Overview
Chemoembolization is the process of injecting chemotherapy drugs into the artery that supplies blood to the tumor in the liver. The artery is then embolized (blocked off) with a mixture of oil and tiny particles, which has the added benefit of depriving the tumor of its blood supply.
The liver is unique in that it has two blood supplies — an artery (the hepatic artery) and a large vein (the portal vein). The portal vein provides about 75 percent of the liver's blood, while the hepatic artery only contributes 25 percent. However, liver tumors are supplied with blood almost exclusively from the hepatic artery. When the artery is blocked, the tumor becomes deprived of oxygen and nutrients. The liver continues to be supplied with blood from the portal vein.
A further benefit of embolization is that no blood washes through the tumor, so drugs stay in the tumor for a much longer time — up to one month. Since the chemotherapeutic drugs are injected directly at the tumor site, dosages 20 to 200 times greater than standard chemotherapy are injected into a vein in the arm. Drugs are trapped in the liver instead of circulating throughout the body, therefore most healthy liver tissue is spared and side effects are decreased.
This treatment has little or no effect on cancers in other parts of the body, but is ideally suited for both primary and secondary liver cancers. The following are examples of liver cancers which may be treated by chemoembolization:
Several tests are performed before the procedure. These include liver function blood tests, and a CAT scan or an MRI of the liver. The doctor checks these test results to rule out the following complications, which could make the patient a poor candidate for chemoembolization:
The Procedure
In preparation for the procedure, patients should not eat or drink the night before. The next morning at the hospital, the patient will receive an IV line that administers antibiotics and other medications.
A radiologist will then place a small catheter in an artery in the groin, and an arteriogram will be performed, which will specifically look at the liver's arteries. After these arteries are identified, the catheter will be directed into the branch of the artery supplying blood to the tumor, and the chemoembolization mixture will be injected.
After this is complete, the patient will return to his or her room, where he will be asked to lie flat in bed for about six hours; more IV fluids will be given overnight. Most patients can be discharged from the hospital the next day.
The most common side effects of chemoembolization are pain, fever, and nausea. These symptoms may vary in intensity, but commonly last only a few hours to a few days. Medications are available to minimize these side effects. Some people also notice slight hair loss.
Although there is a small risk of liver failure or infection, serious complications from chemoembolization are rare.