Ultrasound-guided superior costotransverse ligament block versus thoracic paravertebral block for postoperative analgesia after laparoscopic nephrectomy

Thoracic paravertebral block (TPVB) has been investigated for analgesia after laparoscopic nephrectomy but carries a risk of pleural injury. This prospective randomized non-inferiority trial compared ultrasound-guided superior costotransverse ligament (SCTL) block with TPVB. Patients were randomized 1:1 to SCTL block or TPVB at T10, using 0.4 mL/kg of 0.5% ropivacaine, alongside standardized general anesthesia and morphine-based patient-controlled intravenous analgesia. The primary endpoint was peak cough-evoked numerical rating scale (NRS) pain two hours after skin closure. Of 78 patients screened, 76 were randomized and 72 completed per-protocol analysis (36 per group). One pneumothorax occurred in the TPVB group; none in the SCTL group. The between‑group difference (SCTL group minus TPVB group) was 0.056 (95% CI − 0.341 to 0.452) in the per‑protocol population. In the intention-to-treat analysis ( n = 76), the between‑group difference was 0.12 (95% CI − 0.27 to 0.51). Notably, both CI upper bounds fell below the predefined 1.0 non-inferiority margin, confirming the non-inferiority of the SCTL block. The small sample and low adverse-event count preclude conclusions about comparative safety. A possible reduction in pleural injury with the superficial SCTL injection target remains unproven. (ChiCTR2300075992).