Prevalence of the Computed Tomographic Morphological DISSECT Predictors in Uncomplicated Stanford Type B Aortic Dissection

Abstract

The aim was to analyse the prevalence of computed tomographic (CT) morphological predictors and their influence on early chronic phase aortic diameter expansion in patients with uncomplicated acute Stanford type B aortic dissection (ATBAD). This retrospective analysis reviewed the CT imaging of 140 patients admitted with uncomplicated ATBAD to two tertiary centres between March 2003 and April 2016. The prevalence of the following CT-morphological predictors was determined at baseline: primary entry tear (PET) diameter≥10mm, its location at the concavity of the aortic arch; maximum descending aortic diameter≥40mm; false lumen (FL) diameter≥22mm; partial FL thrombosis and a fusiform index (FI) of ≥0.64. Thoracic aortic diameter expansion (ADE) was evaluated in 65 patients treated by best medical therapy (BMT) (median CT follow up 11.6 months). Study end points were predictor prevalence and ADE. A mean±SD of 2.45±1.35 predictors were registered among all 140 patients; 75.0% of patients showed at least two predictors. In 7.9% of patients, no predictor was found. The prevalence of PET at the arch concavity was 18.6%, PET diameter ≥10mm in 60.0%, maximal descending aortic diameter ≥40mm in 51.4%, FL diameter ≥22mm in 47.9%, partial FL thrombosis in 47.9%, and FI≥0.64 in 20.7%. An ADE ≥5mm was observed in 38 of 65 patients. Median observed ADE was 5.1mm (median follow up (FU) 11.6 months, range-3.2-27.4mm). Regression analysis for multiple predictors showed a basic ADE of 2.5mm plus 1.9mm per predictor at the median FU of 11.6 months (2.5mm±1.9; 95% confidence interval CI -0.2-5.2mm±0.7-3.0mm; p=.003). In the majority of patients, at least one of the investigated morphological predictors of disease progression in uncomplicated ATBAD was detected. An ADE ≥5mm affected 38 of 65 BMT patients. CT based predictors help to define TBAD patients at risk of progression.