title: Growth rate of aortic diameter in patients with type B aortic dissection during the chronic phase.
abstract: BACKGROUND
  The purpose of this study was to evaluate the growth rate of type B double-barrel aortic dissection with computed tomography (CT) and the factors influencing its enlargement.
  
  
  RESULTS
  Sixty-two patients were entered into this study, and regular follow-up CT studies (mean; 49.1 months) were performed. The affected aortas and iliac arteries were divided into 5 segments (aortic arch, descending thoracic, suprarenal abdominal, infrarenal abdominal aorta, and iliac artery). Fifty-two of 62 patients (83.9%) had 1 or more segments increased in size during follow-up period. In a total of 177 segments, the presence or absence of blood flow in the false lumen and aortic diameter were evaluated on CT during the follow-up period. The factors (gender, diabetes mellitus, atherosclerotic disease, smoking, entry site in arch, initial diameter, chronic obstructive pulmonary disease, blood pressure, and age) influencing increase in the diameter and growth rate were also evaluated. Of 177 segments, 132 segments (74.6%) increased in size during the follow-up period. The presence of blood flow in the false lumen was the only significant risk factor for increase in the diameter in the univariate and multivariate analysis. The group with blood flow in the false lumen had a significantly higher mean growth rate (3.3 mm/year) than the group without blood flow (-1.4 mm/year) (P<0.0001). The growth rate of aortic dissections in thoracic aorta and abdominal aorta were 4.1 and 1.2 mm/year, respectively. There was a significant difference in the growth rate between the 2 groups (P=0.0003).
  
  
  CONCLUSIONS
  In type B aortic dissection, the affected aortas have shown a high incidence of enlargement during the follow-up period, and more careful follow-up study is needed for aortic dissections in the thoracic aorta. The presence of blood flow in the false lumen is the most important risk factor for aortic enlargement.
authors.affiliation: Department of Radiology, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501. EijunSueyoshi@aol.com
authors.forename: Eijun
authors.initials: E
authors.lastname: Sueyoshi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sakamoto
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Hayashi
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tatuya
authors.initials: T
authors.lastname: Imada
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D000886:Anthropometry; D001014:Aortic Aneurysm / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D001027:Aortography; D001416:Back Pain / Q000209:etiology; D002637:Chest Pain / Q000209:etiology; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D018056:Hemorheology; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed