Atraumatic tension hemothorax associated with ruptured aneurysm of intercostal artery-azygous fistula: a case report.

Atraumatic tension hemothorax is extremely rare. We report a case of 62-year-old woman presented with obstructive and hypovolemic shock status by tension hemothorax due to ruptured aneurysm of congenital intercostal artery-azygous fistula. Contrast-enhanced computed tomography and aortography revealed an aberrant 12th intercostal artery flowing into the aneurysm with a fistula draining into the azygous vein and the rupture of aneurysm. Our experience indicates that the rupture of congenital arteriovenous fistulas (AVFs) of systemic circulation in the thoracic cavity might cause not only hypovolemic shock but also atraumatic tension hemothorax. Surgery following preoperative endovascular embolization offers a feasible treatment strategy for ruptured aneurysms associated with AVFs.