D Endovascular aortic aneurysm repair
In 1991, the first endovascular stent was performed to repair an infrarenal aortic aneurysm. The development of this technique has created a less invasive approach to aortic aneurysm repair. Because of severe cardiac and respiratory pathology, it is believed that as many as 30% of patients with aortic aneurysms are not surgical candidates. Endovascular AAA repair (EVAR) was initially intended for patients with severe coexisting disease; however, its popularity has increased as the success of the procedure has improved. It is estimated that 20,000 EVAR procedures take place in the United States per year, which comprises 36% of aortic aneurysm repair.
Endovascular aortic aneurysm repair is also being used to treat patients with thoracic aortic aneurysms. The mortality rate for EVAR for elective descending thoracic aneurysm repairs range from 3.5% to 12.5% compared with an open approach, which is approximately 10%. There is a low incidence of spinal cord ischemia and paraplegia, which is reported from 0% to 6%. Potential reasons for the lack of spinal cord complications are no thoracic aortic cross-clamping and no prolonged periods of extreme hypotension. Perioperative hypotension (MAP <70 mmHg) was a significant predictor of spinal cord ischemia in patients having EVAR for thoracic aneurysm repair. Endograft therapy has also been used with success and may eventually become the treatment of choice in patients older than 75 years of age for thoracic aneurysm repair.
The mortality rate for patients with a ruptured AAA who are alive when diagnosed in emergency departments is 40% to 70%. The EVAR approach has been used successfully to repair ruptured AAAs. The number of patients treated and the quality of randomized controlled data on this subject are limited. Medical centers that consider EVAR for ruptured AAA repair should have emergent CT imaging capabilities, a trained endovascular team, adequate endovascular supplies available, and a surgical suite.