Anatomical Evaluation of a Conventional Pectoralis II Versus a Subserratus Plane Block for Breast Surgery

Hal Robinson*, Shailendra Mishra, Lauren Davies, Fiona Craigen, Vija Vilcina, Simon Parson, Shahida Shahana

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


BACKGROUND: Pectoralis I and II (Pecs I/Pecs II) blocks are modern regional anesthetic techniques performed in combination to anesthetize the nerves involved in breast surgery and axillary node dissection. Pecs II spread and clinical efficacy is thought to be independent of whether injection occurs between pectoralis minor and serratus anterior or deep to serratus anterior. Injecting deep to serratus anterior onto the rib may be technically easier; however, our clinical experience suggests that this approach may be less effective for axillary dissection. We undertook a cadaveric study to evaluate a subserratus plane approach for use in breast and axillary surgery.

METHODS: Ultrasound-guided blocks using methylene blue dye were performed on 4 Genelyn-embalmed cadavers to assess and compare dye spread after a conventional Pecs II and a subserratus plane block at the third rib.

RESULTS: Conventional Pecs II injection demonstrated staining of the intercostobrachial nerve, third intercostal nerve, thoracodorsal nerve, long thoracic nerve, medial pectoral, and lateral pectoral nerve. The subserratus plane produced significantly less axillary spread, incomplete staining of the medial pectoral, and very minimal staining of the lateral pectoral nerve. Dye spread was limited to the lateral cutaneous branches of the intercostal nerves in both injections.

CONCLUSIONS: In our cadaveric study, injecting deep to serratus plane produced significantly less axillary spread. For breast surgery excluding the axilla, both techniques may be effective; however, for axillary dissection, the conventional Pecs II is likely to produce superior analgesia and additionally may help achieve complete coverage of the deeper pectoral nerve branches.

Original languageEnglish
Pages (from-to)928-934
Number of pages7
JournalAnesthesia and Analgesia
Issue number3
Early online date16 Jul 2020
Publication statusPublished - 30 Sept 2020

Bibliographical note

Publisher Copyright:
© 2020 Lippincott Williams and Wilkins. All rights reserved.

Copyright 2020 Elsevier B.V., All rights reserved.


Dive into the research topics of 'Anatomical Evaluation of a Conventional Pectoralis II Versus a Subserratus Plane Block for Breast Surgery'. Together they form a unique fingerprint.

Cite this