AV Graft and Fistula Intervention

AV Graft and Fistula Intervention

In order to perform dialysis, a large volume of blood has to be removed from the blood stream at a high speed and pressure, run through a dialysis machine to remove impurities and toxins, and then quickly replaced back into the bloodstream under the same speed and pressure.

The two most common surgically created ways to perform dialysis are arteriovenous fistulas (AVF) and arteriovenous grafts (AVG).  AVF are the result of a surgically created connection directly between an artery and vein.  The vein can then punctured with two needles during dialysis, one needle for the removal of blood and another to return the blood after running the dialysis machine.  An AVG is a synthetic tube called a graft, typically made from Gortex, and is surgically placed just below the skin surface.  One end of the graft is connected to the artery and the other end is connected to a vein.  The graft material can then punctured directly with two needles and dialysis can then be performed.

In both AVF and AVG, the body senses the surgical connection of the artery and the vein or graft as a highly abnormal process.  The body does not want blood to travel from an artery and into a vein or graft so quickly and with such high pressure, so the body will try to shut down the AVF or AVG by forming scar tissue around the blood vessels.  The scar tissue causes the blood vessels to narrow, a process called stenosis, until the blood flow stops completely and dialysis can no longer be performed.

In order to prevent and treat stenosis, the physicians at Midwest Vascular Access perform interventions called angioplasty and stent placement.  These interventions help maintain the AVF or AVG and improved the quality of dialysis.

Angioplasty and Stent Placement

Angioplasty and stent placement require the insertion of a small plastic tube called a catheter, which goes directly into the fistula or graft.  Contrast is injected through the catheter and into the AVF or AVG in order to identify the areas of stenosis (narrowing).  Then, a balloon is placed through the catheter and used to stretch the fistula, which breakdowns the scar.  This stretching will help eliminate the narrowing and allow blood to flow easier through the AVF or AVG.  At the end of the procedure the balloon is removed and there is nothing left in the AVF or AVG.

Sometimes the scar tissue has become too thick and cannot be stretched open with a balloon, and in these instances a metal stent is placed.  A stent is a specially engineered metal tube that is inserted into the fistula through the catheter.  Stents maintains constant outward force on the wall of AVF or AVG, allowing blood to flow easier and reduce further scar formation.  Stents are left in place permanently and cannot be removed once they are inserted.

AVF or AVG Interventions Are Not Surgery

AVF or AVG interventions are not surgery, and patients remain awake during the procedure.  Medications are given during the procedures in order to keep patients comfortable and reduce any pain that might occur during the procedure (commonly referred to as conscious sedation).  A typical procedure last 15-30 minutes, and patients are typically discharged 30 minutes after the procedure with no pain or symptoms.  During the recovery period patients are allowed to rest, visit with family members, watch TV, or enjoy complimentary food and beverage.  Because the medications given during the procedure preclude patients from driving after the procedure, complimentary transportation to and from Midwest Vascular Access is provided.