The patients, Joyce Turner, 68, of Kings Valley and Rob Pardee, 48, of Talent, underwent back-to-back procedures Oct. 23 at OHSU Hospital to repair aneurysms weakened areas of an artery wall that balloon out and fill with fluid that were at risk of rupturing. Both were able to go home the next day.
Stanley L. Barnwell, M.D., Ph.D., associate professor of neurological surgery in the OHSU School of Medicine and the Dotter Interventional Institute, performed the procedure on Turner and Pardee as part of a 120-patient clinical trial for the new Onyx Liquid Embolic System, developed by Irvine, Calif.-based Micro Therapeutics Inc. (MTI).
The Oregon Stroke Center at OHSU is one of 10 sites nationwide participating in the clinical trial for Onyx. Wayne M. Clark, M.D., professor of neurology in OHSU's School of Medicine and the Dotter Interventional Institute, as well as the Oregon Stroke Center's director, is the principal investigator of a study that will compare the Onyx procedure with other aneurysm treatments, such as coiling.
Using a catheter fed from the groin to a carotid artery in the brain, Barnwell locates the aneurysm and injects the Onyx liquid into the sac. When the liquid comes in contact with blood or body fluids, according to MTI, a solvent rapidly diffuses from the liquid, transforming it into a spongy, polymer mass that displaces the blood in the sac and seals off the defect. The solvent, dimethyl sulfoxide, or DMSO, is derived from lignin, a compound found in woody plants.
"It's a little bit like placing putty in a hole in the wall," Barnwell said. "It if stops an aneurysm from growing back, it'll be very useful."