Comparative study of Japanese frozen elephant trunk device for open aortic arch repairs

Objective We performed a multicenter prospective comparative study to determine the impact of a Japanese frozen elephant trunk device on total arch replacement compared with conventional repair without it. Methods Between 2016 and 2019, a total of 684 patients (frozen elephant trunk procedure; n = 369; conventional repair, n =315) from 41 institutions were enrolled. The two procedures were selected according to each center’s strategy. Results The frozen elephant trunk procedure was applied more for aortic dissection, whereas the conventional repairs were predominantly performed for aneurysms. In the former, only hypothermic circulatory arrest time was reduced among the intraoperative parameters. Although there were no differences in the 30-day and in-hospital mortality rates (0.8% and 1.6%, respectively, for the frozen elephant trunk procedure vs. 0.3% and 0.6%, respectively, for conventional repair), the neurological complication rates were significantly higher in stroke (5.7% vs. 2.2%; P = 0.022) and paraplegia (1.6% vs. 0%; P = 0.023). In the propensity score matching analyses using eleven variables, statistical significance disappeared in the differences for mortality and neurological morbidity (stroke and paraplegia/paraparesis) rates of 194 patients of each group, although they were still higher for the frozen elephant trunk procedure. Conclusions The early outcomes of total arch replacement with the frozen elephant trunk procedure were acceptable despite its higher prevalence of emergency or redo surgery, which was comparable with that of the conventional repair. This procedure had higher rates of spinal cord injury than the conventional repair，which is a disadvantage of this approach.