Carlson College of Veterinary Medicine

Going Rogue
Mulan is a rescue that was brought with her littermates to the Rogue Valley Humane Society in Grants Pass, Oregon when they were roughly seven weeks old. “She and her siblings seemed like healthy, normal kittens, so upon intake we scheduled her to get spayed. While she was under, as we were shaving her, we noticed there was a pretty pronounced divot in her sternum,” says Jaclyn Morris, the humane society’s office manager. “So we sent her off to get X-rayed. And that showed that she had a pretty severe bend to her rib cage, where it was almost like in danger of impaling or touching her heart and impacting her lungs so she wasn't able to take full complete deep breaths.”

In fact, the impact was so severe that Mulan even collapsed once after playing. In consultation with their local vet, the humane society made the decision to bring Mulan to Oregon State to access the expertise of veterinary specialists like Balsa and Sandness. “If it was left unchecked, she maybe wouldn’t have survived,” Morris says. “I am really grateful and lucky to work at a facility that is willing to kind of throw the kitchen sink at unique animals that come our way that need specific care. A lot of shelters and facilities may not have the luxury of putting all these resources into a cat like her, but we make that our philosophy — those are the animals that need us the most.” 

Procedural Approach
Dr. Brea Sandness, a small animal surgery faculty member and 2015 college alumna, took the lead on Mulan’s case with Dr. Bianca Reyes, a small animal surgical resident, assisting. Because cases like Mulan’s are rarely corrected (due to lack of resources or because they are caught too late), neither had performed this type of procedure. While working on Mulan, they’d also be teaching a team of veterinary students including fourth-year students Astrid Reyes and Selah Green and second-year student Marissa Patton. That’s the nature of a veterinary teaching hospital. Every patient visit and procedure is an educational experience. 

In preparing for the surgery, Sandness and Reyes focused on building the right team and knowledge base. 

Sandness reached out to Balsa to lend her expertise. Balsa is a board-certified small animal surgeon and a fellow in minimally invasive surgery (small animal soft tissue). Prior to joining Oregon State last fall, she was on the faculty at the UC Davis School of Veterinary Medicine. During her time there, she’d performed a handful of procedures for cases like Mulan’s. “To be able to work with these types of organizations that want to provide specialty care, it provides a great learning opportunity for some of these rarer cases for our residents to see and to learn from, so that they can then go on and hopefully help other animals,” Balsa says. “I’ve done a lot of work with shelters over my career and I've always found it a very gratifying experience with regards to their investment and care for the animals and then the learning that we get out of that.”  

Sandness then moved toward building out the rest of the game plan. “We only scheduled this when I knew that we would have the team, from anesthesia to the nurses to the surgeon scrubbing in with me, to make sure that we were going to be able to give this the best opportunity,” Sandness says. “Once that was confirmed … it was then researching the disease, pulling all the literature, seeing where did they run into complications, did they have any new techniques that were better than what I had read from before?”

There are two options to correcting pectus excavatum: invasive surgery to reconstruct the sternum or a minimally invasive approach where an external splint is sutured to the sternum. 

As a team, Sandness, Reyes and Balsa opted for the minimally invasive approach. “We were lucky in that she was young and still had a lot of flexibility in her bones as they were mineralizing,” Balsa says. “So we were able to do the less invasive external splint coaptation as opposed to some of the more invasive, either internal bracing or removal of some of the bones. Once we lose that flexibility and bones mineralize in place, we have to go to those more invasive things.” 

Saving Sutures 
With Mulan’s chest shaved and prepped for surgery, Sandness, Reyes and Balsa got to work. Step one was molding the plastic splint that would sit on the outside of Mulan’s chest. They cut the basic shape, then heated the plastic with hot water. Now malleable, the team formed the splint to the ideal contour for Mulan’s sternum to conform to over the next six weeks.

After a few minutes to cool, the splint was set and ready for attachment. 

Next, was the critical part. Sandness steadied her hands, gripped a curved suturing needle with forceps and pierced Mulan’s skin. “Three millimeters was the margin of error between the surface of the skin to the inside of the sternum to get the suture around,” Sandness says. Take two credit cards, and lay them flat on top of each other. That’s about three millimeters thick. If Sandness went too deep, she risked piercing Mulan’s heart or lungs. 

She slid the needle down and around the sternum, drawing the suture through the layers of the skin, under the bones and then back up and out the other side. The suture was then cut, leaving several inches hanging out of each side, ready to be laced to the splint. Once, twice … six times, Sandness repeated the process, drawing the suture through as Balsa offered words of guidance and modeled the technique. 

Reyes observed and then grasped the needle for herself to do two sutures as Sandness offered guidance. “I was extremely happy, and I am very grateful to be part of this procedure and the program itself, both under the mentorship of Sandness and Balsa,” Reyes says. “This is a procedure that I've never seen before. I've read and heard about it, but I was very excited to finally be able to firsthand treat and help one of these congenital conditions.”