Diagnosis
The diagnosis of a renal abscess can be made by means of various examinations. The patient’s medical history and symptoms already give an indication of the disease, which is then confirmed by further examinations. With the help of ultrasound, a kidney abscess can often already be visualized.
Other imaging procedures, especially CT, are important to confirm the suspicion and to rule out other causes such as tumors. Blood tests reveal elevated inflammation values such as CRP, procalcitonin and leukocytes. In addition, the so-called retention parameters of the kidney deteriorate.
These are urea and creatinine. The values increase because the kidney can no longer excrete these substances well due to the abscess and is limited in its function. In a urine sample, germs are also examined and the resistance of the bacteria is determined so that a suitable antibiotic therapy can be found.
Sonography, also known as ultrasound, is a simple and important diagnostic tool for identifying an abscess. In sonography, a so-called low-echo mass inside the kidney capsule can be seen.It is called low-echo because it is darker than the surrounding tissue. Echogenic structures are whiter.
Whiter structures, i.e. more echogenic structures, can be seen in the abscess. These are air inclusions. With a special examination, the Doppler sonography, the blood circulation can be visualized. This is very useful for differentiation from a tumor. Increased blood circulation is only visible at the edge of the abscess, whereas the inside of the abscess is not supplied with blood.
Therapy
A renal abscess is always treated conservatively with antibiotic therapy. The antibiotics are given via the vein in the case of a renal abscess. An antibiotic therapy can be carried out with amoxicillin and clavulanic acid and gentamicin or with so-called cephalosporins, for example.
Antibiosis is then adjusted according to the pathogen diagnosis and determination of resistance. This determines to which antibiotics the pathogens react so that the right antibiotic can be selected. Depending on the course of therapy and the patient’s fever loss, antibiotic therapy is given for about 7 to 14 days.
For small abscesses with a diameter of less than 3 cm, conservative therapy is usually sufficient for treatment. Fever-reducing and pain-relieving medication is used as an adjunct. In cases of nausea and vomiting, antiemetics, i.e. medications against vomiting, can also be administered.
Larger abscesses, on the other hand, must also be treated interventionally or surgically, since conservative therapy alone is not sufficient. Further interesting information can be found under: Healing of an abscess – You should pay attention to this! renal abscesses that are larger than 3 cm in diameter must be treated interventionally or operated.
For abscesses between 3 and 5 cm a so-called percutaneous, retroperitoneal drainage of the abscess combined with antibiotic therapy is usually sufficient. In this treatment, the abscess is punctured and emptied to the outside with a tube. The puncture is made from the outside through the skin into the tissue and can be performed under local anesthesia.
A sample of the emptied pus is always sent to the microbiology department for pathogen diagnostics. Abscesses larger than 5 cm may require several punctures or even open surgery. The abscess is removed surgically under anesthesia. In the case of a very large abscess and extensive kidney damage, it may even be necessary to remove the kidney to end the inflammatory process.
