Transplantation of newborn esophagus: an experimental study

The aim of this study was to see if allogeneic transplantation (Tx) of newborn esophagus can create viable esophageal tissue that may be used for treating long gap esophageal atresia.

Specimens of thoracic esophagus from newborn Brown-Norway rats, each were transplanted into a pouch created in the distal omentum of 5-week-old Lewis rats. In group I no immunosuppressant was used. FK-506 was used in group II (0.2 mg/kg), group III (0.6 mg/kg), and group IV (1.2 mg/kg) until a predetermined day of graft harvesting (1, 2, 3, 4, 5, 6, and 8 weeks after Tx). FK-506 was used for only 2 weeks in group V (0.6 mg/kg), and group VI (1.2mg/kg), and transplanted esophageal grafts were harvested 1, 2, 3, and 4 weeks after cessation of 2 weeks course FK-506. Syngeneic esophagus transplants were used as controls. All grafts were examined by H&E staining to assess graft viability and degree of rejection.

Each successfully transplanted esophagus appeared macroscopically as a tube like mass. Each graft could be mobilized to the thoracic cavity, because of the long omental pedicle. Graft survival in the control group was 100%. Rejection was observed in all grafts from groups I, II, V, and VI. In contrast, grafts from groups III and IV showed only minimal or no rejection. There was no evidence of side effects of FK-506 in rats in groups III and IV, except significantly slower weight gain compared with controls (P <.05).

FK-506 successfully prevented rejection, although immunologic tolerance was not achieved. These observations suggest that the authors' procedure has the potential to produce viable esophageal tissue that could be a new option for treating long gap esophageal atresia.