Comparison of Ultrasound-Guided Erector Spinae Plane Block versus Thoracic Paravertebral Block for Postoperative Analgesia in Modified Radical Mastectomy: A Prospective Randomized Controlled Trial

Abstract

Background: Modified radical mastectomy (MRM) is associated with significant postoperative pain. Thoracic paravertebral block (TPVB) has long been considered the goldstandard regional technique for breast surgery analgesia, but it carries risks including pneumothorax, vascular injury and sympathetic blockade. The ultrasound-guided erector spinae plane block (ESPB) is a novel, technically simpler fascial plane block that has emerged as a potentially safer alternative. The present study compared the analgesic efficacy and safety of ESPB versus TPVB after MRM. Methods: In this prospective, randomized, double-blind controlled trial, 80 adult women aged 30–65 years with ASA physical status I– II undergoing elective unilateral MRM were randomly allocated to two equal groups (n = 40 each). Group E received ultrasound-guided ESPB and Group P received ultrasound-guided TPVB at the T4 level, both with 20 mL of 0.375% ropivacaine. The primary outcome was 24-hour cumulative tramadol consumption. Secondary outcomes included Numerical Rating Scale (NRS) pain scores at rest and on movement, time to first rescue analgesia, block performance time, adverse events and patient satisfaction. Results: Twenty-four-hour tramadol consumption was comparable between groups (158.4 ± 31.6 mg in ESPB versus 145.2 ± 28.4 mg in TPVB; p = 0.054). NRS scores at rest and on movement were similar at all time points (p > 0.05). Time to first rescue analgesia was 382.5 ± 68.4 minutes in ESPB and 408.6 ± 72.3 minutes in TPVB (p = 0.10). Block performance was significantly faster in ESPB (7.6 ± 1.8 versus 11.9 ± 2.7 minutes; p < 0.001). Hypotension occurred in 1 patient in ESPB versus 6 in TPVB (p = 0.04). No patient developed pneumothorax or local anaesthetic systemic toxicity. Conclusion: Ultrasound-guided ESPB provided postoperative analgesia comparable to TPVB after MRM, with shorter performance time and fewer haemodynamic adverse events, supporting its use as a safer, practical alternative to TPVB for postoperative analgesia in this surgical population.