The Chimney Technique in Endovascular Aortic Aneurysm Repair: Late Ruptures After Successful Single Renal Chimney Stent Grafts

Background: The chimney graft technique has been proposed as an alternative endovascular treatment of juxtarenal aortic aneurysms, extending the landing zone and enabling successful exclusion of the aneurysm with standard endograft devices. Methods: A prospective observational study assigning patients with juxtarenal aortic aneurysm treated with single renal chimney grafts in a tertiary vascular center in the United Kingdom was conducted. Primary outcome endpoints were defined as technical success, perioperative morbidity and mortality, and freedom from any type of endoleak, reintervention, and aneurysm-related death. Results: Nine patients were enrolled. Successful aortic and chimney graft implantation was achieved in all patients. A proximal type I endoleak noticed on completion angiogram was treated with an aortic extension cuff. None of the patients died within 30 days of treatment. Two patients developed a type IA endoleak during follow-up, resulting in aneurysm rupture and death. Both patients had had uneventful chimney procedures, and no endoleak was evident on previous surveillance computed tomographic scans. All chimney grafts remained patent, and none of the patients developed renal impairment during the follow-up period. Conclusions: Proximal type I endoleak constitutes a weak point of chimney graft interventions. Increased vigilance in surveillance of such patients to prevent late aneurysm-related complications is required. Additional research to identify potential poor prognostic morphologic indicators is expected.