A new approach for brachial plexus block under fluoroscopic guidance

Area of Science:

• Anesthesiology
• Regional Anesthesia
• Anatomical Studies

Background:

• The subclavian perivascular approach to the brachial plexus is used to confirm needle tip location and solution spread.
• A hypothesis emerged that solution injected within the middle scalene muscle's costal attachment spreads into the interscalene space.

Purpose of the Study:

• To establish and validate the supracostal approach for brachial plexus block.
• To prove the hypothesis regarding solution spread within the interscalene space.

Main Methods:

• A total of 173 blocks in 149 adult patients were studied.
• The supracostal approach involved needle insertion 1 cm lateral to the subclavian artery and 1-2 cm above the clavicle, targeting the first rib's costal attachment.
• Radiographs and CT scans were used to visualize needle placement and solution spread; anatomical studies in cadavers were also performed.

Main Results:

• Eighty-four blocks using the supracostal approach with contrast medium achieved 95% success rate.
• Radiological studies showed solution spread from the middle scalene muscle into the interscalene space, without spreading below the first rib.
• The subclavian perivascular approach showed solution confined within the perineural sheath and spreading below the first rib.

Conclusions:

• The supracostal approach is a reliable and easy method for brachial plexus block with a low complication rate.
• Anatomical and radiological findings support the distinct spread patterns of the supracostal versus subclavian perivascular approaches.
• The supracostal approach, when the correct needle entry point is identified, demonstrated no block failures.