Literature References Supporting the Technique ENDOSCOPIC ANNULOPLASTY Spine J. 2004 Sep-Oct;4(5):564-73. Posterolateral transforaminal selective endoscopic discectomy and thermal annuloplasty for chronic lumbar discogenic pain: a minimal access visualized intradiscal surgical procedure. Tsou PM, Alan Yeung C, Yeung AT. 1245 16th Street, #202, Santa Monica, CA 90404, USA. BACKGROUND CONTEXT: Chronic lumbar discogenic pain (CLDP) impairs the patient's physical abilities to function within the normal physiologic loading ranges of activities of daily living. The pathogenesis of CLDP is multifactorial and not well understood. Conservative therapeutic regimens often fail to achieve sufficient pain relief. Surgical options vary greatly in surgical invasiveness as well as outcome. Definitive surgical treatment is often 360-degree fusion. The morbidity associated with this approach is significant, considering that only 65% to 80% of patients obtain satisfactory clinical results. This has spawned interest in minimally invasive surgical options, such as intradiscal electrothermal therapy (IDET; ORATEC Interventions, Inc., Menlo Park, CA), but results are conflicting. PURPOSE: The authors describe their surgical technique of minimal access posterolateral transforaminal selective endoscopic discectomy (SED) and bipolar radiofrequency thermal annuloplasty to treat CLDP. The procedure's rationale is based on the hypothesis that annular defects are the focal points of chronic exposure between neural sensory receptors in the defect and the inflammatogenic nucleus pulposus. In contrast to other percutaneous procedures, this technique allows direct visualization and targeting of the disc nucleus and annular fissures. Our 2-year clinical result is reported. STUDY DESIGN/SETTING: This is a retrospective review of consecutive surgical cases performed by one surgeon (ATY). The procedures were carried out from January 1997 to December 1999. Each patient has a minimum postoperative follow-up of 2 years. PATIENT SAMPLE: A total of 113 patients met the generally accepted clinical criteria for chronic lumbar discogenic pain and were selected for the procedure. OUTCOME MEASURES: Two outcome measures were used for clinical assessment: a surgeon-based modified MacNab method and a patient-based questionnaire. A mandatory poor result was given to any patient who had repeat spine surgery at the same level or has indicated dissatisfaction with the surgical result on the questionnaire response. METHOD: After meeting CLDP selection criteria, provocation contrast/indigo carmine dye discography was performed. This test was used to confirm the suspected discs as pain generators. The subject surgery then followed. Only cases with one and two levels of confirmed painful discs were entered into the study. The nonoperating author (PMT) analyzed the data. RESULTS: Using the surgeon assessment method, 17 patients (15%) had excellent results, 32 patients (28.3%) had good results, 34 patients (30.1%) had fair results and 30 patients (26.5%) had poor results. Of the 30 patients in the poor result group, 12 reported either no improvement or worsening, and refused further surgical treatment. Of the remaining 18 patients in the poor group, 8 had spinal fusion, 3 had laminectomy and 7 had repeat spinal endoscopic surgery. The patient-based questionnaire yielded similar percentages in each category. However, only 73.5% of the 113 patients returned the survey questionnaire. There were no aborted procedures, unexpected hemorrhage, device-related complications, neurologic deficits, perioperative deaths or late instability. CONCLUSIONS: Posterolateral transforaminal SED and radiofrequency thermal annuloplasty were used to interrupt the purported annular defect pain sensitization process, thought to be necessary in the genesis of chronic lumbar discogenic pain. Lack of clinical benefit from the subject procedure did not degrade any subsequent surgical or nonsurgical treatment options. The experience gained from this study warrants further investigation into the cellular and molecular processes that provided back pain relief in these patients. Surg Technol Int. 2003;11:255-63. Advances in endoscopic disc and spine surgery: foraminal approach. Yeung AT, Yeung CA. Arizona Institute for Minimally Invasive Spine Care, Phoenix, Arizona, USA. Endoscopic spine surgery is evolving rapidly due to improvements in surgical technique, endoscope design, and instrumentation. The current technique expands on the basic features and principles of Kambin's access to the spine through the triangular zone. A standardized method for foraminal surgery, the Yeung Endoscopic Spine System (YESS) (Richard Wolf Surgical Instrument Company, Vernon Hills, Illinois, USA) technique is proposed: (1) A protocol for optimal instrument placement by identifying the skin window, annular window, anatomic disc center, and disc inclination plane through topographical coordinates calculated by lines drawn on the skin from the C-Arm image. Adjustments in the trajectory are made to accommodate individual anatomic considerations and the pathologic disorders to be accessed. (2) Evocative Chromo-Discography (Richard Wolf Surgical Instrument Company, Vernon Hills, Illinois, USA). (3) Selective Endoscopic Discectomy (Richard Wolf Surgical Instrument Company, Vernon Hills, Illinois, USA). (4) Thermal discoplasty and annuloplasty. (5) Endoscopic foraminoplasty. (6) Accessing the epidural space in the axilla between the traversing and exiting nerve root. (7) Partially resecting the posterior annulus to get beneath the herniated fragment, if needed. This technique allows access to the epidural space from the lumbar disc as far cephalad as the middle of the vertebral body or approximately 2-3 mm caudally. The foraminal approach is routinely accessible from T-10 to L4-5. L5-S1 can be accessed with special techniques that include foraminoplasty of the lateral facet. Surgical results continue to improve, consistent with refinement of indications and techniques for specific conditions treatable by this endoscopic method. South Med J. 2000 Sep;93(9):885-90. Transcutaneous lumbar diskectomy for internal disk derangement: a new indication. Marks RA. Baylor/Richardson Medical Center, Tex, USA. BACKGROUND: Percutaneous diskectomy has been used effectively to treat lumbar disk herniation. The purpose of this review was to determine whether transcutaneous diskectomy is an effective surgical option for treating lumbar internal disk derangement. METHODS: Comprehensive retrospective review via personal interview included 103 consecutive patients available for long-term follow-up. For determining results as excellent, good, fair, or poor, the criteria included subjective relief of back and/or leg pain, ability to perform preinjury job functions, residual physical restrictions, use of medications, and need for subsequent surgery. Factors affecting results were statistically analyzed. RESULTS: The overall success rate was 83%, with no statistically significant differences in results based on sex, workers' compensation status, or levels of diskectomy. CONCLUSIONS: The favorable results from this series illustrate the high success rate of transcutaneous lumbar diskectomy in a heterogeneous patient population. Coupling the rate of success with a low rate of complications, transcutaneous lumbar diskectomy appears to be an effective, minimally invasive treatment for internal disk derangement. 81% Good-Excellent Outcome World Congress of Minimally Invasive Spine Surgery Dec 2000 Anthony Yeung, MD