Purpose: To present our initial experience with the use of chimney grafts in endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with challenging anatomy. Methods: Among 390 EVAR cases performed at our institution between November 2008 and February 2010, 15 patients (all men; mean age 81.8 years) underwent EVAR with synchronous placement of chimney grafts. The chimney technique involved placing covered stents parallel to the main aortic stent-graft to preserve or rescue flow to aortic branch vessels while extending the proximal fixation zone. All patients presented with pararenal aortic aneurysms with short necks (between 0 and 10 mm long) that required either suprarenal clamping to tailor a proximal anastomosis in open repair or suprarenal fixation to anchor an endoprosthesis. Chimney grafts were implanted into 10 left renal and 5 right renal arteries. Results: The immediate technical success was 100%. One early type II endoleak due to retrograde flow from the inferior mesenteric artery was detected and is under surveillance. Mean follow-up was 6.8 months (range 1–13). One chimney graft occluded 45 days postoperatively; the patient underwent open thrombectomy of the left renal artery and iliorenal bypass. The creatinine value at discharge was 1.6 mg/dL, and resting renal scintigraphy showed 36% perfusion for the left kidney and 64% for the right kidney. During follow-up, no patient required hemodialysis; no aneurysm-related deaths were noted. Conclusion: This limited experience demonstrates that the use of abdominal chimney grafts is feasible and safe. Long-term results in larger patient cohorts are needed evaluate the utility of this alternative endovascular technique.

Purpose To compare short-term outcomes between fenestrated and chimney endografts for pararenal aortic pathologies. Methods An English-language literature search up to January 2012 found 129 articles evaluating the immediate outcomes of endovascular repair of degenerative juxta-/suprarenal aortic aneurysms, type I endoleaks, and para-anastomotic aneurysms using the chimney technique or fenestrated endografts. Data concerning thoracoabdominal aortic aneurysms, ruptured aneurysms, and reports with <5 cases were excluded (n=84). An additional 28 articles were excluded for insufficient data, leaving 17 articles for review: 5 dealing with chimney grafts in 123 patients with pararenal aortic pathologies and 12 presenting data on 631 patients undergoing fenestrated stent-grafting. The composite endpoints were 30-day mortality, deterioration of renal function, new postoperative dialysis dependence, and endoleak rate. Results Cumulative 30-day procedure-related mortality was 0.58% (95% CI 0.0% to 2.93%) for the chimney group (n=3) and 1.17% (95% CI 0.26% to 2.09%, p=0.645) for the f-EVAR group (n=9). In the f-EVAR group, 86 (9.67%;95% CI 4.77% to 14.57%) patients suffered from postoperative renal impairment vs. 16 (12.43%) patients in the chimney group (95% CI 2.39% to 22.48%, p=0.628). In the chimney group, 4 (0.57%;95% CI 0.0% to 2.94%) patients required persistent postoperative dialysis in contrast to the 1.33% (95% CI 0.29% to 2.37%, p=0.567) rate (n=9) in patients undergoing f-EVAR. There were also no significant differences recorded in the endoleak rate: 1.93% (95% CI 0.0% to 4.82%) of the chimney patients had a persistent type Ia endoleak vs. 2.06% (95% CI 0.69% to 3.43%) for the f-EVAR group (p=0.939). For type II endoleaks, the rates were 2.16% (95% CI 0.0% to 10.77%) for the chimney group vs. 6.88% (95% CI 1.92% to 11.83%) for the f-EVAR group (p=0.352). No patient in the chimney group had a type III endoleak, and the rate was low in the f-EVAR group (0.32%,95% CI 0.0% to 0.91%, p=0.079). Conclusion No statistically significant differences were found between the two endovascular approaches for pararenal aortic pathologies in terms of 30-day mortality, renal impairment, or endoleak. These findings support the assumption that chimney grafts may be a reliable alternative in the treatment of pararenal aortic pathologies.

Purpose To present a clinical experience with the use of chimney grafts in the endovascular repair of aortic arch pathologies involving the supra-aortic branches. Methods The chimney technique consists of endovascular stent or stent-graft placement parallel to the main aortic stent-graft in order to preserve or rescue flow to aortic branch vessels and to allow proximal extension of endograft fixation zones. Between April 2009 and January 2011, 9 patients (7 men; mean age 58 years, range 39–76) had chimney grafts installed to the left subclavian artery (LSA) or left common carotid artery (LCCA) during urgent thoracic endovascular aortic repair (TEVAR) of 5 aortic arch aneurysms, a mobile aortic thrombus with peripheral embolism, symptomatic type B dissection, penetrating aortic ulcer, and persistent type I endoleak after TEVAR. Eight chimney grafts were implanted into the LSA in 6 patients and 5 into the LCCA in the other 3 patients. Results The immediate technical success was 88.9%. The post-TEVAR type I endoleak persisted despite the chimney graft; the patient underwent surgical arch replacement. One patient died within 30 days due to cardiac insufficiency. There were 2 access site complications requiring surgery (brachial artery pseudoaneurysm and heavily calcified femoral artery puncture site). Over a median follow-up of 15 months (range 4–22), all chimney grafts remained patent in the 7 surviving and successfully treated patients. Conclusion The use of chimney grafts in selected aortic arch pathologies with involvement of supra-aortic branches is safe and feasible. Long-term results and large series are needed in order to draw robust conclusions regarding this promising alternative endovascular technique.