Endoscopic microsurgery in herniated cervical discs.

The purpose of this study was to make public our results using endoscopic microsurgery in herniated cervical discs. This technique allows us to avoid complications due to conventional exposure, as is the case in traditional approaches. This study was carried out from January 1991 to January 1998. One hundred and seventy-one patients should have undergone traditional surgery for 296 herniated cervical discs. They were, instead, treated by using endoscopic microsurgical techniques. In 273 herniations the surgical procedure was performed by a paramidline right anterior approach, and in 23 herniations by a paramidline posterior approach, with a working sleeve of 4.6 mm outer diameter in both cases. In the anterior approach the tube was firmly placed against the anterior longitudinal ligament and the edge of the anterior part of the vertebral bodies. The neurovascular structures were placed lateral to the working sleeve and the visceral structures were placed medial to the working sleeve. Then, under endoscopic coaxial control, removal of the herniated part was performed, through the intervertebral discs, with microsurgical instruments. In the posterior approach, the tube was placed instead between the inferior and superior lamina, then under the nerve root up to the herniation, which was removed. This posterior approach was used only in the lateral disc herniations. There were no incidents or major complications following these operations. After one month the success rate was 94.7%, after three months 95.9%, after six months 96.4% and after one year 97%. There were no cases of relapse during the follow-up period of these patients. This study suggests that for herniated cervical discs, the endoscopic microsurgical technique is an extremely advantageous and safe method. Moreover, longer follow-up periods and an increased number of patients treated with this procedure should further confirm the usefulness of this technique.