Experimental En Bloc Heart–Lung Transplantation in Swine: Initial Experience in Vietnam

Abstract

Objective: To describe the surgical technique and early outcomes of experimental en bloc heart-lung transplantation in swine at 108 Military Central Hospital. Methods: This prospective experimental case series comprised three transplant procedures performed in 2021. Each procedure involved an organ donor, a recipient, and a blood donor. The heart-lung bloc was procured, preserved under cold conditions, and implanted through a median sternotomy using cardiopulmonary bypass (CPB). Four anastomoses were constructed: the tracheal, inferior and superior vena caval, and aortic anastomoses. Operative times, hemodynamics, blood gases, echocardiographic findings, coagulation parameters, and postoperative survival were analyzed descriptively. Results: Five technical protocols were developed, and all three transplantations were technically successful. Mean operative time was 233.3 ± 50.3 minutes, CPB time was 160.3 ± 46.8 minutes, aortic cross-clamp time was 81.0 ± 9.5 minutes, and cold ischemic time was 17.0 ± 2.6 minutes. All three graft hearts resumed beating; left ventricular ejection fraction after CPB discontinuation ranged from 70% to 85%. At two hours postoperatively, PaO₂ was 81-90 mmHg at an FiO₂ of 0.60, corresponding to PaO₂/FiO₂ ratios of 135-150 mmHg. One recipient required re-exploration for bleeding; postoperative bleeding and coagulopathy were documented in the study report. All three recipients died at 180, 325, and 370 minutes after surgery. Conclusion: To our knowledge, 108 Military Central Hospital is the first institution in Vietnam to perform experimental en bloc heart-lung transplantation. Five protocols provided a framework for coordination among animal preparation and logistics, anesthesia, perfusion, surgical, and postoperative intensive care teams. Technical success in three cases, with survival of approximately 3-6 hours, provides an experimental foundation for further development.