[Clinical analysis of 270 cases of microsurgical lumbar discectomy].

Since 1983, the authors encountered 270 cases of lumbar disc hernia, which were operated on with the microsurgery. In the present study, the operative procedures were described and the results, especially the results of the reoperations were examined. Good results were obtained in 252 patients (93%). In nine patients, some kind of lumbago continued, which required other treatments, such as epidural block (3.3%). Reoperations were performed in nine patients (3.3%). In lumbar discectomy, extent of removal of the bony structures and the disc material seemed important. In "microlumbar discectomy", which was advocated by Williams, only the flavectomy with no bony structure removal was performed. In this procedure, discectomy is limited to the protruded disc material. On the contrary, some authors, who also adopt microsurgical lumbar discectomy as Wilson and Hudgins do, perform subtotal removal of the disc material with removal of some bony structures. In the present series, microsurgical lumbar discectomy following the procedures advocated by Wilson et al was performed. Reoperations after lumbar discectomy have been reported after all kinds of operations. In the present series, the rate of reoperation was 3.3%. As to the reasons for reoperations, true recurrence of disc hernia was the most prevalent. The hernias recurred at the same level and on the same side. Adhesion or fibrosis around the nerve root also played an important role. From the results of the present study, microsurgical lumbar discectomy with good illumination and high magnification has proved to bring satisfactory results. Recurrence, however, can occur after this procedure, so further inventions are required to ensure more satisfactory results.