Embolization Procedures

September 3, 2024

This page was reviewed under our medical and editorial policy by Jonathan Kessler, M.D., associate clinical professor, division of interventional radiology, Department of Diagnostic Radiology, City of Hope^® Cancer Center Duarte

Embolization procedures are image-guided therapies performed by an interventional radiologist. They use tiny particles, such as gelatin sponges or beads, to intentionally block blood vessels to a particular area of the body.

This technique may be used to treat various conditions, including liver and kidney cancers, aneurysms, neuroendocrine tumors or uterine fibroids.

Several different forms of embolization exist. Embolization is sometimes combined with other treatments at the same time, such as chemotherapy or radiation therapy.

What Is Embolization?

Embolization is a medical procedure in which doctors inject special substances into an artery to block blood flow to an area, such as a tumor. Cutting off the blood supply starves the tumor cells of nutrients and oxygen, causing them to die. This technique is often used for larger tumors that surgeons are unable to remove.

During arterial embolization, a thin, flexible tube called a catheter is inserted into an artery through a small incision in the inner thigh. The catheter is then threaded into an artery supplying blood to the tumor. Materials are injected to block the artery and reduce blood flow to the tumor.

Chemoembolization combines embolization with chemotherapy. Tiny beads that release a chemotherapy drug and also block the artery are used during the embolization. Sometimes it is performed in two steps: first, chemotherapy is delivered directly into the artery and then the artery is blocked with other materials.

Radioembolization combines embolization with radiation therapy. Small radioactive beads, called microspheres, are injected into an artery. These beads collect near the tumor and emit radiation directly to the tumor site. The radiation’s effects are primarily limited to the tumor, minimizing damage to surrounding healthy tissue.

Types of Embolization Procedures

There are several types of embolization procedures, each designed to address specific medical conditions and treatment goals. These procedures vary in their methods and the substances used to achieve the desired treatment effects.

Chemoembolization

Chemoembolization, also known as transarterial chemoembolization (TACE), is a procedure used to treat certain types of liver cancer. During the procedure, an interventional radiologist injects chemotherapy medication directly into the arteries supplying the tumor. Along with the chemotherapy, tiny particles are also injected to block blood flow to the tumor. This reduces the supply of oxygen and nutrients, which helps to stop or slow cancer growth.

This procedure is mainly used to treat primary liver cancer (hepatocellular carcinoma) or cancer that has spread to the liver from another cancer, such as colon or breast cancer. Chemoembolization is often part of a broader cancer treatment plan and may be used when surgery is not an option. It may also help shrink tumors, possibly allowing surgery or serving as a bridge to future liver transplantation.

The benefits of TACE include targeted delivery of high-dose chemotherapy directly to the tumor, which may help manage symptoms and prolong survival in some patients. It is often used when patients are not able to have other procedures or treatments.

Potential complications may include infection or liver damage. The health care team closely monitors patients undergoing TACE to manage any side effects.

Y90 Radioembolization

Radioembolization, or Y90 radioembolization, is a minimally invasive procedure in which tiny radioactive spheres (microspheres) are placed directly into the blood vessels that supply a liver tumor. These microspheres contain yttrium-90, a radioactive isotope that emits radiation for about two weeks before becoming inactive. The procedure is used to treat primary liver tumors or cancers that have spread to the liver from other cancers of the body.

During the procedure, an interventional radiologist uses a small catheter to deliver the microspheres into the hepatic artery, the main blood vessel supplying the liver tumor. The microspheres accumulate in the tumor and release radiation, targeting cancer cells while avoiding most of the healthy liver tissue.

Radioembolization might be used alone or as part of a broader cancer treatment plan. It may shrink tumors, make surgery possible later or improve the quality of life for patients with liver cancer. In some cases, it may also serve as a bridge to liver transplantation.

The benefits of this procedure include targeted radiation that minimizes damage to healthy tissue, fewer side effects compared to traditional therapies and no need for large surgical incisions. However, risks may include potential infection, damage to blood vessels and, rarely, complications like ulcers or liver failure.

Tumor Embolization

Tumor embolization refers to any procedure in which medications or synthetic materials, known as embolic agents, are delivered through a catheter into a blood vessel to block blood flow to a tumor. This technique helps control or prevent abnormal bleeding. It may be used to close off vessels supplying blood to the tumor. It is less invasive than open surgery and may help control bleeding and reduce pain associated with tumor growth.

The primary goal of tumor embolization is to cut off the blood supply to a tumor, which may cause it to shrink or slow its growth. This may make future chemotherapy or surgery more successful. This procedure is especially useful for tumors that are difficult or impossible to remove surgically. Specific chemotherapy drugs, like doxorubicin or irinotecan, may also be used during embolization to enhance treatment.

While tumor embolization offers significant benefits, it does come with some risks. One common side effect is postembolization syndrome, which includes pain, nausea, vomiting and low-grade fever. These symptoms are the body’s reaction to the tumor breaking down and usually clear up within a few days.

Sometimes, they may last longer and require medication.

Prostate Artery Embolization

Prostate artery embolization (PAE) is a procedure used to treat conditions like blood in the urine due to prostate cancer or benign prostatic hyperplasia, a noncancerous condition in which the prostate enlarges. PAE may also be used as a palliative treatment for prostate cancer patients experiencing lower urinary tract symptoms, such as frequent urination, urgency, trouble starting urination, a weak urine stream or a feeling of incomplete bladder emptying.

During a PAE, an interventional radiologist inserts a small, hollow tube into an artery in the patient’s leg and guides it to the arteries that supply the prostate. Once in place, the radiologist injects material to block or slow blood flow to the prostate, causing it to shrink. Most complications are minor, such as discomfort when urinating or urinary tract infections.