The aim of this study was to investigate the use of a prosthetic biologic material-lyophilized dura mater (Lyodura) in patching esophageal defects in dogs, having in view its potential use in bridging long gap congenital esophageal atresia and patching acquired esophageal defects. To follow the incorporation process, 20 mongrel dogs had full-thickness, 6 cm2 cervical esophageal defects, patched with Lyodura. The dogs were sacrificed at different postoperative periods and the patched esophagus removed for gross and microscopic examination. In a second group of 10 dogs, a segment of the esophagus was excised and replaced by 3 cm in length and 2 cm in diameter, Lyodura tubes. In this group, prolonged follow-up was undertaken including radiologic, endoscopic, and histological assessment. Special attention was given to the swallowing function and to growth and development. This study shows that: (1) the area of prosthetic replacement was characterized by a narrowing of the esophageal wall and the histopathologic study showed that the epithelialization process was complete in about 2 months; and (2) muscle reconstruction did not take place at the patched areas. We conclude that, pending further studies and improvement, lyophilized dura mater can be considered as a successful alternative for bridging esophageal defects.