Bilateral decompression in lumbar degenrative stenosis associated with unilateral approach under minimally invasive microendoscopy(METRx) / 中华显微外科杂志

Object To discuss the surgical techniques and the clinical outcomes of the bilateral microendoscopic decompression surgery for lumbar spinal canal and lateral recess stenosis through unilateral approach. Methods 18-ram-diameter microendoscopic tubular retractor was placed with fluoroscopic gnidance, bilateral microendoscopic decompression surgery for lumbar spinal stenosis through unilateral approach were managed by adjusting the angle of tubular retractor. During the procedure, supra-interspinal ligament and contralateral bony lamina were well preserved. Results In the group of single-level microendoscopicdecompression, the mean operation time was 94 min and the mean blood loss was 65 ml. In the group of twolevel microendoscopic decompression, the mean operation time was 135 rain and the mean blood loss was 90 ml. The mean bed rest time was 6.5 days. After operation, the average back pain VAS score decreased from 6.5 to 3.1, the average leg pain VAS score decreased from 7.2 to 2.2, the average Oswestry Disability Index (ODI) decreased from 46.8 to 24.6, which had shown significant statistical difference before and after surgery (P ＜ 0.05). According to Nakai criteria, the excellent and good rate was 84%. Conclusion Bilateral microendoscopic decompression of lumbar canal through unilateral approach under METRx system offers a save, effective and minimal invasive option for lumbar spinal stenosis.

Microendoscopic Discectomy (MED) for Lumbar Disc Herniation / 한양의대학술지

Lumbar disc herniation is one of the most common disorders and its current surgical standard is a microsurgical discectomy. The microendoscopic discectomy (MED) was initially developed in 1997 by Foley and Smith and it is a minimally invasive surgical technique. This article discusses the technique, outcome and complications of this procedure. MED is performed by a muscle splitting approach using a series of tubular dilators with consecutively increasing diameters. The original endoscopic procedure is modified with microscope which has led to the development of the Microscopic Endoscopic Tubular Retractor System (METRX, Medtronic Sofamor Danek, Memphis, TN). A tubular retractor is inserted over the final dilator, and then the microscope is placed inside the tubular retractor instead of the endoscope. And then microdiscectomy is performed in the usual fashion via tubular retractor. Clinical outcomes by modified MacNab criteria were revealed excellent to good results in up to 95% of the patients. Average return to work period was within 1 month. Complications included nerve root injury, dural tear, and recurrent disc herniations. MED is at least as effective as microdiscectomy for the treatment of lumbar disc herniations with regard to long-term outcomes. MED can be performed safely and effectively with a smaller incision, resulting in a shortened hospital stay and faster return to work.

Use of microendoscopic tubular retractor system for lumbar intervertebral disc herniation: Report of 550 cases / 中国微创外科杂志

Objective To investigate the efficacy of microendoscopic tubular retractor system (METRx) in the management of lumbar intervertebral disc herniation. Methods By using the METRx system with modified instruments, the lumbar discectomy was performed in 550 cases. During the operation, patients were placed in a knee-chest sitting position, and the instrumentation was utilized into the vertebral canal through the ligamenta flava. Results The patients were followed for 6~36 months (mean, 21 months). According to the Nakai criteria, the curative outcomes were “excellent” in 478 cases (86.9%), “good” in 60 cases (10.9%),“fair” in 6 cases (1.1%), and “poor” in 6 cases (1.1%). The 6 cases with “poor” results obtained “fair” results after a re-operation of lateral recess enlargement and residual nucleus removal under microendoscope. Conclusions Lumbar discectomy with the utilization of the METRx system is minimally invasive, safe and effective.