| Abstract: | Zenoderm (Ethicon Ltd., Edinburgh, Scotland) is porcine skin dermis specially treated so as to be weakly antigenic when implanted. Its use as an extradural spinal and nerve root membrane to reduce postoperative adhesions after laminectomy was tested in 22 rabbits with laminectomy in the second and fourth lumbar vertebra. The sites were reviewed histologically two to 36 weeks after operation. Histologic sections showed that Zenoderm was initially surrounded by hematoma that organized into fibrous tissue and, later, bone. When Zenoderm was placed immediately adjacent to the dura, dense adhesions formed, which were slower to resolve than those in the control sites. The rate of Zenoderm resorption was variable. In general, Zenoderm did not excite excessive fibrous tissue formation and was slowly replaced by bone. Contrary to the experience of others, it was unusual to find adhesions between the laminectomy site, and the dura began disappearing after six to nine weeks. In rabbits, Zenoderm is unlikely to prevent adhesions forming after lumbar disc surgery. The resorption rate is variable, and laminectomy sites are unsuitable for the investigation of material for the prevention of spinal dural adhesions. |
