WHAT IS THE LONG-TERM AORTIC REMODELING OUTCOME AFTER HEMI-ARCH REPAIR FOR ACUTE TYPE A DISSECTION? AN 11-YEAR STUDY

Abstract

Controversy is emerging regarding the optimal extent of arch replacement in acute Type A aortic dissection (ATAAD). Advocates for total arch as opposed to hemi-arch repair suggest improved long term aortic remodeling with extended arch technique due to distal true lumen expansion and false lumen obliteration. However, the data on imaging follow-up after hemi-arch repair in the current era is not robust. Purpose of this study is to determine long term survival and assess aortic remodeling of the descending thoracic aorta following hemi-arch repair for ATAAD. From 2005 to 2017, 133 patients with a mean age of 60 ± 13 years underwent hemi-arch repair for ATAAD. Long term survival was followed through a provincial database. Double oblique cross sectional reconstructions were used to measure aortic diameters and areas at 3 levels on patients presenting with a dissection flap in the descending aorta (DeBakey Type I). Clinical follow-up was 98% complete. Thirty-day mortality was 9.7% (n=13). Kaplan Meier analysis revealed 8-year estimated survival of 69%. Aortic re-intervention occurred in 26 patients for an estimated 5-year re-intervention rate of 24%. The primary indication for re-intervention was in the arch/descending in 81% (n=21), valve/root 12% (n=3), and abdominal aorta 8% (n=2). Median imaging follow-up time was 4.3 ± 2.6 years. Average aortic diameter increased 6.46 ± 3.31 mm in proximal descending aorta, 5.48 ± 3.58 mm in mid descending aorta, and 3.05 ± 1.77 mm at distal descending aorta. The descending aorta grew at >2 mm/year in 46% of patients with 16% growing >4 mm/year. False lumen obliteration at the proximal descending aorta was achieved in 18% of patients. Kaplan Meier estimated survival after hemi-arch surgery for ATAAD appears to be compromised in a relatively young patient population. Aortic re-intervention is more common than previously appreciated. Distal aortic growth and lack of false lumen obliteration occurs in a significant number of patients suggesting adverse aortic remodeling after hemi-arch repair of DeBakey Type I dissections. This survival and imaging data establishes the benchmark for comparison with emerging therapies.