A Shear Force Transfer Coupling for Soft Tissue Repair

DESCRIPTION (provided by applicant): This project will demonstrate feasibility of a new wound closure concept based on shear force transfer - the familiar way in which root tendrils resist being pulled from soil. This is a distinctly different mechanism of action from conventional sutures and staples. Suture closure of surgical or traumatic wounds typically fails absent adequate fibrous tissue in which to place those sutures. Sites ranging from abdominal walls to uteri to severed limbs to cardiac valve annuli can be very problematic. The wounds may either outright separate (dehisce) in a few hours or days--an often life-threatening condition--or they may stretch into a progressively more disabling incisional hernia. We have patented wound closure technology based on this principle and relevant experience developing it for commercial applications. The principle investigator is presently directing an SBIR Phase II applying this principle for cardiac power. The scientific director invented the device and directed validating muscle-prosthetic bonding application evaluations. The research engineer has fabricated devices both for some of these rabbit studies and for a successful canine trial of the cardiac power device by another institution. Our initial work to apply the technology to the problem of a durable load bearing muscle to prosthetic coupling for circulatory support has succeeded. Work to solve orthopaedic fixation problems is ongoing. There is no reason why a device applying this same mechanical principle to load-bearing bonds between soft tissues should not succeed. We propose developing a device, the FiberSecure, for bonding soft-tissue to soft tissue. It will employ a myriad of ultrafine polymer fibers, which disperse to maximize surface contact for minimal implanted bulk. After development, we will demonstrate device feasibility by testing the hypothesis that FiberSecure wound closure is stronger than conventional suture closure. We will use an established wound-healing experimental model: midline laparotomy in New Zealand White rabbits, modified by removal of adjacent fascial sheath. Control procedure is muscle-to-muscle approximation by conventional suturing. Testing is by histology and pull strength at 21 days. The experimental data will be tested for significance using the Student's t-test. Effective demonstration of feasibility would position the FiberSecure as the closure device of choice for difficult wounds in multiple surgical specialties and pave the way for recruiting a commercialization partner for our Phase II SBIR proposal.