title: How to manage the left subclavian artery during endovascular stenting for thoracic aortic dissection? An assessment of the evidence.
abstract: BACKGROUND
  Despite the publication of recent guidelines for management of the left subclavian artery (LSA) during endovascular stenting procedures of the thoracic aorta, specific management for those presenting with dissection remains unclear. This systematic review attempts to address this issue.
  
  
  METHODS
  Systematic assessment of the published data on thoracic aorta dissection was performed identifying 46 studies, which incorporated 1,275 patients. Primary outcomes included the prevalence of left arm ischemia, stroke, spinal cord ischemia, endoleak, stent migration, and mortality. Outcomes were compared between patients with and without LSA coverage and revascularization incorporating factors such as the number of stents used, length of aorta covered, urgency of intervention, and type of dissection (acute or chronic). Statistical pooling techniques, χ(2) tests, and Fisher's exact testing were used for group comparisons.
  
  
  RESULTS
  As compared with other outcomes, LSA coverage without revascularization in the presence of aortic dissection is much more likely to be complicated by left arm ischemia (prevalence increased from 0.0% to 4.0% [p = 0.021]), stroke (prevalence increased from 1.4% to 9.0% [p = 0.009]), and endoleak (prevalence increased from 4.0% to 29.3% [p = 0.001]). However, revascularization was not shown to reverse these effects. Longer aortic coverage (≥ 150 mm) was associated with an increased prevalence of spinal cord ischemia (from 1.3% to 12.5% [p = 0.011]) and mortality (from 1.3% to 15.6% [p = 0.003]).
  
  
  CONCLUSIONS
  In patients undergoing endovascular stenting for thoracic aortic dissection, in cases where LSA coverage is necessary, revascularization should be considered before the procedure to avoid complications such as left arm ischemia, stroke, and endoleak, and where feasible, an appropriate preoperative assessment should be carried out.
authors.affiliation: Department of Cardiothoracic Surgery, St. Mary's Hospital, Imperial College Healthcare Trust, London, United Kingdom.
authors.forename: Syed M
authors.initials: SM
authors.lastname: Rehman
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Vecht
authors.forename: Ryan
authors.initials: R
authors.lastname: Perera
authors.forename: Rozh
authors.initials: R
authors.lastname: Jalil
authors.forename: Srdjan
authors.initials: S
authors.lastname: Saso
authors.forename: Emaddin
authors.initials: E
authors.lastname: Kidher
authors.forename: Andrew
authors.initials: A
authors.lastname: Chukwuemeka
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Cheshire
authors.forename: Mohamad S
authors.initials: MS
authors.lastname: Hamady
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
authors.forename: Richard G
authors.initials: RG
authors.lastname: Gibbs
authors.forename: Jon R
authors.initials: JR
authors.lastname: Anderson
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
mesh_terms: D000208:Acute Disease; D000784:Aortic Dissection / Q000401:mortality / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000401:mortality / Q000601:surgery*; D001132:Arm / Q000098:blood supply; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D016009:Chi-Square Distribution; D002908:Chronic Disease; D057867:Endoleak / Q000209:etiology; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D005548:Foreign-Body Migration / Q000209:etiology; D006801:Humans; D007511:Ischemia / Q000209:etiology; D018570:Risk Assessment; D012307:Risk Factors; D020760:Spinal Cord Ischemia / Q000209:etiology; D015607:Stents; D020521:Stroke / Q000209:etiology; D013348:Subclavian Artery / Q000601:surgery*; D016896:Treatment Outcome