Delayed embolization of an Amplatz(®) canine duct occluder in a dog

A 5-year old, 5.8 kg, castrated male Pomeranian was diagnosed with a type IIa patent ductus arteriosus (PDA) with a minimal ductal diameter of 3.5 mm and ampulla width of 7.1 mm based on angiographic assessment. A 6 mm Amplatz(®) Canine Duct Occluder (ACDO) was deployed within the PDA. Once deployed, the device assumed it's native shape and back-and-forth maneuvering was performed with the delivery cable to assess device stability. Device position and complete occlusion were confirmed with both angiography and transesophageal echocardiography prior to and after release of the device. The device location was confirmed within the ductus arteriosus by echocardiography prior to discharge. The dog was discharged with instructions for strict activity restriction. Two days after discharge, the dog was left unsupervised in the backyard and shortly afterwards was found coughing with severe respiratory distress. The dog was evaluated at an emergency hospital and thoracic radiographs documented embolization of the ACDO to the main pulmonary artery along with a severe alveolar pattern throughout the right lung fields. Shortly after obtaining thoracic radiographs, the dog experienced cardiopulmonary arrest with unsuccessful resuscitation. This case describes a possible complication of transcatheter PDA occlusion with an ACDO, which has not been previously reported. An incident report, or catalog of adverse events with these devices, may prove useful in identifying additional fatal complications that others may have encountered, but are not reported in the literature. The report of this complication emphasizes the importance of strict activity restriction after device placement in dogs.