Efficacy of erector spinae plane block versus thoracic paravertebral block for postoperative analgesia in modified radical mastectomy: a randomized controlled trial

Background: Postoperative analgesia in breast surgery is difficult due to the extensive nature of the surgery and the complex innervation of the breast; general anesthesia can be associated with regional anesthesia techniques to control intra- and post-postoperative pain. This randomized controlled study aimed to compare the efficacy of the erector spinae plane block and the thoracic paravertebral block in radical mastectomy procedures with or without axillary emptying. Methods: This prospective, randomized controlled trial included 82 adult females who were randomly divided into two groups using a computer-generated random number. Both groups received general anesthesia, Groups P and E (41 patients each) associated with a single-shot thoracic paravertebral block and a single-shot erector spinae plane block, respectively. Postoperative pain intensity (expressed as Numeric Rating Scale), patients who needed rescue analgesic, intra- and post-operative opioid consumption, post-operative nausea and vomiting, length of stay, adverse events, chronic pain at 6 months, andthe patient’s satisfaction were recorded. Results: At 2 h (p<0.001) and 6 h (p=0.012) the Numeric Rating Scale was significantly lower in Group P. The Numeric Rating Scale at 12, 24, and 36 postoperative hours did not show significant differences. There were no significant differences also in the number of patients requiring rescue doses of NSAIDs, in intra- and post-operative opioid consumption, in post-operative nausea and vomiting episodes and in the length of stay. No failures or complications occurred in the execution of techniques and none of the patients reported any chronic pain at six months from the surgery. Conclusions: Both thoracic paravertebral block and erector spinae plane block can be effectively used in controlling post-mastectomy pain and reduce intra- and post-operative opioid consumption. Trial registration The study was prospectively registered on Clinicaltrials.com (trial identifier NCT04457115) (first registration 27/04/2020).