The mortality rate of emergency operation for abdominal aortic aneurysm is:

In elective surgery of abdominal aortic aneurysm, the operative mortality rate approximates 1 to 2% whereas after acute rupture the mortality rate of emergency operation generally approximates 45- 50%. Abdominal Aortic Aneurysms Abdominal aortic aneurysm (AAA) is the most common true arterial aneurysm. An aortic aneurysm is defined as a focal dilation of the aorta with a diameter of at least 1.5 times that of the expected normal diameter of that given aortic segment; in the AA, enlargement of the aortic diameter of more than 3 cm is usually considered aneurysmal. A most common site is infrarenal. More common in males than females. Incidence increases with age. At least 90% of all abdominal aortic aneurysms >4.0 cm are related to atherosclerotic disease. Prognosis is related to both the size of an aneurysm and the severity of coexisting coronary artery and cerebrovascular disease. The risk of rupture is directly related to the size of an aneurysm. An abdominal aortic aneurysm is usually asymptomatic. They are usually detected incidentally on routine clinical examinations or investigation performed for some other reasons. As abdominal aortic aneurysms expand, however, they may become painful. Aneurysmal pain is usually a harbinger of rupture and represents a medical emergency. More often, acute rupture occurs without any prior warning, and this complication is always life-threatening. Contrast-enhanced CT is an investigation of choice. MRI is as sensitive and specific as CECT and is used if the use of contrast is precluded. Ultrasound is the screening study of choice and is useful for serial documentation of aneurysm size Operative repair of an aneurysm with the insertion of a prosthetic graft or endovascular placement of an aortic stent graft is indicated for: abdominal aortic aneurysms of any size that are expanding rapidly or are associated with symptoms. for asymptomatic aneurysms, abdominal aortic aneurysm repair is indicated if the diameter is >5.5 cm. The decision to perform an open surgical operation or endovascular repair is based in part on the vascular anatomy and comorbid conditions. Endovascular repair of abdominal aortic aneurysms has a lower short-term morbidity rate but a comparable long-term mortality rate with open surgical reconstruction. (Harrison 18/e) In Elective surgery of abdominal aortic aneurysm the operative mortality, rate approximates 1 to 2% whereas after acute rupture the mortality rate of emergency operation generally exceeds 50%.