Upper Extremity

Upper Extremity Arterial System

Anatomy of the Upper Extremity Arterial System

  • Right Subclavian Artery:
    • Branches from the brachiocephalic artery.
  • Left Subclavian Artery:
    • Branches directly from the aortic arch.
    • Passes between the anterior and middle scalene muscles.
    • Branches include the vertebral, thyrocervical trunk, mammary, and costocervical arteries.
    • At the level of the outer border of the 1st rib, it becomes the axillary artery.

Key Arteries and Branches

  • Thyrocervical Trunk
  • Dorsal Scapular Artery
  • Suprascapular Artery
  • Right Vertebral Artery
  • Common Carotid Arteries
  • Brachiocephalic Trunk
  • Internal Thoracic Artery
  • Thoracoacromial Trunk
  • Posterior Humeral Circumflex Artery
  • Anterior Humeral Circumflex Artery
  • Axillary Artery
  • Subscapular Artery
  • Brachial Artery
  • Circumflex Scapular Artery
  • Lateral Thoracic Artery
  • Thoracodorsal Artery
  • Radial Artery
  • Ulnar Artery
  • Deep Palmar Arch
  • Superficial Palmar Arch
  • Digital Arteries

Axillary Artery

  • Origin:
    • Originates at the lateral margin of the first rib.
  • Location:
    • Lies deep to the pectoralis major and minor muscles.
  • Scanning Position:
    • Pledge position is used during scanning.

Brachial Artery

  • Continuation:
    • Continuation of the axillary artery at the level of the inferolateral border of the teres major muscle.
  • Termination:
    • Ends at the level of the elbow, dividing into the radial and ulnar arteries.

Radial and Ulnar Arteries

  • Radial Artery:
    • Gives rise to the superficial palmar arch.
    • Terminates in the deep palmar arch.
  • Ulnar Artery:
    • Gives rise to the deep palmar arch.
    • Terminates in the superficial palmar arch.
    • Represents a dominant source of blood supply to the hand.

Duplex Ultrasound of the Upper Extremity

Normal Spectral Doppler of Upper Extremity

  • Normal Waveform Characteristics:
    • Triphasic
    • Sharp systolic peak
    • Brief period of diastolic flow reversal
    • Minimal continued forward flow in diastole

Atherosclerosis

  • Abnormal Findings:

    • Elevated PSV (Peak Systolic Velocity)
    • Poststenotic turbulence
    • Dampened distal waveforms with loss of end-systolic flow reversal

  • Velocity Ratio for Stenosis:

    • A velocity ratio ≥2≥2 is consistent with >50\% stenosis.

  • Assessment:

    • Waveform changes and brachial blood pressures can help determine stenosis significance.

  • Example:

    • Figure 13-9 shows an angiogram and duplex ultrasound of left subclavian artery stenosis in a patient with left arm pain during exercise.
    • Duplex ultrasound indicated increased peak systolic velocities (190 cm/s190 \text{ cm/s}) in a subclavian artery lesion.
    • Dampened waveforms were observed distal to the lesion, suggesting that exercise-induced arm pain was likely related to the subclavian artery stenosis.
    • Angiogram demonstrated proximal left subclavian stenosis.

Occlusions

  • Documentation:
    • Absence of flow within the lumen by color and spectral Doppler.
    • Power Doppler may also be used for confirmation.
    • Adjust equipment settings to increase sensitivity to low flow states.
    • Use companion veins to help determine the proper location of the artery.

Hypothenar Hammer Syndrome

  • Definition:
    • Arterial degeneration of the ulnar artery as it passes deep to the hook of the hamate bone.
  • Association:
    • Associated with repeated use of the palm of the hand as a hammer.