The replacement of live animal models with alternatives is an encouraging recent trend in medical education. Where the use of live animals was once standard practice in medical school curricula, today 152 of America’s 159 medical schools (which include allopathic and osteopathic schools) have eliminated these methods in favor of more modern and effective alternatives.
One of the challenges specific to surgical training is the simulation of dynamic, living tissue. Available training models such as mannequins, computer models, virtual reality (VR), and ethically-sourced cadavers all offer valuable training opportunities, but (with the exception of some VR simulators) do not bleed, ooze or pulsate. A solution to that challenge has been developed by Dr. Emad Aboud, a neurosurgeon at the University of Arkansas for Medical Sciences.
Elegant in its sheer simplicity, Aboud’s system involves connecting a human or an animal cadaver to a mechanical pump. Plastic tubing is spliced onto the major arteries and veins, and artificial blood is then pumped into the vessels to fill the specimen’s vascular tree. The other end of each vessel is coupled to a reservoir of “blood” (water mixed with food coloring works fine). The pump can be adjusted for both pulsation speed and pressure. Clear liquids can mimic cerebrospinal fluid when working with head and spine specimens.
Though not yet commercially available, the system has potential for widespread use owing to its flexibility and low cost. It has training application to all kinds of surgical procedures in all surgical fields, including endoscopic (e.g., bronchoscopy and colonoscopy) and endovascular (e.g., angiography, aneurysm repair) procedures; making and suturing incisions in skin or organs; dissecting soft, oozing tissues; ligation of severed vessels; vascular anastomosis (connecting two ends of a severed vessel); intestinal anastomosis; and transplantations. “Living Cadavers” can also be used to practice non-surgical techniques such as withdrawing blood and inserting central and arterial lines (used for obtaining cardiovascular measurements and long-term administration of medications).
Naturally, the method is equally applicable to animal cadavers. In fact, Aboud first tried the technique with a dead fox he removed from a roadside and later using a dog cadaver for laparoscopic and open surgical procedures. According to the Humane Society Veterinary Medical Association, nearly half of the nation’s 28 veterinary schools still conduct terminal surgeries on animals, and Aboud is now seeking to expand his model’s use in veterinary training. Ethical sources of animal cadavers include willed-body programs, animals who have died naturally or in accidents, and animals euthanized for medical reasons. Crucially, acquiring animal cadavers need never involve purpose-breeding or killing animals; thus, Class B dealers—who acquire animals from a variety of sources and then sell them to research institutions or veterinary schools—can and should be kept out of the loop.
Aboud’s model is in regular use at the University of Arkansas and has been featured at training workshops and courses in neurosurgery across the US, as well as Germany, Finland, Syria and the Netherlands. His team is ready and willing to help with setting up the system at other surgical training facilities. “It’s a win-win-win solution,” says Aboud, “providing advanced training at low cost with the promise of further replacing animals in medical and veterinary training.”