Computed tomography predictors of failure of conservative management in isolated superior mesenteric artery dissection

Abstract Purpose To identify contrast-enhanced computed tomography (CECT) features associated with failure of conservative management in participants with acute-phase isolated superior mesenteric artery dissection (ISMAD). Materials and methods This single-center, retrospective, observational study included consecutive patients with acute-phase ISMAD between January 2011 and September 2022. Failure of conservative management was defined as persistent abdominal pain and/or clinical or radiological deterioration despite standardized conservative treatment, prompting close monitoring or consideration of revascularization. The patients were classified into two groups: a failure group (F-G) and a successful group (S-G). The groups were compared with respect to clinical background, Yun classification, true lumen stenosis rate, the cutoff value for the true lumen stenosis rate, and dissection length. Additionally, to evaluate the degree of development of Riolan’s arch (RA), computed tomography images were initially reviewed to confirm visualization, and the maximal vascular diameter was subsequently measured. Results Thirty-two consecutive patients with acute-phase ISMAD (median age, 56.7 years; range, 41–81 years; men, n = 26, 81.3%) were included in this study. Nine and 23 patients were classified as F-G and S-G, respectively, according to the study criteria. The median true lumen stenosis rate was significantly higher in the F-G than in the S-G (100.0 vs. 55.0%, P < 0.05). Receiver operating characteristic analysis yielded an exploratory cutoff value of 66.8%, with an AUC of 0.855 (95% CI 0.71–0.99); sensitivity, 1.000; specificity, 0.652; positive predictive value, 0.50; and negative predictive value, 1.00. RA was more frequently detected in the F-G than in the S-G (9/9 vs. 12/23, P < 0.05). Conclusion A high true lumen stenosis rate and the presence of RA on CECT are associated with failure of conservative management in ISMAD and may assist in identifying patients at risk of a clinical course requiring closer monitoring or consideration of revascularization rather than directly predicting intestinal ischemia.