The liver is the most vital organ of the body’s metabolism and plays an integral part in the regulation of the sugar, fat and protein metabolism. It is responsible for the production of essential proteins such as blood coagulation factors, for the utilisation of food (e. g. the storage of carbohydrates and vitamins), production of bile and the breaking down and excretion of metabolites, drugs and toxins. Nutrients that are absorbed from the gastrointestinal tract into the blood reach the liver via the portal vein and are then released into the bloodstream or removed from the blood, as required.
The liver is located in the right upper quadrant, just below the diaphragm, and its left lobe extends to the left half of the upper abdomen. It consists of liver cells, the socalled hepatocytes, of cells of the biliary tract and cells of a specific immune defence system, the reticuloendothelial system.
According to the model developed by Claude Couinaud, the liver is divided into eight segments. In this context, the portal vein and the hepatic veins are anatomical landmarks for the segmentation and planning of surgery on the liver. Sufficient liver function requires at least 30 percent of healthy liver tissue. When it comes to planning surgery on the liver it is imperative to take this fact into account.
The liver is the most vital organ of the body’s metabolism and plays an integral part in the regulation of the sugar, fat and protein metabolism.
It is responsible for the production of vital proteins, such as blood coagulation factors, utilization of food components (e.g. storage of carbohydrates and vitamins), production of bile and the breakdown and excretion of metabolic products, drugs and toxins. Nutrients that are absorbed from the intestine into the blood reach the liver via the portal vein and are then released into the blood or removed from the blood as required.
ABILTY TO REGENERATE
On the other hand, the liver has a particular ability to regenerate. If a portion of the liver necrotizes or is injured or removed by surgery, liver tissue can regenerate itself. This, however, only applies if the cause of the damage has been removed, a sufficient amount of functional liver tissue remains, and the liver has maintained its regenerative capacity.
The various cell types of the liver may develop benign or malignant tumours which have to be treated surgically. Sometimes a harmless, circumscribed enlargement of the liver tissue due to increased cell production (hyperplasia; focal nodular hyperplasia, FNH) is diagnosed. In this case, surgery is not required.
Clarification of the diagnosis
Due to the widespread use and improved quality of ultrasound examinations, changes in the liver that require further diagnostic examination and appropriate treatment are being seen more and more often. Many of these changes are harmless with no impairment of organ function or risk of malignancy, such as haemangioma, dysontogenetic liver cyst, or focal nodular hyperplasia (FNH).
For proper treatment and follow-up, however, a reliable diagnosis is crucial in order to spare patients unnecessary worry and surgical procedures, and at the same time not to lull them into a false sense of security and overlook dangerous changes.
For further clarification of a lesion in the liver detected by ultrasound, an MRI is the best suited method, both in cysts and in tumours. Contrast-enhanced CT scan (CT) is also of significance in the clarification of the diagnosis. Other methods of imaging such as positron emission tomography (PET-CT) are used in selected cases only.
Furthermore, laboratory blood tests can provide information, in particular on the condition and function of the liver cells and the bile flow. In the case of a suspected liver tumour, the determination of certain tumour markers may be necessary.
For a detailed diagnosis it is essential to be well-informed about the patient’s medical history and any existing ailments and symptoms.
I am pleased to advise you as to the further clarification of unclear test results regarding the liver, such as a cyst or a tumour, and on suitable treatment.
A cyst is a cell-lined, enclosed tissue cavity containing liquid.
Dysontogenetic liver cysts
The most common liver cysts by far are so-called dysontogenetic liver cysts. These are congenital changes in the liver tissue that have existed for many years. They are detected by incidental discovery in ultrasound or CT examinations and are harmless. Dysontogenetic liver cysts cannot turn into a malignant tumour. Surgery is only necessary if there are very large or numerous cysts causing problems or disorders by displacing liver tissue and vessels. In such cases, a larger part of the cyst wall is removed by laparoscopy and the cyst contents are sucked out, thereby preserving all healthy liver tissue (liver cyst deroofing).
Parasitic liver cysts
Parasitic liver cysts are caused by dog tapeworm (Echinococcus granulosus) and fox tapeworm (Echinococcus multilocularis) and are far more dangerous. If left untreated, parasitic cysts may progress and spread throughout the human body if their contents (scolices) reach the biliary tract system. They are diagnosed on the basis of the person’s medical history (living environment, occurrence of worms), evidence of antibodies and antigens in the blood as well as typical signs of parasitic cysts in ultrasound and MRI examinations. If the diagnosis is confirmed, the parasitic liver cyst has to be removed by limited liver resection (pericystectomy).
There are other forms of treatment as well, such as an injection of hypertonic saline solution into the cysts and subsequent aspiration. My advice, however, is to have them removed completely by surgery. Prior to a planned operation the patient receives active medication against the tapeworm for several weeks in order to kill the worm larvae.
In very rare cases, neoplastic cysts, which are usually cystic metastases of various forms of cancer, may occur in the liver.
The differentiation between dysontogenetic, parasitic and neoplastic cysts requires a thorough knowledge of cystic diseases of the liver and their typical features in imaging examination methods, laboratory blood tests and other examinations. I have many years of experience in the diagnostic clarification of liver cysts up to the final diagnosis and in carrying out suitable methods of treatment (deroofing, pericystectomy and liver resection).
Benign and malignant liver tumours, liver cancer (hepatocellular carcinoma) and liver metastases
Liver tumours may be either benign or malignant and may primarily develop from liver cells or secondarily by metastases of malignant primary tumours.
First of all, it is important to distinguish between benign and malignant tumours. This is done by a contrast-enhanced CT scan of the liver in its various phases of blood flow (arterial and venous) and frequently also by MRI with a liver-specific contrast agent. An ultrasound examination alone is not sufficient for a precise distinction of liver tumours. In addition, the testing for certain tumour markers and liver-specific enzymes in the blood can be helpful to establish a precise diagnosis. In case of doubt, a liver biopsy has to be carried out.
Some liver tumours, haemangiomas and focal nodular hyperplasia (FNH) are not dangerous and require surgery only in rare cases (depending on size, growth or location).
The situation is different with adenomas of the liver. With increasing growth, liver adenomas may potentially develop into liver cancer (so-called adenoma-carcinoma sequence) and thus have to be removed in time.
Hepatocellular carcinomas (HCC) and cholangiocellular carcinomas (CCC) are malignant tumours of the liver, and have to be removed by liver resection, if possible. The same applies to metastases of certain types of cancer, for instance, colorectal and rectal cancer (colorectal carcinoma, liver metastases).
I am pleased to provide you with professional advice on the appropriate clarification of your individual situation, organise examinations and plan the treatment. If an operation is necessary, I will perform it in a competent way.
In recent years I have been active in numerous research projects on planning operations on the liver and measures to increase the safety of liver surgery. Our research team was able to show that a certain volume of functioning liver tissue has to remain in the body after surgery to ensure that the body’s normal metabolic function stays intact. The minimum residual volume of the liver depends on various factors; it can, however, be calculated quite precisely even before surgery.
This way, large liver resections can be planned exactly, and the individual risk of post-operative liver dysfunction can be predicted. If it becomes clear during the planning of a radical tumour resection that too much liver tissue has to be removed, interventional and/or ablative treatments will be combined with the liver resection in order to avoid the loss of liver tissue. In this process, the liver resection is combined with intra-operative, ablative methods (microwave or radiofrequency ablation), the volume of the future liver remnant is artificially enlarged before surgery, or the tumour’s size is reduced by chemotherapy before surgery.
Follow-up of liver cancer and liver metastases
In order to detect a recurrence of the disease in time or discover concomitant diseases follow-up examination is necessary and useful.
Regular examinations give you the assurance that everything is alright.
During the first two years after surgery, the intervals between follow-up visits are short, usually every three months. The intervals are extended thereafter to six months, and finally to once a year. After five years, you can change the regular follow-up on a symptom-oriented follow-up.
The tests usually include:
- Physical examination, body weight and size
- Talking about the current condition and current complaints
- Blood laboratory: values for kidney, liver and bile degradation products
- Tumor markers in the blood: AFP, CEA and CA 19-9
- Contrast-enhanced computed tomography (CT) of the lungs and abdomen
- If necessary: Magnetic resonance imaging of the liver
Sometimes additional tests are required. I am happy to organize the follow-up for you and discuss the obtained findings with you.