Abstract

　This study analyzed results of anterior transvertebral herniotomy for cervical disc hernia in order to assess the usefulness of this procedure and possibility of removal of upper thoracic disc hernia using same technique. The advantages of this method are the simplification of postoperative management and less risk of degeneration of the neighboring spinal segments, because the operated segments retain a variable degree of mobility.Materials Anterior transvertebral herniotomy was performed in 30 patients who had cervical disc herniation without spinal canal stenosis. The treated disks were C3/4 in 4 patients, C4/5 in 6 patients, C5/6 in 12 patients, C6/7 in 4 patients, C4/5 and C5/6 in 1 patient, and C5/6 and C6/7 in 3 patients. Methods Under general anesthesia, with the patient in the supine position, the side of the neck opposite to the herniated disc was incised for standard exposure of the anterior surface of the spinal column. If the herniated disc deviated cranially or caudally, the vertebral body on the side of deviation was exposed. Likewise, if there was lateral deviation of the herniated disc, the skin incision was made on the contra lateral side to the herniated mass, and the anterior surface of the vertebral body was exposed. Drilling was started with a high-speed drill at the center of the anterior surface of the adjacent cranial or caudal vertebral body. Drilling proceeded posteriorly or posterolaterally toward the herniated mass, and was stopped when the drill bit penetrated the posterior bone cortex. An operating microscope was introduced, and after checking the drilled-out posterior bone cortex, herniotomy was done through the drill hole, which was about 7 mm in diameter. The previously injected blue dye provided a good delineation of the herniated disc, especially if the mass had been extruded into the space between the superficial and deep layers of the posterior longitudinal ligament. ResultsIn most patients, a good result was obtained, but simultaneous or subsequent anterior intervertebral fusion was necessary in 4 patients. In 1 patient, the two adjacent vertebrae had fused spontaneously. Discussion In patients with cervical disc hernia, not only radiculopathy but also myelopathy can be treated by this operation. However, in most patients with myelopathy the spinal canal is narrow relative to the spinal cord, so radiculopathy patients accounted for about a half of our series. The best indication for this treatment judging from our postoperative results is a large hernia associated with either myelopathy or radiculopathy in a patient without spinal canal stenosis. The most important points are that this procedure should be limited to localized soft disc hernias, and that bulging of the annulus fibrosus should be excluded. Recently Demura et al reported herniotomy between T2/3 using this technique. Usually sternal splitting approach is necessary for this level, therefore, this kind of approach may be useful if surgeons would like to treat patients minimally invasively. ReferencesNoguchi K et al: Anterior decompression for cervical spondylosis using microscope. Bessatsu Seikeigeka 13: 54-57, 1988 (Japanese)Nakai S et al: Anterior transvertebral herniotomy for cervical disk herniation. J Spinal Disord 13: 16-21, 2000