An Updated Review of Automated
Percutaneous Mechanical Lumbar Discectomy
for the Contained Herniated Lumbar Disc
Background: Lumbar disc prolapse, protrusion, and extrusion are the most common causes of nerve root pain and surgical interventions, and yet they account for less than 5% of all low back problems. The typical rationale for traditional surgery is that it is an effort to provide more rapid relief of pain and disability. It should be noted that the majority of patients do recover with conservative management. The primary rationale for any form of surgery for disc prolapse associated with radicular pain is to relieve nerve root irritation or compression due to herniated disc material. The primary modality of treatment continues to be either open or microdiscectomy, although several alternative techniques, including automated percutaneous mechanical lumbar discectomy, have been described. There is, however, a paucity of evidence for all decompression techniques, specifically alternative techniques including automated and laser discectomy. Study Design: A systematic review of the literature of automated percutaneous mechanical lumbar discectomy for the contained herniated lumbar disc. Objective: To evaluate and update the effectiveness of automated percutaneous mechanical lumbar discectomy. Methods: The available literature on automated percutaneous mechanical lumbar discectomy in managing chronic low back and lower extremity pain was reviewed. The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria, as utilized for interventional techniques for randomized trials, and the criteria developed by the Newcastle-Ottawa Scale criteria for observational studies. The level of evidence was classified as good, fair, and limited or poor, based on the quality of evidence scale developed by the U.S. Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to September 2012, and manual searches of the bibliographies of known primary and review articles. Outcome Measures: Pain relief was the primary outcome measure. Other outcome measures were functional improvement, improvement of psychological status, opioid intake, and return to work. Short-term effectiveness was defined as one year or less, whereas long-term effectiveness was defined as greater than one year. Results: Nineteen studies were included; none of the randomized trials and 19 observational studies met inclusion criteria for methodological quality assessment. Overall, 5,515 patients were studied with 4,412 patients (80%) showing positive results lasting one year or longer. Based on USPSTF criteria, the indicated evidence for automated percutaneous mechanical lumbar discectomy is limited for short- and long-term relief. Limitations: A paucity of randomized controlled trials in the literature describing automated percutaneous mechanical disc decompression. Conclusion: This systematic review shows limited evidence for automated percutaneous mechanical lumbar discectomy. Automated percutaneous mechanical lumbar discectomy may provide appropriate relief in properly selected patients with contained lumbar disc herniation. Key words: Intervertebral disc disease, chronic low back pain, mechanical disc decompression, automated percutaneous mechanical lumbar discectomy, internal disc disruption, radiculitis.