Impact of Renal Chimney Grafts on Anatomical Suitability for Endovascular Repair in Ruptured Abdominal Aortic Aneurysm

Abstract

Purpose: To evaluate the impact of renal chimney grafts on anatomical suitability for endovascular aneurysm repair (EVAR) in ruptured abdominal aortic aneurysm (rAAA). Methods: Contrast-enhanced computed tomography images of 206 patients with rAAA [175 men (mean age 75±7.8 years) and 31 women (mean age of 76±7.5 years)] were evaluated in a dedicated 3-dimensional vascular workstation. Assessment of infrarenal EVAR suitability was based on predefined anatomical variables reflecting the Instructions for Use of commercially available stent-grafts. In patients where aneurysm neck length was the only limiting factor for suitability, reevaluation of the proximal sealing zone was done, accounting for chimney grafts in one or both renal arteries. Results: Seventy (34%) rAAA patients were anatomically suitable for EVAR: 65 (37%) of 175 men and 5 (16%) of 31 women (p<0.01). Eighty-nine (65%) of the 136 unsuitable patients had aneurysm necks <15 mm long; short neck was the only exclusion criterion in 33 (24%) cases. In the 33 short-necked aneurysms without other limiting factors, a proximal sealing zone >15 mm could potentially be achieved with one or two renal chimney grafts in 12 (36%) and 25 (76%) patients, respectively, increasing overall suitability to 40% and 46%. If access issues could also be solved and a similar strategy with chimneys for the renal arteries was applied, the EVAR suitability would increase further to 58%. Conclusion: Roughly one third of patients with rAAA are anatomically suitable for EVAR; short aneurysm neck is the most common exclusion criteria. In appropriate cases, chimney grafts in one or both renal arteries may increase overall suitability by 12%. Suitability increases to ~60% when iliac access issues are additionally overcome.