A new publication from the Royal Veterinary College (RVC), reveals that adopting a structured multidisciplinary approach to mitral valve repairs improves short-term outcomes for canines suffering from degenerative heart valve disease. While open heart valve repairs are challenging in both humans and dogs, these findings show that with the appropriate approach, coordination and analysis, excellent results can be achieved for dogs.
Myxomatous mitral valve disease (MMVD) is the most common heart disease in dogs. It affects an estimated 3.5 percent of the UK canine population and is most prevalent in small to medium-sized breeds and is particularly common in the Cavalier King Charles Spaniel. Disease progression is unpredictable and varies greatly, but many will develop left-sided congestive heart failure that is ultimately fatal; with the median survival of one year after onset failure with medical treatment alone.
The preferred treatment for similar degenerative disease in humans is mitral valve repair (MVR) or replacement but open heart surgery in dogs is still in its infancy. Currently, it is only performed in a small number of specialist centres in the world – including at the RVC’s Queen Mother Hospital for Animals.
Significant progress has been made in the last few years, including consensus that surgical repair is an effective treatment option for suitable candidates. This includes a pioneering canine MVR capability performed since 2015 by a specialist RVC team, led by professor Daniel Brockman, professor of small animal surgery. Together, the team has developed and refined an approach and procedure that has resulted in a consistent trend of improved outcomes in the 132 dogs reported, with 30 of the last 33 dogs successfully recovering from the procedure.
Helping improve awareness and understanding of this innovative procedure, the clinical team documented their work as they developed the programme to perform mitral valve repairs in 132 dogs between July 2015 and November 2022. In doing so, they described standard practices adopted by the clinical team; described the population of dogs undergoing MVR, including breed, age, gender and clinical condition; reported the short-term outcomes of the procedure; and reported trends or alterations in causes or suspected causes of mortality, to better understand the interplay between “technical” and “disease” factors and how they influence outcomes.
The results found that to be successful at MVR, the team delivering the therapy must possess a high level of individual expertise, as well as high level coordination and communication to enable:
- Agreement on what constitutes a suitable surgical candidate
- Competence at the technical aspects of cardiopulmonary bypass (CPB); such as circuit building and circuit priming, vascular access and perfusion and cardioplegia techniques
- Familiarity with preoperative and intraoperative assessment of the diseased mitral valve, and thus determine the most appropriate repair
- Competence at anesthetising dogs with severe mitral valve disease and the critical transition “on” and “off” CPB, in particular
- Understanding and meeting the postoperative requirements of dogs recovering from this type of surgery.
Adopting this approach, throughout the study period 107 of the 132 dogs (81 percent) survived to discharge.
Professor Daniel Brockman, professor of small animal surgery at the RVC and lead author of this paper, said: “This manuscript represents the analysis of team performance in a complex sociotechnical environment. The results highlight the importance of team-working habits that include reflective and deliberate practice both by individuals and by the whole team delivering such a complex therapy. In addition, it emphasises the critical importance of ongoing “skills maintenance” once a skill set has been acquired. In practical terms, this means that once the team has learned what needs to be done, they have to keep doing it a lot to maintain a high level of performance.”
