Συγκατάθεση για αρτηριοφλεβική επικοινωνία
The intended benefits: a working arteriovenous fistula (AVF) is one of the best ways to allow effective haemodialysis needed to replace failed kidney function to sustain life. Many types on arms and sometimes legs can be used; the best for you will be discussed with you.
Alternative treatments: peritoneal dialysis–uses a plastic tube inserted into the abdomen through which fluid is run in and out. It can be a very successful method provided that the abdomen is not too scarred but is prone to infections which can need tube removal.
Haemodialysis alternative – can be done through a plastic tube (line) into a major vein but is usually temporary because blockage and infections are common. It can also be done using a graft (a plastic tube embedded beneath the skin and connecting an artery and vein) but these, too are susceptible to infection and blockage.
Serious or frequently occurring risks: none of these methods is durable and some fail immediately or within a year. We can sometimes get them going again by re-operating. Overall, around five to seven in ten are still working after two years and half after five years. The chances of success vary with the site of the AVF or graft and so do the complications.
Up to one in ten patients experience a problem with wound healing which may require further surgery or prolonged dressings. Bleeding from the wound is rare because we take great care to avoid it but it may require a return to the operating theatre. Around one in ten patients develop a wound infection and need antibiotics.
Sometimes too much blood flows through the fistula and not enough into the limb downstream, most commonly affecting the hand. This we call steal and it may require surgery to block the fistula despite which fingers are occasionally lost due to the poor blood supply. Over time some fistulas continue to enlarge (aneurysm) and may clot or bleed.
Rarely nerves lying near the blood vessels are injured, causing numbness or weakness. Around one in ten patients develop a blood clot in veins (DVT). This can occur in either leg and is treated by injections (enoxaparin or Clexane) and then tablets (Warfarin) to reduce the tendency of blood to clot (often termed “thinning the blood”); DVT usually resolves but occasionally may leave a chronically swollen leg or clot may pass to the lungs which can be dangerous (pulmonary embolism or PE, one in ten DVTS do this). Because patients are usually not fully fit when an AVF is needed, there are more general risks due to the stress of surgery and anaesthetic. These include heart attack or heart failure, chest infection, pulmonary embolism, stroke and kidney failure. Overall, death occurs in less than 2% when the operation is planned ahead as “routine case” but in urgent or emergency situations rises towards 10% despite all the supportive care that we can give. Unwell patients spending long periods in bed are also prone to developing bed sores, especially on the heels and bottom. These still occur despite good nursing care and special beds and mattresses.
Modern anaesthetics are generally very safe and you will have the opportunity to discuss this in detail with us. In most patients, local anaesthetic injections to the fistula site are preferable as this avoids any complications from general anaesthesia
Commoner side effects of a local anaesthetic include:
- Bruising at the injection site
- The injection always stings at first but you may feel pain later in the operation, requiring more injections to top up the anaesthetic.
Accidental injection into a blood vessel may affect the brain and heart but is rare.
Commoner side effects of a general anaesthetic (1in 10-100) include: pain during drug injection, aches, pains and backache. Uncommon problems (1 in 1000) include: bladder problems, muscle pains or worsening of an existing medical condition. Rare complications (1 in 10,000-100,000) include: bleeding, nerve damage, serious allergy to drugs, awareness during surgery, equipment failure and death due solely to the anaesthetic.
Any extra procedures which may become necessary during the operation:
- Blood transfusion is rarely needed unless you are already anaemic but transfusions can result in severe allergic reactions or infections despite careful screening of the blood for you
- Photographs and images X-rays are a usual part of this operation but if we want images for teaching or research purposes, we would always ask your special permission
- Other procedures, except for those listed above, are not often required during this operation unless planned in advance, the problems listed above can lead to additional procedures as described.