Efficacy and safety of ozone injection into the intervertebral foramen for treating patients with chronic, intractable postherpetic neuralgia: a one-year follow-up study

Jianglin Wang^1*Hai-Li Li²Xiang-Bo Liu³Jia-Gui Zhao⁴Dong Huang⁵Cheng Wu⁶Jia-Shuang Wang^7*Jun Chen^8*

• ¹The Affiliated Hospital of Southwest Medical University, Luzhou, China
• ²Department of Anesthesiology, Tianfu Hospital Affiliated to Southwest Medical University, Meishan, China
• ³Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province, China
• ⁴First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
• ⁵Xiangya Hospital, Central South University, Changsha, Hunan Province, China
• ⁶Hejiang People's Hospital, Luzhou, China
• ⁷Department of Pain Management, Department of Pain, Guangzhou Red Cross Hospital, Guangzhou, China
• ⁸Institute for Biomedical Sciences of Pain, Tangdu Hosipital,The Fourth Military Medical University, Xi’an, China

Introduction: Chronic intractable postherpetic neuralgia (PHN) is a significant sequel of herpes zoster and significantly impacts patients' quality of life. Although some pharmacotherapies, interventional approaches, and neural modulation have been recommended as clinical options, their efficacy is limited. Here, we reported the efficacy and safety of a standardized therapeutic approach with CT-guided intervertebral foramen injection of ozone (IVFO) in patients with chronic intractable thoracic and lumbar (PHN) (n=56) who had been tolerant or insensitive to first-line drugs, such as gabapentin (GBP) or pregabalin. Methods: Visual analogue scale (VAS), quantitative sensory testing (von Frey filaments only), and infrared thermography were used to identify and quantify the pain intensity, area of mechanical hyperalgesia, and skin temperature in the included patients with PHN before and after IVFO treatment. Moreover, the dosage of and the time to discontinue GBP and complications were also documented after discharge from hospitals. Results: In this one year follow-up study, the primary endpoint outcomes measured by VAS showed that IVFO treatment resulted in significant relief of spontaneous pain by 59.19% [2.67±0.66] for immediate, 68.18% [2.08±0.89] for half year and 70.79% [1.91±1.19] for one year after discharge vs. admission), dramatic decrease in spatial area of mechanical hyperalgesia by 52.35% [3.11±0.70] for immediate and 87.41% [0.82±0.50] for half year after discharge vs. admission) and skin temperatures by 63.01% [0.85±0.35] for immediate after discharge vs. admission). Moreover, half of the patients stopped taking GBP 3 months after discharge. No serious complications were reported during the one-year follow-up after IVFO treatment. Conclusion: These results suggest that CT-guided IVFO treatment is a safe and effective interventional approach for the relief of chronic, drug-resistant, thoracic and lumbar PHN.