A 36-year-old lady presented with a history of two failed attempts at an AVF creation in her left arm – both at the site of her elbow (antecubital fossa). She was right hand dominant and needed a new fistula. This is not an uncommon scenario for most dialysis patients. They have failed access and are in need of a new access.
The key to success of an AVF created in a dialysis patient is from planning on this BEFORE the patient is on dialysis. Non-invasive assessment to assist in fistula planning including adequacy of arterial inflow and venous outflow helped to maximize opportunities for AVF over bypass graft.
Further investigation into the arterial inflow (flow towards the hand) of the extremity (after duplex ultrasonography = doppler) includes non-invasive testing with segmental pressures, PVR (pulse volume recording) or CT angiography, and possibly diagnostic angiography to identify potentially treatable inflow disease.
When planning diagnostic studies that require contrast administration, the nephrotoxic effects of the contrast should be carefully weighed to determine if the study is truly necessary or if alternative diagnostic modalities are preferable. In this care, choosing an alternative anatomic site for hemodialysis access is also a consideration.
Table 1: Recommendations for Routine Non-invasive Assessment
- Vein diameter of 2.5 mm or greater for arteriovenous fistula using one’s own vein
- Vein diameter of 4.0 mm or greater for artificial arteriovenous grafts
- Absence of blockage in the veins in the chest into which the fistula shall drain
- No significant (>20 mm Hg) systolic blood pressure differential between arms
- Arterial lumen diameter of 2.0 mm or greater
- Patent palmar arch for radial-based fistulas
- Make sure your surgeon has examined you
- Adequacy of blood flow into the hand through the blood vessels in the arm / forearm
- Measurement of blood pressure in both arms.
- He has, if needed done an ultrasound of your veins and / or arteries
- Assess the need for more invasive tests (angiogram) or more specialized tests (PVR / TcPO2) – if you have had prior procedures in the arms / chest – either failed fistulas or grafts
- Almost everybody has some sort of access that can be created and DOES NOT have to be stuck with a catheter.