complications
Last reviewed 01/2018
An arteriovenous fistula (AVF) may give rise to the following complications:
- infection
- responsible for 20%of all AVF related complications
- the severity may vary from localised cellulitis (erythema and heat) to abscess formation (fluctuance and tenderness) and bacteraemia (pyrexia, rigors, and feeling unwell)
- screen patients using microbiological swabs and serum samples for
- meticillin resistant Staphyloccocus aureus
- vancomycin resistant enterococci
- extended spectrum β lactamase producing organisms
- if AVF becomes the source of recurrent septic emboli, surgical closure may be required
- thrombosis
- can be due to pre-existing or acquired anatomical lesions, stenosis, hypercoagulability, and compression of the fistula.
- antiplatelets may be beneficial during the early postoperative period (when the risk of thrombosis is high)
- stenosis
- stenosis describes the narrowing of the lumen for more than 50% and is the most common cause of late failure of fistulas
- if caused during the first month of creating the AVF, technical error is the usual cause
- assess for evidence of stenosis (can be carried out in the clinic or by the patient at home)
- have the fistula arm dependent with the fist close
- observe for the filling of the vein
- slowly raise the arm – the AVF should collapse in the absence of a stenosis
- if a section of the AVF has not collapsed, the stenosis lies at the junction
- preferred treatment of choice is percutaneous angioplasty
- aneurysm
- may occur as a natural process with time due to increase in blood flow
- evidence of overlying skin changes and ulceration (indicates increased risk of rupture and severe haemorrhage) may warrant surgical repair
- ischaemic polyneuropathy
- patient may present with paraesthesia, dysaesthesia, severe pain, and muscle weakness
- more common in pre-existing diabetes and peripheral vascular disease (when AVF is created using brachial artery)
- Steal syndrome
- seen in 8% of the patients receiving haemodyalisis but the rate increases to 75-90% in elderly patients, patients with diabetes and peripheral vascular disease
- patients may present with
- considerable pain
- a cold hand, and discoloration of the skin due to relative hypoperfusion of the extremity
- weak or absent pulse
- with time neuropathic features may develop resulting in a typical “claw hand” contracture.
- high output cardiac failure
- caused by shunting of arterial blood from the left to right sided circulation
- cardiac output is estimated to be increased by 15% and end diastolic ventricular pressure by 4%
- risk of developing high output cardiac failure is higher when the AVF is proximal
- patients will have typical cardiac failure symptoms - dyspnoea and peripheral oedema
- limb hypertrophy in children - result from congenital fistulae. The whole of the limb is increased in length and volume, with the skin warmer and pinker than the normal side
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