Congenital heart defect prompts rare canine heart surgery

Tetralogy of Fallot is a set of four structural heart abnormalities uncommon in dogs and often fatal before the age of one.  Called “blue baby syndrome” in humans, the congenital heart defect prevents oxygenated blood from properly circulating through the body.

This was the situation for Lilly Rose, a beagle, before she found herself at Colorado State University College of Veterinary Medicine and Biomedical Sciences (CSU-CVMBS), and the James L. Voss Veterinary Teaching Hospital.

The solution involved two heart operations, one in September 2014 and a second surgery in July. Today, Lilly Rose returned to CSU-CVMBS for her one-month post-surgery check-up.

While Lilly Rose’s prognosis is palliative, her quality of life and chances for long-term survival have improved. (She has now celebrated her one-year birthday.)

“The dog came here blue and is going home pink,” said Christopher Orton, DVM, PhD, Diplomate American College of Veterinary Surgeons, and professor of clinical sciences at CSU-CVMBS, after the July operation.  

Oren, a pioneer in canine heart surgery, performed the three-hour surgery. Marisa Ames, DVM, Dipomate ACVIM (cardiology) and assistant professor of clinical sciences at CSU-CVMBS, assisted Orton with the surgery, along with a team of veterinary residents.

The first procedure the beagle underwent, last fall, involved performing a balloon valvuloplasty. In this minimally invasive procedure, a thin catheter is inserted into the heart, and a balloon at the tip is inflated to stretch open a constricted heart valve. This improves the flow of blood to the lungs for oxygenation.

The valvuloplasty bought time until doctors could perform heart surgery to install a shunt that further increases blood flow from the heart to the lungs for life-giving oxygen. Called a modified Blalock-Taussig shunt, the device is a small, artificial tube that diverts blood, in this case, for the purpose of recirculating through the lungs to pick up more oxygen before it travels into the body to enliven cells and tissues.

The shunt connects a systemic artery, which carries oxygenated blood to the body, to the pulmonary artery, which carries deoxygenated blood to the lungs.

“Dr. Orton uses synthetic tubing to connect a branch of the aorta to her pulmonary artery. This gives the blood a second shot to pick up oxygen,” said Ames. “This is blood that has already gone through the entire heart. But we’re saying, ‘Let’s take one more spin through the lungs and pick up more oxygen.'

“Our senior cardiology resident, Dr. Christian Weder, is writing up [Lilly’s] case, so her story will hopefully help other dogs,” said Ames. “This sequence of treatments has been described only once in veterinary literature, yet no follow-up information is available.”

NEWStat Advancements & research News