The intercostobrachial (ICB) nerve enters the axilla by piercing the upper part of the serratus anterior muscle

The ICB nerve innervates the skin of the axilla and the upper medial part of the arm

Loukas M, Hullett J, Louis RG, Holdman S & Holdman D: The gross anatomy of the extrathoracic course of the intercostobrachial nerve. Clinical anatomy 19:106-111 (2006)

The subcutaneous tissue superficial to the axillary artery is visualized and infiltrated with 10 mL of local anaesthetic

The intercostobrachial nerve typically innervates the floor and the skin of the axilla and the adjacent part of the medial side of the upper limb

The ICB nerve block is performed by subcutaneous infiltration from anterior to posterior across the axillary vessels

Inject 10 mL of local anaesthetic

Sonographically, the suprascapular nerve is seen as a flattened, hyperechoic structure in the bony groove of the scapular notch underneath the superior transverse scapular ligament (not visible with ultrasound)

Color Doppler can be used to visualize the vessels superficial to the ligament

Ref: Harmon D & Hearty C (2007)

Place the patient in the sitting position with flexion of the back and neck

Place a high-frequency linear probe parallel to the scapular spine

Make a parallel shift of the probe in the cranial direction until you visualize the trapezius muscle, the supraspinatus muscle and the suprascapular fossa underneath

Move the probe lateral until you identify the bony groove in the upper margin of the scapula that is called the scapular notch. The groove is converted to an aperture by the superior transverse scapular ligament. The suprascapular nerve runs via the aperture. The blood vessels run superficial to the ligament.

Insert the needle with in-plane technique from the medial end of the probe. The endpoint of injection is perineural spread in the scapular notch. The typical volume of local anaethetic is 5 mL.

The intercostobrachial (ICB) nerve should be anaesthetized when the surgical procedure involves the axilla and the adjacent part of the medial side of the upper limb – including a tourniquet

Harmon D & Hearty C: Ultrasound-guided suprascapular nerve block technique. Pain Physician 10:743-746 (2007)

Siegenthaler A, Moriggl B, Mlekusch S, Schliessbach J, Haug M, Curatolo M & Eichenberger U: Ultrasound-guided suprascapular nerve block, Description of a novel supraclavicular approach.
Regional Anesthesia and Pain Medicine, 37(3) 325-28 (2012)

The nerve roots of C5 and C6 fuse and become the superior trunk of the brachial plexus

The suprascapular nerve typically branches off the superior trunk immediately after the fusion from the nerve roots of C5 and C6

Other nerves from the superior trunk: the subclavian nerve

Other nerves from the C5 nerve root: the long thoracic nerve, the dorsal scapular nerve

Other nerves from the C6 nerve root: the long thoracic nerve (which branches off the nerve roots from C5, C6 and C7)

The anterior tubercle of the transverse process of the C6 vertebra is prominent and is called “Chassaignac’s tubercle”

The transverse process of the C7 vertebra has no anterior tubercle