Minimally Invasive Spinal Surgery

Minimally Invasive Spinal Surgery: A Historical Perspective

Issada Thongtrangan, M.D.; Hoang Le, M.D.; Jon Park, M.D.; Daniel H. Kim, M.D. Neurosurg Focus 16(1), 2004. © 2004 American Association of Neurological Surgeons

Posted 03/04/2004

Abstract and Introduction

Abstract The concept of minimally invasive spinal surgery embodies the goal of achieving clinical outcomes comparable to those of conventional open surgery, while minimizing the risk of iatrogenic injury that may be incurred during the exposure process. The development of microscopy, laser technology, endoscopy, and video and image guidance systems provided the foundation on which minimally invasive spinal surgery is based. Minimally invasive treatments have been undertaken in all areas of the spinal axis since the 20th century. Lumbar disc disease has been treated using chemonucleolysis, percutaneous discectomy, laser discectomy, intradiscal thermoablation, and minimally invasive microdiscectomy techniques. The initial use of thoracoscopy for thoracic discs and tumor biopsies has expanded to include deformity correction, sympathectomy, vertebrectomy with reconstruction and instrumentation, and resection of paraspinal neurogenic tumors. Laparoscopic techniques, such as those used for appendectomy or cholecystectomy by general surgeons, have evolved into procedures performed by spinal surgeons for anterior lumbar discectomy and fusion. Image-guided systems have been adapted to facilitate pedicle screw placement with increased accuracy. Over the past decade, minimally invasive treatment of cervical spinal disorders has become feasible by applying technologies

similar to those developed for the thoracic and lumbar spine. Endoscope-assisted transoral surgery, cervical laminectomy, discectomy, and foraminotomy all represent the continual evolution of minimally invasive spinal surgery. Further improvement in optics and imaging resources, development of biological agents, and introduction of instrumentation systems designed for minimally invasive procedures will inevitably lead to further applications in minimally invasive spine surgery.

Introduction Since the 1930s, the relationship between disc herniation and sciatica has been well recognized. Since that time, intraoperative tools have been developed to facilitate surgical approaches and treatment of disc disease. Pool used a modified illuminated otoscope to perform myeloscopic examinations of the dorsal nerve roots in cases of disc herniations.[71] In 1955, Malis used the operating microscope and bipolar coagulation in facilitating his surgical approach.[42] With the introduction of the operating microscope, Yasargil and Caspar[6] both described the minimally invasive concept of microdiscectomy. During the same period, biochemical advances in the treatment of disc herniations were also developed. In 1964, Smith[74] was able to dissolve the nucleus pulposus in a rabbit model via percutaneous enzymatic applications; this technique was later successfully applied in humans.[21] In 1975, Hijikata[28] described the first percutaneous discectomy, which later evolved into automated discectomies. In addition to automated techniques, adjuvant treatments of discogenic disruption have included the use of lasers and thermal heating probes.[36,58,79] In 1984, Ascher and Heppner[2] used an Nd-YAG laser to heat the nucleus pulposus in attempts to shrink the disc and relieve the symptoms of nerve compression. Since the 1990s, with the application of video imaging to standard endoscopy, minimally invasive endoscopic and thoracoscopic procedures have gained rapid use and have persified in their clinical applications. In this report, we review the historical perspectives and the concept of minimally invasive spinal techniques as they are used in different portions of the spinal column.

Lumbar Spine

Chemonucleolysis Chymopapain was discovered and isolated by Jansen and Balls[30] in 1941 from the latex of the fruit of Carica papaya. By depolymerizing the proteoglycan and glycoprotein macromolecules of the nucleus pulposus, chymopapain can reduce the water content of the extracellular matrix of the nucleus pulposus and cause reductions in intervertebral disc height and bulge. In addition to reducing intradisc pressure, chymopapain may also have an antiinflammatory role in the nerve root itself. Watts[82] proposed that chymopapain interacts with the sensory fibers of the anulus to produce a total or partial neurectomy effect. The first clinical treatment of sciatica by using chymopapain was applied by Smith[74] in 1964. In the following three decades, chemonucleolysis was actively used to treat disc disease; however, controversial issues surrounding its safety and efficacy, arose despite the fact that it has the approval of the US Food and Drug Administration. Overall, the efficacy of chemonucleolysis was noted to be between 74 and 77% in several reports.[11,19,31] The largest series was reported by Nordby and Javid;[54] they published a 14-year study of 3000 patients and noted a success rate ranging between 82 and 87.2%. Other published outcome reports were inconclusive, however, and brought into question the safety and efficacy of chymopapain.[31,53,55] Anaphylactic reactions to this substance can result in death. An inadvertent intrathecal chymopapain injection can cause hemiparesis and paraplegia, raised intracranial pressure, meningitis, and hemorrhage.

A review of the literature nevertheless does reveal data supporting the continued use of chemonucleolysis for the treatment of lumbar disc

herniations.[25,43,44,78,83] Proper patient selection is crucial for success. Chemonucleolysis should be reserved for patients with radicular symptoms caused by a soft herniated disc as demonstrated by imaging studies. Patients older than 60 years of age may lack sufficient mucoprotein for hydrolysis and tend to respond poorly to this procedure.[4 …… 此处隐藏：53638字，全部文档内容请下载后查看。喜欢就下载吧 ……