Risk stratification and outcomes of transluminal endografting for abdominal aortic aneurysm: 7-year experience and long-term follow-up

Purpose: To determine early and late outcomes of transluminal endografting (TE) in patients with abdominal aortic aneurysm (AAA), stratified by predic ted risk of procedure-related mortality with conventional operation. Materials and methods: A retrospective study was conducted in consecutive r isk-stratified AAA patients undergoing TE at a not-for-profit cardiovascula r referral center from March 1994 through November 2000 with follow-up thro ugh February 2001. With use of conventional risk strata (0=low, 1=minimal, 2=moderate, and 3=high), predicted procedure-related mortalities were 0%-1% in stratum 0 (n=40), 1%-3% in stratum 1 (n=118), 3%-8% in stratum 2 (n=116 ), and 8%-30% in stratum 3 (n=31). Main outcome measures were: (i) TE proce dural success, (ii) procedure-related mortality, (iii) major nonfatal compl ications, (iv) composite adverse outcome (ii + iii), (v) length of stay (LO S), (vi) freedom from AAA rapture, (vii) late survival, (viii) late complic ations, and (ix) endoleaks and their classification and management. Results: Women were significantly less likely than men to qualify for and u ndergo endografting: 24 of 91 (26.4%) women underwent TE, compared to 281 o f 684 (41.1%) men. Of 305 attempted TE procedures, 291 (95.4%) were success ful, four (1.3%) were urgently converted to open repair, and 10 (3.3%) were aborted. Procedure-related mortalities occurred in eight cases (2.6%) over all and one of 40 (2.5%), one of 118 (0.8%), four of 116 (3.4%), and two of 31 (6.5%) cases for risk strata 0-3, respectively. Perioperative survivors were significantly younger than nonsurvivors (74.3 y +/-9 vs 81.6 y +/-5.1 ; P=.0087). Forty-six patients (15.1%) had major complications. Composite a dverse outcome was worse for patients in stratum 3 than those in stratum 1 (P=.0296) and those in strata 0, 1, and 2 combined (P=.026). Procedure-rela ted mortality declined with institutional experience, from 4% among the fir st 100 patients undergoing TE to 1% among the last 105. For strata 0-3, med ian LOS were 2, 3, 3, and 4 days, respectively. Seventy patients (22.9%) ha d 75 endoleaks, of which 30 necessitated additional procedures, 17 self-res olved, and 22 were untreated as of March 1, 2001. Five patients with endole ak died of unrelated causes. One late-onset type IA endoleak (26 mo) result ed in the only AAA rupture and death in the follow-up period among the 291 patients who underwent successful transluminal. endograft implantation. Act uarial survival rates at 1 year after TE were 90.3%+/-1.9% for the overall study group and 97.5%+/-2.5%, 94%+/-2.5%, 86.9%+/-3.3%, and 81.3%+/-7.7% fo r risk strata 0-3, respectively. At 5 years, overall actuarial survival was 69.6%+/-6.1%. Thirty-eight late deaths were attributable to post-TE AAA ru pture (n=1), AAA rupture late after failed TE with no further treatment (n= 1), other cardiovascular disorders (n=7), cancer (n=15), other causes (n=10 ), and unknown causes (n=4). Late deaths occurred in risk strata 0-3 at the following rates: two of 40 (5%), 10 of 118 (8.5%), 16 of 116 (13.8%), and 10 of 31 (32.3%), respectively (stratum 0 vs stratum 3, P=.0017; stratum 1 vs stratum 3, P=.003). Conclusions: TE is safe and confers durable protection against AAA rupture in treated populations. Still, protection is not absolute in patients with endoleaks, because late AAA enlargement and even rupture can occur. Given c urrent knowledge, technology, and practice, careful patient selection and c lose surveillance of patients after implantation of transluminal endografts is essential.