Nationwide Analysis of Persistent Type II Endoleak and Late Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in Japan: A Propensity-Matched Analysis

Abstract

Background: We reviewed the results of endovascular aneurysm repair in patients from the Japanese Committee for Stentgraft Management registry to determine the significance of persistent type II endoleak (p-T2EL) and the risk of late adverse events, including aneurysm sac enlargement.

Methods: The prospectively captured medical records of 17 099 patients <75 years of age who underwent endovascular aneurysm repair for abdominal aortic aneurysm from 2006 to 2015 were reviewed. Patients were divided into 2 groups (with or without p-T2EL) and compared to examine the correlation between p-T2EL and the occurrence of aneurysm sac enlargement after endovascular aneurysm repair.

Results: Of the patients, 4957 (29.0%) had p-T2EL and 12 142 (71.0%) had no p-T2EL (non-T2EL). Mean age was significantly higher (P<0.001), and there were fewer men (P<0.001) in the p-T2EL group. Among comorbidities, hypertension (P=0.019) and chronic kidney disease (P=0.040) were more prevalent and respiratory disorders were less prevalent (P<0.001) in the p-T2EL group. From each group, 4957 patients were matched according to propensity score to adjust for differences in patient characteristics. The cumulative incidence rates of abdominal aortic aneurysm-related mortality (p-T2EL: 52 of 4957 [1.0%] versus non-T2EL: 21 of 12 142 [0.2%]), rupture (p-T2EL: 38 of 4957 [0.8%] versus non-T2EL: 13 of 12 142 [0.1%]), sac enlargement (≥5 mm; p-T2EL: 1359 of 4957 [27.4%] versus non-T2EL: 332 of 12 142 [2.7%]), and reintervention (p-T2EL: 739 of 4957 [14.9%] versus non-T2EL: 91 of 12 142 [0.7%]) were significantly higher in the p-T2EL than the nonpT2EL group (P<0.001). Propensity score matching yielded higher estimated incremental risk, including abdominal aortic aneurysm-related mortality, rupture, sac enlargement (≥5 mm), and reintervention for p-T2EL (P<0.001). Cox regression analysis revealed older age (P=0.010), proximal neck diameter (P=0.003), and chronic kidney disease (P<0.001) as independent positive predictors and male sex as an independent negative predictor (P=0.015) of sac enlargement.

Conclusions: The Japanese Committee for Stentgraft Management registry data show a correlation between p-T2EL and late adverse events, including aneurysm sac enlargement, reintervention, rupture, and abdominal aortic aneurysm-related mortality after endovascular aneurysm repair. Besides p-T2EL, older age, female sex, chronic kidney disease, and dilated proximal neck were associated with sac enlargement.

Keywords: analysis; aortic aneurysm, abdominal; endoleak.

Figure 1.

Study population and inclusion/exclusion criteria. *Other diseases: 40 patients with other vascular pathologies—aortoiliac occlusive disease in 15, vascular injury in 11, renal artery aneurysm in 3, subclavian artery aneurysm in 2, aortoiliac fistula in 2, ureteroaortic fistula in 2, thrombosis in 2, femoral artery aneurysm in 1, superior mesenteric artery aneurysm in 1, and inferior mesenteric artery aneurysm in 1—were excluded. AAA indicates abdominal aortic aneurysm; EVAR, endovascular aortic repair; CT, computed tomography; IMA, inferior mesenteric artery; and p-T2EL, persistent type II endoleak.

Figure 2.

Cumulative incidence curves (entire cohort). A, Cumulative incidence of abdominal aortic aneurysm (AAA)–related mortality was significantly higher in the persistent type II endoleak (p-T2EL) group than in the non-T2EL group (P<0.001). B, Cumulative incidence of AAA rupture after endovascular aortic repair (EVAR) was significantly higher in the p-T2EL group than in the non-T2EL group (P<0.001). C, Cumulative incidence of aneurysm sac enlargement (≥5 mm) was significantly higher in the p-T2EL group than in the non-T2EL group (P<0.001). (D) Cumulative incidence of reintervention was significantly higher in the p-T2EL than in the non-T2EL group (P<0.001). AAA,; EVAR,; p-T2EL,.

Figure 3.

Cumulative incidence curves (propensity score–matched cohort). A, Cumulative incidence of abdominal aortic aneurysm (AAA)–related mortality was significantly higher in the persistent type II endoleak (p-T2EL) group than in the non-T2EL group (P<0.001). B, Cumulative incidence of AAA rupture after endovascular aortic repair (EVAR) was significantly higher in the p-T2EL group than in the non-T2EL group (P<0.001). C and D, Cumulative incidence of aneurysm sac enlargement (≥5 mm; P<0.001) and reintervention (P<0.001) was significantly higher in the p-T2EL group than in the non-T2EL group.