Background Airway obstruction by postoperative hemorrhage after thyroid resection is a serious adverse and potentially life-threatening event. The aim of this study is to investigate if the possible pressure caused by a postoperative hematoma in the neck would be sufficient to compress the trachea and therefore leads to a mechanical airway obstruction.Methods In this ex vivo model varying pressures (0-250 mmHg) were applied on 30 human cadaver tracheas. The primary outcome was the anterior-posterior and latero-lateral tracheal diameter during the application of different pressures.Results At the highest pressures of 250 mmHg, there was an average compression of only 67.80 % in anterior-posterior direction and of 60.09 % in latero-lateral direction.Conclusions This study suggests that even pressures of 250 mmHg in neck-hematomas would be insufficient to cause a mechanical airway occlusion.Pathophysiology of airway obstruction caused by wound hematoma after thyroidectomy: an ex vivo study T. von Ahnen · M. von Ahnen · U. Wirth · A. Schroll · H. M. Schardey · S. Schopf Original Article 2 Pathophysiology of airway obstruction caused by wound hematoma after thyroidectomy: an ex vivo study