At Zentralklinik Bad Berka, Prof. Dr. med. Merten Hommann combines outstanding medical expertise with deep human care. As Chief Physician of the Clinic for General Surgery and Visceral Surgery, he specializes in the treatment of neuroendocrine tumours, liver surgery and pancreatic surgery. Under his leadership, the clinic stands for state-of-the-art, interdisciplinary care that offers patients with complex clinical pictures excellent treatment. Zentralklinik Bad Berka is a recognized center for the treatment of neuroendocrine tumors throughout Europe. Since 2013, the center has held the coveted certificate of the European Neuroendocrine Tumor Society (ENETS) as a center of excellence, which confirms the outstanding quality of medical care.
Prof. Dr. Hommann and his team rely on innovative treatment methods that include minimally invasive techniques as well as state-of-the-art technologies for precise diagnostics and therapy. This includes the high-energy gamma probe, with which tiny neuroendocrine tumors and metastases can be precisely localized during surgery. The team also uses state-of-the-art methods in pancreatic surgery, including irreversible electroporation (IRE), a procedure for targeted tumor obliteration.
Interdisciplinary cooperation plays a central role at Zentralklinik. Experts from surgery, internal medicine, radiology and nuclear medicine work closely together to develop a customized treatment strategy for each patient. This close networking not only enables precise diagnosis and treatment, but also ensures holistic care that focuses on the patient as a person.
Prof. Dr. Hommann's commitment to his patients is particularly impressive. He is not only committed to the highest medical standards, but also attaches great importance to personal and empathetic care. Every patient is given comprehensive information about their illness and individual treatment options so that they are actively involved in the decision-making process. This philosophy creates trust and gives patients security in an often challenging life situation.
Thanks to his many years of experience, his continuous striving for medical innovation and his tireless commitment, Prof. Dr. Hommann has achieved a leading position in the treatment of pancreatic and liver diseases and neuroendocrine tumors. Patients at Zentralklinik Bad Berka benefit from state-of-the-art medical technology, in-depth expertise and a unique quality of treatment that is recognized far beyond Germany's borders.
In a detailed and interesting discussion, Prof. Dr. Hommann explained what liver surgery involves and provided information about possible additional ablative procedures (e.g. microwave ablation).
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Liver surgery plays a central role in the treatment of benign and malignant liver diseases and includes both surgical procedures to remove tumors as well as modern minimally invasive procedures. In the case of malignant liver tumors in particular, innovative ablation procedures such as microwave ablation are increasingly being used in addition to traditional resections. This gentle method makes it possible to destroy tumor tissue in a targeted manner without unnecessarily affecting healthy liver tissue. By combining surgical interventions with advanced ablation techniques, patients can receive individually tailored treatment strategies that improve the chances of recovery and minimize the burden of therapy.
Surgical resection of the liver is preferred above all if the tumor can be removed anatomically, there is no extensive liver disease such as advanced cirrhosis and the patient has sufficient (residual) liver function to tolerate the procedure. It is considered the best curative option, particularly in the case of liver metastases of colorectal origin, for example.
"Tumor resection is considered for malignant tumors or metastases, i.e. secondary tumors. Liver metastases are more common than primary liver tumors and this occurs most frequently in colorectal carcinoma. Resection is rarely considered for benign findings. Of course, there is also the option of resection for benign tumors - large adenomas are an issue here. For malignant tumors, the gold standard is resection with tissue resection. This allows the resection margins to be assessed and complete removal to be verified. Of course, ablative procedures are justified, especially if it is determined that resection is not possible. This is the case, for example, if the foci in the liver are distributed in such a way that too little functioning liver remains after resection or if the liver tissue is pathologically altered. Even if the patient has cardiopulmonary restrictions, resection is sometimes decided against due to the risk of anesthesia. The advantage of ablative procedures is that only a small amount of functioning liver tissue is affected. Treatment can be carried out with pinpoint accuracy while maintaining the necessary safety distance from the remaining tissue. This means that as much healthy tissue as possible is preserved. If, for example, you have a small focus, a liver metastasis that is centrally located and needs to be removed while taking a lot of healthy tissue with it, the decision tends to be in favor of ablation. Ablation techniques have become much better and finer, and you don't risk losing too much healthy tissue. After all, there is still the option of a later resection operation," explains Prof. Dr. Hommann at the beginning of our conversation.
„People need at least five grams of functioning, healthy liver tissue per kilogram of body weight. There are methods to measure this before an operation. Volumetry can be carried out using MRI or CT. Various measurement methods can also be used to determine liver function, including potentially remaining liver function. With volumetry, it must always be taken into account that the fat content of the liver also accounts for a certain percentage, which must be deducted from the result of the remaining functional reserve. The healthier a liver is, the more favorable the treatment options. If the tissue is severely pathologically altered, ablation is often the best treatment option," explains Prof. Dr. Hommann.
The size of the tumor is also a decisive factor in deciding on the treatment procedure. While smaller tumors can be considered for resection or ablation, larger lesions (> 5 cm) are preferably removed surgically, as ablation therapies for large tumors result in incomplete tumor destruction and a higher risk of recurrence. The location also plays an important role: if the tumor is located near large blood vessels, ablation may be less effective due to the “heat sink effect” - where the blood flowing past dissipates the heat and thus reduces the effectiveness of the treatment. Another important consideration is the number of tumors and their distribution in the liver. A complex distribution pattern, e.g. bilateral, is often more of an indication for ablation or a combination of resection and ablation.
“Unfortunately, there are also patients, for example with colorectal liver metastases, who are primarily suitable for resection, but in whom too little functioning liver tissue can be preserved due to the distribution pattern of the foci in the liver. We then usually plan ablation treatment. And if the distribution pattern of metastases is also too high in terms of size and number, we must also refrain from ablation and concentrate on a different (systemic) therapy. There are other treatment options that depend on the size and number of liver metastases, such as transarterial chemoembolization (TACE) or selective internal radiotherapy (SIRT), which are suitable for a complex distribution pattern. In order to be able to perform an ablation successfully, there is a basic rule that says: a maximum of five foci, the largest of which may have a maximum diameter of five cm. If there are more foci and one foci is larger, ablation is also possible in principle in individual cases. It is also conceivable to first use a therapy to reduce the size of the foci and then carry out a resection or ablation,” explains Prof. Dr. Hommann.
Microwave ablation (MWA) is a modern and highly effective procedure for the targeted destruction of tumor tissue, which has established itself as a valuable alternative or supplement to surgical interventions, particularly in the treatment of liver tumors.
“In ablation, there are thermal procedures and non-thermal procedures. Thermal procedures include those that work with heat, such as microwave ablation and radio wave ablation, which are used to generate heat that then destroys the tumor. Cryoablation is a procedure that destroys the tumor with cold. And then there are non-thermal procedures that use lasers (LIT = Laser Induced Therapy) or irreversible electroporation, which destroys the cell membrane with high-voltage current surges, leading to the destruction of metastases or tumors. Overall, there are differences in the application and complexity and, of course, also in the costs. In the vast majority of cases, clinicians agree on a practicable, very good and effective procedure to be used in the treatment of liver foci and may have a second procedure 'up their sleeve'. We have concentrated on thermal procedures, as these can be used at any time, e.g. if it becomes apparent during the operation that resection is not possible and the surgical strategy needs to be adapted. Thermal ablation procedures are very effective and precise. They work regardless of the type of tumor. A non-thermal procedure can sometimes be more suitable if metastases or the tumor are located very close to blood vessels or very close to the bile ducts because the structures are not damaged as much. Ablation procedures can also be performed percutaneously, with ultrasound, CT or MRI support, or laparoscopically or by open surgery. Of course, we always try to provide the gentlest method for the patient and, in the case of percutaneous procedures, we ask our colleagues from radiology or internal medicine to perform the ablation,” explains Prof. Dr. Hommann and adds:
“Ablation procedures have been around since the 1990s, and they are becoming technically better and more effective all the time. There are better and better applicators and instruments, and the aim is of course to work very effectively and with few side effects in as little time and with as little effort as possible (just one applicator). In the last 25 years, the application and speed have improved and the effectiveness has also increased. The effectiveness and safety of ablation procedures improve the prognosis for patients. The gold standard is still the complete removal of tumors and/or metastases. The combination of surgical liver resection and ablation procedures such as microwave ablation or radiofrequency ablation can also significantly improve the long-term prognosis of patients with liver tumors. This combined therapy enables individually tailored treatment that allows both the complete removal of large or centrally located tumors as well as the targeted destruction of smaller, difficult-to-access lesions”.
The aggressiveness of a liver tumor depends on its type, its growth pattern and its ability to metastasize.
Benign tumors such as hemangiomas or focal nodular hyperplasia grow slowly, remain confined to the liver and rarely cause local symptoms. Malignant tumors, on the other hand, such as hepatocellular carcinoma (HCC) or cholangiocarcinoma, grow rapidly, invade surrounding tissue and can form metastases. Liver metastases originating from other types of cancer are aggressive, which means that the tumor disease is advanced. The type of metastasis significantly influences the choice of therapy and the prognosis.
“Tumors naturally have different levels of aggressiveness and blood flow. But in the end, metastases from a colon carcinoma or a hepatocellular carcinoma, for example, cannot technically be ablated differently. The crucial question is whether it is possible to completely destroy the metastases or the tumor focus. The proof of a resection is provided after the procedure under the microscope, as it can be seen that there are really no tumor cells left at the edge of the incision. With ablation, this cannot be checked in this way; here you have to be sure and be able to rely on the fact that the ablation has been carried out as effectively as possible. The only way to check whether a focus is still active is with interval checks using tumour markers or cross-sectional imaging with contrast medium, including PET/CT,” explains Prof. Dr. Hommann.
Handling devices for ablation procedures requires the utmost precision and careful planning to ensure safe and effective treatment.
“The colleagues who perform the ablation, whether internists, surgeons or radiologists, must be familiar with the procedure and know the applicators and generators they use. With a practiced hand, a good team and functioning equipment, ablation is neither worse nor better in any location. The technique is easy to learn. You have to be able to think three-dimensionally, know where you are in the organ intraoperatively with ultrasound and also know which structures could be damaged,” says Prof. Dr. Hommann about the skills required for successful ablation.
Experience in managing potential complications is also required. This includes avoiding damage to neighboring organs and blood vessels as well as the correct handling of the so-called heat-sink effect when treating nearby vessels. Post-operative care and aftercare are also crucial in order to ensure the success of the ablation and to react early to possible recurrences or side effects.
Prof. Dr. Hommann comments on the future of AI and robotics: “There will certainly be AI- or robot-assisted systems for better navigation in the future in order to precisely target the metastasis or tumor. This is already being used intensively in the field of neurosurgery, so it will also find its way into liver ablation procedures”.
The prognosis for liver cancer has improved significantly in recent years thanks to improved diagnosis and treatment options. Advances in imaging enable earlier detection of tumors, which increases the chances of successful treatment.
“The prognosis for patients has improved, but not because it can be linked to one procedure, but because several procedures are available, which can also be used in combination. The therapy sequence and the next step in treatment are always discussed in a tumor board. It is the option of combining procedures that ultimately increases the effectiveness of therapy based on the guidelines. And this ultimately leads to an improvement in the overall prognosis for the patient due to the complexity of the treatment,” explains Prof. Dr. Hommann and concludes our conversation with a few tips on how to look after your liver:
“The liver naturally loves a healthy diet - for example in the form of Mediterranean food with lots of vegetables and good water. What the liver particularly loves are bitter substances. Unfortunately, these have been bred out of our diet because most people don't seem to like them. If you think of chicory or radicchio, these vegetables used to taste much more bitter. However, these bitter substances can also be consumed as a tea or powder, which can also be taken as a 3-month diet. Bitter substances from bitter root, wormwood, gentian, dandelion, milk thistle or artichoke can be found in non-alcoholic capsules or powders in health food stores."
Many thanks, Professor Dr. Hommann, for this impressive insight into the treatment of liver diseases!
