Vascular Disorders of the Hand

Anatomy

• Blood supply is from the radial and ulna arteries.
• Some people have a residual median artery as well.
• Split into:
  • Deep Palmar Arch (Radial)
  • Superficial Palmar Arch (Ulna)
• Flow distribution:
  • Radial artery & deep arch: 50%
  • Ulna artery: 25%
  • Equal contribution: 25%

Radial Artery and Deep Palmar Arch

• Before snuffbox, radial artery gives:
  • Superficial palmar vessel → completes the superficial palmar arch.
• After snuffbox, Terminal Radial artery splits into:
  • Princeps Pollicis → digital vessels to thumb.
  • Radialis Indicis → radial digital artery to index finger.
• Then radial artery dives between:
  • Two heads of 1st dorsal interosseous and adductor pollicis.
• Deep palmar arch formation:
  • 80% contribution from radial artery.
  • Located 1 cm proximal to superficial arch.
  • Three palmar metacarpal branches → contribute to common digital arteries (2nd – 4th web spaces).

Ulna Artery and Superficial Palmar Arch

• Terminal ulna artery is the chief contributor to the Superficial Palmar Arch.
• Lies at level of 1st web space (thumb extended).
• 5 Main branches:
  • Deep palmar branch → completes deep arch.
  • Ulna digital artery → little finger.
  • 3 common palmar digital arteries → split to form digital arteries.

Dorsal Blood Supply

• Less dominant than palmar blood supply.
• Derived mainly from radial artery.
• Forms dorsal carpal arch at the wrist.
• Gives off dorsal metacarpal branches.

Diagnosis

Allen’s Test

• Screening tool for vascular sufficiency.

Cold Stimulation Testing

• Measures time for hand to return to normal after ice bath submergence.
  • 10 min → normal.
  • 20 min → abnormal.

Imaging Techniques

• Doppler
• Arteriography
• Colour Duplex (as effective as arteriography).
• Triple Phase Bone Scan:
  • 1st phase → Maps arterial tree.
  • 2nd phase → Shows perfusion.
  • 3rd phase → Not useful for vascular disease.

Occlusive Arterial Conditions

Embolic Disease

• Originates from the heart → affects major vessels or microvessels.
• Treatment: Embolectomy ± streptokinase.

Small Vessel Disease

• Associated with connective tissue diseases:
  • Sjogren syndrome
  • SLE
  • Scleroderma
  • RA
• Buerger’s Disease → male smokers.

Hypothenar Hammer Syndrome

• Post-traumatic thrombosis or aneurysm of ulna artery.
• Caused by blunt injury to hypothenar eminence.
• Symptoms:
  • Cold insensitivity.
  • Nerve compression.
• Management:
  • Thrombectomy.
  • Vein grafting.

Vasospastic Diseases

Colour Changes

1. White → Flow cessation.
2. Blue → Cyanosis.
3. Red → Reperfusion (painful and tingling).

Raynaud’s Phenomenon

• Underlying vascular cause.
• Asymmetrical.
• Treatment: Target underlying condition.

Raynaud’s Disease

• Idiopathic (no known cause).
• Bilateral.
• Young to middle-aged women.
• Management:
  • Calcium channel blockers.
  • Sympathectomy (if severe).

Frostbite

• Extracellular fluid freezes → ice crystal formation.
• Causes intracellular dehydration and cell necrosis.
• Management:
  • Rapid rewarming in 40°C water.
  • Address core temperature.
  • Debridement/amputation if gangrene occurs.

Thoracic Outlet Syndrome (TOS)

Anatomy

• Subclavian artery and brachial plexus roots exit between:
  • Anterior & middle scalene.
• Nerves → Superior to artery.
• Subclavian vein → Anterior to anterior scalene.
• Costoclavicular ligament → Lies anterior to subclavian vein.
• All structures between clavicle and 1st rib.

Causes of Obstruction

• Cervical rib (may be cartilaginous, seen on MRI).
• Anomalous scalene insertion.
• Clavicle or 1st rib fractures/malunion.
• Apical lung tumour.
• Postural causes.

Types of TOS

1. Neurologic (most common in orthopaedics).
2. Arterial.
3. Venous.

Neurologic TOS

• Young women most affected.
• T1 and C7 involvement → Pain along inside of arm.
• May cause intrinsic hand weakness.
• Clawing of all fingers (unlike isolated ulnar nerve compression).

Provocative Tests

• Adson’s Test:
  • Extend neck, turn towards affected side, deep breath.
  • Positive → Reduced radial pulse.
• Wright’s Test:
  • Arm abducted & externally rotated.
• Roo’s Test:
  • Arms above head, open & close fingers rapidly.
  • Look for neurologic symptoms or pulse change.

Investigations

• CXR → Detects cervical rib or long C7.
• MRI.
• NCS/EMG → Often not useful.

Differential Diagnoses

• Ulnar nerve compression.
• Tumour.
• Cervical degenerative disease.

Management

• Operative exploration if non-operative treatment fails.
• Supraclavicular approach.

Venous Compression (TOS)

• Pain & swelling of arm on overhead use.
• Common in bodybuilders.
• May present with venous thrombosis.

Diagnosis

• Duplex scan.
• Venography.

Management

• Surgical release if non-operative treatment fails.
• Anticoagulation for thrombosis.

Arterial Compression (TOS)

• Rarest form of TOS.
• Unilateral Raynaud’s as presenting feature.
• Usually due to tumour or aneurysm.

Diagnosis

• MRA.
• Duplex ultrasound.
• Bruits over affected area.

Management

• Surgical intervention if:
  • Non-operative measures fail.
  • Aneurysm/tumour present.