Clinical Outcomes and Exploratory Haemodynamic Numerical Simulation of Patients with Multichannelled Aortic Dissection: A Multicentre, Retrospective Cohort Study.

Abstract

Objective: Multichannelled aortic dissection (MCAD) is a rare type of aortic dissection with limited data on its clinical features and outcomes. This multicentre, retrospective cohort study compared clinical outcomes between MCAD and double channelled aortic dissection (DCAD) and explored haemodynamic differences.

Methods: Patients with aortic dissection were enrolled from three tertiary hospitals. Patients with one true lumen and one false lumen were classified as having DCAD, whereas those with one true lumen and multiple false lumina were classified as having MCAD. Propensity score matching balanced baseline characteristics. Primary outcomes were 30 day and five year all cause mortality after diagnosis. Secondary outcomes included preprocedural mortality, aortic dissection related mortality, post-operative complications, and re-intervention. Overall survival was assessed using Kaplan-Meier analysis. Haemodynamic differences were evaluated by exploratory computational fluid dynamics (CFD) analysis.

Results: After matching, 50 patients were included in each group (n = 100). The difference in 30 day mortality was significant (p = .046) and largely reflected preprocedural deaths, which occurred in six patients with MCAD (12%) and none with DCAD (p = .027). Overall survival differed between groups (log rank p = .037; hazard ratio 2.72, 95% confidence interval 1.03 - 7.18; p = .044). Kaplan-Meier estimated mortality at 30 days, one year, and five years was 16%, 23%, and 29% in MCAD compared with 4%, 8%, and 12% in DCAD, respectively. Among treated patients, re-intervention was more frequent in MCAD than in DCAD (21% vs. 6%; p = .036), whereas post-operative complication rates did not differ. Exploratory CFD analysis suggested greater false lumen haemodynamic burden in MCAD.

Conclusion: MCAD was associated with greater preprocedural mortality and more frequent re-intervention than DCAD. These findings may identify MCAD as a higher risk phenotype warranting closer surveillance and timely evaluation. Haemodynamic observations remain exploratory and require validation in larger prospective cohorts.