Dialysis Access
One important step before starting regular hemodialysis sessions is preparing a vascular access, which is the site on your body where blood is removed and returned during dialysis. A vascular access should be prepared weeks or months before you start dialysis. The early preparation of the vascular access will allow easier and more efficient removal and replacement of your blood with fewer complications.
AV Fistula
An AV fistula requires advance planning because a fistula takes a while after surgery to develop. A surgeon creates an AV fistula by connecting an artery directly to a vein, frequently in the arm/forearm. Connecting the artery to the vein causes more blood to flow into the vein. As a result, the vein grows larger and stronger, making repeated needle insertions for hemodialysis treatments easier. For the surgery, you’ll be given an anesthetic. In most cases, the procedure can be performed on an outpatient basis.
A properly formed fistula is less likely than other kinds of vascular access to form clots or become infected. Properly formed fistulas tend to last many years—longer than any other kind of vascular access.
AV Graft Fistula
If you have small veins that won’t develop properly into a fistula, you can get a vascular access that connects an artery to a vein using a synthetic tube, or graft, implanted under the skin in your arm. The graft becomes an artificial vein that can be used repeatedly for needle placement and blood access during hemodialysis. A graft doesn’t need to develop as a fistula does, so it can be used sooner after placement, often within two or three weeks.
Compared with properly formed fistulas, grafts tend to have more problems with clotting and infection and need replacement sooner. However, a well-cared-for graft can last several years.
Hemodialysis Catheter
If your kidney disease has progressed quickly, you may not have time to get a permanent vascular access before you start hemodialysis treatments. You may need to use a venous catheter as a temporary access.
A catheter is a tube inserted into a vein in your neck, chest or leg near the groin. It has two chambers to allow a two-way flow of blood. Once a catheter is placed, needle insertion is not necessary.
Catheters are not ideal for permanent access. They can clog, become infected and/or cause narrowing of the veins in which they are placed. But if you need to start hemodialysis immediately, a catheter will work for several weeks or months while your permanent access develops.
Access Monitoring and Planning
- Monitoring: The examination and evaluation of the vascular access by means of physical examination to detect physical signs that suggest the presence of dysfunction.
- Surveillance: Periodic evaluation of the vascular access by using tests that may involve special instrumentation and for which abnormal test results suggest the presence of dysfunction.
- Diagnostic Testing: Specialized Doppler/duplex testing that is prompted by some abnormality or other medical indication and that is undertaken to diagnose the cause of the vascular access dysfunction
Fistulogram
Blood clots or blockages may interfere with your dialysis. The fistulogram helps the doctor find any blockages. A fistulogram is an examination of the blood vessels that make up your fistula. X-ray dye is injected through a small needle (or sometimes a small plastic tube) placed in your fistula. This dye mixes with blood and provides an X-ray picture (like a road map) of the blood vessels that would otherwise be invisible on an X-ray. The images are then interpreted by the surgeon who carries out the procedure.
Balloon Angioplasty
Balloon angioplasty with or without vascular stenting is a minimally invasive procedure performed to improve blood flow in the body's arteries and veins. In an angioplasty procedure, imaging techniques are used to guide a balloon-tipped catheter, a long, thin plastic tube, into an artery or vein and advance it to where the vessel is narrow or blocked. The balloon is then inflated to open the vessel, deflated and removed. During angioplasty, a small wire mesh tube called a stent may be permanently placed in the newly opened artery or vein to help it remain open.
Thrombectomy
A thrombectomy is a surgical procedure used to remove a blood clot (thrombus) from a vein or artery. In a thrombectomy, the clot is usually accessed via a dialysis access catheter, and removal may be followed by placement of a stent or filter. Medication might be used to prevent further clotting at the area.
Renal Angiography
Renal angiography provides the highest-resolution image of the renal blood vessels of any test available. Its purpose is to examine the renal blood vessels (which supply blood to the kidneys) for signs of blockage or abnormalities which may be causing bleeding. A contrast dye injected via a catheter threaded into the blood vessels of the kidneys makes them visible on a fluoroscope, allowing detection of any abnormalities affecting blood supply to the kidneys. After studying the X-rays, the surgeon may be able to detect abnormalities such as a clogged renal artery or a tumor or cyst.
Peritoneal Dialysis Access
Peritoneal dialysis (PD) is a type of dialysis which uses the peritoneum in a person’s abdomen as the membrane through which fluid and dissolved substances are exchanged with the blood. It is used to remove excess fluid, correct electrolyte problems, and remove toxins in those with kidney failure.
A peritoneal dialysis catheter is the only type of access for peritoneal dialysis (PD). A PD catheter is a flexible hollow tube about the size of a straw that’s surgically placed in your lower abdomen. A small piece of tubing is left outside of the body that can be covered when not in use.