Aortic Remodeling in Type B Aortic Dissection: Effects of Endovascular Stent-Graft Repair and Medical Treatment on True and False Lumen Volumes

Purpose: To analyze aortic remodeling processes in terms of true (TL) and false lumen (FL) volumes in patients with type B aortic dissection undergoing thoracic endovascular aortic repair (TEVAR) versus patients treated medically. Methods: Serial contrast-enhanced computed tomography (CT) scans of 27 type B dissection patients (24 men; mean age 60 +/- 13 years) who underwent TEVAR (n=17) or medical therapy only (n=10) were analyzed. TL and FL volumes over the entire descending aorta at baseline and at follow-up were quantified by 3-dimensional reconstruction. Results: Follow-up in the 27 patients was a mean 14 +/- 6 months. TEVAR resulted in a continued gain in total TL volume (132 +/- 56 mL at baseline, 164 +/- 51 mL early after TEVAR, and 220 +/- 68 mL at follow-up, p<0.001), whereas TL volume was almost unchanged in the medical therapy group (113 +/- 34 to 120 +/- 41 mL, p=0.195). Total FL volume decreased significantly in TEVAR patients during follow-up (257 +/- 147 mL at baseline to 178 +/- 140 mL, p<0.001), whereas there was no significant change in FL volume in the medical therapy patients. The increase of TL and the decrease of FL volume in the TEVAR group were mainly observed in the descending thoracic aorta. Conclusion: TEVAR for type B aortic dissection results in a significant increase in TL and a decrease in FL volumes, not only acutely but also over time due to continued remodeling processes primarily in the thoracic aorta, with little impact on abdominal aortic volumes. Our data provide insight into the mechanism of a potential therapeutic benefit of TEVAR over medical therapy in type B dissection, which remains to be confirmed in a randomized clinical trial.