Microsurgical reconstruction of the lymphatic and nerve system in small bowel transplantation: the rat model, first results.

The goal in tissue transplantation is the restoration of all natural (physiological) communication pathways between the host and the graft. To this end, the effects of microsurgical reconstruction of artery, vein, lymphatic vessel, and nerve during grafting were investigated. Allogenic (MHC class II incompatible) and isogenic orthotopic (graft in functional continuity) small bowel recipients with immediate microsurgical lymphatic and nerve anastomosis were observed clinically as well as by immunological and histological examination. To explain the influence of the lymphatic system in allograft survival, short-term therapy was applied with the immunosuppressant cyclosporin A (10 mg/kg i.m.) for only 5 postoperative days. Average allograft survival ended in the control group after 10 days without any therapy, increased up to 20 days after immunosuppressive therapy (in both groups acute rejection and graft-versus-host disease were seen) and increased further to more than 200 days following lymphatic connection of the host and the graft during allografting. In this group no lymphatic edema of the graft was seen. To determine the optimal location of nerve anastomoses between the host and the graft without irritating the host nerve system, isografts in the same model were investigated. No paralysis of graft neighboring tissues was seen when the last ganglion function, and its following nerve plexus, of the host is saved. Nerve reconstruction must be undertaken after this last crossing of regional nerve fibers before entering the organ. The same rule is effective for organ explantation.