An AV fistula is a connection, made by a vascular surgeon, of an artery to a vein. Arteries carry blood from the heart to the body, while veins carry blood from the body back to the heart. Vascular surgeons specialize in blood vessel surgery. The surgeon usually places an AV fistula in the forearm or upper arm. An AV fistula causes extra pressure and extra blood to flow into the vein, making it grow large and strong. The larger vein provides easy, reliable access to blood vessels. Without this kind of access, regular hemodialysis sessions would not be possible. Untreated veins cannot withstand repeated needle insertions. They would collapse the way a straw collapses under strong suction
Mapping of arm vessels before surgical creation of dialysis access has been shown to be useful in helping achieve a higher percentage of arteriovenous fistula (AVF) placements as well as an increased fistula success rate.
This is done in the office using ultrasound, and is painless. Our board-registered Vascular Technologist, with years of experience, will perform the examination. The exam takes 45-60 minutes to image.
Fistulagrams/AV Graft Angiograms
An AV fistula is created when an artery is surgically connected to a vein.
Example of a Radial-Cephalic AV Fistula:
The point at which the vessels are connected is called the anastomosis. While a surgeon may create “designer” fistulas the most common vessels for fistula creation are: Cephalic and Basilic veins and either the Radial or Brachial artery.
Example of a BrachioCephalic AV Fistula: Example of a Brachiobasilic AV Fistula:
An AV Graft is created when synthetic tubing is used, most commonly Gortex, to surgically create a connection between an artery and a vein.
Grafts are most frequently connected between a vein and an artery in a patient’s arm. Thigh grafts and necklace grafts, connecting a vein to an artery are also possible. The location of the graft is determined by the surgeon and depends on the patient’s vascular system.
Dialysis fistula/graft declotting and interventions are minimally invasive procedures performed to improve or restore blood flow in the fistula and grafts placed in the blood vessels of dialysis patients.
Using imaging guidance, we can perform angioplasty and/or vascular stenting, to help declot a fistula or graft. During angioplasty an inflatable balloon, mounted at the tip of a catheter, is inserted through the skin into the fistula or graft and advanced to the blockage. There, the balloon is inflated and deflated. In this process, the balloon expands the vein or artery wall, increasing blood flow through the fistula or graft. A stent may be placed to hold the vessel open.
Alternatively, using x-ray guidance and a contrast material that helps show the blood vessel, the physician will insert a catheter through the skin into the fistula or graft and direct it to the thrombosis, or blockage. The blood clot will then be dissolved in one of two ways:
- by delivering medication directly to the blood clot (thrombolysis).
- by positioning a mechanical device at the site to break up the clot (thrombectomy).
Inferior Vena Cava (IVC) Filter Placement/Removal:
In an inferior vena cava filter placement procedure, interventional radiologists use image guidance to place a filter in the inferior vena cava (IVC), the large vein in the abdomen that returns blood from the lower body to the heart. The most common approach is to gain access through the jugular vein in the neck, using ultrasound guidance initially.
Blood clots that develop in the veins of the leg or pelvis, a condition called deep vein thrombosis (DVT), occasionally break up and large pieces of the clot can travel to the lungs. An IVC filter traps large clot fragments and prevents them from traveling through the vena cava vein to the heart and lungs, where they could cause severe complications or even death.
Until recently, IVC filters were available only as permanently implanted devices. Newer filters, called optionally retrievable filters, may be left in place permanently or have the option to potentially be removed from the blood vessel later. This removal may be performed when the risk of clot travelling to the lung has passed. Removal of an IVC filter eliminates any long-term risks of having the filter in place. It does not address the cause of the deep vein thrombosis or coagulation. Your referring physician will determine if blood thinners are still necessary. However, not all retrievable IVC filters are able to be retrieved. These filters can be safely left in place as permanent filters.
Removal of an IVC Filter can be as easy as placing one. Using ultrasound guidance, the physician will access the jugular vein. In order to grab the filter, a snare or retrieval device is used to pull it out through the access sheath.