# Lyodura

Lyodura was a medical product used in neurosurgery that has been shown to transmit Creutzfeldt–Jakob disease, a degenerative neurological disorder that is incurable, from affected donor cadavers to surgical recipients. Lyodura was introduced in 1969 as a product of B. Braun Melsungen AG, a leading hospital supply company based in Germany.
The product was used as a quick and effective patch material for surgery on the brain. It was a section of freeze-dried tissue which could be stored for extended periods on hospital shelves and could be made ready for use simply by soaking it in water for a few minutes.
What was not known by the consumer was the origin of the source material, the efficacy of its processing methods, and the danger of its use.
The raw material for Lyodura was the dura mater of a human cadaver. The tissue would usually be harvested during an autopsy and then sold to the manufacturer. After neurological diseases were linked to use of Lyodura, an investigation determined that the manufacturer had obtained the donor tissue by black market methods. Autopsy staff would remove the tissue from cadavers, regardless of whether the deceased's family had agreed to an autopsy or not, and sell it in quantity to representatives of the manufacturer. Due to this illegal method of collection, no record of patient history accompanied the tissue to production.
The harvested tissue was sterilized in large batches using gamma radiation and freeze-drying. The manufacturer believed that its sterilization procedure was sufficiently powerful to render any diseases in the tissue harmless and was therefore unconcerned about cross-contamination from CJD-containing tissue to other tissue in the same sterilization vat. It is now believed that almost all affected Lyodura product was tainted with Creutzfeldt–Jakob disease through this process. In 1987, after the first deaths linked to Lyodura, the manufacturer began processing tissue from each individual donor separately to prevent cross-contamination and rinsing it with sodium hydroxide, a proven means of deactivating prions, afterwards. That same year, the American Food and Drug Administration issued a safety alert advising medical professionals to dispose of all Lyodura that they could not confirm was from a different batch than the contaminated one, then an import alert stating that Lyodura was believed to carry Creutzfeldt-Jakob disease and shipments of it should be stopped by US customs agents as an "adulterated drug". The Australian Therapeutic Goods Administration also revoked its approval for use in 1987.
Lyodura was removed from sale in 1996. The World Health Organization recommended in 1997 that the medical field move away from cadaver-sourced dura mater grafts due to the risk of transmitting Creutzfeldt-Jakob disease highlighted by Lyodura-related cases. Dural grafts are now made from bovine tissue, various synthetic materials, or part of the patient's own body.
In 2017, 154 patients in Japan had been diagnosed with Creutzfeldt-Jakob disease after receiving dural grafts. Every patient where the brand of graft could be identified from medical records had received a Lyodura graft. Patients continued to develop symptoms up to thirty years after their surgery. In 2004, five Australian patients had been diagnosed with Creutzfeldt-Jacob disease after receiving Lyodura grafts. Due to the long latent period of Creutzfeldt-Jacob disease, epidemiologists remain uncertain how many people will be affected by the disease.
An award-winning documentary was produced on the subject. The Canadian Broadcasting Corporation's The Fifth Estate segment, "Deadly Harvest", dealt with the product's history, sale in Canada, and health effects worldwide. The product has since been banned for use in Canada.