An otolaryngology resident and bioengeneering student at the University of Washington have teamed up to create a low-cost cartilage model for surgical practice using 3D printing. The innovation will allow surgeons to perfect the construction of realistic ears.

 

Surgeons approach the task of fixing a missing or underdeveloped ear by harvesting rib cartilage from the child and carving it into the shape of an ear. The rib cartilage is limited, and surgeons try to harvest as little as possible.

Because of the nature of the procedure, surgical residents are unable to practice the procedure on authentic material. Normally, surgical residents use a bar of soap, a carrot or an apple to practice complicated procedures like making a new ear for children. Some are able to use cadaver or pig rib cartilage as a substitute, but they don’t match the size or consistency of children's.

 

This new method of 3D printing cartilage is a low cost alternative that offers the most authentic model to practice on to date.

 

Working in the UW BioRobotics Lab under electrical engineering professor Blake Hannaford, the researchers described the development in an abstract at the American Academy of Otolaryngology — Head and Neck Surgery conference held in Dallas this week.

“It’s a huge advantage over what we’re using today,” said Angelique Berens, a UW School of Medicine otolaryngology — head and neck surgery resident, who was lead author on the abstract. “You literally take a bar of Lever 2000 while the attending is operating and you carve ear cartilage. It does teach you how to get the shape right, but the properties are not super accurate — you can’t bend it, and sewing it is not very lifelike.”

 

The study included three seasoned surgeons who practiced carving, bending and suturing with the researchers’ silicone models. The models were created with a 3D printed mold and a CT scan of an 8-year-old with a malformed ear. The researchers compared the models for firmness, feel and suturing compared to other practice materials. All three surgeons preferred the UW models.

 

A lack of realistic training models limits many surgeons, making it difficult for them to become comfortable executing delicate and complicated procedures, said Kathleen Sie, a UW Medicine professor of otolaryngology and director of head and neck surgery at the Childhood Communication Center at Seattle.

Because so few surgeons are properly trained, children in need of ear reconstruction must wait 6 to 12 months at Seattle Children’s Hospital.

 

“It’s a surgery that more people could do, but this is often the single biggest roadblock,” said Sie. “They’re hesitant to start because they’ve never carved an ear before. As many potatoes and apples as I’ve carved, it’s still not the same.”

 

The 3D printed material is also advantageous because it’s printed from a CT scan, so it will mimic the unique anatomy of the patient. Now, even experienced surgeons will have the opportunity to practice the complicated procedures on material specific to the patient.

 

Photos via University of Washington