Introduction
Dialysis access is critical for patients who develop renal failure and require haemodialysis.
To be able to perform haemodialysis blood needs to be removed from the patient, run through a dialysis machine that removes toxic substances and then the blood needs to be returned to the patient.
To allow this to occur, some form of dialysis access needs to be created. A number of options exist for this, but the 2 main choices are the use of a tunneled line (permacath) or creation of an arterio-venous (AV) fistula.
Causes
Renal or kidney failure requiring dialysis has a multitude of causes. These are generally managed by a Renal Physician who will stabilise the kidney function as much as possible and decide on when dialysis will be required. Once it is clear that a patient will require dialysis then we will consider the best type of access and then proceed to have that created.
Tests
To help decide on the best location to create dialysis access an ultrasound is usually performed to assess the quality of veins and arterial supply. Occasionally a CT scan is also performed to assess the larger veins in the chest and abdomen.
Surgery
The 2 main types of access are:
- Tunneled line – this is an external catheter that usually passes into a larger vein in the neck.
- Arterio-Venous Fistula – this is a surgically created fistula that joins a vein to an artery. This can be performed at the wrist or elbow crease depending on the size and quality of the veins in the arm.
Which type of access is best depends on many factors, however an AV fistula is better in the long term. A tunneled line is useful in an urgent situation as it does take at least 6 weeks for an AV fistula to be ready for use.