Hybrid Surgical Approach Using Amplatzer Occluder for Treatment of VSD in a Cat

Ventricular septal defect (VSD) is among the most common feline congenital heart malformations. Although usually treated by pulmonary artery banding or pharmacotherapy, neither method is curative. Curative procedures have been performed in humans. Treatment of VSD is usually not required in dogs and cats, but is necessary in cases of non-restrictive VSD. Dogs with non-restrictive VSD are treated either using surgical correction under open-heart surgery, or percutaneous insertion of an occluder under interventional radiation. In our experience, neither method alone is appropriate for treating ventricular septal defect in cats with non-restrictive VSDs. We have applied a hybrid surgical method in a 13-month-old, female Maine Coon cat weighing 3.5 kg. A catheter was inserted and an occluder placed directly at the defect through thoracotomy. This method is less invasive than open-heart surgery and requires no special equipment, using direct puncture of the heart to minimize the distance to the defect and improving maneuverability. By combining the advantages of both surgical defect closure and occlusion guided by interventional ultrasound, treatment that could not be performed with either method alone became possible. In this case, the VSD could not be embolized, but some important points were suggested regarding surgical treatment of VSD in cats. One is that a sizing balloon catheter may be the most accurate method to measure VSD in cats. Amplatzer occlusion of a large non-restrictive VSD in a cat is currently not an option, but the described hybrid technique may still be an option for smaller non-restrictive VSDs. However, criteria and adjustments must be considered carefully.