Current Evidence of Minimally Invasive Spine Surgery in the Treatment of Lumbar Disc Herniations.

With the advent of new instrumentation and better imaging techniques that allowed less tissue trauma compared with traditional open procedures, while providing adequate or enhanced visualization of the pathologic site and based upon the successful experience of outpatient spine surgery to assist early ambulation, the trend and evolution toward ''minimal access'' or minimally invasive spine surgery began to develop with greater intensity. Many surgical techniques have flourished with the promise of delivering a safe and efficient alternative, including chemonucleolysis, manual percutaneous discectomy (MPD), automated percutaneous lumbar discectomy (APLD), and percutaneous lumbar laser discectomy (PLLD). Unfortunately, most of these techniques have been demonstrated to be inefficient with high complication rates. Only modifications of the original open discectomy in which direct visualization of the disc is obtained through either microscopic or endoscopic techniques have proven to be successful. This review outlines the historical journey that has inspired the development of these techniques and delineates the progressive clinical experience gained from their advent.