Interpectoral and Pectoserratus Plane Blocks Compared with Serratus Anterior Plane Blocks for Postoperative Pain Management in Breast Surgery (Mastectomy, Lumpectomy, and Reconstruction): A Narrative Review.

Postoperative pain remains a major concern following breast surgery, with persistent pain rates varying by definition and duration of follow-up. Optimizing perioperative analgesia is essential to enhance recovery and reduce the risk of chronic postmastectomy pain syndrome (PMPS). Ultrasound-guided fascial plane blocks, including interpectoral plane (IPP), pectoserratus plane (PSP), and serratus anterior plane (SAP) blocks, have gained increasing use as regional analgesic techniques targeting chest wall innervation while avoiding the risks associated with more invasive regional approaches such as thoracic epidural or paravertebral blocks. A narrative review of the literature was conducted using PubMed, with studies selected based on relevance to postoperative pain outcomes in breast surgery. Evidence suggests that IPP, PSP, and SAP blocks are associated with reduced postoperative pain scores and opioid consumption compared with systemic analgesia alone. Comparative studies generally demonstrate similar overall analgesic efficacy between techniques, although differences in dermatomal coverage and onset characteristics have been reported. IPP primarily targets the pectoral nerves, whereas PSP provides broader coverage of the intercostal and intercostobrachial nerves, including the axillary region. In contrast, SAP blocks provide wider lateral thoracic wall coverage through blockade of the lateral cutaneous branches of the intercostal nerves. Evidence regarding effects on chronic pain outcomes remains limited and heterogeneous. These techniques demonstrate favorable safety profiles when performed under ultrasound guidance. Selection of block technique should be individualized based on surgical approach, anticipated pain distribution, and patient-specific factors.