Source:CNS 1998 Seattle, Washington

Abstract:
The purpose of this study was to examine the feasibility, efficacy and safety of this novel endoscopic approach. During the past six months, six patients underwent a new outpatient small endoscopic manual procedure. A skin puncture opening (less than 5 mm) is made; under local anesthesia with IV sedation, 1 cm off midline, for interlaminar access.

Equipment consisted of a 4.2 mm outer cannula, a 2.8 mm fiber-optic working channel endoscope, micro-dissectors, suction and micro-graspers. The six patients ranged in age from 30 to 41, 4 males and 2 females. All had free fragments in the spinal canal at L5-S1 ruptured lateral to the dura. Open microdiscectomy had already been recommended in all cases. All had radicular pain, numbness and weakness for at least six weeks consistent with the herniation. Five had large fragments extending posteriorly to the ligamentum flavum. The 41 year old male had only a medium size fragment.

Results (Macnab criteria): 4 excellent (no symptoms, no restriction of activity) 2 good and still improving (the 38 and 41 year old males have occasional symptoms). The only adverse effect was a transient, mild hyperpathia (localized to the dorsum of the foot), lasting 1 week, which occurred in the 41 year old male. It was concluded that because his fragment was smaller there was not the same cushion effect to the endoscope, creating more contact with the nerve root. This technique appears to be the smallest, most direct, least traumatic method for treating sizeable free fragments at L5-S1.