Types of aneurysms
There are several types of aneurysms. The deadliest are aortic aneurysms and cerebral aneurysms. Aneurysms in other parts of the body, such as the legs, are not as fatal. Aortic aneurysms cause around 13,000 deaths  yearly in the United States.
Thoracic aortic aneurysm
Thoracic aortic aneurysms also affect the aorta, but they are significantly less common than abdominal ones. Thoracic aortic aneurysms account for only about 25 percent  of all aortic aneurysms. Many who develop this condition suffer from atherosclerosis.
This type affects the part of the aorta running through the diaphragm. Without treatment, thoracic aortic aneurysms have a survival rate of 50 percent . Without surgery, the survival rate goes up to 85 percent .