SPSIP Block for Pain Control After Breast Reduction Surgery (SPSIP-RM)

Reduction mammaplasty, also known as breast reduction surgery, may be associated with early postoperative pain because it is usually performed bilaterally and involves wide surgical dissection and tissue resection. Multimodal pain treatment is commonly used after this procedure to provide adequate pain control and to limit opioid exposure.

The serratus posterior superior intercostal plane block (SPSIP block) is an ultrasound-guided fascial plane block used for thoracic wall analgesia. Recent studies have evaluated this block in breast surgery, but data specific to reduction mammaplasty remain limited. In routine practice, surgical local anesthetic infiltration is often used during reduction mammaplasty. Therefore, this trial will evaluate whether adding bilateral SPSIP block to standard anesthesia, surgical local infiltration, and standard postoperative pain treatment provides additional opioid-sparing benefit.

This study is designed as a prospective, randomized, parallel-group, assessor-blinded, single-center clinical trial. Participants scheduled for elective bilateral reduction mammaplasty will be assigned in a 1:1 ratio to either the SPSIP block group or the control group. In the SPSIP block group, bilateral SPSIP block will be performed under ultrasound guidance after induction of general anesthesia and before surgical local infiltration and skin incision. The control group will not receive SPSIP block.

Both groups will receive the same standardized general anesthesia, surgical local anesthetic infiltration, postoperative multimodal analgesia, and rescue analgesia protocol. The local anesthetic agent, concentration, volume, and maximum safe dose limits for the block and surgical infiltration will be standardized before study enrollment.

The trial is planned to reflect routine plastic surgery practice. Surgical technique, pedicle selection, resection amount, drain use, and the use of dermal graft or internal support when clinically needed will be decided by the surgical team according to participant anatomy and routine clinical judgment. These variables will be recorded to describe surgical variability and may be considered in additional analyses if needed.

Postoperative pain assessments will be performed by ward nurses who are blinded to group allocation. Opioid use will be obtained from medication administration records. Block-related events and surgical complications will be recorded during routine postoperative care and up to 30 days after surgery.