Midterm outcomes and evolution of gutter area after endovascular aneurysm repair with the chimney graft procedure

The objective of this study was to describe our experience with endovascular aneurysm repair (EVAR) with the use of chimney grafts for branch vessel preservation.

Patients treated with a chimney graft procedure between October 2009 and May 2015 were included for analysis. Patients who were not considered eligible for open surgical repair or for conventional, branched, or fenestrated endovascular repair were selected. A standardized operating procedure with left brachial or axillary artery cutdown access for the chimney grafts and bilateral femoral artery cutdown access for the aortic main device was used. Outcomes were noted according to the Society for Vascular Surgery reporting standards. In addition, evolution of gutter area over time was determined. Estimated rates of survival, freedom from aneurysm growth, and clinical success at 24 months of follow-up were calculated.

Thirty-three patients (mean age, 77.6 ± 6.8 years; 87.9% male) with a mean preoperative maximum aneurysm diameter of 71.7 ± 13.5 mm were included. A total of 54 of an intended 54 chimney grafts were deployed. Primary technical success and 30-day secondary clinical success rates were 87.9% and 84.8%, respectively. The early mortality rate was 6.1% (n = 2). The early type IA endoleak rate was 6.1% (n = 2), and the chimney graft occlusion rate was 6.1% (n = 2). Median follow-up duration was 26 months (interquartile range, 14.8-37.3 months). The estimated 2-year actuarial survival rate was 78.1% (standard error, ±7.4%). Late complications included type IA endoleak (n = 1), chimney graft occlusion (n = 2), type II endoleak with aneurysm growth (n = 4), and distal stent graft limb kinking and occlusion (n = 1). Late reinterventions included coil or glue embolization (n = 3), distal limb extension (n = 2), open endoleak ligation (n = 2), Palmaz stent placement (n = 1), repeated EVAR (n = 1), and femorofemoral bypass graft (n = 1). At 2 years, the estimated secondary clinical success and freedom from aneurysm growth rates were 80.5% (±7.2%) and 84.4% (±7.2%). Gutter size showed a small but significant decrease over time at the level of the proximal markers and at 10 mm distal from the markers.

Midterm results show that a standardized procedure for EVAR using chimney grafts for branch vessel preservation is an acceptable option for high-risk patients with large, complex aneurysms who are unfit for open repair and who have been excluded from fenestrated EVAR. Gutter size decreases over time, but the rate of branch vessel loss and reinterventions demonstrate that this approach should remain reserved for those who are at truly prohibitive risk for open or fenestrated stent graft repair.