Interventional Radiology

Tampa General Hospital provides the following interventional radiology procedures.

Abdominal Aortic Aneurysm (AAA) Repair
This minimally invasive technique is performed by an interventional radiologist using imaging to guide the catheter and graft inside the patient’s artery. For this procedure, an incision is made in the skin at the groin and a catheter is passed into the femoral artery and directed to the aortic aneurysm. Through the catheter, the physician passes a stent graft that is compressed into a small diameter within the catheter. The stent graft is advanced to the aneurysm, then expanded or opened creating new walls in the blood vessel through which blood flows and also cutting off the blood supply to the aneurysm.

Congenital Vascular Malformation (CVM) Repair 
All CVMs are treated according to the type of blood flow and many can be followed without treatment.  There are two main types of treatment for CVMs depending if they are composed more of arteries or veins.   In CVMs that are composed of more arteries (Arteriovenous malformation – AVM), a tiny tube, called a catheter is fed to the arteries that are  feeding the nest of vessels and blocks them  off with a medical grade glue or alcohol.  In CVMs with a network of veins (Venous Malformation – VM), injection of medical grade glue or alcohol is performed directly into the abnormal veins with a tiny needle to cause them to shrink or close.

Carotid Stenting 
As vascular experts, interventional radiologists treat atherosclerosis, “hardening of the arteries,” throughout the body. In some patients, atherosclerosis, specifically in the carotid artery in the neck, can lead to ischemic stroke. Plaque in the carotid artery may result in a stroke by either decreasing blood flow to the brain or by breaking loose and floating into a smaller vessel, depriving a portion of the brain of blood flow. In patients at high risk of having a stroke, the narrowed section of artery may be reopened by an interventional radiologist through angioplasty and reinforced with a stent, thereby preventing the stroke from occurring. Vascular stents are typically made of woven, laser- cut or welded metal that permits the device to be compressed onto a catheter and delivered directly into the hardened artery.

Interventional radiologists pioneered angioplasty and stenting, which was first performed to treat peripheral arterial disease. Using imaging for guidance, the interventional radiologist threads a catheter through the femoral artery in the groin to the blocked artery in the legs. The balloon is then inflated to open the blood vessel where it is narrowed or blocked. In some cases this is then held open with a stent, a tiny metal cylinder. This is a minimally invasive treatment that does not require surgery, just a nick in the skin the size of a pencil tip.

Cerebral Aneurysm Treatment 
For spinal anomalies resulting from compression fractures, practitioners insert cannulas resembling tubes, directly into the problem site and work through them to alleviate any pressure on the nerve area in order to relieve the pain.  What makes it possible for practitioners to utilize this minimally invasive technique is technology which transmits internal images of the brain or the spine on a large screen throughout the procedure allowing them to clearly visualize the problem area.  Interventional treatments are considered less invasive than more traditional modes of treatment yet yield optimal treatment outcomes, they are often attractive options to patients.

Deep Vein Thrombosis (DVT) Treatment 
DVT may be treated with the use of blood thinners, but if a patient has severe pain, difficulty walking, significant swelling or if there is a clot blocking the pelvic veins (iliac veins), a more invasive procedure such as thrombolysis is used to dissolve DVT.  Anyone with a DVT who experiences worsening symptoms while on blood thinners or is having difficulty walking, should consider evaluation by an interventional radiologist. When performed early, thrombolysis is highly effective at dissolving clots and preserving the valves in the veins.

If it is decided that a patient needs a clot removed by thrombolysis, it is performed under x-ray guidance by interventional radiologists. This procedure, performed in a hospital’s interventional radiology suite, is designed to rapidly break up the clot, restore blood flow within the vein, and potentially preserve valve function to minimize the risk of post-thrombotic syndrome. The interventional radiologist inserts a tiny tube into the vein behind the knee or other leg vein and threads it into the vein containing the clot using x-ray guidance. The catheter tip is placed into the clot and a “clot busting” drug is infused directly to the thrombus (clot). The fresher the clot, the faster it dissolves – in one to two days. Any narrowing in the vein that might lead to future clot formation can be identified during the procedure and treated by the interventional radiologist with a balloon or stent.

Feeding Tube Insertion 
Doctors often recommend placing a gastrostomy tube in the stomach for a variety of conditions in which a patient is unable to take sufficient food by mouth. During this  procedure, a feeding tube is inserted through a small nick in the skin and into the stomach under X-ray guidance.

Fistulagram/AV Graft Study 
An arteriovenous fistula (AVF) is surgically placed for dialysis access and is considered the gold standard for maintaining access to one’s circulatory system to provide life-sustaining dialysis.  An AVF is surgically made by connecting an artery to a vein directly, most commonly in the arm.  An artery contains oxygen rich blood flowing at high pressure away from the heart.  Veins are larger vessels with low pressure containing de-oxygenated blood flowing to the heart.  In an AVF, the blood flows directly from a large artery in the arm into a large vein.  After the artery and vein are connected, the vein grows larger due to the flow making it easier for a dialysis nurse to access the vessel with a needle, this is termed “maturation” of the AVF.  Once matured, two needles are placed into the vein for dialysis. One needle is used to draw blood and run through the dialysis machine; the second needle returns the cleansed blood. AV Fistulas can remain patent and be used for dialysis for several years, but they can occasionally clot due to poor flow or narrowing of the vessels in the AVF.  Interventional radiologists monitor AVFs to avoid complications such as infection, blockage from clotting and poor blood flow. Interventional radiologists also keep AVFs or other accesses open or unclogged through minimally invasive techniques such as angioplasty or stenting. These interventions are safer, less costly and equally effective as surgery, and they improve the quality of life for dialysis patients.

Occasionally, an AVF can get a tight spot in the vein or artery that cannot be repaired with a stent or balloon. A Surgeon can then replace the vein with a synthetic vessel, called a graft.  Grafts have slightly less  long term patency than AVF so they are typically placed when  an AVF fails.  The anatomy of an AV Graft is similar to an AV fistula as the graft is attached to the artery surgically and the other end is attached to a large vein.

IVC Filter Placement 
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 retrievable filters, may be left in place permanently or have the option to be removed from the blood vessel later. This removal may be performed when the risk of clot traveling 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.

IVC filter removal may be necessary for those who had older filters placed.  Older IVC filters are made of flexible metal that can fracture causing pieces of the metal to push through the wall of the vein into the intestines or bones adjacent to the vein.  The removal of the IVC filter is generally a quick outpatient procedure performed through a tiny hole in the vein of the neck.  Typically, patients are lightly sedated and can go home one to two hours after the removal.

Radiofrequency Ablation 
Radiofrequency ablation (RFA) for inoperable liver tumors offers a nonsurgical, localized treatment that kills tumor cells with heat, while sparing healthy liver tissue. Thus, this treatment is much easier on the patient than systemic therapy. Radiofrequency energy can be given without affecting the patient’s overall health and most people can resume their usual activities in a few days.

During this procedure, the interventional radiologist guides a small needle through the skin into the tumor. From the tip of the needle, radiofrequency energy (similar to microwaves) is transmitted to the tip of the needle, where it produces heat in the tissues. The dead tumor tissue shrinks and slowly forms a scar. The FDA has approved RFA for the treatment of liver tumors.

Cryoablation 
Cryoablation is delivered directly into the tumor by a probe that is inserted through the skin using imaging to guide it internally. Cryoablation uses an extremely cold gas to freeze the tumor to kill it. This technique has been used for many years by urologists in the operating room, but in the last few years, the needles have become small enough to be used by interventional radiologists through a small incision in the skin without the need for an operation. The “ice ball” that is created around the needle grows in size and destroys the frozen tumor cells.

The interventional radiology treatment is less invasive and easier on the patient. This treatment spares the majority of the healthy kidney tissue and can be repeated if needed.  The treatment has an excellent safety profile, and most patients are sent home the same day as the procedure or go home the next day. The most common complication is a bruise (hematoma) around the kidney that goes away by itself.  These interventional treatments also offer valuable benefits to those patients with advanced or metastatic renal cell carcinoma. While not considered curative for these patients, the lesions can be re-treated as needed.

NanoKnife™
The NanoKnife™ system employs irreversible electroporation – a novel new option in cancer treatment technology that uses a series of microsecond electrical pulses instead of extreme heat, freezing, radiation or microwave energy – to permanently open cell membranes in cancerous tumors. Once the cell membrane pores are opened, the death of the targeted cancer cells is induced. Surrounding veins, nerves and ducts within the targeted area are largely unaffected by the process around them, providing a compelling tool for procedures in difficult-to-treat parts of the body.

Embolization 
Embolization is a minimally invasive procedure performed by interventional radiologists using imaging for guidance. During the outpatient procedure, the interventional radiologist inserts a thin catheter, about the size of a strand of spaghetti, into the femoral vein in the groin and guides it to the affected vein using X-ray guidance. To seal the faulty, enlarged vein and relieve painful pressure, an interventional radiologist inserts tiny coils often with a sclerosing agent (the same type of material used to treat varicose veins) to close the vein. After treatment, patients can return to normal activities immediately.

Venous Access Port Placement 
A central venous access catheter (CVAC) is a tube that is inserted beneath your skin so there is a simple, pain-free way for doctors or nurses to draw your blood or give you medication or nutrients. When you have a CVAC, you are spared the irritation and discomfort of repeated needle sticks. More than 3.4 million CVACs are placed each year, and doctors increasingly recommend their use. There are several types of CVACs, including tunneled catheters (Hickman or Broviac), peripherally inserted central catheters (also called PICC lines or long lines), dialysis catheters, and implantable ports.

Transjugular Intrahepatic Portosystemic Shunt (TIPS) 
Transjugular Intrahepatic Portosystemic Shunt (TIPS) placement involves placing a shunt (tube) between the portal vein, which carries blood from the intestines/spleen and to the liver, and the hepatic vein which carries blood from the liver to the vena cava and the heart.

The TIPS procedure is performed through a small incision in the right side of the neck through the Internal Jugular vein, the largest vein in the neck.  Under x-ray guidance a stent (metal tube/shunt) is placed from the hepatic vein to the portal vein.  This allows the blood flow to return to the heart without passing through the scarred liver tissue and lowers the build-up of blood and portal hypertension.

Uterine Fibroid Embolization 
Uterine fibroid embolization (UFE), also known as uterine artery embolization, is performed by an interventional radiologist, a physician who is trained to perform this and other types of embolization and minimally invasive procedures. It is performed while the patient is conscious, but sedated and feeling no pain. It does not require general anesthesia. The interventional radiologist makes a tiny nick in the skin in the groin and inserts a catheter into the femoral artery. Using real-time imaging, the physician guides the catheter through the artery and then releases tiny particles, the size of grains of sand, into the uterine arteries that supply blood to the fibroid tumor. This blocks the blood flow to the fibroid tumor and causes it to shrink and die.

Catheter-directed Embolization 
Catheter-directed embolization is a non-surgical, outpatient treatment performed by an interventional radiologist using imaging to guide catheters or other instruments inside the body. Through mild IV sedation and local anesthesia, patients are relaxed and pain-free during the approximately two-hour procedure.

For the procedure, an interventional radiologist makes a tiny nick in the skin at the groin using local anesthesia, through which a thin catheter (much like a piece of spaghetti) is passed into the femoral vein, directly to the testicular vein. The physician then injects contrast dye to provide direct visualization of the veins so s/he can map out exactly where the problem is and where to embolize, or block, the vein. By using coils, balloons, or particles, the interventional radiologist blocks the blood flow in the vein which reduces pressure on the varicocele. By embolizing the vein, blood flow is re-directed to other healthy pathways. Essentially, the incompetent vein is “shut off” internally by preventing blood flow, accomplishing what the urologist does, but without surgery.

Dialysis Catheter Placement & Care 
For a patient whose kidneys have failed, venous access, or access to the blood system, must be established and maintained for dialysis treatments. Placement of a dialysis catheter can provide this access.  Dialysis catheters are essentially large IVs with the tip of the catheter in a big vein in the chest.  The tunneled catheters, meaning they pass under the skin for several inches before entering the vein, have a small “cuff” on them that resides under the skin in the tunnel. The cuff of the tunneled dialysis catheter acts to hold the catheter in place. In addition, it is designed to cause a fibrotic reaction, creating a physical barrier to bacteria that prevents bacterial migration and spread from the tunnel to the veins in the body. The cuff is positioned within the tunnel at a distance from the exit site that will facilitate removal.

Generally, for tunneled dialysis catheter placement, the preferred veins for central access are the right internal jugular, or left internal jugular veins.  If these veins clot from the dialysis catheter they do not  prevent future AVF placement as subclavian vein dialysis catheters do.

If tunneled dialysis catheters are kept clean and used/flushed several days a week they can be used for dialysis for months or possibly several years.  AV fistulas are still the preferred route for long term dialysis but tunneled catheters are effective in patients that have clotted AV fistulas or cannot receive one due to poor veins in the arms.  Catheters have a higher risk of spreading infection in the body because they are exposed outside the body.  If the catheter becomes infected it must be removed and another catheter placed for dialysis.

Occasionally, dialysis catheters can grow scar over the tip in the vein, this is called a “fibrin sheath”.  Fibrin sheaths cause poor flow in the catheter during dialysis but are easily treated.  In patients with a suspected fibrin sheath the catheter is removed over a wire and a balloon expanded in the vein which tears the scar away from the catheter.  A new catheter is then put back in the same location and can be used for dialysis immediately.  This procedure only takes 15 minutes and involves minimal pain.