Bilevel Erector Spinae Plane Block Versus Pectoserratus Block for Analgesia in Modified Radical Mastectomy

Breast cancer remains the most frequently diagnosed cancer and a major cause of cancer-related mortality among women worldwide. Modified radical mastectomy (MRM), a common surgical procedure for breast cancer, is associated with significant postoperative pain, which may delay recovery and contribute to the development of chronic postmastectomy pain syndrome (PMPS). To address this, regional anesthesia techniques have been increasingly incorporated into multimodal analgesia strategies to reduce opioid consumption and enhance patient outcomes. Interfascial plane blocks, in particular, offer safe and effective analgesia under ultrasound guidance. The erector spinae plane block (ESPB), first described in 2016, involves injection of local anesthetic deep to the erector spinae muscle and may spread to the paravertebral space, providing both somatic and visceral analgesia. A bilevel approach may enhance dermatomal coverage. Meanwhile, the pectoserratus plane block (PSPB), which combines PECS II and serratus anterior blocks, targets nerves of the anterior and lateral chest wall and has shown efficacy in breast surgery