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 the workplace about the words ‘FISTULA’ and ‘DIALYSIS.’ You might have come across your relatives who have been taking their parents or elders 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
The construction of a good fistula is of paramount importance for successful dialysis. A dialysis machine is just like an artificial kidney. Dialysis maintains a safe level of some basic elements, like sodium, potassium, and bicarbonate, in the blood of a kidney patient. For the proper functioning of a dialysis machine, one requires a sustained blood flow of a large amount 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 a minimum of 300 ml/minute and a maximum of 500 ml/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). Its 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 a high-pressure pipe with a low-pressure pipe.
For dialysis, you need two things: firstly, a sustained flow of a large amount of blood at high pressure, and secondly, an easily accessible blood pipe in the upper limb. For that purpose, the dialysis machine should ideally be connected to a high-pressure blood pipe, which is an artery. But sadly, all arteries are situated deeply and are inaccessible, being far from the skin surface. Therefore, putting a puncturing needle into this pipe to establish communication with the 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 are, therefore, 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 a 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 the surgical construction of a fistula is possible. The best site is the left wrist. The second-best site is the left elbow. The reason is that the majority of 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 the construction of an A-V fistula is not possible on the left hand, either due to unfavorable anatomy or an unsuccessful previous attempt at making a fistula, the option of the right upper limb is explored, either at the wrist or right elbow.
Types of Fistula
Fistula is of two types, depending on its anatomy.
- R-C or B-C Fistula:
– An R-C fistula (Radiocephalic A-V fistula) is constructed at the wrist in a single-stage surgery.
– A B-C fistula (Brachiocephalic A-V fistula) is constructed at the elbow only after the R-C fistula has stopped functioning or when, due to anatomical difficulty, the construction of an R-C fistula is not possible.
- B-B Fistula (Brachio-Basilic A-V Fistula):
This is constructed surgically in two stages. This B-B fistula is created only after the construction of the B-C fistula is not possible due to anatomical difficulty.
– In the first stage, the Brachial artery and Basilic vein are joined together surgically at the elbow.
– In the second stage, after 8 weeks, the 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 the R-C (Radiocephalic) fistula on the left wrist.
What to Do If All Attempts to Make a 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, the A-V grafting procedure is adopted. In this procedure, an artificial blood pipe is used in place of veins and is surgically 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 a functioning A-V fistula or A-V grafting fail, the technique of permacath insertion is adopted. A permacath is an artificial catheter inserted directly into the central line in the neck, with its other end taken out from the chest wall. Generally, the permacath is placed on the right side of the neck.
Current Status of Fistula Construction in the Indian Subcontinent
It has been observed, especially in small towns, that many kidney patients are advised to undergo the construction of an A-V fistula by a general surgeon and sometimes by a plastic surgeon. This results, in the majority of cases, in the failure of the fistula and unnecessary, avoidable scars on the skin. Sometimes, two or three unsuccessful attempts are made at various sites in both the left and right upper limbs. In some places, nephrologists (Kidney Physicians) themselves attempt the construction of the fistula.
The surgical procedure of making an A-V fistula in the Indian subcontinent is woefully considered a highly underrated task. People should realize that constructing an A-V fistula is a very refined surgical procedure that requires high precision. An attempt to construct an A-V fistula by a kidney physician without any basic surgical training in this field is certainly not advisable.
Where to Go for Fistula Construction
Kidney patients must go to a hospital where there is an experienced full-time vascular surgeon and a full-fledged department of vascular surgery. Always choose hospitals where regular dialysis and kidney transplant surgeries are performed.
Always remember: A vascular surgeon is the only authorized, competent surgeon worldwide for constructing an A-V fistula.
Dr K K Pandey is Senior Vascular & Cardiothoracic Surgeon, Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi
Dr K K Pandey
dr********@***il.com