Inconsistent false lumen enhancement predicts late aortic events after hemiarch replacement in Acute type A aortic dissection

The impact of inconsistent enhancement within the patent false lumen on the occurrence of late aortic events remains uncertain. We enrolled a total of 55patients who exhibited a patent false lumen following hemiarch replacement. The Hounsfield unit(HU) measurements in the patent false lumen were obtained at two 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 Hounsfield units within the patent false lumen. We investigated the cutoff 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 cutoff value and compared the cumulative incidence of the late aortic events. Analysis of the receiver operating characteristics curve showed the cutoff value of the false lumen HU score was 0.345. Based on this cutoff value, we divided them into two groups: GroupA(score<0.345,n=26) and Group B(score≧0.345,n=29). The baseline characteristics were similar between the two groups. Cumulative incidence of the late aortic events was significantly lower in Group A(7.8% at 5years) than in Group B(39.9% at 5years) (p=0.02). The false lumen HU score might be useful to predict the incidence of late aortic events following hemiarch replacement.