Patients of kidney disease must take fistula seriously

Dr KK Pandey *

In our country,you would have noticed a gradual and sustained increase in the number of patients suffering from kidney disease. You must have often heard in your friend circles or at your workplace, about the word 'FISTULA' and another word 'DIALYSIS'. You might have come across your relatives who have been taking their parents or elderlies in the family to hospitals for dialysis on a regular basis. This causes a lot of monetary expenses and mental stress.

A good fistula is essential for successful dialysis

Construction of a good fistula is of paramount importance for a successful dialysis. A dialysis machine is just like an artificial kidney. A dialysis keeps a safe level of some basic element like sodium, potassium and bicarbonate in the blood of a kidney patient. For a proper functioning of a dialysis machine, one requires a sustained blood flow of large amounts to and fro, at a high speed.

This is possible only with a successfully functioning fistula which is the only source of providing a large amount of blood flow at a high speed between minimum 300ml/minute and maximum 500ml/minute to the dialysis machine.

What is Fistula all about?

Fistula is a layman's term. In medical language, its full name is arterio-venous fistula (A-V Fistula). It's simple meaning is an artificial communication between a high pressure blood pipe (Artery) and a low pressure blood pipe (Vein). This A-V Fistula is constructed surgically by joining high pressure pipe with low pressure pipe.

For dialysis, you need two things, firstly a sustained flow of a large amount of blood a thigh pressure and secondly an easily accessible blood pipe in the upper limb. For that purpose, dialysis machine should ideally be connected to a high pressure blood pipe that is artery.

But sadly, all arteries are situated deeply and inaccessible being far away from skin surface and therefore putting a puncturing needle into this pipe to establish communication with dialysis machine is not possible. So we have to depend upon low pressure but easily accessible blood pipes (Veins) which are situated superficially just beneath the skin surface, and therefore being accessible and most suitable for easy puncturing.

For the purpose of dialysis, a low pressure vein has to be converted into a high pressure pipe, by connecting the accessible vein to a high pressure artery through surgery. After artificially establishing communication with an artery, a low pressure vein becomes the high pressure one and thus becomes suitable for conducting dialysis. Now you have understood what a fistula means,and why its construction is important.

Suitable sites for fistula construction in the body

There are a few suitable sites in the body where a surgical construction of a fistula is possible. The best site is the left wrist. The second best site is the left elbow. The reason being majority of our people are right handers and generally do not use their left hand for writing and other finer activities, that is why A-V fistula construction is preferred on the left hand. If construction of A-V fistula is not possible on the left hand either due to unfavorable anatomy or unsuccessful previous attempt at making fistula, the option of right upper limb is explored either at the wrist or right elbow.

Types of fistula

are of two types depending upon its anatomy. First type includes either R-C or B-C fistula. An R-C fistula (Radiocephalic A-V fistula) is constructed at the wrist in a single-stage surgery. Another one B-Cfistula (Brachiocephalic A-V fistula) is constructed at the elbow only after R-C fistula after construction has stopped functioning or due to anatomical difficulty, construction of R-C fistula is not possible.

The second type is B-B fistula (BRACHIO-BASILIC A-V fistula) which is constructed surgically in two stages. This B-B fistula is created only after B-C fistula construction is not possible due to anatomical difficulty. In the first stage, Brachial artery and Basilic vein are joined together surgically at the elbow. Then in the second stage, after 8 weeks, a fistulous vein is surgically brought forward under the skin to make it superficial for the purpose of dialysis. Always remember, the most preferable A-V fistula is R-C(Radiocephalic) fistula on the left wrist.

What to do, If all attempts to make any viable A-V fistula fail: -

If one after another A-V fistula construction fails successively and ultimately no proper site is available in the upper limb. In such situations where all attempts at making A-V fistula are exhausted, A-V grafting procedure is adopted. In this procedure, an artificial blood pipe is used in place of veins and surgically it is placed beneath the skin to make it accessible for the purpose of dialysis.

If A-V fistula and A-V grafting both fail

When all attempts to make either functioning A-V fistula or A-V grafting fail, the technique of permacath insertion is adopted. Permacath is an artificial catheter which is inserted directly into the central line in the neck and its other end is taken out from the chest wall. Generally, permacath is placed on the right side of the neck.

Current status of fistula construction in India

It has been observed,in small towns especially many kidney patients are advised for construction of A-V fistula by a general surgeon and sometimes by a plastic surgeon. This results, in majority of the cases, into failure of fistula and unnecessary avoidable scar in the skin. Sometimes two or three unsuccessful attempts are made at various sites in both the left and right upper limb. In some places, nephrologists( Kidney Physicians ) themselves make an attempt for construction of the fistula.

The surgical procedure of making an A-V fistula in India is woefully considered a highly underrated work. People should realize that a construction of A-V fistula is a very refined surgical work with high precision, and attempting to construct an A-V fistula by a kidney physician without any basic surgical training in this field is certainly not advisable.

Another disadvantage of non-functioning fistula and multiple unsuccessful attempts to construct it, is that the patient remains dependent upon artificial central lines in neck and groin for a longtime, as these lines are used temporarily for the purpose of dialysis. These body sites for central lines are more vulnerable for infection, if used for a longtime. It is not any easy talk to control infection in a kidney patient as he is already immune compromised with a very low defense system.

Where to go for fistula construction

Kidney patients for fistula construction must go to a hospital where there is an experienced full time Vascular surgeon and there should be a full-fledged department of Vascular surgery. Always choose preferably those hospitals where regular dialysis, and kidney transplant surgeries are done. Always remember that a Vascular surgeon is the only authorized competent surgeon all over the world for constructing an A-V Fistula.