Pioneering Pacemaker Research
Research with pigs opens pathways for interdisciplinary connections
BY ANNMARIE CORNEJO AND LAUREN MCEWEN
“I'm thrilled to have applied my experience as a certified veterinary assistant to help care for animals in such an important study."— Molly Azevedo
For Emma Barrett, standing vigilant with surgeons and veterinarians provides a glimpse into a life of animal and human connection. On one such day, the fourth-year animal science major, along with Daniel Bermudez, Elena Valiaveedan, Elizabeth Beebe and Molly Azevedo, stood attentive as a pacemaker was surgically implanted into a pig at the Cal Poly veterinary clinic.
The team of students were on hand to aid the surgeons and veterinarians with x-rays, ultrasounds and the handing off of any surgical tools that the surgeons needed during the procedure. The students also monitored the pig’s vitals during the surgery and assisted in administering anesthetic.
Cal Poly Animal Science Professors Rodrigo Manjarín, Kim Sprayberry and Rachael Lyons, partnered with Cal Poly’s Biological Sciences faculty Magdalena Maj, Michael Jones and Tim Spade, abdominal surgeon Joseph Manuel, the University of Southern California and MEDIPACE are leading cutting-edge research to develop a new treatment for gastrointestinal disorders in humans. The project, funded by the National Institutes of Health, is studying the efficacy of using a pacemaker to relieve chronic constipation and other gastrointestinal issues in humans. Pigs are an ideal translational model of human disorders due to their similarities to humans in anatomical structure and physiology.
“Being part of this enterprise has taught me integral skills in pre- and post-op care of the pigs through hands on experience, skills that I am thankful to have learned and can carry into my future career,” Barrett said. “These experiences have reinforced the notion that devotion to their health and welfare is of the utmost importance.”
The research is timely as an increasing number of Americans, particularly older individuals, are experiencing gastrointestinal disorders such as chronic constipation and irritable bowel syndrome, Manjarín said, adding that pigs are helpful in studying these problems because of their similarities with humans.
During the surgical procedure three cables with stimulator leads and accelerometers were inserted into the pig and connected to the pacemaker that was implanted into the animal’s back. The pacemakers are meant to stimulate indirectly the gastrointestinal tract by activating the vagus and sacral nerves at the neck and sacrum, respectively.
Currently, there is no solution for individuals battling chronic gastrointestinal issues such as constipation. It has been established that a pacemaker can stimulate the vagus nerve and now researchers are hoping the same can be done through the sacrum to stimulate the colon – which could ultimately provide a plausible treatment.
Manjarín specializes in research on colonic inflammation and intestinal issues, which led researchers at the University of Southern California to seek the partnership. The opportunity was a win for student learning, he said. “Our program provides many Learn by Doing opportunities for Cal Poly students who are interested in doing biomedical research on campus,” he said. The hands-on opportunities for students are abundant — from assisting during surgery and recovery to collecting data and caring for the animals involved in the study at Cal Poly’s swine unit daily. In addition, students are responsible for running neurobehavioral tests on the animals to under stand the effect of electrical stimulation on pig’s memory, anxiety and activity. There are 46 animal science students and eight biology students involved in the research study.
Bermudez, a second-year animal science major, said he continues to learn new skills with each opportunity. “The skills learned in this enterprise are a once in a lifetime opportunity because there is a lot of trust built for us to be involved,” he said. Molly Azevedo, a third-year animal science major on the pre-veterinary track, said that this research has given her a deep appreciation for the level of attention and dedication required to maintain the health and welfare of the animals. “I’m thrilled to have applied my experience as a certified veterinary assistant to help care for animals in such an important study. At the same time this project has given me exciting insights into animal research and its impact on human health,” she said.
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