Angiographic classification of patent ductus arteriosus morphology in the dog.

OBJECTIVES

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.

ANIMALS, MATERIALS AND 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.