Traumatic Pulmonary Arteriovenous Malformation Presenting as Spontaneous Hemothorax.

Pulmonary arteriovenous malformations (PAVM), also known as pulmonary arteriovenous fistulas, are abnormal connections between the pulmonary arterial and venous systems. The majority occur secondary to the congenital syndrome hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu disease. Trauma is an extremely rare etiology of PAVM, comprising less than 1% of all reported cases. Trauma can be associated with both immediate and delayed development of PAVM, and present similarly to PAVM associated with HHT. We report a case of a traumatic PAVM that developed in a patient one year following blunt thoracic trauma with a rib fracture. The patient subsequently developed a rupture of the PAVM, resulting in spontaneous hemothorax. She required multi-unit blood transfusion and multiple thoracostomy tube placements. The patient subsequently underwent a failed attempt at angioembolization of the PAVM. She eventually required a thoracotomy for surgical excision of the PAVM. We discuss the traumatic etiologies, clinical presentation, diagnostic assessments, and therapeutic modalities for the management of PAVM.