Role of False Lumen Area Ratio in Late Aortic Events After Acute Type I Aortic Dissection Repair

The aim of this study was to investigate whether distal aortic maximum false lumen area (MFLA) ratio predicts late aortic dilation and reintervention after open repair of acute type I aortic dissection.We analyzed 309 nonsyndromic acute type I aortic dissection patients who were treated with a repair to the proximal aorta between 1994 and 2017. In 230 patients who did not show completely thrombosed false lumen on postoperative computed tomography, the MFLA ratio (MFLA/aortic area) on the descending thoracic aorta (DTA) was measured with postoperative computed tomography. Patients were divided into 3 groups according to the quartile range of MFLA ratio: low MFLA,0.62 (n = 57); intermediate MFLA, 0.62 to 0.81 (n = 116); and high MFLA, ≥0.82 (n = 57).The aortic expansion rate was significantly higher in the high MFLA group (11.1 ± 21.2 mm/y) compared with intermediate (3.0 ± 7.4 mm/y; P.01) and low (0.6 ± 6.6 mm/y; P.01) MFLA groups. High MFLA was found to be an independent risk factor for significant aortic expansion (adjusted hazard ratio, 5.26; 95% CI, 1.53-18.12; P.01) and aorta-related reintervention (hazard ratio, 4.99; 95% CI, 2.23-11.13; P.01), and the MFLA ratio was significantly related to proximal DTA reentry tears (adjusted odds ratio, 12974.3; P.001; area under curve, 0.807).A high MFLA ratio on the DTA after acute type I aortic dissection repair is associated with increased risk of late aortic reintervention and distal aortic dilation. A high MFLA ratio is strongly associated with proximal DTA reentry tears.