August 15, 2001
Use of Cadaver Brain Tissue Threatens Safety of
Brain Surgery Patients
Public Citizen Calls on FDA to Ban Material That Risks Transmission of Creutzfeldt-Jakob Disease
WASHINGTON, D.C. ? The continued use of cadaveric dura mater ? a membrane surrounding the brain ? for transplantation in neurosurgical patients unnecessarily exposes them to Creutzfeldt-Jakob Disease (CJD) and variant CJD, the human version of mad cow disease, Public Citizen told a Food and Drug Administration (FDA) official today.
In a petition filed with the FDA, Public Citizen called on the agency to ban the sale of all human cadaveric dura mater and recall all such tissue not yet used in surgery because the tissue has caused at least 114 cases of always-fatal CJD. Great Britain banned the material 12 years ago and Japan did so four years ago, without any subsequent evidence of harm to patients. The World Health Organization (WHO) recommends against its use.
The FDA?s unwillingness to ban cadaveric dura mater is unacceptable in light of the availability of acceptable substitutes, Public Citizen said. Several synthetic dura mater grafts have been approved by the FDA for marketing in the United States. Tissue from the side of a patient?s own leg or implants from animals also are widely accepted alternatives to cadaveric dura mater.
“The FDA must act now to completely ban this material from future use,” said Dr. Peter Lurie, deputy director of Public Citizen?s Health Research Group. “CJD is a fatal disease, and there is no need to expose patients to it when clearly there are safer alternatives.”
Lurie sits on the FDA Transmissible Spongiform Encephalopathies (TSE) Advisory Committee. CJD, variant CJD and mad cow disease are all considered TSEs. CJD and variant CJD are similar conditions, but CJD is not known to be related to the consumption of contaminated meat. Existing procedures to decontaminate the dura mater and screen patients for the risk of CJD transmission are inadequate, Lurie said.
Cadaveric dura mater is obtained from deceased persons and has been used for decades in transplant operations for patients who undergo neurosurgery for conditions such as brain cancer and trauma. Of the approximately 20,000 neurosurgery grafts that take place in the United States each year, roughly 5,000 to 10,000 involve cadaveric dura mater.
However, the safety of dura mater was called into question in Japan beginning in the mid-1980s, when at least 65 patients developed CJD following receipt of a dura mater graft. The first of three U.S. cases of CJD caused by cadaveric dura mater implants was recorded in 1987, in a 28-year old woman. Cases of CJD from already-implanted dura mater are likely to continue because the incubation period of CJD can be as long as 18 years.
Following the initial case in the United States, the Centers for Disease Control and Prevention (CDC) stated that the use of human cadaveric dura mater increases the risk of contracting CJD, and emphasized that alternatives to dura mater were available.
Further, when the WHO responded to the dura-associated CJD epidemic in Japan in 1997, it recommended that “cadaveric dura mater no longer be used, especially for neurosurgery, unless no other alternative is available.”
However, the FDA has not followed the guidelines set by the WHO. In 1997, the TSE advisory committee discussed the issue of CJD transmission from dura mater and concluded that cadaveric dura mater was not necessary in any surgical procedure. Nevertheless, the committee fell short of banning the material, voting instead to recommend that the use of cadaveric dura mater be avoided whenever possible, but that the operating neurosurgeon should decide whether to use it. In 1999, the FDA issued a voluntary guideline that formalized this approach.
Public Citizen?s petition was also signed by Dr. John A. Jane, chairman of neurological surgery at the University of Virginia and editor of the Journal of Neurosurgery. Dr. Jane indicated that cadaveric dura mater is no longer used in his department.
Dr. Sidney Wolfe, director of Public Citizen?s Health Research Group, used to sit on the FDA TSE Advisory Committee and voted against the FDA guideline.
“Leaving this critical decision in the hands of neurosurgeons is a woefully inadequate step in protecting patients,” Wolfe said.