Daniel S J CHOY


Percutaneous Laser Disc Decompression (PLDD) was performed in 309 cases of contained herniated lumbar discs. This is based on the principle that in an enclosed hydraulic space, such as an intact disc, a minute change in volume is associated with a large change of pressure. Nd: YAG laser energy is directed via an optical fiber through a discogram needle to vaporize approximately 65 mm3 of nucleus pulposus. The fall of intradiscal pressure is about 50%, and this results in the herniated portion receding away from the affected nerve root. Pain relief is immediate in 75%. There is an associated return of straight leg raising to normal. 309 PLDDs have been performed by my group since February 1986. The longest followup is 98 months, the mean, 50 months. The overall success rate according to the MacNab criteria is 75%. I speculate that the 25% failure rate is due to failure of even the best MRI to diagnose free fragments 20% of the time The complication rate was 1%, consisting of one case of sterile disciitis, and two of septic disciitis. All recovered with appropriate therapy. There were no serious neurologic or other sequelae. I conclude that PLDD is a relatively non-invasive, safe, simple, and effective treatment for herniated lumbar disc without sequestered free fragments.