Posterior Endoscopic Discectomy Using as Endoscopic Lumbar Discectomy System Developed in Japan

Summary

The characteristics of the endoscopic lumbar discectomy system (ELDS) developed in Japan are introduced, and the first 50 cases are clinically evaluated. The patients included four cases of double disc herniation at two levels, one of cranially and three of caudally migrated discs, three of spinal canal stenosis, one of synovial cyst, and three of persistent ring apophysis. In four central disc herniation cases, one case was approached bilaterally and the other three cases unilaterally. Using a step-dilator system, the targeting interlaminar space was exposed and a tubular retractor of either 16 or 18 mm diameter was inserted through the paravertebral muscle. A 30° endoscope of 3-mm diameter was installed into a tubular retractor. Partial laminectomy and resection of the ligamentum flavum were performed using microsurgical instruments, followed by medial retraction of the symptomatic nerve root and incision of the herniated disc. The average surgery time was 119 min, and the average estimated blood loss was 49.1g. The patients left their beds at an average of 1.9 days postoperatively, and the average hospital stay was 11.5 days. The recovery ratio of the Japanese Orthopaedic Association (JOA) score was 80.7%. The average visual analogue pain score on the first postoperative day was 2.9cm, and the C-reactive protein level on the 7th day was 0.4 mg/dl. Adjacent two-level discectomy was possible with one midline skin incision. Coexistence of severe lumbar spinal canal stenosis was the most technically demanding pathology. The ELDS provided a brightened and magnified surgery field. This can be an effective assistant for minimally invasive lumbar disc surgery.