With chemoembolization, a catheter is placed into the patient's femoral artery. From there, the catheter is selectively advanced into the hepatic artery, which is the main blood supply for the liver. A liquid contrast agent is injected into the catheter to determine how the blood vessels fan out into the liver tissue. The interventional radiologist then injects a mixture of drugs and embolic agents
An oily substance called Ethidiol, which is mixed with three chemotherapeutic drugs, is injected and collects in the cancerous tissue.
Because these drugs are injected directly into the tumor site, the tumor is exposed to much higher doses than could be achieved via a peripheral infusion. Flow into the tumor bed is obstructed with polyvinyl alcohol (PVA) particles. The combination of PVA and Ethiodol trap the high doses of chemotherapy in the liver, preventing systemic effects.
Researchers have found that Ethidiol can help lock drugs within the liver for up to a month following chemoembolization.
Healthy liver tissue survives because another vessel, the portal vein, supplies blood to much of the organ. The tumor is killed without harming normal liver tissue, and the portal vein will take over the function
that the hepatic artery can no longer do.
Approximately 60 percent of patients have the classic arrangement of blood vessels feeding the liver, as described in most medical texts. The treating physician must be acutely aware of any variation in a patient to prevent adverse outcomes.
In particular, a physician must block the hepatic artery past a vessel that branches off to feed the bowel. Otherwise, the lack of blood flow combined with highdose chemotherapy to that organ creates severe ulcers.
Another issue is that patients with liver cancer have cirrhosis, a chronic liver disease that is often a result of alcohol abuse or exposure to other toxic chemicals.
Many patients develop cirrhosis from viral hepatitis type C or other infection. Regardless of the cause, the liver, which functions in part to process toxic chemicals, becomes overwhelmed by the insult and tries to repair itself by bumping up its rate of cell division.
That rapid cell division increases the risk of some cells becoming the abnormal, cancerous cells of liver cancer. And it produces scar tissue that replaces functional tissue involved in maintaining the body's metabolism, blood pressure, and other functions.
The cirrhosis leads to tumor development while it limits treatment options, as the remaining liver is severely diseased. Therefore, patients with HCC and cirrhosis are more at risk of dying if a medical procedure reduces remaining liver function too drastically.
Fewer than 20% of patients are candidates for surgery. Although the interventional radiologists at Mallinckrodt Institute have had great success with liver ablative techniques, patients must be carefully chosen to avoid treating those patients with an inadequate reserve of liver function.
Washington University interventional radiologists have been successful with chemoembolization and other procedures because of their careful selection of patients and their expertise with the techniques. Because of their large volume of referred patients, they have a better understanding of the boundaries of treatment than do physicians at many medical centers.
Patients are treated at Mallinckrodt Institute that other hospitals have turned away.
Patients with liver cancer have lived an average of 20 months after diagnosis. Treatment that relies on peripheral chemotherapy or supportive management have reported an average survival of only three months.
Patients who receive chemoembolization at Mallinckrodt Institute also benefit from staying only one or two days in the hospital, as compared to the week or so required for traditional surgery.
And patients avoid not only the weeks of treatment required for traditional chemotherapy but also chemotherapy's potential adverse effects, such as hair loss and weakened immune system function.