Low profile vascular plug for transarterial occlusion of patent ductus arteriosus in small dogs.

BACKGROUND

Minimally invasive transcatheter occlusion using Amplatz canine duct occluder (ACDO) is the treatment of choice for dogs with left-to-right shunting patent ductus arteriosus (PDA). However, in small dogs the femoral artery diameter is often too small to accommodate the guiding catheter required for ACDO deployment.

OBJECTIVE

Describe the effectiveness of transarterial implantation of Amplatzer Vascular Plug 4 (AVP-4), the only self-expandable nitinol mesh occlusion device which can be implanted through a 4 French diagnostic catheter, in small dogs with left-to-right shunting PDA.

ANIMALS

Seven client-owned dogs.

METHODS

Descriptive case series. Dogs with hemodynamically relevant left-to-right shunting PDA and a femoral artery diameter less than 2.0 mm measured preoperatively with ultrasonography were prospectively enrolled.

RESULTS

Angiography after releasing the device showed complete immediate PDA closure in 5 dogs, where the manufacturers' recommendation were strictly followed (30%-50% device oversizing of the ductal ampulla's diameter). Trivial residual flow on angiography in the 6th dog, whose device was slightly undersized, had resolved on echocardiography within 2 hours after placement. Marked device undersizing in the 7th dog resulted in severe residual shunting, which necessitated the addition of a coil. In this dog, the AVP-4 embolized into the pulmonary artery within 2 weeks after placement.

CONCLUSIONS AND CLINICAL IMPORTANCE

Transarterial implantation of AVP-4 is a safe, effective and technically easy procedure for PDA occlusion in small dogs and offers a valuable alternative to coil implantation. Accurate PDA measurement and device sizing is essential to prevent residual shunting, inadvertent device embolization, and protrusion of the device into the aorta.