Angiography is an invasive X-ray imaging test. It is performed by inserting a needle into a blood vessel. A catheter is then selectively advanced inside it to the area of the body that needs to be imaged. Contrast material is injected into the blood vessel to obtain precision images and to look for blockages in the area of interest. If a problem is detected that requires further treatment, a minimally invasive endovascular intervention is usually performed at the same time. Angiography can be performed for the patient's native arteries and veins, as well as any prior operations such as bypass grafts
Angioplasty and stenting are minimally invasive endovascular treatments for occlusive disease (blockages and narrowed blood vessels). They are preformed in conjunction with angiography. Angioplasty is the most common method for treatment of blocked vessels, and is used both for arterial and venous interventions. A balloon is expanded inside the narrowed blood vessel to stretch it open, then the balloon is removed leaving the vessel stretched open.
Stents are expandable metallic tubes that are inserted angiographically. They are used inside treated blood vessels in certain situations. They are left inside the vessel to ensure that the blockages that have been treated have less chance of closing up again.
Hemodialysis is the most common treatment for chronic kidney failure. This treatment requires that the patient's blood is removed from the circulation, filtered through a dialysis machine to remove the waste products, and returned back into the body.
The access to the bloodstream can be provided by an IV inserted into a large neck vein called a catheter. Catheters are used as a short-term access and for emergent dialysis. The preferred method, used for long-term access, is called arteriovenous (AV) dialysis access. It requires insertion of two needles into a blood vessel. A patient's own arm veins are the optimal vessels. This access is called an AV fistula. Some patients have no suitable veins. Then, a synthetic tube called an AV graft has to be used. Venous blood flow is insufficient for dialysis; therefore, the vein is connected to an artery. This increases blood flow, and makes the vein enlarge and strengthen to mature the vein for dialysis use.
The AV fistulas, AV grafts and dialysis catheters are prone to malfunction. They can clot, get infected, develop scarring and narrowing, or can be worn out with continued use. The dialysis catheter interventions involve angiographic procedures to insert and reposition a catheter, or to clear clots and blockages. AV dialysis access is created by surgery. Variety of surgical and angiographic procedures can help mature the access. Correction of problems of a working access involves angioplasty and stenting of narrowed vessels, clot removal and occasionally surgical revision. A worn out AV access is repaired or replaced by surgery. Occasionally, angiographically placed devices called stent-grafts are used for access repair.
Dr. Nishanian is a Vascular Specialist and specializes in the creation, maintenance and repair of all three types of hemodialysis access to ensure the best possible care and outcomes of his patients.
» Contact Dr. Nishanians orange county offices in Irvine and Mission Viejo for more information about Minimally Invasive Vascular Interventions.