Open discectomy is useful for most patients but still carries the risk of general anesthesia and risk to sofi tissues. joints. nerves, and the invariable production of epidural fibrosis. Chemonucleolysis was introduced by Smith in 1964 as an alternative method but, it carries many complications such as anaphylaxis, subarachnoid hemorrhage, transverse myelitis, and severe back pain. Because of reducing this complications automated percutaneous lumbar discectomy has been advocated as an alternative treatment of herniated intervertebral disc in selected patients.

Twenty patients with symptomatic lumbar disc herniation were treated with automated percutaneous lumbar discectomy from August 1989 to October 1991 in Ewha Women University Hospital. They were followed up for more than 12 months. Changes in the objective and subjective signs and aymptoms of patients were examined preoperatively and postoperatively.

The results were as follows :

1) Age was ranged from 14 to 54 years with average 30 years, and 12 males and 8 females.

2) LA-5 was the most commonly involved level(80%).

3) In MRI classification subannular herniation was 11 cases and subligamentous herniationwas 4 cases.

4) Average duration of procedure was 31 minutes. and average amount of tissue aspirated was 3.9cc and average hospitalization period was 5 days.

5) Clinical results were satisfactory in 85% and unsatifactory in 15% of patients.

6) Unsatisfactory results were combined stenosis, insufficient removal of disc material, or recurred herniation of interverebral disc.

7) There was no significant complications postoperatively.

From this results, automated percutaneous lumbar discectomy is a good treatment method for selected cases of lumbar dsic herniation.