Ultrasound-guided axillary approach for axillary nerve block: a cadaveric study

Area of Science:

• Anesthesiology
• Regional Anesthesia
• Ultrasound Guidance

Background:

• Interscalene brachial plexus block is standard for shoulder surgery pain.
• Phrenic nerve palsy is a risk with interscalene blocks.
• Combined suprascapular and axillary nerve blocks (ANBs) are alternatives.

Purpose of the Study:

• To perform ultrasound-guided axillary nerve block (ANB) via the axillary approach.
• To investigate the optimal injection point for ANB.
• To evaluate the spread of anesthetic solution during ANB.

Main Methods:

• 18 fresh-frozen cadaveric specimens were used.
• Ultrasound identified the axillary nerve in the axillary fold.
• In-plane needle insertion with latex and methylene blue solution injection.

Main Results:

• Ultrasound visualization and block manipulation were successful in all specimens.
• Blue latex stained the bifurcation of anterior and posterior axillary nerve branches.
• Methylene blue spread to anterior branch, deltoid, and teres minor muscle branches.

Conclusions:

• Ultrasound-guided axillary approach accurately blocks anterior and posterior axillary nerve branches.
• The axillary approach is an effective alternative to posterior approaches for ANB.