Outcomes of elective use of the chimney endovascular technique in pararenal aortic pathologic processes

In the treatment of pararenal abdominal aortic aneurysms and aortic pathologic processes, chimney endovascular aneurysm repair (CHEVAR) represents an alternative technique for urgent cases. The aim of the study was to evaluate the outcomes of CHEVAR in the elective setting.

We performed a retrospective analysis of prospectively collected records of 165 consecutive asymptomatic CHEVAR patients who were treated between March 2009 and January 2018 with the Endurant stent graft (Medtronic, Santa Rosa, Calif). A total of 244 chimney grafts (CGs) were implanted. The primary end point was clinical success, defined as freedom from procedure-related mortality, persistent type IA endoleak, occlusion or high-grade stenosis (>70%) of CGs, and any chimney technique-related secondary procedure for the entire follow-up period. Secondary clinical success included patients with successful treatment of a primary end point with a secondary endovascular procedure.

All 244 targeted chimney vessels were successfully cannulated. Total perioperative morbidity was 7.8% (n = 13), including 3 (1.8%) cases of bowel ischemia, 1 (0.6%) patient with renal ischemia, and 1 patient (0.6%) with stroke. Median follow-up was 25.5 ± 2.2 months. Both 30-day and follow-up procedure-related mortality rates were 1.8% (n = 3). Primary and secondary freedom from persistent type IA endoleak rates were 96.4% (n = 159) and 99.4% (n = 164), respectively. Primary and secondary CG patency rates were 92.2% (n = 225) and 95.9% (n = 234), respectively. The rate of reinterventions related to the chimney technique was 10.9% (n = 18), and 83.3% of them were performed by endovascular means. The estimated cumulative primary patency and freedom from persistent type IA endoleak were 87.5% and 95.3%, respectively, and the primary and secondary clinical successes rates at midterm were 80.3% and 87.5%, respectively.

The elective use of CHEVAR with the Endurant stent graft in our series showed favorable midterm clinical results, which are similar to the published results of other total endovascular modalities. A prospective randomized trial of elective treatment of pararenal abdominal aortic aneurysms and aortic pathologic processes with current endovascular options is needed to assess the value of CHEVAR in the elective setting.