Fistulograms are diagnostic procedures performed to monitor the function of a dialysis fistula or graft. During the procedure, a contrast dye is injected, which allows the interventional radiologist to examine the blood flow from the arterial anastomosis to the central circulation system.
The purpose is to identify the area in the vascular system that is the cause of a problem associated with the dialysis fistula or graft. Indications for this procedure may include weak thrill or bruit, prolonged bleeding, cannulation difficulties, high venous pressures and/or low flow rates.
An angioplasty procedure is performed on the dialysis access site when the physician determines that decreased blood flow is caused by stenosis (narrowing of the vein).
To correct the problem, the physician places a balloon catheter across the targeted area to dilate and expand the vein and increase the blood flow. The procedure lasts approximately 30 minutes and the hemodialysis access is immediately ready for use at the dialysis center.
The main indication for peripheral arterial stenting is the failure of a balloon angioplasty to achieve a satisfactory treatment of a narrowing or stenosis in the vein or adjacent artery. If the vein is too weak, covered stents can be used to repair extravasations, which are specific areas of injury.
The stent is a metal tube that is put in the vein or artery to keep it open for optimal blood flow. Stents have withstood the test of time but do require maintenance to optimize patency. The stent is placed in the vein in order to maintain an open and healthy blood flow through the fistula. This is a safe approach designed to optimize results and improve the overall lifestyle of the dialysis patient.
Thromboembolectomy combines two procedures, thrombectomy and balloon embolectomy. The thrombectomy procedure is performed to clear a blood clot that has formed at or near the dialysis access site.
To de-clot the access, minimally invasive techniques are used, sometimes along with TPA, a medication that is used to dissolve the clot. Balloon embolectomy is used to break up and pull out the clot, thus restoring function of the graft or fistula.
Before a fistula is placed, a Doppler study may be ordered to help the physician evaluate the flow of blood through your veins and arteries. The test uses ultrasound waves to make a picture of the blood going through your blood vessels. The physician can then make a “road map” of your veins and arteries.
During a Doppler test, a handheld instrument (transducer) is passed lightly on the skin above a blood vessel. The transducer sends and receives sound waves. The sound waves bounce off solid objects, including blood cells.
The movement of blood cells causes a change in the pitch of the sound waves. If no blood flows through an area, the pitch does not change. The sound waves are sent to a computer, which changes the sound waves into pictures.
Central Venous Access Placement
Some patients may need a catheter for dialysis during the interval period required to mature a fistula, or when the immediate need for dialysis is more important than fixing the fistula or graft.
In these instances, the physician places a catheter in your neck or groin using our ultrasound machine. Our ultrasound machine can show the best place to put a catheter without having to try several times.
Our physicians can also treat your catheter if it gets blocked up because of blood or a fibrin deposit on the catheter. To do this, we either use medication to dissolve the blood or fibrin, mechanically remove the clot, or change the catheter over a wire.