Amber, a 10-year-old Yorkshire terrier cross, came into the RVC for evaluation by the Cardiology Service, having previously collapse at home. Myxomatous mitral valve disease was confirmed.

Myxomatous degeneration of the valve is where the valve leaflets become ‘floppy’ or loose. As a result the valve does not open and close properly. The possibility of Amber being a candidate for mitral valve repair was discussed.

Amber's heart disease was stage C, meaning her heart was enlarged secondary to her valvular disease and this resulted in her developing congestive heart failure. Her valve was severely affected and there was evidence of ruptured chords, which may have been responsible for the collapse weeks before.

Surgery

Amber returned to the RVC the following month for mitral valve repair. The surgical team accessed the mitral valve via a left atriotomy, under conditions of cardiopulmonary bypass. Amber’s mitral valve was found to be severely diseased, with thickening to all valve edges, stretching of all chords and a small fissure in the parietal valve leaflet.

Three artificial chords (Gore-Tex sutures) were placed between the papillary muscles and the edge of the septal valve leaflets, and two artificial chords were placed in a valve leaflet. The fissure was closed with a suture.

Within the same operation, the team also performed a mitral purse-string annuloplasty to bring the orifice where the valve sits back down to a normal size.

Recovery and outcome

Amber progressed very well after surgery and echocardiography confirmed that the repair was a success.

A month after surgery Amber came back to the RVC for post mitral valve repair evaluation. Her energy levels had returned and her appetite had improved. Echocardiography confirmed that the valve repair was stable, there was trivial residual mitral valve regurgitation and no signs of clots or thrombi. The echocardiography measurements confirmed that Amber's heart had returned to a normal size.

Amber was also examined at the RVC for her three-month post mitral valve repair evaluation and this confirmed that the repair was stable and her heart was functioning normally. Amber was doing extremely well, off all medications and enjoying life to the full.

Henry, a two-year-old Labrador retriever in heart failure, was flown from the United Arab Emirates (UAE) to be treated by the RVC’s Cardiothoracic Surgery team.

He was treated for a double-chamber right ventricle, a congenital heart defect that would have ended his life within six months if not treated. The condition restricted the flow of blood from his heart into his lungs, which reduced his strength and put extreme strain on his heart muscle.

He was referred to the RVC as the UAE lacks veterinary surgical expertise in this unusual field. The owner felt that because Henry was so badly affected and so young, they wanted to give him the best chance of an active and enjoyable life. She found out about the RVC’s expertise in this area online.

Arrival and presentation

Henry was extremely weak by the time he arrived at the RVC. On physical examination he had limited alertness, couldn’t walk and his mucous membranes were pale.

Listening to the heart (auscultation) revealed muffled heart sounds and there was ventral dullness in his chest, indicating a build-up of fluid. He appeared to be, as surgeon Professor Dan Brockman put it, “at death’s door”.

Support and surgery

The surgery for double-chamber right ventricle requires an ‘open heart’, under conditions of cardiopulmonary bypass. This was particularly risky considering how weak Henry was, but the owner was keen he underwent the operation as it seemed a ‘now or never’ situation.

Henry was given supportive care, which included inotropic support (drug therapy aimed to improve the function of the heart), chest drainage and fluid therapy, until surgery could be performed.

In surgery, Henry underwent resection of the stenotic membrane affecting his right ventricular outflow tract along with ‘patching’ using Gore-Tex, in an operation that took three hours.

Aftercare and outcome

Surgery went well and Henry was able to stand and eat the following day. A postoperative echocardiogram (echo) revealed a massive reduction in the mid-right ventricular pressure gradient and a corresponding reduction in his tricuspid valve regurgitation.

Henry also appeared alert and in excellent spirits. He remained at the RVC’s small animal referral hospital for a week, where he was cared for by the Critical Care, Cardiology and surgical teams.

He stayed in the UK for four weeks after discharge to be reviewed by the RVC team and have his sutures removed. During his last visit, on physical examination, except for a soft heart murmur and surgical scars, Henry appeared healthy and very lively.

There was a small amount of tricuspid regurgitation but nothing like what there had been prior to surgery. The owner was advised that he was well enough to travel back to the UAE and resume normal physical activity.

After returning home the owners saw playful behaviour and energy levels in Henry that they had never seen before, due to the debilitating impact the condition had on him up to the point of his treatment at the RVC.

Mabel was the first dog to have open-heart surgery to successfully treat a stenotic tricuspid valve. The three-year-old Labrador came to the RVC for surgery in 2016 and her story got into news media across the world.

Background

One of the main symptoms of Mabel’s congenital tricuspid dysplasia was increasing fatigue after exercise – she had been struggling to keep up with the other dogs in her family when out for a walk.

Due to her heart failure fluid had built up in her abdomen. However, the referring vet had managed this medically and there was no fluid in her abdomen when she arrived at the RVC.

Mabel, was initially referred to the RVC Cardiology Service. The tricuspid valve was found to be completely fused in the middle, with just two very small holes for her blood to flow through. Groundbreaking surgery was required to open the valve so that blood could flow properly.

The owners were made aware of the risk of Mabel not surviving surgery and their decision to go ahead was made by weighing surgical risks against the certainty that Mabel would have a very diminished and shorter life if the stenosis was not alleviated.

Surgery

Surgery was carried out by Professor Dan Brockman, assisted by a large team to provide complete pre and postoperative care.

The surgical team comprised a perfusionist, a senior anaesthetist, an anaesthesia veterinary specialist-in-training and an anaesthesia nurse, two surgery nurses, three surgeons and a cardiology veterinary specialist-in-training.

The operation completely relieved the stenosis and Mabel’s energy levels markedly increased rapidly.

Recovery and aftercare

After surgery, Professor Brockman stayed involved in Mabel’s care but the RVC Emergency and Critical Care team and our Cardiology Service collaborated to support her recovery.

After surgery, Mabel’s stenosis was resolved and she was found to have a mild to moderate amount of regurgitation into the right atrial chamber. She returned home after a few more days of additional monitoring at the RVC.

Mabel’s owner kept in touch with the RVC team and reported on her renewed energy levels and quality of life within the family.