Impact of Suprarenal Neck Angulation on Endovascular Repair Outcomes

Abstract

Hostile infrarenal proximal neck (β) anatomy of abdominal aortic aneurysm (AAA) has been associated with increased risk of aneurysm-related complications after endovascular repair (EVAR). However, there is a paucity of literature addressing the suprarenal angle (α). The aim of this study is to evaluate short and long-term outcomes after EVAR in patients with severe suprarenal neck angulation (>60°). A retrospective review of the medical records of 501 patients who underwent EVAR between January 2005 and December 2017 was performed. High-resolution computed tomography images of 462 patients (92.2%) were available. Patients were grouped into angulated (α > 60°) and nonangulated (α ≤ 60°) groups. The primary end point was freedom from type IA endoleak. Secondary end points included 30-day mortality, long-term survival, primary clinical success and freedom from aneurysm rupture and graft migration. Primary clinical success was defined in according to Society for Vascular Surgery guidelines as clinical success without the need for an additional or secondary surgical or endovascular procedure. Of 462 patients, 47 (10.17%) were included in the angulated group (α > 60°). The median follow-up time was 33 months (interquartile range, 14-55). Compared with patients in the nonangulated group, those in the angulated group had larger neck diameter at the level of the renal arteries (mean, 25.8 ± 3.8 mm vs 24.6 ± 3.4 mm; P = .029) and increased infrarenal angle (β; mean, 50.1 ± 22.6° vs 41.7 ± 23.9°; P = .02). The 3-year freedom from type IA endoleak estimates were 80.9% for the angulated group compared with 97.9% for the nonangulated group (P < .001; Fig). The angulated group showed significantly higher 30-day mortality (12.8% vs 0.5%; P < .001). In contrast, the 3-year results showed that patients in the nonangulated group had higher rates of primary clinical success (89% vs 68.1%; P < .001), freedom from rupture (99% vs 97.2%; P = .02), freedom from migration (100% vs 92.6%; P < .001), and long-term survival (91.4% vs 75.2%; P = .003) compared with those in the angulated group. After adjusting for age, gender, neck diameter, and infrarenal angle (β), severe suprarenal neck angulation was associated with higher odds of type IA endoleak (adjusted hazard ratio [aHR], 8.8; 95% confidence interval [CI], 2.9-26.6), loss of primary clinical success (aHR, 4.4; 95% CI, 2.4-7.9), and 30-day mortality [adjusted odds ratio, 29.4; 95% CI, 5.3-162) compared with an α of 60° or less (all P < .001; Table). This is the first report to show a significant increase in operative mortality in patients undergoing EVAR with a severely angulated suprarenal neck. Patients who survive the operation are at increased risk of secondary interventions. These findings suggest that EVAR should be used with caution in patients with severe α angulation and underpin the role of close follow-up in this particular population.TableOutcomes after endovascular aneurysm (EVAR) repairOutcomesAngulated (n = 47)Nonangulated (n = 415)P valueAdjusted odds ratio (95% confidence interval)P value30-Day mortality, no. (%)6 (12.77)2 (0.48)<.00129.37 (5.32-162)<.0013-Year outcomes Freedom from type IA endoleak, %80.997.9<.0018.8 (2.9-26.64)<.001 Primary clinical success, %68.189.6<.0014.34(2.39-7.87)<.001 Freedom from migration, %92.6100<.001 Freedom from rupture, %97.299.024.27 (0.61-29.67).14 Long-term survival, %75.291.4.0031.9 (0.5-7.0).33 Open table in a new tab