We have previously reported on a straight artificial trachea developed by our group that can be applied to the cervical and thoracic trachea. In this study, a new Y-shaped artificial trachea was designed and adapted for experimental replacement of defective tracheal bifurcations in 20 dogs. The Y-shaped Marlex mesh tube was reinforced with a polypropylene spiral and coated with collagen made from porcine skin. This coating process makes the prosthesis biocompatible and airtight. Replacement of the tracheobronchial bifurcation was performed through a right thorachotomy, and omentopexy was added in all 20 dogs. Six of the 20 dogs have survived. The causes of death of the other 14 dogs were obstruction of the main bronchus (one dog), omental necrosis (three dogs), and air leakage from the prostheses and suture points (10 dogs). In all six surviving dogs, the artificial tracheas are covered with regenerated tissue and there is no evidence of stenosis or dehiscence. These results indicate that the prosthesis can be effective and safe in the long-term; however, air leakage from the prosthesis is a serious complication. Therefore, a better method is needed to make the prosthesis airtight to improve the postoperative result.