title: Growth rate of affected aorta in patients with type B partially closed aortic dissection.
abstract: BACKGROUND
  Our purpose was to evaluate the growth rate (GR) of the affected aorta and to clarify whether a partially closed false lumen can affect aortic enlargement in patients with type B double-barrelled aortic dissection (AD).
  
  
  METHODS
  Seventy-one patients (mean age, 64.4 years) who had experienced AD were enrolled in this study. Regular follow-up computed tomography studies (mean, 48.9 months) were performed. During the follow-up period, aortic diameter was measured with computed tomography. The fastest GR was calculated.
  
  
  RESULTS
  Based on final computed tomography findings, the patients were divided into three groups: those with completely closed false lumens (n = 8), those with partially closed false lumens (n = 20), and those with patent false lumens (n = 43). Among the patients with partially closed false lumens, 3 of 20 (15%) had a sac formation type and 17 (85%) had a non-sac formation type. The mean fastest GRs for groups with a completely closed false lumen, partially closed false lumen, and patent false lumen were -0.2 +/- 0.6, 4.0 +/- 4.3, and 4.9 +/- 4.5 mm/year, respectively. The differences among the three groups were statistically significant (p = 0.0149). In the partially closed false lumen group, the mean fastest GRs of the sac and non-sac formation types were 12.7 +/- 1.1 and 2.6 +/- 2.7 mm/year, respectively; this difference is statistically significant (p = 0.007).
  
  
  CONCLUSIONS
  Affected aortas with partially closed false lumens do not exhibit the highest GR. The status of a partially closed false lumen is not a significant risk factor for enlargement; however, careful follow-up study is needed whenever the sac formation type of partially closed false lumen is identified.
authors.affiliation: Department of Radiology, Nagasaki University School of Medicine, Nagasaki, Japan. eijunsueyoshi@aol.com
authors.forename: Eijun
authors.initials: E
authors.lastname: Sueyoshi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sakamoto
authors.forename: Masataka
authors.initials: M
authors.lastname: Uetani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000254:growth & development*; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000254:growth & development*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000379:methods*