Abdominal aortic aneurysm: a 6-year comparison of endovascular versus transabdominal repair

Abstract

Objective: To test the hypothesis that endovascular repair of abdominal aortic aneurysm (AAA) will result in a significant reduction in mortality and morbidity rates and cost when compared with open transabdominal repair.

Summary background data: Since the introduction of endovascular repair of AAA this decade, multiple groups have evaluated different endovascular grafts. Despite the excellent results reported initially, there has been a paucity of well-controlled, comparative studies looking at long-term outcome.

Methods: From 1992 to 1998, the first 100 consecutive patients undergoing endovascular AAA repair (mean age 74.7, AAA size 5.6 cm) were compared to 100 patients undergoing transabdominal repair (mean age 72.9, AAA size 5.9 cm). All patients undergoing endovascular repair received a device manufactured by Endovascular Technologies, Inc. (Menlo Park, CA) and were prospectively followed with periodic examination, contrast-enhanced computed tomography, and duplex scanning. Of the 200 patients, 198 have been available for long-term follow-up.

Results: The two groups had similar preoperative risk factors. Surgical time (211 vs. 256 minutes, p < 0.005), blood loss (326 vs. 1010 ml, p < 0.005), and blood replacement (0.4 vs. 1.6 units, p < 0.005) were all decreased in the endovascular group. Median intensive care unit stay (0 vs. 2 days) and hospital stay (2 vs. 7 days) were significantly reduced in the endovascular group. Insignificant trends in lower morbidity rates (myocardial infarction 1 % vs. 5%, respiratory failure 1 % vs. 5%, colon ischemia 0% vs. 2%) were present in patients undergoing endovascular repair. This led to decreased hospital cost and increased hospital profit. The surgical mortality rate (2% vs. 3%) and 5-year survival rate (65% vs. 72%) have been equivalent between the two groups.

Conclusions: The surgical mortality rate is low for both groups and not statistically different. Endovascular repair significantly reduces resource utilization (surgical time, blood replacement, intensive care unit and hospital stay) and cost when compared to transabdominal aneurysm repair. Long-term survival is equivalent in patients undergoing AAA repair regardless of technique. Although endovascular repair appears durable for up to 6 years, longer follow-up studies are warranted.

Figures

Figure 1. Open repair of abdominal aortic aneurysm (AAA). (A) Standard transabdominal repair of AAA using a tube prosthesis. (B) Transabdominal repair of AAA using a bifurcated prosthesis in the setting of aneurysmal degeneration of the distal aorta, proximal iliac arteries, and/or occlusive disease in the iliac arteries.

Figure 2. Endovascular repair using the EVT devices. (A) A tube prosthesis is deployed in the infrarenal aorta when adequate proximal and distal aortic tissue (neck) is available for attachment. Note the pins that embed in the aortic tissue for attachment, allowing exclusion of the AAA. (B) A bifurcated endovascular prosthesis with two distal attachment systems for iliac artery deployment. (C) The aortouniiliac endovascular prosthesis. This configuration requires an extraanatomic femorofemoral bypass graft with a contralateral occlusion device in the common iliac artery. This device is used when significant aneurysmal disease is present in the contralateral iliac artery, precluding successful bifurcated graft placement.

Figure 3. Five-year survival curves. The survival rate is 72% for patients undergoing transabdominal repair of AAA and 65% for patients undergoing endovascular repair of AAA (p NS). The standard error exceeds 10% for only the last two data points on the EVT curve. For reference, the 5-year survival rate for all U.S. men aged 73 is 87%.