Researchers develop 3-D printed implantable materials to repair the ear
Since its debut in the 1980s, 3-D printing has opened many doors in modern medicine.
For a research team at Mass. Eye and Ear, the technology may be key to developing the perfect implant for patients who need surgery for middle ear repair.
Creating a better graft for repairing eardrums
In collaboration with the Wyss Institute at Harvard, Mass. Eye and Ear’s Aaron K. Remenschneider, M.D., MPH, and Elliott D. Kozin, M.D., have led efforts to design and manufacture 3-D printed tympanic membrane (eardrum) grafts for patients with perforated eardrums that need to be repaired. While the grafts are not quite ready for prime time in humans, the team has shown that they can be “tuned” to better transmit sound, potentially improving hearing for patients undergoing surgery. Experiments using the 3-D printed grafts in an animal model are currently underway.
In 3-D printing, the researchers also recognized an opportunity to overcome the limitations of current graft materials (fascia, cartilage) for eardrum repair. These grafts sometimes fail, because they do not possess similar structural features as the native tympanic membrane. The freedom to customize with 3-D printing may ultimately reduce potential complications (such as chronic ear infections) in these procedures.
“Right now, physicians must use imperfect materials for tympanic membrane grafts,” Dr. Remenschneider said. “Unfortunately, these grafts fail in a subset of patients. Many individuals don’t obtain a satisfactory hearing result or are left with recurrent infections, and the surgery has to be repeated. If we could design a graft material from the ground up, and include optimized features, this would be a huge step forward. I think 3-D printing may now offer the means to produce such a graft.”
Designed using non-absorbable materials and biologics (collagen and fibrin), the 3-D printed grafts have acoustic properties that can be tuned to reflect the sound-induced motion patterns of the human eardrum.
Further study is needed before the grafts are ready to be tried in humans. The researchers need to further assess how grafts become incorporated into the ear and how the normal healing process affects sound transmission over the long-term.
While they work away, the possibilities for enhanced patient care are becoming a reality as the applications of 3-D printing in the surgical field continue to expand.
“Three-dimensional printing is exciting as it provides surgeons the ability to rapidly study, design and modify anatomic structures on a micron scale,” Dr. Kozin said. “Surgeons can now think and act outside the box in terms of what is possible.”
“If you can imagine it, you can create it,” said Dr. Remenschneider.