Chemoembolization is a procedure used to treat some tumors of the liver, including those that originally arise from liver tissue and tumors which spread to the liver from other sites, such as carcinoid and related tumors.
In this procedure, chemotherapy drugs are injected directly into the arteries of the liver. This allows for high concentrations of the drugs where the tumor is, but with lower concentrations in the rest of the body where they could cause side effects. Material is also injected into the arteries to reduce the blood supply to the tumor, effectively starving the tumor and keeping the treatment at the disease site.
The liver is unusual in that it has two sources of blood supply: the hepatic artery and the portal vein, with the portal vein typically supplying about 75% of the blood to the liver. When a tumor develops in the liver, its blood supply generally comes from the hepatic artery, so injecting chemotherapy into that artery will affect tumors more than it will affect healthy liver tissue. Carcinoid tumors tend to have a particularly rich blood supply provided by well-developed arteries that make them a particularly good candidate for treatment by this method.
How this works
The procedure consists of an angiogram (an X-ray that takes pictures of blood flow) done through a catheter (long thin tube). The tube is inserted through an artery at the groin and advanced to the arteries that supply the liver. X-ray dye is injected and pictures are taken to show how the vessels are arranged and where they go. The artery that supplies the affected portion of the liver is identified. Two materials are injected into that artery: the chemotherapy drug and a material that blocks flow in the blood vessel.
In the last few years, new embolic materials (materials that block flow in the blood vessel) have been developed. Called drug-eluting beads (DEB), these bind to the chemotherapy drugs so that the drugs are released slowly by the particles that are blocking the arteries in the tumor, allowing for still greater drug concentration in the tumor with less effect on the rest of the body.
What to expect
Sedation is given for the angiogram. This requires the patient to arrive two to three hours before the procedure to check blood work, start an IV for the sedation and administer any necessary drugs. The procedure typically takes one to two hours and requires three to four hours of bed rest afterward, including up to four hours of lying flat in bed.
Patients are generally admitted overnight. Some patients will have discomfort or nausea rarely lasting more than 24 hours. While in the hospital they can receive any fluids or pain medication that they might need. Most patients will go home the next day, but may experience considerable fatigue lasting for a few days to a few weeks after the procedure.
If disease is spread in different portions of the liver, which is usually the case with carcinoid metastases, the whole liver may need to be treated. Because there is some arterial blood supply to healthy liver, the procedure has some effect on the normal liver as well as the tumor, albeit a lesser effect, and multiple (usually two) treatments may be necessary to treat the entire liver to lessen the risk of liver dysfunction.