Esophageal transplantation in the rat.

Purpose: Esophageal replacement surgery has been used to treat long-gap esophageal atresia, caustic esophageal stricture, and esophageal avulsion. Here, we report total esophageal transplantation in rats without vascular anastomosis as an option for esophageal replacement surgery.

Methods: Fourteen total segments of esophageal transplants were harvested from 24-week-old male Sprague-Dawley rats using a harvesting procedure. The segments were transplanted through the mediastinum in the esophageal bed of 15-week-old male Sprague-Dawley rats without adjacent vascular anastomosis using the transhiatal pull-up technique. The ends of the transplanted esophagus were ostomized using cervical and abdominal esophagostomies. An immunosuppressive-treated (IT) group (n = 7) received cyclosporine and cotrimoxazole for 10 days, while an untreated (UT) group (n = 7) received only cotrimoxazole for 10 days. On post-operative day 10, the rats were sacrificed, and the transplant and recipient esophagi were evaluated macroscopically and histopathologically.

Results: All transplantations were successful and all transplanted rats survived. Upon macroscopic evaluation, no evidence of complications was observed and all transplanted esophagi in the two groups appeared to exhibit excellent firm tissue; however, mild necrosis was observed in the cervical end of the transplant in one rat in the IT group. Histopathologic examination showed a viable esophageal structure in all rats. Inflammation and muscular atrophy were lower in the IT group than in the UT group, whereas vascularity was higher in the IT group than in the UT group.

Conclusion: Total esophageal transplantation was performed directly without vascular anastomosis into recipients in a rat model. This procedure should be done in larger animal models before being attempted in humans.