Dialysis access-associated steal syndrome

Dialysis access-associated steal syndrome or haemodialysis access-related hand ischemia arises as a complication of arteriovenous (AV) access.

Epidemiology

Symptomatic dialysis access-associated steal syndrome has been reported in up to 6% of AV access patients ^ref. Prevalence is higher in brachial artery AV access than in radial artery AV. Other risk factors include ¹:

• diabetes

• female sex

• coronary artery disease

• cerebrovascular disease

• hypertension

• age >60 years

• smoking

• previous dialysis access-associated steal syndrome

Clinical presentation

Presentations may be acute (occurring within hours of access creation), subacute, or chronic. Acute presentations are more common in the setting of arteriovenous grafts and are associated with poor vessel quality. Patients present with symptoms distal to the fistula secondary to reduced blood flow/pressure to affected tissues including ⁴:

• poikilothermia

• paresthesia

• diminished/absent pulses

• rest pain

• nail changes, e.g. pale, cyanotic fingernail beds

• muscle weakness

In severe cases, hand ischemia can progress to tissue loss with ulcerations and necrosis. Ischemic monomelic neuropathy due to focal nerve ischemia and can result in irreversible neurological deficits ⁵. Patients with ischemic monomelic neuropathy may demonstrate signs of acute denervation on electromyography ^ref.

Diagnosis

Diagnosis is predominantly on the basis of history and physical examination. Key findings are improvement of symptoms on occlusion of the AV access due to improved distal perfusion. Symptoms may also be exacerbated during dialysis sessions ¹.

Pathology

Post-AV access creation, the higher resistance of arteries in the diastole can cause retrograde flow in the arteries distal to the AV anastomosis into the AV access. Preferential shunting of blood through the AVF can lead to steal phenomenon in cases of blood flow restriction to the hand due to peri-access arterial occlusive disease, excess blood flow through the AV fistula conduit, and/or lack of vascular adaptation or collateral flow reserve to the increased flow demand from the AV conduit ^2,3.

Classification

Dialysis access-associated steal syndrome is staged by the severity of symptoms and correlated with the need for intervention ^ref:

• stage 1: retrograde diastolic flow without symptoms, physiological steal

• stage 2: pain during exercise/dialysis

• stage 3: pain at rest

• stage 4: tissue loss (ulceration/necrosis/gangrene)

Radiographic features

Ultrasound

Digital finger pressure and plethysmography, with and without AV fistula compression, is a sensitive test for steal diagnosis. Digital pressure <60mmHg or digital brachial index <0.4 in a patient with AV access is highly associated with hand ischemia ^ref.

Duplex ultrasound can quantify flow and identify arterial stenosis and/or flow reversal ⁶.

Angiography (DSA)

In suspected proximal steal syndrome, if treatment is being considered, upper extremity arteriography may be appropriate. This can provide insight into the AV fistula anatomy and identify stenosis/decreased anterograde flow ⁶.

Treatment and prognosis

Non-surgical management options may include modification of dialysis parameters, pharmacological dilation of peripheral vessels and local wound care. Surgical options include AV access ligation for severe ischemia, banding to reduce blood flow in high-flow AV access, or procedures to modify access hemodynamics to improve distal blood flow ^2,7.

Differential diagnosis

Differentials are other causes of upper extremity ischemia ^ref:

• atherosclerotic disease

• arterial embolism

• arterial dissection

• arteritis

In the acute presentations, surgical incision-related pain, infection, hematoma, peripheral nerve compression, and carpal tunnel syndrome should be excluded ^ref.