In the case of tumour diseases, infections or even accidentally discovered masses in an organ, it is possible that despite exhausting all currently available imaging procedures such as ultrasound, computer tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography-CT (PET-CT), it is not possible to describe the exact cause of a change or to say definitively whether it is a benign, malignant or inflammatory change.

If no diagnosis can be made using imaging procedures, it may be necessary to obtain tissue samples from an organ by means of a puncture. Even in the case of known tumours, it may be necessary to obtain tissue from a patient's known tumour in order to obtain information about the fine tissue structure of the tumour from the tissue sample obtained and thus find the best possible therapy for the patient.

Tissue samples can be taken from practically all organs. For many years, we have specialised in the sonographically assisted puncture of organs for tissue sampling. The liver and lymph nodes as well as the thyroid gland are the organs that are punctured most frequently.

Using an example of liver tissue sampling, we would like to explain the most important things you need to know as a patient. If a puncture is planned for you, you will first receive an information sheet in which you are informed in writing about the planned procedure. At the end of the information sheet, you must sign to give your consent to the planned puncture and confirm that you have been informed in detail and sufficiently about the possible risks of the puncture.

What must also be taken into account before a planned puncture is the intake of medication that can influence blood clotting. These are medications such as aspirin, combination preparations (e.g. headache tablets), painkillers that also contain aspirin in certain doses or medications such as Ibubrofen® or Voltaren®. You should consult us if you have to take medication such as Marcumar® or Plavix®. Precise arrangements may need to be made here so that the planned puncture can be carried out without complications for you. You can click here to download a leaflet on anticoagulant medication.

To summarise, we need the following information before a puncture:

• Written information and declaration of consent
• Current blood values (blood count, coagulation values)
• a list of the medication you take regularly
• Discontinuation of anticoagulant medication or agreed procedure if anticoagulant medication cannot be discontinued

On the day of the puncture, you should come to the ultrasound diagnostics centre on an empty stomach. If you are travelling by car, you should ensure that you are given any painkillers that may impair your ability to drive. You must not actively participate in road traffic for 24 hours after receiving such medication; if necessary, think of an accompanying person! For the actual puncture, you will need an indwelling venous cannula, which allows the injection of medication (painkillers) and a sufficient supply of fluids.

Once the indwelling cannula has been inserted, the site where the puncture is to be performed is marked using ultrasound. After marking and disinfecting the skin at the corresponding site, a local anaesthetic is injected at this point.

The medication used for this is similar to that which you may have already received at the dentist for local anaesthesia (e.g. mepivacaine) and is very well tolerated. Side effects are extremely rare.

A painkiller is then injected into the indwelling cannula. We use Dipidolor, a strong painkiller, which can occasionally cause nausea as a side effect. To prevent this, you will be injected with another medication (metoclopramide) at the same time. You will usually feel a little tired after the injection. Thanks to the local anaesthetic and the painkiller in the vein, we can guarantee you an almost completely pain-free puncture.

The disinfected and anaesthetised puncture site is then covered with a sterile cloth. This helps to prevent infection from the puncture. Next, only sterile-packed materials or disposable items are used, i.e. the transducer is also given a sterile cover.

A needle guide is then clipped onto the transducer, through which the puncture needle can be guided precisely to its target in the patient's body with the aid of the ultrasound device's electronic puncture aid. A small skin incision is then made at the puncture site using a sterile scalpel. In order to be able to insert the hair-thin needle into the patient's body, a slightly thicker guide needle is required, through which the actual puncture needle is then pushed. The doctor then checks the puncture site again with the already sterile-packed transducer and the inserted guide needle.

The cell samples are then spread out on a microscope slide. Usually two to three puncture procedures are carried out. This cell material is then taken on the slides to a specialised laboratory where it is examined under a microscope by a specialist. The cells can then be used to determine the type of tissue being examined and a possible malignant or inflammatory disease. In addition to puncturing with a very thin needle (0.7 mm), it may be necessary to puncture an entire tissue bandage from a tissue. This is only possible with a slightly thicker needle (0.95 mm). A so-called biopsy gun is used to obtain a tissue bandage. Otherwise, the puncture procedure is completely identical, except that a guide needle is not required. The risk of bleeding is minimally increased due to the slightly larger needle thickness. Once the puncture has been completed, a plaster bandage is applied to the puncture site and a sandbag is placed at the puncture site to prevent secondary bleeding.

If the puncture is performed on you as an outpatient, you will be monitored in the outpatient department of the medical clinic for approx. 3-4 hours after the puncture, i.e. your pulse and blood pressure will be recorded every 30 minutes and you will be connected to a monitoring device. After approx. 3 hours, your blood count will be checked again, i.e. it will be checked whether the puncture reveals any blood loss.

After the blood sample has been taken, a final ultrasound examination is carried out and the puncture site and neighbouring organs are examined again very closely. If the ultrasound examination and the blood count check are OK, the doctor who performed the puncture will discharge you. You will be informed again about special behaviour such as physical rest and about further appointments with the doctor.

The complication rates for the cytological puncture described above (puncture in which only cells are obtained) are extremely low. Serious complications have never occurred with this type of puncture in our ultrasound laboratory. The results of our puncture results and complication rates have been published in various English-language journals.