Clinical Observation of CT-Guided Intervertebral Foramen Puncture and Radiofrequency Thermocoagulation for the Treatment of Refractory PHN in the Superior Thoracic Segment.

BACKGROUND: Post-herpetic neuralgia (PHN) is a typical neuropathic pain. Conventional oral analgesics and nerve block therapy can only obtain temporary analgesia in many cases. This study summarized the clinical effect of CT-Guided intervertebral foramen puncture and radiofrequency thermocoagulation through the superior margin of costotransverse joint for the treatment of refractory PHN in the superior thoracic segment. OBJECTIVES: To observe the efficacy of CT-Guided intervertebral foramen puncture and radiofrequency thermocoagulation (RFT) treatment of refractory PHN in the T1 ~ T3 spinal innervation area. STUDY DESIGN: A retrospective, observational study. SETTING: Pain department, Jiaxing and Hangzhou, China. METHODS: Thirty-six patients with intractable superior thoracic PHN were admitted to the Pain Department. After the positioning image of CT was taken by prone, the upper thoracic segment was scanned in axial position with the layer thickness of 3 mm of spinal model.The puncture path was designed by selecting the slice of the foramen and costotransverse joint from the obtained images. The needle was inserted to the corresponding foramen. After confirmation by high and low frequency current stimulation tests, the RFT was performed at 90 degrees C for 180s. A numeric rating scale (NRS) for pain was recorded before surgery, 2 hours, 1 week, 4 weeks and 8 weeks after surgery and the mental state was assessed with the SF-36 clinical questionnaire before surgery, 4 weeks and 8 weeks after surgery. RESULTS: Following RFT intervention the measured pain NRS significantly decreased after 2 hours, 1 week, 4 weeks and 8 weeks (P < 0.01). SF-36 scores in all categories increased 4 and 8 weeks after the operation (P < 0.01). No serious adverse effects were reported during the study period and no hypoxemia was found under intraoperative nasal catheter oxygen inhalation. LIMITATIONS: Limitations of this study include the small sample size, and nonrandomized retrospective design. CONCLUSION: CT-Guided intervertebral foramen puncture and RFT through the superior margin of the costotransverse joint can effectively improve refractory PHN in the superior thoracic segment with good safety.