Contralateral Interlaminar Keyhole Percutaneous Endoscopic Lumbar Surgery in Patients with Unilateral Radiculopathy.

OBJECTIVE: Percutaneous endoscopic surgery is increasingly used as an alternative to open microsurgery for treating lumbar spinal diseases. The purpose of this study was to determine the feasibility and efficacy of contralateral keyhole endoscopic surgery for treating unilateral radiculopathy.

METHODS: We performed percutaneous endoscopic sublaminar decompression via the contralateral interlaminar approach in 14 patients with unilateral radiculopathy. All procedures were performed under epidural anesthesia. The epidural space was accessed under fluoroscopic guidance; only the tongue portion of the handmade working sheath was placed within the epidural space to prevent nerve compression injury by the instruments. The base of the spinous process, caudal edge of the upper lamina, and rostral edge of the lower lamina were partially removed using a 3.5-mm drill bit under direct endoscopic visualization. After undercutting the ventral surface of the lamina by an endoscopic drill, the ligamentum flavum was removed using a punch, rongeurs, and forceps. The lateral recess and the traversing nerve roots were completely decompressed.

RESULTS: Symptoms were relieved immediately after surgery. The mean operating time was 68.2 minutes. Visual analog scale and Oswestry Disability Index scores improved significantly from 6.8 points and 61.6% preoperatively to 2 points and 22.2% at 6 months after surgery. A postoperative epidural hematoma was observed in 1 patient. No postoperative complications, such as dural tear, neurologic injury, or infection, were reported.

CONCLUSIONS: Contralateral keyhole endoscopic surgery is a safe and useful technique to decompress unilateral lateral recess stenosis or facet cyst.