ABSTRACT
The percutaneous decompression of herniated disks is a well-established clinical approach with over 500, 000 procedures performed during the past 20 years. Several percutaneous techniques are in practice including chemonucleolysis, percutaneous lumbar discectomy, laser discectomy, and intradiscal electrothermoplasty (IDET) (1-6). These procedures have a reported success rate of approximately 70-75% but are associated with various individual limitations. During the IDET procedure, a needle is inserted into the affected disk under x-ray guidance. A special wire is then threaded through the needle into the disk, and after proper positioning has been achieved, it is heated. This causes partial melting of the annulus or wall of the disk, which, in turn, stimulates the growth of new protein fibers to provide annular reinforcement. In addition, small nerve fibers that have invaded the degenerating disk are also destroyed resulting in pain relief since many episodes of low back pain are due to annular tears. The coblation radio-frequency diskal nucleoplasty (CRDN) procedure described herein is newer procedure that is similar to IDET but utilizes a special radio-frequency probe (Wand) that is inserted into the disk through a needle rather than a heated wire. This Wand generates a highly focused plasma field with enough energy to break up the molecular bonds of the gel in the nucleus. As a result, 10-20% of the nucleus is “vaporized,” which decompresses the disk and reduces the pressure both on the disk and surrounding nerve roots. Since the high-energy plasma field is generated at relatively low temperatures, damage to surrounding tissues is minimized so that CDRN may be more effective and safer than IDET for relieving sciatic pain. A coagulation mode can subsequently be used to thermally provide further decompression of the intervertebral disk, as illustrated in Fig. 1a and b.The results of this dual action are depicted in Fig. 2.
