Aortic Morphologic Findings After Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

IMPORTANCE Thoracic endovascular aortic repair (TEVAR) is used in the treatment of type B aortic dissections. Information related to aortic morphologic findings and the condition of the abdominal aorta after TEVAR is limited. OBJECTIVE To analyze aortic morphologic findings after TEVAR for type B aortic dissections. DESIGN, SETTING, AND PARTICIPANTS After a retrospective database review, the data for 30 patients who underwent TEVAR from January 1, 2007, through December 31, 2013, for type B aortic dissection were analyzed. Imaging software was used to calculate aortic diameters and volumes of the aorta on computed tomography (CT) or magnetic resonance imaging (MRI). Mean follow-up was 14.4 months. INTERVENTIONS We performed TEVAR to cover proximal thoracic aorta tears in patients who underwent acute or chronic type B aortic dissections. MAIN OUTCOMES AND MEASURES Aortic morphologic findings of pre-TEVAR CT or MRI were compared with the most recent findings of post-TEVAR CT or MRI. Frequency of thoracic false lumen thrombosis (FLT) and false lumen patency (FLP) was determined and the effect on post-TEVAR aortic morphologic findings analyzed. RESULTS Mean (SD) TEVAR increased true lumen diameter (19.50 [6.92] mm to 31.19 [5.36] mm, P < .001) and volume (77.92 [41.70] mL to 166.95 [69.69] mL, P < .001) and decreased false lumen diameter (29.77 [12.55] mmto 21.92 [12.05] mm, P = .001) on post-TEVAR CT or MRI when compared with pre-TEVAR scans. Seventy percent of patients experienced thoracic FLT; 30% had FLP. True lumen volume expansion and false lumen volume regression occurred in patients with FLT (82.07 [46.95] mmto 180.55 [77.99] mm, P < .001 and 161.84 [106.36] mmto 115.76 [140.77] mm, P = .002, respectively) and FLP (68.23 [21.43] mmto 128.22 [21.46] mm, P < .001 and 238.64 [174.00] mmto 198.93 [120.46] mm, P = .04, respectively). Patients with FLT had increased true lumen diameter (15.67 [6.43] mmto 26.13 [7.62] mm, P < .001) and volume (54.86 [30.52] mL to 88.08 [41.07] mL, P = .001) in the abdominal aorta after TEVAR, with no change in total abdominal aortic volume (161.94 [70.12] mL vs 160.36 [82.11] mL, P = .90). Total abdominal aortic volume significantly increased in patients with thoracic FLP (187.24 [89.88] mL to 221.41 [82.64] mL, P = .02). CONCLUSIONS AND RELEVANCE Favorable aortic remodeling of the thoracic aorta occurs after TEVAR for type B aortic dissections in patients with thoracic FLT and FLP. However, failure to achieve thrombosis of the thoracic false lumen negatively influences aortic morphologic findings of the contiguous abdominal aorta.