Complications of Arteriovenous Fistula

What is arteriovenous fistula?

An arteriovenous fistula occurs when there is an abnormal connection between a vein and an artery. Although most examples of the condition are congenital, they can be acquired if there is damage to, or erosion of, an arterial aneurysm. Continue reading to understand the complications of arteriovenous fistula.

Normally, blood flows from arteries into capillaries, before entering the veins. When an arteriovenous fistula is present, however, the capillaries are bypassed and the blood goes directly from the artery into the vein.

When an arteriovenous fistula occurs genetically or is acquired, it may present problems and require treatment. However, in some cases an arteriovenous fistula is created by physicians in order to facilitate some kind of medical treatment.

When a person is suffering from kidney dysfunction or failure, for example, they may require dialysis. In order to administer effective treatment, physicians must find a way to access the blood, in order for it to be cleansed. Creating an arteriovenous fistula allows a connection from a vein to an artery and often allows for good blood flow. Although it may take weeks until an arteriovenous fistula can be used for effective treatment, once created it becomes a natural part of the body.

As the arteriovenous fistula has been created intentionally, it should not cause any side effects, providing the patient is monitored regularly.

What are the complications of arteriovenous fistula?

As an arteriovenous fistula is an abnormality or deformity, most people expect there to be complications of arteriovenous fistula. While an arteriovenous fistula may not always present with symptoms, if the arteriovenous fistula is particularly large, it may have a damaging effect on blood flow.

A large arteriovenous fistula allows blood to flow into the veins under a high pressure. However, vein walls are not designed, nor able, to withstand this increased pressure. As a result, the walls of the vein may stretch and bulge.

Once the vein has started to stretch, the blood flow is increased beyond normal measure. As a result, patients may experience symptoms of low blood pressure due to complications of arteriovenous fistula. Fainting, dizziness and light-headedness can all occur as a result of low blood pressure and secondary injuries may be acquired if the patient faints regularly.

Further complications of arteriovenous fistula involve the heart and cardiac output. If the body starts to experience low blood pressure, the heart will beat faster in order to try and increase the pressure. In the case of arteriovenous fistula, however, this merely has the effect of allowing more blood to enter the veins under high pressure.

If treatment isn't administered, complications of arteriovenous fistula may result in heart failure occurring, due to the extra strain placed on the heart muscle. While there are clearly serious heart complications of arteriovenous fistula, the condition can also result in an illness known as ‘steal syndrome'.

Steal syndrome occurs when a large arteriovenous fistula diverts blood from the affected area. As blood is not travelling around the body normally, it may be preventing from accessing certain parts. As a result, patients may experience numbness, discoloration, pain and skin sores.

It is clear, therefore, that there are numerous complications of arteriovenous fistula. Due to this, physicians may recommend medical intervention when a patient presents with a congenital or acquired arteriovenous fistula.

Can an arteriovenous fistula be treated?

If a congenital arteriovenous fistula is relatively small and is not causing any symptoms, it may not be necessary for treatment to be administered. Of course, when symptoms occur or there is a risk of complications of arteriovenous fistula, action must be taken.

In the case of congenital arteriovenous fistula, treatment is normally endovascular. Physicians will block the abnormal connection between the artery and vein, thus forcing the blood to flow normally.

Although this procedure can be performed via a catheter, it must be carried out by an experienced surgeon. While scans can provide some insight into the severity of the arteriovenous fistula, it is not always clear how extensive it is until the procedure is commenced. To avoid complications of arteriovenous fistula, it is advisable to seek treatment from a specialist.

When an acquired arteriovenous fistula occurs, different treatment is normally appropriate. Often, surgeons will attempt to resolve the arteriovenous fistula as quickly as possible. As acquired arteriovenous fistula are normally characterized by one, fairly large connection between the vein and artery, surgeons can generally cut the connection and simply sew the vein and artery closed, thus facilitating the normal flow of blood.

While there is a risk of complications of arteriovenous fistula, treatment is not always essential. Should symptoms occur, it may be advisable for surgeons to treat the condition in order to prevent cardiac stress. Although congenital or acquired arteriovenous fistula can have negative consequences for the patient, if the arteriovenous fistula is created intentionally in order to facilitate medical treatment, it may prove to be lifesaving, rather than life-threatening.