INDICATIONS
The ideal patient for alcohol injection has fewer than three Hepatocellular Carcinoma (HCC) tumors, each of which is:
- well defined (distinct margins)
- less than 3cm in diameter
- surrounded by a shell consisting of scar tissue (fibrous encapsulation)
- not near the surface of the liver
Generally PEI is used in small liver cancer not suitable for resection, either because they are multiple, because of their position in the liver, or because of severe hepatic dysfunction. Patients with tumor recurrence or residual tumor after successful chemoembolization are also good candidates for PEI.
It does not appear that PEI will be as effective in the patient with metastatic cancer to the liver, since most metastases are relatively hard and avascular in a normally soft liver. This allows spillage of the alcohol into the surrounding liver substance, hurting the liver next to the tumor while not killing the tumor because the alcohol doesn't stay in place long enough to have the desired effect. On the other hand, in the hard, cirrhotic liver with a highly vascular and soft HCC, PEI is worth consideration as a method of liver cancer treatment.
PEI is contraindicated in patients with gross ascites, severe coagulopathy, obstructive jaundice, extrahepatic disease, and main portal vein thrombosis.
ADVERSE REACTIONS
The most common adverse effects of PEI are pain, fever, a feeling of alcohol intoxication and elevated transaminase. Pain most often is localized to the injection site. Occasionally pain is experienced elsewhere in the abdomen or the shoulder, probably related to leakage around the hepatic capsule. Pain and fever have been shown to be dose-related. With dose under 10 ml per session, pain sufficiently severe to require analgesia has been reported to occur in 11% to 13% of sessions versus 29% with injection doses greater than 10 ml in a given session.
Similarly, fever over 38 degrees celsius occurred in 6% of sessions in which the administrated dose was less than 10 ml versus 29% of sessios tn which more than 10 ml of ethanol were injected. Although the mechanism of the phenomenon has not be elucidated fully, it is likely to be in part related to the volume of tumor necrosis. Transient pain has also been shown to be more intense following injection of lesions on the surface of the liver than following injection of deeper lesions
Segmental chemical portal vein thrombosis has been known to occur in a few patients. Spontaneous resolution has been reported within 1-6 months in most cases.
Procedure-related mortality is rare. It was shown that this modality does carry the risk of disseminating the tumor by facilitating the passage of malignant cells into the blood stream, but that was opposed by other authors, who consider that because ethanol diffuse along the needle tract, its cytotoxic effect and small vessel thrombosis minimize the risk seeding.