Localization of the brachial plexus: Sonography versus anatomic landmarks

Area of Science:

• Anesthesiology
• Medical Imaging
• Anatomy

Background:

• Interscalene brachial plexus blocks are crucial for shoulder surgery perioperative management.
• Traditionally, anatomic landmarks (AL) guide needle placement for these blocks.
• Variability in AL accuracy can impact block effectiveness and safety.

Purpose of the Study:

• To compare the actual location of the brachial plexus using sonography (US) versus the anticipated location determined by AL.
• To assess the reliability of US in identifying brachial plexus roots for interscalene blocks.

Main Methods:

• Evaluated brachial plexus location in 96 subjects using both US and AL.
• Measured the distance between US-identified and AL-predicted locations.
• Utilized multivariate and 2x2 analyses of variance to assess significance and demographic influences (gender, height, BMI).

Main Results:

• The brachial plexus was found an average of 1.8 cm inferior and 0.2 cm lateral to the AL-determined site.
• The difference in location was statistically significant (p=0.0001 for inferior, p=0.09 for lateral).
• Gender significantly influenced the findings (p=0.03), but height and BMI did not.

Conclusions:

• Sonography (US) is a reliable and accurate method for pinpointing brachial plexus roots.
• The brachial plexus is frequently located inferior to the position predicted by anatomic landmarks.
• US guidance enhances precision for interscalene brachial plexus blocks, potentially improving patient outcomes.