Hybrid Reconstruction of the Aortic Arch Using a Double-Branched Stent-Graft in a Canine Model

Purpose: To report the results of a hybrid approach to aortic arch repair using an innovative unibody double-branched stent graft in a canine model. Materials and methods: The stent-graft system consists of two parts: the main body and two branches for reconstruction of the supra-arch branches. There is a 2-cm-long suturing portion at the proximal end of the main body. Twenty adult German sheep dogs underwent a hybrid surgical treatment to place the stent-grafts into the proximal descending aorta and the supra-arch branches. Outcomes were assessed by operative mortality, complications, imaging studies, and histomorphometric analyses. Results: Placement of the stent-graft was performed successfully in all dogs without complications. One dog died of respiratory failure due to early extubation. The other dogs survived to 6 months without complications, at which time they were sacrificed. The mean cardiopulmonary bypass time was 80.3 +/- 7.3 mins and hypothermic circulatory arrest time was 10.7 +/- 1.9 min. The average blood loss was 373.5 mL. At 6 months, postoperative aortic imaging indicated that the main body and branches of the stent-graft were fully open and in satisfactory position. No migration, deformation, or endovascular leakage was observed. Histomorphometric results showed normal arrangement of medial and adventitial elastic fibers, moderately proliferated intima, with or without neo-microvessels, and microscopic morphological changes in internal elastic lamina. Conclusions: These results demonstrate that it is possible and safe to reconstruct the aortic arch with the novel open-branched stent-graft placement.