Pulmonary vein injury through repetitive clip friction: an unusual cause of hemothorax.

Massive hemothorax developed in a 58-year-old man 12 hours after a left pneumonectomy. The source of bleeding was a tear in the pulmonary vein stump caused by a titanium clip that had been used during mediastinal lymphadenectomy. Postoperatively, the clip progressively sawed through the vascular wall of the pulmonary vein due to friction during the cardiac cycle.