Modified Transverse in-Plane Costotransverse Foramen Block for Thoracic Postherpetic Neuralgia: A Prospective Case Series.

PURPOSE: Thoracic paravertebral block (TPVB) is frequently employed for pain management in patients with postherpetic neuralgia (PHN), but it carries risks of pneumothorax and inadvertent neuraxial spread. We describe an ultrasound-guided modified transverse in-plane costotransverse foramen block (tCTFB) and evaluate its short-term analgesic effects and impact on sleep quality in patients with refractory thoracic PHN. PATIENTS AND METHODS: A prospective case series enrolled 10 adults with refractory thoracic PHN at the Department of Pain Medicine, Taihe Hospital, Shiyan, Hubei, between January 12 and January 27, 2026. All patients underwent ultrasound-guided tCTFB. Contrast distribution within the thoracic paravertebral space was confirmed by computed tomography (CT) performed within 5 minutes post-procedure. Pain intensity was assessed using the Numeric Rating Scale (NRS) before intervention, at 30 minutes, and on days 1, 3, and 7. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI) before intervention and on days 1 and 7. RESULTS: Median NRS decreased from 7.0 (IQR 6.0-8.0) at baseline to 1.5 (IQR 1.0-3.0) at 30 minutes, 3.0 (IQR 2.0-4.0) on day 1, 3.5 (IQR 2.0-4.5) on day 3, and 3.5 (IQR 3.0-4.5) on day 7 (Friedman test: χ2 = 18.6, df = 4, p < 0.001). PSQI decreased from 15.5 (IQR 13.0-18.0) to 9.0 (IQR 7.0-10.0) on day 1 and remained at 8.5 (IQR 7.0-10.0) on day 7 (Friedman test: χ2 = 16.2, df = 2, p < 0.001). LIMITATIONS: This single-center prospective case series included 10 consecutive patients without a control group. PSQI was not assessed at 30 minutes or day 3, limiting evaluation of the acute sleep response. Moreover, the 7-day follow-up cannot capture sustained analgesia, PHN progression, or sleep architecture normalization in this chronic condition. CONCLUSION: This study demonstrates that ultrasound-guided tCTFB is technically feasible and associated with rapid analgesia and short-term improvement in sleep quality in patients with refractory thoracic PHN.