The learning curve effect on outcomes with frozen elephant trunk technique for extensive thoracic aorta disease

The purpose of this study was to analyze the learning curve effect on hospital mortality, postoperative outcomes, freedom from reintervention in the aorta and long-term survival after frozen elephant trunk (FET) operation.

From July 2009 to June 2018, 79 patients underwent surgery with the FET technique. They had type A aortic dissection (acute 7.6%, chronic 33%), type B aortic dissection (acute 1.26%, chronic 34.2%), and complex thoracic aortic aneurysm (24%). 27.8% were reoperations and 43% received concomitant cardiac procedures. To compare the results, the sample was divided into group 1 (G1) (first half of the sample - operations from 2009 to 2014) and group 2 (G2) (first half of the sample - operations from 2015 to 2018).

The in-hospital mortality was 20.25%, 30.7% for G1 and 10% for G2 (P = .02). The mean cardiopulmonary bypass time, myocardial ischemia time, and selective cerebral perfusion at 25°C time were 154 ± 31, 118 ± 32, and 59 ± 12 minutes, respectively, similar for both groups. Stroke and spinal cord injury occurred in four and two patients, with no difference between groups (P = .61 and P = .24). The necessity for secondary intervention on the downstream aorta for both groups was also similar (P = .136). Five of sixty-three surviving patients died during the follow-up period and the estimated survival rate was different between groups 49% vs 88% (P = .007).

The learning curve with the FET procedure had a significant impact on hospital mortality and midterm survival over the follow-up period, albeit did not influence the freedom from reintervention on the downstream aorta.