Table 2Local ablative therapies for primary hepatocellular carcinoma reviewed in this report

Treatment StrategyMechanism of Cell DeathSettingPerformed BySpecific Harms
Radiofrequency ablation (RFA)RFA is performed by generating an alternating current between at least two electrodes in the radiofrequency range that generates heat without muscle contraction. The procedure aims to generate tissue temperatures of 90°C–100°C, which produces protein denaturation and coagulative necrosis.16The procedure is performed under intravenous (IV) narcotics for the percutaneous, awake approach and does not require a hospital stay. For laparoscopic or open RFA, the procedure is performed under general anesthesia and results in a longer recovery period.17
Each radiofrequency ablation takes approximately 10 to 30 minutes, with additional time required if multiple ablations are performed. The entire procedure is usually completed within 1 to 3 hours.18
Interventional RadiologistPossible side effects after RFA therapy include abdominal pain, mild fever, increase in liver enzymes due to damage to the bile ducts, abscess, infection in the liver, skin burns, and bleeding into the chest cavity or abdomen. Serious complications are uncommon, but are possible, including hepatic failure, hydrothorax, bile duct leaks, intraperitoneal bleeding, and tumor seeding (spill of tumor cells and subsequent growth in an adjacent site).18,19
Percutaneous ethanol injection (PEI)/Percutaneous acetic acid injection (PAI)PEI involves the injection of a high concentration of ethyl alcohol directly into liver tumors with ultrasound guidance.20 Injections into the tissue or into the blood vessel feeding the tissue leads to cell death by destroying cell membranes, modifying the temperature of cellular enzymes, and blocking the blood vessels.
PAI is a variation of PEI where the ethyl alcohol solution is approximately 50% acetic acid. Variations in the drug regimen are outside the scope of this review. Therefore, PEI and PAI will be treated as the same intervention.
PEI is performed as either an inpatient (typical in Japan) or an outpatient (e.g., in European countries) procedure. The patient is given IV sedation and analgesia. Each procedure lasts approximately 20–30 minutes and is repeated twice a week until ethanol seems to be injected throughout the lesion.20Interventional RadiologistCommon adverse effects include pain, fever, and a feeling of alcohol intoxication. Serious complications are rare and include ascites, right pleural effusion, jaundice, intraperitoneal hemorrhage, hepatic infarction, a transient decrease in blood pressure, seeding of malignant cells in the puncture tracks, hepatic vascular and bile duct injury, liver abscess, and liver necrosis.20
Cryosurgical ablation (Cryoablation)The mechanism of action is based on the rapid formation of intracellular ice crystals during the freezing process. The procedure uses repetitive freezing and thawing of the tissue to produce necrosis and irreversible tissue damage, which occurs at temperatures between -20°C and -40°C.21,22This type of treatment typically does not require a hospital stay if the percutaneous method is used. An open procedure requires an abdominal incision under general anesthesia and results in a longer recovery period.Interventional RadiologistSerious complications are uncommon, but are possible, and for cryosurgical ablation include cryoshock phenomenon (acute renal failure, acute respiratory distress syndrome, disseminated intravascular coagulation, and liver failure), myoglobinuria leading to renal failure, bile leakage, hepatic abscess, pleural effusion, consumptive coagulopathy, thrombocytopenia, hepatic iceball fracture, organ failure, and biliary fistula.19,23
Microwave ablation (MWA)MWA uses high-frequency electromagnetic radiation to create heat through the excitation of water molecules.16 The heat causes thermal damage that leads to coagulation necrosis.This type of treatment typically does not require a hospital stay if the percutaneous method is used. An open procedure requires an abdominal incision under general anesthesia and results in a longer recovery period.Interventional RadiologistVery little has been published about the complications associated with MWA.23 Many patients experience a low-grade fever and pain for a few days following MWA. Major complications include liver abscess, bile duct injury, pleural effusion, intestinal obstruction, infections, bleeding and skin burn, and potential inadvertent injury to adjacent structures.19 23

From: Introduction

Cover of Local Therapies for Unresectable Primary Hepatocellular Carcinoma
Local Therapies for Unresectable Primary Hepatocellular Carcinoma [Internet].
Comparative Effectiveness Reviews, No. 114.
Belinson S, Yang Y, Chopra R, et al.

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