title: Angiographic classification of patent ductus arteriosus morphology in the dog.
abstract: OBJECTIVE
  To characterize angiographic morphology and minimum internal transverse diameter of left-to-right shunting patent ductus arteriosus (PDA) in a large series of dogs.
  
  
  BACKGROUND
  PDA is the most common congenital cardiac malformation in the dog. Transarterial ductal occlusion is increasingly performed to close this defect. While accurate assessment of ductal morphology and luminal diameter is important to assure optimal occlusion using catheter-delivered devices, such information is currently limited.
  
  
  METHODS
  In 246 dogs representing 31 breeds with left-to-right shunting PDA, right lateral selective aortic angiograms were recorded and reviewed.
  
  
  RESULTS
  PDA morphology conformed to four general phenotypes (types I, IIA, IIB, and III) which varied according to degree of ductal tapering, and the presence, absence, or location of abrupt ductal narrowing. Minimum internal ductal diameter for all dogs averaged 2.9mm (median, 2.5mm; range, 1.0-9.5mm) and was not correlated to age or body weight. There was no significant difference in minimum internal diameters between types I, IIA or IIB PDA, whereas, type III PDA was significantly wider (p=0.024) than other phenotypes. The most frequently-encountered variant (type IIA) was identified in 54.4% of cases (average minimum internal diameter, 2.3mm [median, 2.2mm; range, 1.0-5.5mm]).
  
  
  CONCLUSIONS
  PDA angiographic morphology was categorized based upon the degree, presence, or absence of ductal narrowing, and the location of ductal attenuation. When planning PDA repair, this information should assist planning, selection and deployment of transcatheter occluding devices.
authors.affiliation: Department of Small Animal Medicine and Surgery, and The Michael E. DeBakey Institute of Comparative Cardiovascular Sciences in Biomedical Devices, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Miller
authors.forename: Sonya G
authors.initials: SG
authors.lastname: Gordon
authors.forename: Ashley B
authors.initials: AB
authors.lastname: Saunders
authors.forename: Wendy G
authors.initials: WG
authors.lastname: Arsenault
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Meurs
authors.forename: Linda B
authors.initials: LB
authors.lastname: Lehmkuhl
authors.forename: John D
authors.initials: JD
authors.lastname: Bonagura
authors.forename: Philip R
authors.initials: PR
authors.lastname: Fox