One in every 8,000 to 10,000 births in the United States result in one of two congenital malformations of the ear: anotia, the complete lack of an ear, or microtia, a cartilage stump for an ear.

Now, thanks to two novel tools developed by Johns Hopkins Medicine researchers, the traditionally difficult surgery to create a replacement ear from a patient’s rib cartilage may soon be done faster, more simply and accurately, without wasting valuable tissue. The tools also offer the ability to “custom fit” the new organ for each patient.

Anirudh Arun, an interventional and diagnostic radiology surgery resident at Johns Hopkins, and former Hopkins resident Angelo Leto Barone invented the two assistive devices using 3D manufacturing.

The first is a simple-to-use carving tool that precisely slices rib cartilage removed from the patient to any desired thickness and minimizes tissue waste.

“The cartilage-slicing device basically doubles the amount of cartilage tissue available for surgery, meaning that less has to be harvested to safely produce the entire ear,” says Arun. “We only need two-and-a-half ribs instead of the traditional four from prior techniques — [meaning] less waste and less discomfort for the patient.”

The second is a “cookie-cutter-like” press using steel blades — shaped in patterns fashioned from a patient’s normal ear — to yield the pieces of cartilage that are brought together during surgery to form the new organ. When placed into the cutter, the cartilage slices are precisely trimmed into the components of the new ear in minutes rather than the hours needed to do it manually with a scalpel.

“Not only is the process quicker, but the template eliminates the cartilage damage that often accompanies the sculpting done in previous reconstruction methods,” says Leto Barone, now a craniofacial and pediatric plastic surgeon at Nemours Children’s Health in Orlando, Florida. “This makes our system highly reproducible, user friendly, time efficient and cost effective. Best of all, it consistently yields a natural-looking ear that helps children avoid being teased or bullied, and enables adults to do things others take for granted, like wearing glasses.”

The researchers recently put their assistive devices to the test in the first in-human trial of the procedure — a surgery on a teenage patient. The successful outcome is described in a research letter in Facial Plastic Surgery & Aesthetic Medicine. A patent has been approved for the two-device system.