Device May Improve Chest Closure

The polymer ties clamp the sternum
parts back together; © Will Kirk/JHU

Physician Malcolm Lloyd and heart surgeon Mark Sumeray challenged Johns Hopkins University students to devise a better way to close the chest after heart surgery. “The premise was based on an unmet need identified by cardiothoracic surgeons,” Lloyd said. “The students came up with a working prototype that hit all of the engineering requirements we proposed. The end result was better than my partner and I expected, particularly given the limitations they had in terms of resources.”

In a class called Biomedical Engineering Design Teams, the project was adopted last fall by a group led by Chris Weier, a 23-year-old senior from Sterling Heights, Mich., and Neha Malhotra, a 20-year-old junior from Dubai, United Arab Emirates. The students produced their prototype, which resembles a stapler and uses standard locking cable ties. A roughly 8-inch curved piece extends from the handheld tool to guide the tie between and under the ribs, enabling a surgeon to connect both ends and pull the severed sternum parts toward one another. When one end of the tie is reinserted into the tool and the handles are squeezed, the device operates like a ratchet, tightening the clasp and bringing the pieces of the breastbone firmly together so that the healing process can begin.

If the prototype advances through further development and testing, many patients could benefit, the student inventors said. “We think it will reduce potential injuries to both the patients and the surgeons because the surgeon isn’t physically pushing a needle through a bone,” Malhotra said. Although the students used commercial cable ties for their prototype, they said patients would best be served by a biocompatible polymer clasp that would dissolve harmlessly in the body after two years, when the sternum is fully healed.

MEDICA.de; Source: Johns Hopkins University