Principle
Transarterial chemoembolization (TACE) is a commonly used, minimally invasive treatment for cancer, particularly tumors with abundant vascularity. TACE is performed in the angiography suite by interventional radiologists using fluoroscopy guidance to inject chemotherapeutic drugs directly into the target through the blood vessels in tumors. The blockages induced in the targeted blood vessels induce ischemia and hypoxia in tumors. Only the targeted tumors are exposed to high concentrations of toxic chemotherapy.

TACE is widely used to treat patients with liver cancer who cannot undergo resection surgery or have tumor recurrence, particularly multiple small tumors. TACE is considered one of the most promising of the alternative therapies. The hepatic portal vein supplies approximately 75% of the blood to the liver, whereas the hepatic artery supplies only 25%. Thus, arterial embolization interrupting the tumor's blood supply has less impact on the health of the liver. This limits the spread of chemotherapeutic agents to the embolization site, thereby reducing side effects.
 

Benefits of TACE
TACE has little effect on liver function, which means that it can be used to treat people with poor liver function who cannot undergo hepatectomy. Patients do not need general anesthesia for this treatment and the procedure can be performed quickly. The majority of patients are eligible for TACE; the only contraindications are for those patients with jaundice and those who suffer from severe liver cirrhosis. These limitations are reduced if TACE is applied to organs other than the liver, such as renal cell carcinoma or retroperitoneal tumors. TACE reduces the supply of blood to the tumor, which means that it can be used to stop bleeding when a tumor ruptures, or prevent bleeding prior to surgery. TACE can be used to treat multiple tumors at the same time or for repeated procedures. Moreover, TACE can be used in conjunction with local ablation, radiation therapy, or chemical target therapy.
 

Limits of TACE
TACE is not suitable for patients with poor liver function, cirrhotic patients with severe jaundice and ascites, or patients with metastatic liver cancer to the hepatic portal vein. TACE is not the primary treatment option in cases of distant metastases. Drug-eluting microspheres have recently been developed for TACE treatment and preliminary clinical reports have shown that this approach has fewer side effects. Unfortunately, this new TACE treatment is not covered by health insurance in Taiwan. Currently, there is no evidence demonstrating that the therapeutic effects of the new TACE are superior to the traditional approach.

The developer required for the angiography used with TACE may be harmful to the kidneys. Therefore, individuals with poor renal function are generally not considered candidates for TACE or other perfusions.

The pattern blood vessels in some patients make it difficult to place the catheter when carrying out such treatment. The same problem is occasionally encountered in patients undergoing repeated procedures.
 

When to use

1. Vascular embolotherapy, such as TACE, is the first choice of treatment for individuals that do not qualify for surgery or local ablation treatment, as well as those with an excessive number of tumors, those with poor organ function, and cases in which the tumor is difficult to reach.
2. TACE has been used to treat primary liver cancer, liver neuroendocrine tumor, renal cell carcinoma, and various cases of hemostasis when the tumor ruptures. The new generation of drug-eluting microspheres carry drugs for specific types of cancer, which means that it can be used in the treatment of cancer which is not otherwise suitable for embolization therapy, such as colorectal liver metastases.
    

Preoperative considerations of TACE

1. Regular testing of blood, liver and kidney function, and coagulation.
2. Consent forms.
3. Patients receiving local anesthesia do not have to fast, but they must not eat excessively.
4. Local shaving.
    

Intraoperative considerations of TACE

1. Patients should lie down and avoid moving.
2. Local anesthesia is required.
3. Intraoperative conscious patients in any discomfort should contact healthcare providers.
    

Postoperative considerations of TACE

1. Patients should rest in bed and drink water to promote the excretion of contrast medium via urine.
2. Pressure is applied to stop bleeding. Patients may get out of bed as long as there is no bleeding after twelve hours. Some hemostatic dressings can reduce the time patients must remain prone.
3. Patients may take antipyretic analgesics to relieve abdominal pain and fever.
4. On the third day following treatment, patients should undergo tests of liver and kidney function.
5. One month after treatment, imaging is performed to evaluate the therapeutic effects. If successful, testing is continued every three to four months. Patients may undergo TACE treatment again, in cases of abnormally elevated fetoprotein (AFP) levels or new or recurrent tumors, as determined by ultrasound, CT, or other imaging methods.
    

Risks and Complications
Most patients develop fever, fatigue, and even abdominal pain after TACE treatment; however, these symptoms usually disappear after two to three days. TACE is a safe and minimally invasive cancer treatment. Complications may include liver infection, impaired kidney function, pulmonary or parenteral embolism, subcutaneous hematoma, or arterial injury leading to aneurysm formation. However, the occurrence rate of complications is not high, and most of the complications can be treated using conservative medical treatment and observation. Complications such as liver abscesses may require puncture and drainage treatment, and kidney failure may require hemodialysis treatment. Serious complications such as gallbladder or gastrointestinal vascular injury, cholecystitis, and intestinal necrosis, may require surgery.​