Authors: Tokita H et al.
Anesthesiology. November 10, 2025. DOI: 10.1097/ALN.0000000000005842
Summary:
This single-center, cluster-randomized trial evaluated whether adding PECS I (interpectoral) blocks to either paravertebral blocks or serratus anterior plane blocks improves postoperative analgesia after bilateral mastectomy with immediate expander reconstruction. Paravertebral block alone is a widely accepted technique for breast surgery, but the relative value of combining fascial plane blocks remains uncertain. The investigators hypothesized that combination approaches would reduce opioid consumption.
A total of 1507 patients were randomized by month between 2019 and 2023 into three groups: paravertebral block alone (n=492), paravertebral plus PECS I (n=446), and serratus anterior plane plus PECS I (n=568). The primary endpoint was postoperative opioid use, with secondary outcomes including pain scores, antiemetic use, discharge time, adverse events, chronic pain, and patient-reported quality of recovery.
Rates of high postoperative opioid use were 26% in the paravertebral group, 27% in the paravertebral plus PECS I group, and 22% in the serratus anterior plane plus PECS I group. The combined block strategies showed a non-significant 1.9% reduction in high opioid use compared with paravertebral block alone, with confidence intervals crossing zero and a p-value of 0.4. No secondary outcomes differed significantly after adjustment for multiple comparisons.
The authors conclude that neither paravertebral plus PECS I nor serratus anterior plane plus PECS I provided clinically meaningful improvement over paravertebral block alone. All three techniques are reasonable options, and block selection should be guided by practitioner experience, patient anatomy, and safety factors rather than expected differences in opioid consumption.
What You Should Know
• Adding PECS I to either paravertebral or serratus anterior plane blocks did not reduce postoperative opioid use.
• No differences were observed in pain scores, antiemetic use, discharge time, chronic pain, or quality of recovery.
• Paravertebral block alone performed equivalently to more complex combination approaches.
• All three regional techniques appear acceptable and safe for mastectomy with expander reconstruction.
• Block choice should be guided by clinician preference, patient factors, and anatomical considerations.
Key Points
• Combination blocks (paravertebral + PECS I or serratus anterior + PECS I) did not outperform paravertebral block alone.
• No significant differences were found across any primary or secondary outcomes.
• Paravertebral block remains an effective, reliable choice for postoperative analgesia in expander-based mastectomy.
• Fascial plane blocks did not demonstrate added benefit when layered on top of paravertebral block.
• Technique selection can reasonably be individualized, as all three approaches are acceptable.
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