title: Distinction between acute and chronic type B aortic dissection: is there a sub-acute phase?
abstract: OBJECTIVE
  This study aims to assess the relevance of the definition of acute dissection, to analyse whether there is a sub-acute phase and to determine early outcome of thoracic endovascular aortic repair (TEVAR) in acute complicated type B aortic dissection.
  
  
  METHODS
  Dual-centre consecutive case series.
  
  
  METHODS
  Between 1999 and 2011, 102 patients underwent TEVAR for non-traumatic acute complicated type B dissection in Zurich, Switzerland, and Uppsala, Sweden. In addition, 22 patients treated for an acute dissection-related complication occurring >14 days after onset of symptoms were included. Median age was 68 years, 35% were women.
  
  
  METHODS
  Demographic, procedural and outcome data were collected prospectively. The patients were followed up on 1 January 2012.
  
  
  RESULTS
  In the 22 sub-acute patients (18%), there were no early deaths or neurological complications. The predominant complication in these patients was rapid aortic enlargement, whereas rupture was more prevalent in patients treated within 14 days. In total, there were nine (7%) early deaths, three (2%) post-intervention paraplegias and six cases of stroke (5%).
  
  
  CONCLUSIONS
  TEVAR was performed with low early mortality and few neurological complications. A significant proportion of patients presented with acute complications >14 days after onset of symptoms, indicative of a sub-acute phase in the transition between acute and chronic dissection, questioning the relevance of the current definition.
authors.affiliation: Department of Surgical Sciences, Vascular Surgery, Uppsala University, Uppsala, Sweden. joste@live.se
authors.forename: J
authors.initials: J
authors.lastname: Steuer
authors.forename: M
authors.initials: M
authors.lastname: Björck
authors.forename: D
authors.initials: D
authors.lastname: Mayer
authors.forename: A
authors.initials: A
authors.lastname: Wanhainen
authors.forename: T
authors.initials: T
authors.lastname: Pfammatter
authors.forename: M
authors.initials: M
authors.lastname: Lachat
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000145:classification / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000145:classification / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery*; D001019:Aortic Rupture / Q000209:etiology; D002908:Chronic Disease; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010264:Paraplegia / Q000209:etiology; D011446:Prospective Studies; D020521:Stroke / Q000209:etiology; D016019:Survival Analysis; D013548:Sweden; D013557:Switzerland; D009626:Terminology as Topic; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome