Plastic Ties Could Revolutionize Certain Surgeries

Saw open the chest. Fix the heart. Reattach the two halves of the breastbone. Cardiothoracic surgery in three steps. The last of those steps sounds routine but involves an extra-sharp needle that can puncture other organs or the surgeon's hand, and stiff wire tightened by pliers. If the surgeon twists the ends too tightly, the wire might cut the bone. Too loosely, and the bone may not knit. Even if there are no complications, the wire stays in the patient's body forever. "You can't send them through metal detectors," says Johns Hopkins biomedical engineering major Neha Malhotra. "And after a while, the wires can cause bone damage."Malhotra, a junior, is co-leader, with senior Chris Weier, of a team of 11 undergraduates who spent the last academic year mending split cadaveric sternums with a material that may revolutionize the 700,000 open-chest surgeries done worldwide each year: dissolvable plastic cable ties. The invention won the students first prize in the university's Biomedical Engineering Design Day competition in May. "It basically looks like a stapler," says Malhotra. But instead of staples, the $1,500 prototype shoots out a sturdy plastic cable. "It threads the cable ties through the ribs and tissue," she explains, "and then ratchets to fasten the ends together tightly on top."Read more at...Johns Hopkins Magazine, September 2006.