CHAPTER 93: Percutaneous and Endoscopic Disc Procedures

INTRODUCTION

Minimally invasive treatments have undertaken all areas of the spine over the past 50 years. The majority of these minimally invasive techniques use a small passage to access the appropriate anatomical area thereby minimizing the resultant injury to the neural, muscular, and ligamentous soft tissues. Spinal disc disease has been treated with chemonucleolysis, percutaneous discectomy, laser discectomy, intradiscal thermoablation, and other minimally invasive microdiscectomy techniques. The goals of minimally invasive spinal procedures embody achieving clinical outcomes comparable to conventional open surgery while reducing the risk of iatrogenic complications. With the advent of modern surgical technologies such as digital fluoroscopy image guidance, high-resolution endoscopy, and minimally invasive surgical tools, less invasive approaches have become popular over the past decade among interventional pain physicians, neurosurgeons, and orthopedic spine specialists.

Percutaneous and endoscopic techniques, such as those used for cholecystectomy by general surgeons, have evolved into procedures performed by spinal surgeons for discectomy and fusion. Fluoroscopy image systems have been adapted to facilitate pedicle screw placement with great accuracy and to treat compression fractures with vertebroplasty and kyphoplasty. The progression of endoscopy and video image guidance systems, microscopy, radiofrequency, and laser technology along with percutaneous technique provide the foundation on which minimally invasive spinal surgery is based. Further improvement in optics and imaging resources, development of biologic agents, and introduction of instrumentation systems designed for endoscopic procedures will inevitably lead to further applications in minimally invasive spine surgery that will continue to challenge interventional pain management and spine surgeons.

HISTORICAL PERSPECTIVES

In the 1930s, Mixter and Bar recognized the relationship between disc herniation and sciatica.¹ In 1964, Smith was able to dissolve the nucleus pulposus via chemonucleolysis in a rabbit model via percutaneous enzymatic applications; this technique was later successfully applied in humans and later abandoned because of complications.^2,3 In 1973, Kambin and Gellman initiated a percutaneous indirect spinal canal posterolateral extracanal nonvisualized approach through an anatomically safe triangle appropriately named Kambin's triangle (see Fig. 93-1).⁴ Then Hijikata et al. in 1975 reported the first percutaneous nucleotomy for posterolateral lumbar disc herniations using arthroscopic techniques.^5-7 Kambin and Gellman reported a 72% success rate for 136 patients treated with a percutaneous lateral technique similar to method adopted by Hijikata.⁸ This success was due to a reduction of intradiscal pressure by forming fenestrations in the outer annulus. In 1983, Frost and Hausmann first introduced a modified arthroscope into the intervertebral disc space.⁹ In 1985, Onik et al. described the automated percutaneous lumbar discectomy using a 2-mm blunt-tipped suction cutting probe.¹⁰ Additionally, percutaneous laser discectomy was introduced by Choy et al. in the late 1980s.¹¹ Kambin published the first intraoperative discoscopic views of herniated nucleus pulposus in 1988.12