Pulmonary Hypertension in a Dog after Embolic Coil Placement for Interventional Occlusion of Patent Ductus Arteriosus

An 8 month-old female Pomeranian dog was presented with major complaints of heart murmur andcardiomegaly. Diagnostic study found the left-to-right patent ductus arteriosus (PDA) with moderate heart failure(ISACHC II). The PDA occlusion was successfully accomplished using a 5 mm × 3 loops embolic coil through rightfemoral artery. Two months later, the dog came back to clinic with marked hypotension, severe diarrhea and pleuraleffusion. Diagnostic study found severe pulmonary hypertension and tricuspid regurgitation. The clinical condition wascontrolled by the administration of sildenafil (3 mg/kg, PO, TID). However, the dog was expired by dislodged emboliccoil and inconsistent medication by the owner. Postmortem study found the pulmonary hypertension was occurred bythe abnormally dislodged embolic coil. Although the embolic coil is widely used for PDA occlusion in toy dogs withPDA, the more careful evaluation for the size and shape of PDA is necessary to minimize the risk of dislodgementof pre-placed coil.