December 02, 2018

Synthetic Cadavers for Surgical Training

Maintaining the ethics of animal care while meeting the educational needs of students is becoming easier with new technologies and practices. 
By Meredith Rogers, MS, CMPP
Most people enter veterinary school because they want to help animals, but then they are confronted with the prospect of potentially hurting animals during the course of their studies. Whereas a newly graduated human doctor needs to be proficient only at giving injections and suturing minor skin wounds, veterinarians are expected to have a comfort level with a variety of surgical techniques right out of school.
 
Learning how to perform surgery cannot be gleaned from books or computer programs; it demands hands-on experience. Veterinary schools do all they can to prepare students for real surgeries, but today’s curricula require practicing on cadavers and eventually live animals. This creates a moral dilemma for many students, who may question how cadaver animals are acquired and be concerned that their immature surgical skills may result in harm to live animals, potentially turning away many students from pursuing a surgical career.

Results from survey studies of veterinary students have shown that those enrolled in surgical courses experienced significantly greater anxiety than those in nonsurgical courses, and about 63% of students experienced negative emotions prior to their first encounter with live-animal surgery.1,2

PROXIES AND CADAVERS IN VETERINARY EDUCATION
A variety of proxies are used to assist in teaching students surgical skills in the forms of models, mannequins, and simulators. Plastic models help clarify morphologic concepts, mannequins assist with clinical skills training, and simulators, such as suture trainers, help students practice specific techniques. However, none of these surrogates can substitute for the real thing, which is where cadavers come in.

Traditional sources of cadavers include the euthanasia of healthy but unwanted dogs at shelters, ex-racing greyhounds, and abattoir specimens. However, none of these types of cadavers are considered “ethically sourced,” even if the death of the animal was not dependent on its use at a veterinary school. Ethically sourced cadavers are animals that have died due to natural causes or have been euthanized because of a terminal disease or an unrecoverable trauma. However, the supply of ethically sourced cadavers is substantially limited compared with traditional supply chains.

Interestingly, fewer than half of veterinary students indicate a preference for donated cadavers, and as their studies progress, their preferences shift toward cadavers from traditional sources.3 A variety of explanations have been proposed for this shift, including a general increased acceptance of euthanasia of healthy animals, a decline in moral development, desensitization with greater exposure, and increased sentiment that healthy animal cadavers offer a superior learning experience.3 In addition, a practical consideration with cadavers is their storage, which involves large freezers that can be expensive to run and maintain.

The culmination of the veterinary school curriculum is surgery on live animals. As with cadavers, the animals used for live surgeries are often acquired from shelters. Being alive and relatively healthy, these animals offer an unparalleled practice opportunity to perfect advanced surgical techniques. Upon completion of the surgery, these animals used to be routinely euthanized, which is why this teaching practice is called terminal surgery. The ethics of this controversial practice are less complex because most of these animals would have been euthanized regardless because of the overcrowding of shelters. As Jennifer Schneider, VMD, a small animal practitioner from Herndon, Virginia, says, “These animals were going to be sacrificed anyway, and by using them as teaching tools, their deaths were not wasted. We believed that each animal would help us save many more lives in the future.

Nevertheless, euthanizing otherwise healthy animals goes against the tenets of veterinary medicine, which is why many veterinary schools have been limiting terminal surgeries, and some have eliminated the practice entirely. Today, most veterinary schools partner with shelters to provide spay/neuter and other services, which provide the students with valuable experience and the shelters with more adoptable animals. Of course, even though the students operate under faculty supervision, they are still learning and deaths are inevitable.

SYNTHETIC CADAVERS: A VIABLE ALTERNATIVE
An alternative to both cadavers and live surgeries is the synthetic cadaver. Ultrarealistic human models are commonplace in medical schools, but an animal model was introduced in only 2016. The Synthetic Canine cadavers produced by SynDaver Labs (syndaver.com) are made of water, fiber, and salt, and they breathe and bleed just like a real dog. They are anatomically correct, with individual muscles, bones, organs, fat, fascia planes, and complete vasculature and can mimic a variety of pathologies. The University of Florida College of Veterinary Medicine, which assisted in development and holds the patent, was an early adopter, and the Veterinary Technology program at Wichita Area Technical College (WSU Tech) in Kansas and Texas A&M College of Veterinary Medicine & Biomedical Sciences started using them last year. Private specialty practices are also using them to help train residents on procedures they may not have encountered during school.

RELATED
J. Brad Case, DVM, MS, DACVS, associate professor of small animal surgery at the University of Florida and a codeveloper of the Synthetic Canine, has been using synthetic cadavers to teach for several years, and he believes they improve on real cadavers in many ways. He and other say that some of the most valuable features of synthetic cadavers are that they behave and move the way live animals do on the oper- ating table, they do not require freezers for storage, and they are not preserved in formalin or formaldehyde, so they are healthier for students to work with.

Amanda Hackerott, RVT, director of WSU Tech’s Veterinary Technology program, says that most of her students have never seen the inside of a dog before starting the program, so the Synthetic Canine is particularly useful for teaching anatomy because the colors of the organs and tissues are closer to those of a live animal. Furthermore, because a Synthetic Canine can be used repeatedly, each one replaces more than 1 live animal, which helps institutions meet the US Department of Agriculture’s mandate to “reduce, refine, and replace” animal use in teaching programs. The synthetic cadavers also allow students to repeat procedures until they get it right, something that cannot be done with either cadavers or live animals.

David Danielson, DVM, vice president of veterinary technologies at SynDaver Labs, said that one of the greatest benefits is that the platform is completely customizable, so students can get exposure to illnesses, conditions, and complications that they otherwise would not see until they got into practice. Elizabeth Scallan, DVM, MBA, MS, CVA, CCRP, clinical assistant professor at Texas A&M University College of Veterinary Medicine, agrees, noting that the ability to practice difficult surgeries that would not be ethical to conduct on live animals is a significant advantage. “It produces better graduates because it’s something that could not be done before,” she said. Dr. Danielson also practices in Tampa, Florida, and experienced this firsthand when a new graduate hire in his practice was able to complete a complicated procedure that he had never performed on a real dog but had perfected using the Synthetic Canine while in school.

A consideration that is both a positive and a negative is that each synthetic cadaver is identical. Although this can be helpful initially for learning basic techniques, in reality every dog is different, which may be better appreciated by working with a variety of real animal cadavers. Although only a canine model is currently available, SynDaver Labs recently introduced a feline model at the National Science Teachers Association National Conference on Science Education, and the company is working on a variety of others, including a horse, a rabbit airway trainer, and models for specific scenarios, such as a trauma dog for teaching cardiopulmonary resuscitation on the battlefield.

One inhibitor to greater uptake is that these models are very expensive (about $30,000 for the Synthetic Canine); however, they can be used over and over, and even when 1 part of the model reaches the end of its usable lifespan, the remaining tissues can be adapted for use in other labs. In addition, the models can be returned to SynDaver for refurbishment on a regular basis, at which time they are given a deep cleaning and upgraded if advances in the technology have been made.


References
  1. Langebæk R, Eika B, Jensen AL, Tanggaard L, Toft N, Berendt M. Anxiety in veterinary surgical students: a quantitative study. J Vet Med Educ. 2012;39(4):331-340. doi: 10.3138/jvme.1111-111R1.
  2. Langebæk R, Eika B, Tanggaard L, Jensen AL, Berendt M. Emotions in veterinary surgical students: a qualitative study. J Vet Med Educ. 2012;39(4):312-321. doi: 10.3138/jvme.0611.068R1.
  3. Tiplady C, Lloyd S, Morton J. Veterinary science student preferences for the source of dog cadavers used in anatomy teaching. Altern Lab Anim. 2011;39(5):461-469.

Ms. Rogers has a bachelor of science degree in animal health from the University of Connecticut and a master of science degree in microbiology and molecular genetics from Rutgers University. She has more than 19 years of experience creating content for a variety of health care audiences. She lives in Kingston, New Jersey, and shares her life with a horse, a dog, and a cat.

 

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