Continuous Erector Spinae Plane Block versus Thoracic Epidural Analgesia After Thoracotomy: A Randomized Controlled Assessor-Blinded Non-Inferiority Trial

Purpose: Thoracic epidural analgesia (TEA) remains the current gold standard for postoperative pain control after thoracotomy, but is associated with significant complications and contraindications. This study evaluated whether continuous erector spinae plane block (ESPB) provides non-inferior analgesia to TEA. Patients and Methods: Adult patients scheduled for elective thoracotomy were randomized 1:1 to receive continuous TEA or ESPB. Outcome assessors were blinded to group allocation. In the TEA group, an epidural catheter was inserted at T6-7 under fluoroscopic guidance with tip confirmation at T5. In the ESPB group, a catheter was placed under ultrasound guidance at the T5 transverse process. Both groups received 0.2% ropivacaine boluses before incision, followed by patient-controlled analgesia for three days. The primary endpoint was resting numeric rating scale pain score on postoperative day 1 with a 2-point non-inferiority margin. Secondary endpoints included pain scores on days 2-3, opioid consumption, QoR-15K scores, and chronic pain assessments at 3 and 6 months. Results: Fifty-three patients were enrolled; 44 were included in the modified intention-to-treat analysis (ESPB n=23; TEA n=21). Mean resting NRS scores on postoperative day 1 were 4.22±1.93 (ESPB) versus 4.81±1.78 (TEA). The between-group difference was -0.59 (95% CI, -1.72-0.54; P=0.296), meeting the predefined non-inferiority margin. Secondary outcomes, including pain scores, opioid consumption, Quality of Recovery-15 scores, and chronic pain assessments at 3 and 6 months, were comparable between groups. No major complications occurred. Conclusion: Continuous ESPB demonstrated analgesic efficacy comparable to TEA for postoperative pain control after thoracotomy. Combined with its superior safety profile and technical simplicity, ESPB may serve as an effective alternative to TEA in thoracic surgery.