intramural hematoma: The less-deadly acute aortic syndrome?

OBJECTIVE: To evaluate the short- and midterm outcomes of surgically managed acute type A intramural hematoma (IMH) versus classic acute type A aortic dissection (ATAAD).

METHODS: From 1996 to February 2023, a total of 106 patients with acute type A IMH and 795 patients with classic ATAAD presented for open aortic repair at our institution. Data were obtained from the local Society of Thoracic Surgeons' Data Warehouse and medical chart review.

RESULTS: Compared with the classic ATAAD group, the IMH group was older (65 vs 59 years, P < .001) and more likely to be female (45% vs 32%, P = .005), with fewer comorbidities such as severe aortic insufficiency (5.0% vs 25%, P < .001), acute stroke (2.8% vs 8.3%, P = .05), acute renal failure (5.7% vs 13%, P = .04), and malperfusion syndrome (8.5% vs 26%, P < .001) but more cardiac tamponade (18% vs 11%, P = .03). The IMH group had less aortic root replacement (15% vs 33%, P < .001), zone 2 arch replacements (9.4% vs 18%, P = .02), and shorter crossclamp times (120 minutes vs 150 minutes, P < .001). The operative mortality was significantly lower in the IMH group (0.9% vs 8.8%, P = .005) and a multivariable regression model showed IMH to be protective, odds ratio of 0.11, P = .03. The 10-year survival was similar between the 2 groups (65% vs 61%, P = .35). The hazard ratio of IMH for midterm mortality after surgery was 0.73, P = .12.

CONCLUSIONS: Acute type A IMH could be treated with emergency open aortic repair with excellent short- and midterm outcomes.