Distal Arch and Proximal Descending Aorta Treatment in Aortic Dissection: Treat First what Kills First!

Objectives: Total aortic arch replacement (TAR) with an elephant trunk represents the most complete procedure for surgical treatment of acute type-A aortic dissection (ATAAD) involving the aortic arch and the descending aorta. Nevertheless, this demanding surgical approach has a higher perioperative mortality compared to hemiarch replacement (HAR) followed in a two-step procedure by a subsequent extrathoracic transposition of the left subclavian artery and a thoracic endovascular repair (TEVAR) of the descending aorta. Aim of the study was to compare these two procedures in terms of 30-day mortality and the need for aortic redo surgery in the long-term follow up.

Methods: From 155 patients with ATAAD treated between December 2010 and September 2019 in our unit, the distal aortic arch was affected in n = 101 (65%). The ascending aorta was replaced and the arch inspected under hypothermic circulatory arrest (HCA) at 26°C and selective cerebral perfusion (SCP). In 35 patients, a TAR using the isle (n = 31; 89%) or individual anastomosis technique (n = 4; 11%) was performed. In n = 11 (31%) from these patients the descending aorta was treated using a (frozen) elephant trunk. In 66 patients initially a HAR, and later on a TEVAR was performed if needed.

Results: EuroSCORE II was 14.9 ± 11.6 for TAR and 17.3 ± 12.7 for HAR patients. Mean CPB (294 ± 88 vs. 240 ± 70 min), cardiac arrest (187 ± 86 vs. 141 ± 55 min), HCA (95 ± 44 vs. 52 ± 29 min), and SCP-times (79 ± 35 vs. 52 ± 34 min) were longer for TAR. 30-day mortality was 18% for HAR (n = 12). Two patients died intraoperatively due to coronary dissections. For TAR the 30-day mortality was higher (28%; n = 10; p = 0.01), caused by mesenteric ischemia (n = 5), stroke (n = 4), and myocardial ischemia (n = 1). Readmission for a second aortic procedure was needed in one TAR patient, who received an emergent TEVAR caused by a distal anastomosis problem, respectively in five HAR patients: one with a conventional redo-TAR and four treated electively with TEVAR after extrathoracic transposition of the left subclavian artery. All redo and second-step procedures following HAR were successful.

Conclusion: In patients with ATAAD by replacing the ascending aorta and the proximal aortic arch we treat first what kills first. If the tissue structure permits, HAR should be considered because of the lower perioperative risk. Subsequently, an extrathoracic transposition of the supraaortic vessels creating a proper landing zone for TEVAR is possible.