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Conventional Nerve Repair Wisdom Defied in First-Ever Multicenter Clinical Study with Processed, Donated Nerve Tissue



SAN FRANCISCO, Jan. 12, 2012 /PRNewswire-USNewswire/ --  In the first-ever multicenter clinical trial on processed nerve allograft, researchers from The Buncke Clinic in San Francisco found that treatment of severed peripheral nerve with processed >nerve allograft showed meaningful recovery in 87 percent of patients, comparing favorably to traditional >nerve repair (autograft nerve). The study findings were published in the January 2012 issue of Microsurgery .(i)

"It is commonly accepted among surgeons who do peripheral nerve repair that success of surgery depends on the type of injury, length of nerve discontinuity, the patient's age and the type of nerve. Our study findings show that with processed nerve allograft, patients can have meaningful recovery regardless of these factors," said Darrell Brooks, M.D., plastic surgeon, of The Buncke Clinic and the study's principal investigator. "Based on our findings, the information I use to counsel my patients prior to surgery will change — this is a paradigm shift."

Believed to be the largest-of-its-kind in peripheral nerve repair, the study found processed nerve allografts are a safe and effective alternative for nerve reconstructions. This observational study includes data collected from 12 collaborative institutions with 25 surgeons, each using their own standard of care, preferred surgical techniques, rehabilitation plan and follow-up. A total of 132 individual nerve injuries were treated using the processed nerve allograft.

Findings in the study's subset analysis show nerve allograft is effective:

  • Across all types of nerves where 89 percent of sensory nerves, 86 percent of motor nerves and 77 percent of the traditionally more difficult to treat mixed nerves achieved meaningful recovery;
  • In both short and long nerve gaps, with meaningful recovery achieved in 100 percent of nerve gaps less than 15mm, 76 percent of nerve gaps 15-29mm and 91 percent of nerve gaps 30-50mm;
  • For adults of any age, with meaningful recovery achieved in those ages 18-29 (70 percent), 30-49 (88 percent) and 50+ (93 percent); and
  • No graft-related adverse experiences were reported, and no reported implant complications, tissue rejections or adverse events related to the use of processed nerve allografts.

"Nerve injuries can have a devastating long-term impact on patients who suffer from them. Traditional repair techniques do not work for all patients, and surgeons need additional tools to help more patients," said Darrell Brooks, M.D., "This study confirms that processed nerve allograft is an effective and safe additional treatment that can help patients with peripheral nerve injuries get back to their day-to-day lives."


Subset and additional data analysis from this study will also be presented at three medical meetings in Las Vegas this week, the American Association for Hand Surgery Annual Meeting, the American Society for Peripheral Nerve Annual Meeting and the American Society for Reconstructive Microsurgery Annual Meeting.


About Nerve Repair
Peripheral nerves are the communication network between the central nervous system and the rest of the body, allowing for sensory perception and muscle movement. If a peripheral nerve is severed by traumatic injury or due to surgical intervention, the communication lines are disrupted and the person will lose function related to that nerve. Not being able to feel or move a portion of the body can have a significant impact on an individual's quality of life.

To restore function to a severed nerve, surgery is required to reconnect the peripheral nerve. Traditionally, during a nerve repair procedure, surgeons attempt to meticulously reconnect the cut nerve. If there is a significant loss of nerve tissue, then a nerve conduit or nerve autograft were typically required to bridge the severed nerve. Nerve conduits have been shown to work well over very short nerve gaps, but have been found to be less effective and less reliable for longer nerve gaps.(ii) Nerve autograft requires an additional surgery; one surgical procedure harvests a healthy, less important peripheral nerve(s) from the patient's body and a second to repair the severed nerve. Nerve autograft will cause patients to lose function at the site of the harvest and may have increased risk of scarring and the development of painful neuromas. Additionally, these procedures result in longer anesthesia time, increased complication rates and higher overall costs due to the second surgical site.(iii)

By contrast, processed nerve allograft (AxoGen Avance® Nerve Graft is a peripheral nerve from a human donor that is used to bridge gaps in severed peripheral nerves. The donated nerve tissue is processed to remove cells and cellular debris and provide a sterile scaffold for nerve regeneration. 


About the Study
All repairs in the study were performed by experienced plastic or orthopedic surgeons who at a minimum completed a fellowship in hand or hand and microsurgery. The study was open to all adult patients implanted with processed nerve allograft AxoGen Avance® Nerve Graft at the 12 centers. Centers enrolling subjects in the study included Level 1 trauma centers, academic medical centers, military treatment facilities, community medical centers and ambulatory surgical centers that actively performed nerve repair.

About the Buncke Clinic
The Buncke Clinic was founded at the Davies Medical Center in San Francisco in 1970. Since that time over two hundred clinical and research fellows and residents have trained at the Clinic; twenty-seven have subsequently become plastic surgery department chairmen or co-chairmen at leading medical and research facilities around the world. Over 400 articles, books, and chapters have been published from our service, and hundreds of scientific papers presented globally. The Buncke Clinic continues to attract the best and brightest plastic surgeons nationally and internationally to teach, train and lead.

(i) Brooks, D. et. al, Processed Nerve Allografts for Peripheral Nerve Reconstruction: A Multicenter Study of Utilization and Outcomes in Sensory, Mixed, and Motor Nerve Reconstructions. Microsurgery 2012: DOI 10.1002/micr.20975.

(ii) Weber RA, et. al. A randomized prospective study of PGA conduits for digital nerve reconstruction in humans. Plast Recon Surgery 2000;106:1036-1045.

(iii) IJpma FF, et al. Sural nerve donor-site morbidity: Thirty-four years of follow-up. Ann Plast Surg 2006;57(4):391-395.

Posted: January 2012