Related Experiment Video
Updated: Aug 16, 2026
A Preclinical Model of Orthotopic Heart Transplantation in Bama Miniature Pigs Using Biatrial Technique
Published on: June 13, 2025
Heart and en-bloc thymus transplantation in miniature swine
Douglas R Johnston1, Ashok Muniappan, Ruediger Hoerbelt
1Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Background:
Donor-specific tolerance to organ allografts might be induced by cotransplantation of a sufficient amount of vascularized donor thymus. To facilitate donor thymus-induced cardiac allograft tolerance, we have developed a novel technique for heart and en-bloc thymus transplantation in swine.
Methods:
Donor heart and en-bloc thymus grafts were prepared by a technique that preserves the entire arterial supply and venous drainage of the right thymic lobe. En-bloc grafts (n = 4) were transplanted heterotopically into the abdomens of major histocompatibility complex-matched miniature swine. Recipients received 12 days of cyclosporine intravenously. Grafts were monitored by palpation, electrocardiographic monitoring, and periodic open biopsy. Engraftment of the donor thymus was demonstrated by measuring the proportion of recipient-type thymocytes in the donor thymus with flow cytometry.
Results:
All of the heart and en-bloc thymus grafts had normal cardiac contractility and immediate perfusion of the thymus. All en-bloc grafts were accepted for more than 200 days without significant acute cellular rejection or cardiac allograft vasculopathy. Thymic tissue of en-bloc grafts displayed normal architecture and supported thymopoiesis of recipient-type cells.
Conclusion:
We have validated a new technique of donor thymus transplantation that could have utility in human heart transplantation.
