Preventing Post-Laminectomy Peridural Fibrosis

DESCRIPTION (provided by applicant): Post-operative peridural fibrosis (scarring) is an associated event of lumbar microdiskectomy, and it significantly increases the hazard of revision spine surgery. The formation of scar tissue is part of the normal heal ing process and also an unavoidable consequence of procedures involving laminectomy. Epidural scar formation can result in fibrous adhesions around nerve roots imposing tension by entrapping the exiting nerve root resulting in mechanical tethering and even tually nerve damage; it can also cause compression of the spinal cord leading to subsequent pain. Dense adhesions and excessive scarring of the dura following lumbar surgery can cause radicular pain, low back pain, and even arachnoiditis. All these could r esult in the need for subsequent re-operation. The goal of this project is to develop a biocompatible and biodegradable in situ gelable hydrogel system to transiently seal the laminectomy site to prevent adhesion caused by excessive fibrotic tissue formati on. The performance characteristics of the hydrogel formulations will initially be optimized; this is followed by validation of its biocompatibility. The project will be concluded after performing in vivo efficacy evaluations in rabbit laminectomy epidural fibrosis models. This Phase I SBIR project will set the stage for developing future treatment to greatly reduce the rate of revision surgery on procedures involving laminectomy. PUBLIC HEALTH RELEVANCE: Lumbar diskectomy has evolved as the most common neu rosurgical procedure in the U.S., with nearly 300,000 procedures performed annually because of the epidemic problem of radicular leg and back pain, which translates into 15 million annual physician visits per year. It has been estimated that the financial burden on society exceeds 50 billion annually. The formation of scar tissue is part of the normal healing process and also an unavoidable consequence of procedures involving laminectomy Post-operative peridural fibrosis (scarring) is an associated event o f lumbar microdiskectomy, and it significantly increases the hazard of revision spine surgery. Extensive epidural scar formation can result in fibrous adhesions around nerve roots imposing tension by entrapping the exiting nerve root resulting in mechanica l tethering and eventually nerve damage; it can also cause compression of the spinal cord leading to subsequent pain. Dense adhesions and excessive scarring of the dura following lumbar surgery can cause radicular pain, low back pain, and even arachnoiditi s. Current re-operation rates after lumbar microdiskectomy are estimated at 9-14%. Re-operation rates after decompressive surgery for degenerative conditions (laminectomy, diskectomy) has increased in patients treated in the early (1990-1993) versus late ( 1997-2000) 1990's, despite better treatment options. The goal of this project is to develop a biocompatible, bioresorbable and in situ gelable polymeric vehicle to be administered as a post-laminectomy anti-adhesion therapy designed to enhance the effica cy for microdiskectomy leading to decrease in the rate of re-operation.