Technology Bulletin 1366

Biomaterial replacements for cartilages undergoing FDA tests

A biomaterial developed by researchers at the Georgia Institute of Technology could be available in five years for patients needing artery or knee cartilage replacement. It also could help speed repair of damaged nerves in patients with spinal cord injuries or as the basis for an implantable drug delivery system. The patented material, a hydrogel called "Salubria," derives its name from the Latin words for "safe" and "healthy." The material has a high water content, making it similar to, and thus biocompatible with, human tissue, according to David Ku a professor of mechanical engineering at Georgia Tech, and a professor of surgery at Emory University. It is an organic polymer, rather than being made from silicone, which is suspect in inflammatory disorder in breast-implant patients. Also, it has enough mechanical strength that it won't burst under normal physiological conditions. And it has enough elasticity and compliance that it will pulsate in rhythm with the heart under normal physiological conditions. Proof-of-concept studies have shown Salubria's potential for use in artery replacement, including those in the heart, because of its mechanical strength. Also, the material shows promise for meeting the large demand for knee cartilage replacement in patients suffering from sports injuries, rheumatoid arthritis, and osteoarthritis, Ku reports. The researchers have secured investors for a private start-up company to produce and market the biomaterial. E-mail [email protected]

Surgical technique offers longer-lasting bypasses

Coronary bypass is a common surgery performed every year on some 400,000 patients whose arteries are blocked or hardened by a disease that restricts delivery of blood to the heart. The surgery creates an alternate route of blood supply by making a connection between the aorta and the blocked coronary artery, bypassing the obstruction. Over the last 20 years, surgeons gradually have been substituting veins with chest arteries, known as internal thoracic arteries. The arteries outpace veins, remaining disease-free at least twice as long. Now, a new surgical technique called the T-graft configuration, may bring even longer relief for patients. The procedure uses arteries from both the arm and chest to form a T-shaped conduit around the diseased portion of the heart. After operating on 650 patients, researchers at the Washington University School of Medicine in St. Louis tracked survival, wound infection, and incidences of conditions such as stroke. Only one patient died within 30 days of the operation, giving a mortality rate of 0.2%. The rate for low-risk patients who undergo standard procedures is thought to be between 1 and 3%. The surgical technique is controversial, says Hendrick B. Barner, who developed the procedure, because some surgeons have been concerned that the T-graft may not provide enough blood flow to the heart muscle. "Our studies show that not to be the case," he adds. E-mail [email protected] .

Computer program 'sees' beyond 3D to save lives

Data classification, often considered a humdrum task, becomes no such thing when the stakes are high. For example, quick, errorless identifications are a must for physicians reviewing medical images. That's why a sophisticated new data classification scheme is incorporated into the design of Sandia National Laboratories' handheld "lab-on-a-chip" chemical sensor system. Based on human perception, rather than mathematical equations, the classification method, called VERI (Visual-Empirical Region of Influence), is based upon the human ability to visually group real-world objects seen near each other, says the technique's principal developer Gordon Osbourn. "We discovered a way to capture in a software model the way human judgments empirically group patterns in 2D plots or 3D patterns, so that these judgments can be mathematically applied to high-dimensional data," Osbourn explains. The system under development will help identify chemicals released on a battlefield, explosives found in an airport, or substances collected on interplanetary explorations. However, the researchers see no reason that it can't be adapted to pinpointing treatments for physicians based on medical images. E-mail [email protected].

Novel gene therapy clears clots in leg arteries

Stanford University researches have devised a way to deliver a clot-busting gene to blocked leg arteries in animals, effectively restoring blood flow to the damaged vessels. In the procedure, the researchers inserted the gene for human tPA (tissue plasminogen activator), a common clot-busting agent, into a healthy leg vein in rabbits. The vein, which began pumping out large quantities of tPA, then served as a bypass for an adjacent artery constricted by a blood clot. The procedure reduced clotting by 75% and effectively restored normal blood flow in the legs of the test animals, says Michael Kuo, a radiology resident at Stanford's Medical Center. The technique also has the potential to greatly improve the results of coronary artery bypass surgeries that often fail as a result of arterial clotting, Kuo adds. Theoretically, surgeons would inject the tPA gene into the patient's saphenous vein before removing it from the thigh. The procedure would then follow its standard course, with doctors sewing the clot-resistant vessel into the patient's chest to channel blood past the diseased artery. E-mail [email protected].

Trials test experimental treatment for farsightedness

Another Stanford University project promises a fast, painless outpatient procedure that uses radio-frequency (RF) energy to reshape the front of the eye. In patients treated to date, the technique has provided immediate improvement in vision, according to Edward E. Manche, assistant professor of ophthalmology at the Stanford University School of Medicine. Vision continued to sharpen weeks after the procedure, as the eye settled into its new shape, Manche adds. The procedure, known as hyperopic radiofrequency thermokeratoplasty, works by heating and shrinking the cornea with RF energy. After numbing the eye with anesthetic drops, Manche inserts a thin probe about the thickness of a pin into the cornea and zaps the tissue with a burst of RF. He repeats this step several times at different points around the cornea. The exact number depends on the severity of the patient's vision problems. Total time for the procedure: two to five minutes. Within a year, Manche and his colleagues expect to have enough data on the procedure's effectiveness to present to the FDA for its approval. E-mail [email protected].

Sterilization changes promise longer life for hip implants

Changes in a sterilizing process for materials used in hip replacement surgery could substantially increase the life expectancy of hip implants. So reports Thierry Blanchet, associate professor of mechanical engineering at Rensselaer Polytechnic Institute. Preliminary results of Blanchet's research indicates that tying up free radicals in the polyethylene used in the implants can reduce wear by a factor of three. One major cause of failure, Blanchet explains, is a "cascading chain of events" that begins when the polyethylene cup is irradiated during manufacture to sterilize it. The radiation strips hydrogen from the hydrocarbon chains, creating free radicals that react with oxygen from the surrounding environment. These aging reactions cut the polymer chains, and the polymer abrades, releasing debris. The bone reacts, and the implant loosens. Blanchet has received funding from the Whitaker Foundation to confirm the preliminary findings and to explore new approaches. E-mail [email protected].

Internet analysis to aid in improving healthcare delivery

Two Austin, TX, companies, Sulzer Orthopedics, a supplier of implantable devices and biomaterials, and @outcome Inc., a developer of patient communicator software, have joined forces to apply Internet-based technology to the task of collecting and analyzing medical data. Sulzer will implement @outcome's Communictor^TM software to collect surgical data for accreditation, quality-care documentation, and clinical process/patient care improvement in orthopedics. The software connects physicians and their patients via the Internet or local network. Users can access the system to send and receive messages, review educational or wellness information, and input data about their current health status, risks, ongoing chronic disease condition, or their satisfaction with recent treatments. The system allows healthcare organizations to order, collect, store, aggregate, and report the results in real-time. "This data will guide us in the development of new therapies and products that will result in enabling the physician to deliver the best possible care to the patient," says Gary Sabins, general manager/VP of Sulzer Orthopedics. E-mail [email protected].

Interactive guides let users know when to head for the ER

Parents of children with sore throats can now find out whether a trip to the emergency room, a call to their pediatrician, or a simple dose of aspirin is the best course of action. A new Self-management of Symptoms (SOS) guide launched by AHN.COM, the Web site of America's Health Network, makes it possible. The sore-throat guide comprises one of 24 interactive pediatric guides designed to provide users with an easy, interactive way to manage common healthcare complaints--without visiting or calling a healthcare provider. By following a set of symptoms through a flow chart, users are led to an appropriate level of action, from visiting an emergency room to contacting a doctor to managing the symptoms from home. Guides also provide a glossary of terms, facts about the symptoms, and helpful information, such as when to throw out a toothbrush if strep throat is a possibility. Each guide also suggests other guides that may be associated with the chief complaint. A multidisciplinary clinical team of physicians, nurse practitioners, and registered nurses researched each guide before a review by board-certified physicians. More than 100 guides in two other categories, Adult Health and Women's Health, also are available 24 hours a day. More than 300 SOS guides are planned. E-mail [email protected].