COMPLETE SURGICAL REMOVAL of tumors primarily or secondarily involving the trachea may require segmental excision. Occasionally grafting is necessary in the management of tracheal deformities after injury or infection. Numerous experimental studies and several clinical trials have done much to advance our knowledge of the problems involved in tracheal reconstruction and replacement. Recent reviews of these studies1,2indicate that such efforts have been plagued with infection, migration of the graft, ingrowth of fibrous tissue, and stenosis. Recent investigations in this laboratory have demonstrated that tubes of heavy mesh made of Marlex, a high-density polyethylene, will function satisfactorily as grafts for circumferential defects in the cervical trachea.1,3,4Such a graft has functioned without difficulty for more than 2 yr in a patient who required circumferential tracheal excision for recurrent carcinoma.5The present investigation was carried out to determine if similar grafts were applicable to the intrathoracic