Stent Graft Therapy for False Lumen Aneurysmal Degeneration in Established Type B Aortic Dissection (FADED) Results in Differential Volumetric Remodeling of the Thoracic versus Abdominal Aortic Segments

Abstract

Despite optimal medical therapy of type B aortic dissections, false lumen aneurysmal degeneration of these established dissections (FADED) occur over long term (>6months). The efficacy of thoracic stent grafts (thoracic endovascular aortic repair [TEVAR]) in promoting aortic remodeling when placed at late time points remains controversial and was the focus of this investigation. Utilizing tomographic scans, the volume of 6 distinct aortic compartments were calculated including the stented true lumen and stented false lumen (STL and SFL), below-stent true and false lumens (BSTL and BSFL), and the infrarenal aorta true and false lumens (IRA TL and IRA FL) when applicable. Cross-sectional areas were calculated at 1-cm intervals, collated, and volumetric ratios were derived from preoperative values. From 2004 to 2011, 21 patients met inclusion criteria. Complete false lumen (FL) thrombosis was achieved in 85.7% of SFL and 26.3% of BSFL. Volumetric analysis demonstrated that 71% of patients had increased STL volume and 71% had decreased SFL. In the below-stent region, 75% of patients had increased true lumen (TL) with 59% concurrently decreased FL volume. The IRA TL volume increased in 85% of patients and the IRA FL also expanded in 75% of this cohort. At the latest time point, overall growth was noted in the infrarenal aortic segment. Utilization of TEVAR in patients suffering from FADED can promote TL expansion with concurrent FL regression; however, progressive dilation in the total infrarenal aorta volume may occur and warrants close surveillance.