Vascular access in haemodialysis machines

What is the vascular access?

Vascular access represents the gateway connection to a patient for hemodialysis. A vascular access makes it possible to save the patient by means of hemodialysis. Hemodialysis is a treatment for kidney failure, which uses a device to send the patient's blood through a filter, called dializor, outside the body. Access to a vein is surgically created used for disposal and return of blood during hemodialysis. Blood passes through a needle, and then through a tube to the dialysis apparatus. Inside the dialysis apparatus blood flows through some thin fibers that filter waste and extra fluid out of it. The device returns the filtered blood into the body through a tube. A vascular access perminte large amounts of continuous blood flow during hemodialysis treatments, to filter out as much blood as possible during treatment. Approximately 500 ml flow through every minute. A vascular access should be made weeks or months before the first hemodialysis treatment.


Two types of vascular access designed for long term use include arteriovenoasa (AV) fistula and graft AV. A third type of venous vascular access is, which is used on short notice.

What is a fistula arteriovenoasa?

An AV fistula is connection, a vascular surgeon, of an artery to a vein. Arteries carry blood from the heart throughout the body, while veins carry blood from the body back to the heart. Vascular Surgeons specialize in surgery of blood vessels. The surgeon inserts, usually in the forearm or AV fistula in the arm. An AV fistula causes additional pressure in the vein, thus makes the grow big and strong. The largest vein access easily and securely to the bloodstream. Without this type of access, regular hemodialysis sessions would not be possible. Untreated veins can't resist some repeated introductions of the needle. They would destroy the way a straw is destroyed under the action of a suctiuni.

Health care providers recommend an AV fistula before other types of access, because:

  • Offers a good blood flow for dialysis
  • Lasts longer than other types of access
  • It is less likely to infect or cause blood clots, than other types of access

Before installing AV Fistula, the surgeon may perform a test mapping blood vessels. The mapping uses Doppler ultrasound for evaluation of blood vessels that the surgeon may use to make AV fistula. Ultrasound use a device called a transducer, which bounced on the painless to create waves an image of the structure of internal organs. A specially trained technician performs the procedure in the Cabinet of a health care provider, an outpatient center or a hospital. A radiologist, physician specializing in medical imaging, interpret the images. The patient does not require anesthesia. A Doppler ultrasound shows how far and fast flowing blood through the arteries and veins, so the surgeon can select the very best blood vessels.

A surgeon performs an AV fistula in a patient in a hospital or under local anesthesia to numb the area where the surgeon creates AV fistula.

An AV fistula requires often 2-3 months to develop, or to reach maturity before the patient to be able to use for hemodialysis. If an AV fistula matures not after surgery, the surgeon must repeat the procedure.


At the beginning of a session of hemodialysis, a health care provider or the patient insert two pins in the vascular access. A needle body carries blood at dializor. The other carries blood filtered back into the body. In order to distinguish those, needle that carries blood from the body into the arterial needle is called dializor. The needle that carries blood back into the body is called venous needle. Some patients prefer to enter their own ace in vascular access, which requires training to learn how to how to previ infection and protect the vascular access. No matter who inserted the needles, the patient must be educated on how to take care of the insertion of the needle area to prevent infection.

If no AV fistula matures, a greafa AV is second choice for a long-term vascular access.

What is a registry of arteriovenoasa?

An AV graft is a curved plastic tube that connects an artery to a vein. A vascular surgeon performs the surgery type AV graft like surgeries of type AV fistula in an outpatient center or hospital. As in the case of AV Fistula, the patient may need to stay overnight in the hospital, although many patients can go home after the procedure. Is done under local anesthesia to numb the area where the surgeon creates AV graft.

A patient can usually use a graft AV in 2-3 weeks after surgery. An AV graft is more likely to have problem clotting and infection than an AV fistula. Repeated blood clots can block the flow of blood through the registry. However, a well-kept graft can last for many years.


Vascular Access Setup before starting hemodialysis

Patients should Sarmale a good vascular access before starting hemodialysis, as fistulele AV and AV grafts to take time to mature to be ready for use. A health care provider can help you schedule a meeting with a vascular surgeon long before you start hemodialysis patient, even if the latter feels good. Providing enough time for his mature vascular access, can help prevent problems with veins are narrow, poor blood flow and blood cheguri.

Before the procedure, workers must educate the patient on how to do simple exercises that help the growth and development of blood vessels. The same AV fistula exercises help to develop in order to its functioning position.