Wednesday, January 6, 2010

Digital Hypoperfusion Ischemic Syndrome

Digital hypoperfusion ischemic syndrome (DHIS) refers to hand ischemia due to peripheral hypoperfusion after arteriovenous access (e.g., for hemodialysis). Its older name, arterial steal syndrome, is felt to be less accurate, since a majority of patients with arteriovenous access demonstrate clinically silent arterial steal (i.e., retrograde flow).

The exact etiology is poorly understood, but is felt to be related to a combination of true steal from the distal arteries, arterial stenosis throught the arm (proximal and distal), and distal arteriopathy.

Patients commonly present with cold hand, numbness, and hand pain on and/or off dialysis. The radial pulse is usually diminished. In advanced cases, there may be ischemic ulcers and dry gangrene. DHIS is more common in patients with brachial artery than radial artery based accesses. Symptoms are also more frequent in patients with diabetes and in smokers.

The presentation may be acute or insidious. In the acute case, symptoms occur almost immediately after creation of the access. The treatment in these cases is ligation of the access.

The symptoms may also occur weeks or months after access. They may later resolve due to development of collateral circulation.

Differential Considerations

Differential considerations for hand pain in chronic dialysis patients can be narrowed somewhat:
  • Carpal tunnel syndrome: Increased prevalence in long-term hemodialysis. There may be atrophy of the lateral thenar muscles.
  • Tendopathy: Increased prevalence in long-term hemodialysis.
  • Arthropathy: Increased prevalence in long-term hemodialysis. There may be deformity and instability of interphalangeal joints and localized tenderness.
  • Reflex sympathetic dystrophy: Pain and swelling of an affected extremity.
  • Ischemic monomelic neuropathy: Complication of vascular access seen almost exclusively in patients with diabetes, typically in those with peripheral neuropathy and atherosclerotic peripheral vascular disease. There is acute pain, weakness, and paralysis of forearm and hand muscles that occurs within minutes to hours after the creation of an arteriovenous access. The etiology is ischemic infarction of the vasa nervosa. As opposed to DHIS, the hand is typically warm. The radial pulse is variably present. Treatment is access ligation.
  • Diabetic neuropathy.

References

Leon C, Asif A. Arteriovenous access and hand pain: the distal hypoperfusion ischemic syndrome. Clin J Am Soc Nephrol. 2007 Jan;2(1):175-83.

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