RT Journal Article SR Electronic T1 Ultrastructural changes of compressed lumbar ventral nerve roots following decompression JF Saudi Medical Journal JO Saudi Med J FD Prince Sultan Military Medical City SP 955 OP 961 VO 27 IS 7 A1 Wagih G. El-Barrany A1 Raid M. Hamdy A1 Abdulmonem A. Al-Hayani A1 Sawsan M. Jalalah A1 Mohammed J. Al-Sayyad YR 2006 UL http://smj.org.sa/content/27/7/955.abstract AB OBJECTIVE: To study whether there will be a permanent lumbar nerve root scarring or degeneration secondary to continuous compression followed by decompression on the nerve roots, which can account for postlaminectomy leg weakness or back pain.METHODS: The study was performed at the Department of Anatomy, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia during 2003-2005. Twenty-six adult male New Zealand rabbits were used in the present study. The ventral roots of the left fourth lumbar nerve were clamped for 2 weeks then decompression was allowed by removal of the clips. The left ventral roots of the fourth lumbar nerve were excised for electron microscopic study.RESULTS: One week after nerve root decompression, the ventral root peripheral to the site of compression showed signs of Wallerian degeneration together with signs of regeneration. Schwann cells and myelinated nerve fibers showed severe degenerative changes. Two weeks after decompression, the endoneurium of the ventral root showed extensive edema with an increase in the regenerating myelinated and unmyelinated nerve fibers, and fibroblasts proliferation. Three weeks after decompression, the endoneurium showed an increase in the regenerating myelinated and unmyelinated nerve fibers with diminution of the endoneurial edema, and number of macrophages and an increase in collagen fibrils. Five and 6 weeks after decompression, the endoneurium showed marked diminution of the edema, macrophages, mast cells and fibroblasts. The endoneurium was filled of myelinated and unmyelinated nerve fibers and collagen fibrils.CONCLUSION: Decompression of the compressed roots of a spinal nerve is followed by regeneration of the nerve fibers and nerve recovery without endoneurial scarring.