Access Surgery is required to prepare a patient for dialysis.

Options for access include

• AV fistula(Arteriovenous fistula)
• AV graft(Arteriovenous graft)

Venous catheters

Permacath Temporary dialysis catheter. Dialysis treatment requires a faster than normal blood flow through the dialysis machine which these access options provide

AV Fistula

Arterio-Venous Fistula (AVF), which is a connection of an artery and a vein (most commonly in the lower arm or wrist) that allows blood to flow from the artery directly into the adjacent vein.

When the artery and vein are joined, the blood flows at a higher pressure, which causes the vein to enlarge and the vein wall to thicken. This makes it easier to insert the needles required for dialysis. The joining of the vein and artery is known as AV fistula creation.

AV Graft

If the patient’s own veins are not suitable, an artificial tube or ‘prosthetic graft’ made of a synthetic material can usually be used as an alternative.

Arteriovenous grafts take 2 weeks to mature before they can be accessed. Long term maintenance of dialysis access Maintenance of your arteriovenous fistula and graft is important to avoid loss of the access.With ongoing use, these fistulaes and grafts change with time.

Long term changes include

• Aneurysms(ballooning)
• Stenosis(Narrowing)
• Thrombosis(Blocked)

Aneurysmal segments in the access need to be addressed only if impairs dialysis or if overlying skin is at risk of breakdown causing life threatening bleeding.

Stenosis in the access can causes reduced blood flow and as a result inefficient dialysis.

Treatment

Angioplasty- Ballooning of the narrow segments to improve blood flow. Rarely stents maybe used to keep the flow maintained at good level. Surgical repair- Narrowed segments can be surgically opened up to maintain good flow Thrombosis- Once completely blocked, a dialysis access can be reopened to restart the blood flow.

Treatment options for thrombosis

• Thrombolysis and angioplasty- strong blood thinning agents are injected and angioplasty of the narrow segements are done to improve blood flow
• Surgical repair- Open surgical thrombectomy (removal of blood clots) in combination with angioplasty can help to improve blood flow

Most AV fistula or AV graft pass through a phase of narrowing(stenosis) before it gets completely occulded(thrombosed). Regular surveillance of AVF by clinical examination and doppler scans prevents loss of fistulae and extends their lifespan.

Venous catheters

In a patient with rapidly progressed drop in renal function, immediate dialysis would be required. A temporary venous catheter can be inserted in the neck or thigh for immediate use. These are not for ideal for long term as they may get infected easily or may get blocked and may cause narrowing of major veins in the chest. Permacath is a tunnelled venous catheter which can be used immediately after insertion and also for long term use. The catheter is inserted into the veins in the neck and is tunnelled under the skin to the upper chest where two pipes protrude from the skin which can be connected to the dialysis machine through tubings. Permacath is a good alternate for patients who cannot undergo an AV fistula or an AV graft surgery but not a long term option as like other venous catheters they are prone for infection and may get blocked.

Daily Care Of Dialysis Access Site

• Make Sure Your Nurse Or Technician Checks Your Access Before Each Treatment.
• Keep Your Access Clean At All Times.
• Use Your Access Site Only For Dialysis.
• Be Careful Not To Bump Or Cut Your Access.
• Don’t Let Anyone Put A Blood Pressure Cuff On Your Access Arm.
• Don’t Wear Jewelry Or Tight Clothes Over Your Access Site.
• Don’t Sleep With Your Access Arm Under Your Head Or Body
• Don’t Lift Heavy Objects Or Put Pressure On Your Access Arm
• Check The Pulse In Your Access Every Day.