The chimney technique for preserving the left subclavian artery in thoracic endovascular aortic repair

Abstract

OBJECTIVESThe objective of the present study was to evaluate short- and mid-term outcomes of the left subclavian artery (LSA) chimney stent implantation (LSACSI) during thoracic endovascular aortic repair (TEVAR), and to summarize our experience with this technique.METHODSFrom June 2010 to September 2012, 59 patients (49 men; mean age of 57.4 ± 13.3 years, range from 26 to 83 years) who underwent TEVAR and LSACSI were enrolled. Patients suffered from Stanford type B aortic dissection (n = 27), penetrating aortic ulcer (n = 18), aortic arch aneurysm (n = 9), pseudoaneurysm of the aortic arch (n = 4) and proximal type I endoleak after TEVAR of aortic dissection (n = 1). Elective settings were performed in 72% and emergent in 38% of all patients. Follow-up was performed at postoperative 3 months, 6 months and yearly thereafter.RESULTSThe technical success rate was 98.3% (58/59), and 69 thoracic stent grafts were used. Sixty-two chimney stents, including 55 uncovered and 7 covered stents, were implanted in 59 LSAs. The overall immediate endoleak rate was 15.3% (9/59); type I endoleak was observed in 5 patients and type II in 4 patients. The difference in the immediate endoleak rate related to the anatomy between the outer and the inner curvature was statistically significant (35 vs 4%, P = 0.018). Chimney stent compression was observed in 3 patients and another stent was deployed inside the first one. Perioperative complications included stroke (3.4%, 2/59) and left upper limb ischaemia (1.7%, 1/59). The median follow-up period was 16.5 (range 1–39 months). The mortality rate during follow-up was 5.4% (3/56). Complications during follow-up included endoleak [overall, n = 8 (14.3%, 8/56); type I, n = 5; type II, n = 3], retrograde type A aortic dissection (n = 1), collapse (n = 3, 5.4%) or occlusion (n = 2, 3.6%) of the chimney stent.CONCLUSIONSShort- and mid-term results showed that it is feasible to preserve the patency of the LSA in TEVAR with the chimney technique for thoracic aortic pathologies close to the LSA. However, TEVAR combined with LSACSI was not advocated for lesions located at the outer curve of the aortic arch due to a high possibility of endoleak.

Early Results of Chimney Technique for Type B Aortic Dissections Extending to the Aortic Arch

“…As a result, the gutter should be formed as far away from ET as possible. We observed its consistence with prior studies that the immediate endoleak rate was higher especially when the ET was located at the greater curvature of the aortic arch [17]. Theoretically, the supraaortic branches took off from the greater curvature, and it was hard to keep the gutter away from ET located at the greater curvature.…”

“…This technique, firstly performed in 2002, was thought to be a ''bailout'' option to rescue inadvertently covered vessels, and the follow-up observation proved the good results of this alternative [14,16]. This technique was then used even in planned procedures for patients considered unsuitable for open repair [12,17]. Its relatively easy procedure, familiar to most practicing surgeons, has shown its potential advantages and has been reported by increasingly more literature [3][4][5][6].…”

Chimney Grafts in Aortic Stent Grafting: Hazardous or Useful Technique? Systematic Review of Current Data

“…Overall mortality of patients with visceral CGs has been reported as 0%, 14 5%, 7 14%, 19 16%, 20 and 57%. 23 The corresponding data for thoracic CGs have been reported as 5%, 35 17%, 32 68%. 37 This raises some doubt about the claim of other investigators that patients were not candidates for open repair.…”

“…However, the frequency ranges 48 between 2% and 25% 6,20,21 for the visceral CGs, and from 8% to 44% for the thoracic CGs. 15,30,35,37 The larger diameter required for a brachiocephalic chimney is associated with a higher risk of endoleakage and may partly explain these differences. Yet another potential factor is that endoleaks seem less likely in dissections than in aneurysms.…”

Technical success is not the same as good patient outcome

“…Xue et al [1] show the immediate and mid-term outcome data. The authors of the present article need to be acknowledged for presenting their honest data in this challenging patient cohort.…”