A case of ruptured descending thoracic aortic aneurysm into the right pleural cavity: Importance of preoperative drainage of the right pleural cavity

We present an unusual case of a ruptured descending thoracic aortic aneurys m into the right pleural cavity of a patient with pectus carinatum. The pre sence of pectus carinatum played an important role in the development of th e aneurysm at the atypical site and the rupture into the right pleural cavi ty. A small amount of right pleural bleeding on admission can increase and develop to massive hemothorax until emergency operation. Massive bleeding i n the right pleural cavity where the dependent lung is located causes atele ctasis and increased shunt fraction under one lung ventilation. Therefore, continuous drainage of the right pleural cavity is essential to prevent ser ious hypoxia during graft replacement in a case of ruptured descending thor acic aneurysm into the right hemithorax.