The frequency of trachealmalacia or stenoses following operations for struma or recurrent struma initiated our study of the pathogenesis of such changes. This study revealed that mechanical factors, such as compression of the trachea and the like, had been reported in the literature as the causative factors. The present paper investigates to what extent disturbances in the blood supply of the trachea, particularly after ligature of the inferior thyroid artery during thyroidectomy, influence changes in the tracheal mucosa, the connective tissue, and the adjacent cartilage. In twelve experiments on domestic pigs, the blood supply of the cervical trachea was interrupted. After varying periods of survival time, the animals were sacrificed and the tracheas histologically examined. In all cases, ischemic changes in the tracheal mucosa and cartilage could be found in addition to inflammatory reactions with scar formation. It seems justified to conclude that both mechanical factors and disturbances in local blood supply can cause tracheal tissue changes after thyroidectomy. The inferior thyroid artery and its branches also seem to play a central role in the success or failure of tracheal reconstructions following end-to-end anastomoses after stenosis resections. As a consequence, this paper also deals comprehensively with the detailed anatomy of this vessel.