Hybrid Technologies for Reconstruction of Proximal Aortic Dissection.

The aim of the study is to evaluate the efficacy of various types of hybrid technology in compare to the classical repair of the aortic arch of type I aortic dissection treatment in the in-hospital period.

Materials and methods: A retrospective observational study has been conducted, the results of surgical treatment of 213 patients with DeBakey type I aortic dissection operated on within the period from 2001 to 2017 were compared. Patients were divided into three groups: in group 1, patients undergone a hemiarch type of aortic repair or the total arch replacement (n=121); in group 2, a hemiarch aortic reconstruction and implantation of bare metal stent was performed (n=55); in group 3, a frozen elephant trunk technique was used (n=37). Taking into consideration the retrospective character of the investigation and nonequivalence of the groups by separate characteristics, they were equalized to improve the reliability of the results using the PSM (propensity score matching) pseudorandomization method. As a result, three groups of comparison were formed which were equalized by the PSM method and called PSM 1, 2, and 3. The mortality and complication rate in the in-hospital period, as well as the frequency of false lumen thrombosis development depending on the treatment method, have been analyzed.

Results: The mortality rate in the PSM 1 group was 15 patients: group 1 (standard technique) - 10 patients (9%), group 2 (uncoated stents) - 5 patients (11%). A significant difference was found in the number of major bleedings (group 1 - 8%, group 2 - 21%, p=0.031) and cases of bowel ischemia (group 1 - 1%, group 2 - 9%, p=0.028). Complete false lumen thrombosis of the thoracic aorta was observed significantly more often in group 1 than in group 2 (22% vs 5%, p=0.015).In the examined group PSM 2, hospital mortality rate was 4 patients: group 1 - 3 patients (12%), group 3 - 1 patient (3%). No differences between the groups were found in the number of complications. In group 3, complete false lumen thrombosis of the thoracic aorta was observed in 59% of cases, whereas in group 1 it was found only in 4% of patients (p<0.001).In comparison group PSM 3, the mortality was 8 patients: group 2 - 5 patients (11%), group 3 - 3 patients (9%). The number of neurological complications differed significantly: in group 2 - 27%, in group 3 - 6% (p=0.019). Besides, 3% of cases of complete false lumen thrombosis were found in group 2, while there appeared 55% (p<0.001) of such patients in group 3.

Conclusion: The comparative analysis showed that the use of bare metal stents and hybrid prostheses demonstrated a comparable low level of in-hospital mortality compared to the standard surgical technique of aortic arch reconstruction. At the same time, the use of the bare metal stents is associated with a higher rate of perioperative complications (bleeding, postoperative bowel ischemia, neurological complications) compared to the standard treatment and repair of the aortic dissection using hybrid prostheses. Complete thrombosis of the false lumen occurred significantly less commonly in case of using bare metal stents than with standard treatment and hybrid prostheses.