title: Follow-up interval for small untreated pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia.
abstract: OBJECTIVE
  To investigate the natural history of untreated small (<3 mm) and microscopic pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia (HHT) in order to discern the optimal frequency of follow-up thoracic computed tomography (CT).
  
  
  METHODS
  A retrospective analysis was performed on the follow-up data for definite and suspected HHT patients with untreated PAVMs.
  
  
  RESULTS
  For small PAVMs in definite HHT (n=13), PAVM enlargement was identified in one patient (1/13, 7.7%) after 10.7 years follow-up and was successfully treated using transcatheter embolisation (TCE). For microscopic PAVMs in definite HHT (n=28), two patients (2/28, 7%) developed small asymptomatic PAVMs, which did not meet the size criteria for TCE after 6.8 years of follow-up. For small PAVMs in suspected HHT (n=5), feeding artery enlargement was seen in one patient (1/5, 20%) after 7.9 years, but again, this did not meet the size criteria for embolisation. No macroscopic PAVM development was identified after a median follow-up of 5.4 years in suspected HHT with microscopic PAVMs (n=20).
  
  
  CONCLUSIONS
  For small and microscopic PAVMs in HHT, PAVM enlargement was found to be more infrequent than would be expected based on current guidelines; therefore, potentially challenging the current surveillance imaging recommendation of a repeat thoracic CT every 5 years.
authors.affiliation: National HHT Centre, Mercy University Hospital, Grenville Place, Cork, Ireland; Department of Radiology, Mercy University Hospital, Grenville Place, Cork, Ireland. Electronic address: davidryan1895@yahoo.co.uk.
authors.forename: D J
authors.initials: DJ
authors.lastname: Ryan
authors.affiliation: National HHT Centre, Mercy University Hospital, Grenville Place, Cork, Ireland; Department of Respiratory Medicine, Mercy University Hospital, Grenville Place, Cork, Ireland.
authors.forename: T M
authors.initials: TM
authors.lastname: O'Connor
authors.affiliation: National HHT Centre, Mercy University Hospital, Grenville Place, Cork, Ireland.
authors.forename: M M
authors.initials: MM
authors.lastname: Murphy
authors.affiliation: National HHT Centre, Mercy University Hospital, Grenville Place, Cork, Ireland; Department of Radiology, Mercy University Hospital, Grenville Place, Cork, Ireland.
authors.forename: A P
authors.initials: AP
authors.lastname: Brady
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001165:Arteriovenous Malformations / Q000000981:diagnostic imaging* / Q000209:etiology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging; D011667:Pulmonary Veins / Q000002:abnormalities* / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000150:complications / Q000000981:diagnostic imaging*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D057832:Watchful Waiting / Q000379:methods*; D055815:Young Adult