Laminectomie

A laminectomy is a surgical procedure that removes a portion of a vertebra called the lamina, which is the roof of the spinal canal. It is a major spine operation with residual scar tissue and may result in postlaminectomy syndrome. Depending on the problem, more conservative treatments (e.g., small endoscopic procedures, without bone removal) may be viable. The lamina is a posterior arch of the vertebral bone lying between the spinous process (which juts out in the middle) and the more lateral pedicles and the transverse processes of each vertebra. The pair of laminae, along with the spinous process, make up the posterior wall of the bony spinal canal. Although the literal meaning of laminectomy is 'excision of the lamina', a conventional laminectomy in neurosurgery and orthopedics involves excision of the supraspinous ligament and some or all of the spinous process. Removal of these structures with an open technique requires disconnecting the many muscles of the back attached to them. A laminectomy performed as a minimal spinal surgery procedure is a tissue-preserving surgery that leaves more of the muscle intact and spares the spinal process. Another procedure, called the laminotomy, is the removal of a mid-portion of one lamina and may be done either with a conventional open technique or in a minimalistic fashion with the use of tubular retractors and endoscopes. The reason for lamina removal is rarely, if ever, because the lamina itself is diseased; rather, it is done to break the continuity of the rigid ring of the spinal canal to allow the soft tissues within the canal to: 1) expand (decompress); 2) change the contour of the vertebral column; or 3) permit access to deeper tissue inside the spinal canal. A laminectomy is also the name of a spinal operation that conventionally includes the removal of one or both lamina, as well as other posterior supporting structures of the vertebral column, including ligaments and additional bone. The actual bone removal may be carried out with a variety of surgical tools, including drills, rongeurs and lasers.