For the first time, in the 100-year history of the University of Pretoria (UFS)’s faculty of veterinary science in Onderstepoort, two of the university’s veterinary surgeons have performed what will rank as a ‘ground-breaking’ achievement.
Dr Adriaan Kitshoff and Dr Ross Elliott saved the lives of two dogs by performing heart surgery on them using what is considered one of the innovative techniques in the history of the veterinary hospital.
The university described the achievement “as an exciting way to start the next century of veterinary service to the country”.
The doctors are specialist veterinary small animal surgeons working in small animals surgery in the department of companion animal clinical studies. The dogs are a 7-month-old French Bulldog Daisy and a 6-month-old Cocker Spaniel called Tallen. Daisy is a service dog that can sense when her owner, who has fibromyalgia, is in pain and sleeps on her as a means of comfort.The technique used by the veterinary surgeons entails dilating the opening of a heart valve with a balloon.
Elated, the duo claimed “this procedure is limited to hospitals overseas with surgeons or internists with special interest in cardiology. It is only hospitals that have the equipment that can perform the surgery.”
They said both their patients have pulmonic valvular stenosis, an abnormally shaped or fused heart valve that is situated between the heart and the artery leading to the lungs.
Explained the surgeons: “Both these patients had valves where a component had fused together. These valves are supposed to allow the blood to flow in one direction, meaning that they have times that they are closed and times that they are open and these times are determined by whether the heart contracts or not.”
They said in the case of valves that are fused, the valve can’t open properly when the blood should leave the heart (during contraction) and also does not close properly (when the heart relaxes).
“This created a scenario that is similar to you filling your lungs with air and blowing out through your mouth with your lips pursed. The force of the heart trying to squeeze out blood through a small opening places tremendous strain on the heart muscle,” they added.
By performing the surgery on the dogs they aimed to “increase the size of the opening by dilating the valve”. To successfully pull off this delicate and sensitive surgery, a long balloon-tipped catheter was placed in one of the neck veins. Through fluoroscopy (“real-time X-rays”), the balloon was guided through two of the heart chambers and through the small opening in the valve. After inflation of the balloon the opening was stretched (balloon valvuloplasty), the duo further explained.
They said the anatomy of a dog’s heart is similar to that of a human’s, also consisting of four chambers and four valves. “This is probably the reason why most of the clinical trials for heart transplants were performed on dogs. This set the stage for Dr Chris Barnard’s first successful heart transplant in 1967,” they added.
The surgery is risky, they noted, as these patients have heart disease and need to be placed under general anaesthesia. Due to irritation of the heart muscle as the balloon passes through it, it can result in abnormal heart rhythms during the anaesthesia that might need to be treated with medication during the operation. Stretching of the valve can cause tearing of some blood vessels.
“These abnormal rhythms and tearing of blood vessels can be fatal in a very small percentage of patients. In some dogs the opening between the fused valve can be so small that it is not possible to pass the deflated balloon through it. In these patients the chest needs to be opened up, a hole needs to be made in the beating heart and an instrument passed into the heart to stretch the opening of the valve,” added the surgeons.
They said the procedure they have just performed on the dogs implies that “we can offer a service not previously offered by Onderstepoort Veterinary Academic Hospital. This might be the start of other minimally invasive heart surgeries in the future. This also provides us with the opportunity to extend the life of special pets like these.”
They said the surgery also creates more possibilities for the Onderstepoort Veterinary Academic Hospital. These include setting up a centre of excellence in minimal invasive surgery and cardiology at the facility and offering more advanced surgeries like valve replacements and heart transplants.
The surgeons said the dogs are doing well after their procedure. However, they added, they need follow-up heart scans every three months as in 15% of such cases the stretched opening of the valve can start to narrow again. They said this means the repeat of the same procedure.
The veterinary surgeons acknowledged the role played by other professionals during the procedure saying its success “was a team effort”. They thanked anaesthetists, Dr Justin Grace and Dr Abdur Kadwa, theatre nurse sister Adele Rossouw and theatre assistant Mike Shabangu”.