Management of the Left Subclavian Artery during Endovascular Stent Grafting for Traumatic Aortic Injury – A Systematic Review

Objectives and designTraumatic thoracic aortic injuries are serious and may be associated with high morbidity and mortality. Endovascular stent grafting is now an established treatment option which often requires proximal landing zone extension through left subclavian artery (LSA) origin coverage. This in turn can lead to downstream ischaemic complications which may be lessened by LSA revascularisation. This study investigates the consequence of LSA coverage and potential benefit of revascularisation.Materials and methodsSystematic literature review of studies between 1997 and 2010 identified 94 studies incorporating 1704 patients. Chronological trends in LSA management practice for trauma were sought. Designated outcomes of interest were prevalences of left arm ischaemia, stroke, spinal cord ischaemia, endoleak, stent migration, need for additional procedure and mortality. These outcomes were compared in patients with and without LSA coverage (taking account of the degree of coverage). The impact of revascularisation on these outcomes was also explored. Statistical analysis included examination with Chi-Square or Fisher’s tests as appropriate.ResultsIsolated total LSA coverage without revascularisation increases the prevalence of left arm ischaemia [prevalence of 4.06% versus 0.0% (p < 0.001)]; stroke [prevalence of 1.19% versus 0.23% (p = 0.025)]; and need for additional procedure [prevalence of 2.86% versus 0.86% (p = 0.004). In contrast there were no reported cases of stroke, spinal cord ischaemia, endoleak, stent migration or mortality when the LSA origin was only partially covered. When the LSA territory was revascularised, again no cases of left arm ischaemia, stroke, spinal cord ischaemia, endoleak, or mortality were reported.ConclusionCurrent evidence suggests that LSA coverage in patients undergoing endovascular stent grafting of the thoracic aorta for trauma should be avoided where possible to avoid ensuing downstream ischaemic complications. When coverage is anatomically necessary, partial coverage is better than complete in terms of avoiding these complications and revascularisation may be considered, however these decisions must be made in the context of the individual patient scenario.