Analysis of preoperative MSCT features in early death patients with Stanford type B aortic dissection after endovascular repair

Objective: To evaluate preoperative multislice spiral CT (MSCT) imaging manifestations in predicting early death of patients with Stanford type B aortic dissection after endovascular repair. Methods: The clinical follow-up data and preoperative MSCT imaging materials of 158 patients with acute and subacute Stanford type B aortic dissection, who received endovascular repair treatment during the period from January 2014 to December 2018, were retrospectively analyzed. The following observation indexes on the preoperative CT image were measured and recorded: the anatomical location of the rupture (the distance between the rupture site and the left subclavian artery), the size of the rupture, the maximum diameter of descending aorta, the aortic diameter at the tracheal bifurcation plane, the ratio of false lumen area to total aortic lumen area at the tracheal bifurcation plane, the involvement of main aortic branches, the status of false lumen (including unclosed, partial thrombosis, complete thrombosis) and the involvement of abdominal aorta (such as DeBakey IIIa or IIIb). The correlation between preoperative CT observation indexes and the incidence of postoperative early death (within 30 days) was analyzed. Results: Emergency intervention with endovascular repair (within 48 hours after onset of disease) was carried out in 88 patients and non-emergency intervention with endovascular repair (over 48 hours after onset of disease) was performed in 70 patients. The early mortality rate (within 30 days after treatment) was 9.5% (15/158). Univariate analysis of early mortality showed that the early mortality rate in emergency intervention group was 13.6% (12/88), which was significantly higher than 4.3% (3/70) in non-emergency intervention group (X² = 3.967, P = 0.046). The percentage of patients with the ratio of false lumen area to total aortic lumen area at the tracheal bifurcation plane ≥ 50% in early death group was 93.3% (14/15), which was 0.7% (1/143) in non-early death group (X² = 135.581, P < 0.001). The percentage of patients who showed involvement of main aortic branches in early death group and non-early death group were 66.7% (10/15) and 32.9% (47/143) respectively, the difference was statistically significant (X² = 6.725, P = 0.010). Both the above indexes in early death group were strikingly hither than those in non-early death group. No statistically significant differences in the anatomical location of the rupture, the size of the rupture, the maximum diameter of descending aorta, the aortic diameter at the tracheal bifurcation plane, the status of false lumen and the involvement of abdominal aorta existed between the two groups (P > 0.05). Logistic multivariate regression analysis revealed that emergency intervention (OR = 1.31, 95% CI: 1.08-3.53, P = 0.026) and the ratio of false lumen area to total aortic lumen area at the tracheal bifurcation plane ≥ 50% (OR = 9.53, 95% CI: 3.69-12.47, P < 0.001) were independent risk factors for early death after endovascular repair of Stanford type B aortic dissection. Conclusion: Preoperative MSCT is of great value in predicting the occurrence of early death in patients with Stanford type B aortic dissection after endovascular repair. Emergency intervention and the ratio of false lumen area to total aortic lumen area at the tracheal bifurcation plane ≥ 50% are independent risk factors for early death after endovascular repair of Stanford type B aortic dissection. (authors)