When an extraordinary bird developed an often-fatal cancer on her large beak, her ZooTampa caregivers refused to give up on her—instead, they drafted a top-tier medical team of human and veterinary experts to save her life.
Veterinarians at ZooTampa in Tampa, Fla., worked with hospital physicians, biomedical engineers and veterinary specialists from two universities to surgically remove the complex tumor from the Great Hornbill’s casque and replace it with a custom-designed, 3D-printed prosthetic.
The experts, including a private biomedical 3D laboratory, all volunteered their expertise for the surgery, the first of its kind on a hornbill in the U.S. and just the second in the world.
As with critically ill human patients, the team of specialists swung into action to save 25-year-old Crescent. The three-foot-long bird’s caregivers noticed an odd lesion at the base of her casque, the helmetlike growth on a hornbill’s upper beak. The Zoo’s veterinarians suspected it might be squamous cell carcinoma, a common skin cancer in humans that’s usually deadly in hornbills.
“After Crescent’s diagnosis, we went through multiple meetings to see how we were going to tackle this difficult tumor,” said Dr. Kendra Baker, D.V.M. and associate veterinarian at ZooTampa. “We met with human and veterinarian oncologists, and imaging scientists who specialized in human CT imaging and scanning. It was an all-in effort.”
ZooTampa consulted with radiology and 3D clinical application experts from the University of South Florida (USF) Morsani College of Medicine’s Department of Radiology, who work with Tower Radiology at Tampa General Hospital. The dedicated faculty often volunteer their time after-hours to help the nonprofit Zoo with specialty imaging on its residents.
“We asked ourselves, if this was a human, what would we do? So we began to plan how to fix Crescent’s casque using the technology we use every day on our human patients—3D printing,” said Dr. Summer Decker, associate professor, vice chair for research and innovation, and director of the 3D Clinical Applications Division for the Department of Radiology in the USF Health Morsani College of Medicine and Tampa General Hospital.
ZooTampa veterinarians anesthetized Crescent for a CT scan at Tower Radiology with the USF Health Radiology team, which revealed a large, meandering tumor. To increase chances of success, complete removal of the tumor was the best option. But Crescent’s cancer was near the back of her casque, close to her skull. And when the cancer was removed, her sinuses would be exposed.
“This tumor is typically found near the front of the casque in hornbills, but hers was in the back,” Baker said.
For Crescent to live normally, the team decided to call on cutting-edge technology to design and print a new custom 3D casque, along with a 3D-printed surgical guide to make sure all of the cancer was removed.
USF Health Radiology’s biomedical engineer Dr. Jonathan Ford; Decker; and their team began modeling the pieces in complex, rotating 3D images that incorporated the tumor location from the CT scans, the edge of the skull and other critical anatomical features. Multiple tiny tweaks along the way ensured that the surgical guide and new casque would fit Crescent perfectly, even aligning the guide’s screw holes so they could be reused for the casque’s final placement.
The unique prosthetic needed to be lightweight, hard and durable. Drs. Decker and Ford reached out to their colleagues at Formlabs, a leading manufacturer of 3D printing solutions that specializes in medical-grade materials.
Formlabs was in the midst of developing BioMed White Resin, a photocurable material to print biocompatible parts with performance that met the prosthetic's requirements. Formlabs donated the material, and the USF Health Radiology 3D team printed the surgical guide and new casque on a Formlabs 3D printer developed for healthcare use.
Using the 3D guide, ZooTampa veterinarians and two visiting veterinary surgeons from the University of Florida on 28 January carefully excised the irregularly shaped tumor and extra margins around it.
“This was a great collaborative effort to be a part of,” said the lead surgeon, Dr. Alex Fox-Alvarez, D.V.M., DACVS-SA, an assistant professor at the University of Florida College of Veterinary Medicine.
As with complex human surgeries, the team thoroughly examined the treatment approach in advance, from fine-tuning the 3D cutting guide and prosthetic to discussing the anesthesia and operative plan on the surgery day. They also reviewed the surgical approach on a 3D-printed replica of Crescent's head before performing the procedure.
The surgery would have been “much more challenging” if not for the pre-surgical planning and 3D-printed guides, said Fox-Alvarez, who was assisted by Dr. Kaitlyn McNamara, D.V.M, and UF senior surgical resident at UF.
“Using (surgical) cutting guides based on the CT scan images took the guesswork out of how much casque to remove and allowed us to leave as much healthy tissue as possible,” he explained. “In a way, we do the surgery ‘virtually’ before ever doing it in real life.”
The team also connected with the surgeon in Singapore who performed the only other operation of this type.
After the tumor was removed, the surgeons adhered the 3D-printed casque to Crescent’s beak with dental acrylic before permanently attaching it with titanium screws. The prosthetic covers her sinuses, and Crescent immediately had full use of her beak.
After the surgery, Crescent is doing well, with no change in her behavior, appetite or vocalizations, and her prognosis is good, Baker said. ZooTampa’s animal care experts and veterinarians monitor Crescent daily, watching closely as the casque regrows to make sure the lesion doesn't return. She has returned to her home in an outdoor aviary.
“It’s our responsibility, and our privilege, to care for all of our residents,” Baker said. “And this bird needed us to pull out all of the stops.”
Collaboration between physicians and veterinarians is leading to excellent care for animals in human care. The USF Health radiology team has worked with more than 50 species so far, including manatees, penguins and sloths, but the hornbill was a first, said USF Health Radiology’s Decker.
“There is such a gap between human medicine and animal medicine,” she said. “We take it for granted. For us to be able to help in a small way, working together and making a difference, was definitely worth it. And the ZooTampa animal care teams are amazing.”
An unexpected benefit came when Crescent began preening within hours after surgery. The Formlabs resin happened to be compatible with the yellow preening oils secreted from the glands above her tail, giving the new casque the same bright glow as her original one.
Viewed from the front, hornbills’ casques are U-shaped, with a concave top and two ridges forming points at the front. The birds, which can reach four feet long from tip of tail to beak and weigh up to nine pounds, are native to Nepal, Bhutan, India, mainland Southeast Asia and Sumatra.
Their numbers are decreasing, and great Indian hornbills are listed as Vulnerable by the International Union for Conservation of Nature.