Inconsistent False Lumen Enhancement Predicts Late Aortic Events After Hemiarch Replacement in Acute Type A Aortic Dissection

Abstract

The impact of inconsistent enhancement within the patent false lumen on the occurrence of late aortic events remains uncertain. We enrolled 55patients who exhibited a patent false lumen after hemiarch replacement. The Hounsfield unit (HU) measurements in the patent false lumen were obtained at 2 specific locations: the aortic arch (a) and the descending aorta (b). The false lumen HU score was calculated as the absolute value of 1 - a/b, representing the discrepancy in HUs within the patent false lumen. We investigated the cut-off value of the false lumen HU score with the receiver operating characteristics curve to predict the incidence of late aortic events. We divided the patients based on the cut-off value and compared the cumulative incidence of the late aortic events. The analysis of the receiver operating characteristics curve showed that the cut-off value of the false lumen HU score was 0.345. Based on this cut-off value, we divided them into 2 groups: Group A (score <0.345, n = 26) and Group B (score ≥0.345, n = 29). The baseline characteristics were similar between the 2 groups. The cumulative incidence of the late aortic events was significantly lower in Group A (7.8% at 5 years) than in Group B (39.9% at 5 years) (p = 0.02). The false lumen HU score might be useful to predict the incidence of late aortic events after hemiarch replacement.

Keywords: Hounsfield unit; acute type A aortic dissection; patent false lumen; reoperation.