Background A true aneurysm is defined as a localized dilatation of the aorta, 50% over the normal diameter, which includes all three layers of the vessel, intima, media, and adventitia. According to Crawford classification, thoracoabdominal aneurysms are divided into types I to IV depending on the location of the dilation from the left subclavian artery to the abdominal segment. This is a case of trivial trauma leading to asymptomatic thoracoabdominal aortic aneurysm rupture in the right pleural space.
Case Report An 88-year-old elderly woman with a past medical history of well-controlled hypertension presented to the emergency room after a fall. She was trying to reach for the upper shelf in her closet when she lost her balance and fell down. The patient denied any loss of consciousness and was asymptomatic except for pain in her left knee. On initial evaluation in the emergency room, she was found to be hypertensive (with a BP of 170/80 mm Hg), tachycardic (pulse rate 100/min), and afebrile. She was breathing comfortably, with a respiratory rate of 16/min, and denied any chest pain or shortness of breath. Her initial laboratory data showed hemoglobin 10.5 g/dL/hematocrit of 31.1. Basic chemistries and renal and liver functions were essentially unremarkable. Her chest radiograph revealed large right-sided pleural effusion with dilated and tortuous descending thoracic aorta. This was particularly surprising as the patient denied any present or past pulmonary problems and had no current respiratory symptoms. However, in view of the incidental finding of large pleural effusion, the patient underwent CT of the chest without intravenous contrast to further delineate the exact pathology. The study revealed catastrophic findings of a descending thoracic aortic aneurysm with rupture and large hemothorax. The patient underwent emergent surgical repair of the ruptured aneurysm.
Discussion The most serious complications of thoracic aortic aneurysm are dissection or leakage, which can cause pain, or rupture, most often into the left intrapleural space or intrapericardial space. A descending thoracic aortic aneurysm can rupture into the adjacent esophagus, producing an aortoesophageal fistula and presenting with hematemesis. Rupture is often catastrophic, being associated with severe pain and shock. Painless dissection is very uncommon and is usually seen in patients who have a prior history of DM, aortic aneurysm, or cardiovascular surgery. A trivial trauma leading to painless thoracoabdominal aneurysm rupture, although rare, can be fatal, and the index of suspicion should be high in patients who present after a fall, especially as timely treatment can be lifesaving.