Hepatectomy (Minor and Major)
The liver is an essential organ in the body, and is divided into 8 anatomical segments. Hence, irreversible liver failure is incompatible with life as the liver is a vital organ.
The liver performs a myriad of functions that are crucial for survival; among them are the metabolism of carbohydrates, proteins, fats, and hormones. It rids the body of harmful toxins and excretes drugs. It synthesizes bile that dissolves fat. It also stores glycogen, Vitamin A, Vitamin B12, and iron and releases them into the blood stream when critical levels are reached in the body. When the liver fails to do its function (i.e., when it is diseased), there is no organ support machine that can take over its function just like when the kidneys, heart, or lungs fail.
Removal of the portion of the liver may be necessary when there is abnormal growth or tumour in the liver. Hepatectomy is a surgical procedure of removing a portion of the liver. Hepatectomy is also medically termed as liver resection. Minor hepatectomy is defined as the removal of 3 or less segments of the liver. Major hepatectomy is generally defined as the removal of 4 or more segments of the liver. One amazing thing about the liver is its capacity to regenerate itself. If a part of the liver is resected, it regains its lost function over time, so long as healthy liver cells are intact.
What Is Hepatectomy?
Hepatectomy involves the removal of liver tumours, leaving the healthy remnant liver tissue intact. The distinction between minor and major hepatectomy is important as major hepatectomy entails at least double the surgical risk compared to minor hepatectomy. In addition, with the advent of newer surgical techniques and advances in laparoscopic technology, many minor hepatectomies can be performed laparoscopically by trained hepatobiliary surgeons.
Tumours can be benign or malignant. Benign tumors include the following:
- Hepatocellular adenoma
- Large hemangioma (which are symptomatic)
- Biliary cystadenoma
A malignant tumor, which arises from the liver cell is a primary liver tumor and is termed hepatocellular carcinoma. However, the most common malignant tumors or neoplasms of the liver are secondaries, which means they are the result of metastasis from cancers from other sites, such as from the following:
- Colon and rectum
- Ovaries and uterus
Hepatectomy in Liver Cancer
The technique for the hepatectomy can be done as an open surgical procedure or as a laparoscopic procedure. Imaging tests such as a computerized tomography (CT) or magnetic resonance imaging (MRI) with angiography are first done to visualize the location and extent of the cancer and will determine if the cancer can be safely removed. Resecting the portion of the liver with the cancer nodule greatly prevents the cancer from spreading. Surgical planning with remnant liver volume calculation may be required in some patients to ensure sufficient remnant liver volume after removal of liver tumour.
The decision for minor or major hepatectomy depends on the size, location, and number of the cancer. The surgeon removes a part of the liver where the abnormal tumor is located or an entire lobe.
However, not all tumors can be removed. Generally, patients with large tumors with invasion into major liver vessels, multiple tumors located at different lobes of the liver, and with tumors that have spread outside of the liver may not be eligible for hepatectomy.
For selected patients, liver transplant can be a better option in the treatment of liver cancer.