Prevention of cranial reossification after surgical craniectomy.

An experimental study in rats was designed to see whether the pericranium, used as a graft over the dura, can prevent or delay osseous reunion after craniectomy. A 10 x 3-mm section of the frontal and parietal bones, including the coronal suture line, was resected in 15 rats. Pericranium was then used as a free graft on one-half of the defect to cover the dura and separate it from the cut edges of the craniectomy. The other side acted as a control. All animals were killed 2 months after operation, the skull was removed, and any remaining bony defect on either side of the midline was revealed. The area of residual defect in 13 specimens was determined by statistical image analysis using the Oxford Modular Cataract Image Analysis System (Oxford, England) and Wilcoxon's rank sum test and showed a highly significant difference between the treated and the untreated sides (p = 0.002).