Kidney malformations


The normal position of the kidneys is at the level of the 11th and 12th ribs.

The kidney is a complex organ with many important functions for the human body. As an excretory organ, it helps to get rid of unimportant or even harmful substances in the body, keeps the water balance in balance, plays an important role in regulating blood pressure and ensures that our mineral balance and the acid-base balance are correct. In order to be able to perform all of these tasks, a highly complex structure of the kidney is necessary. Some things can go wrong during development, which determines the frequency and variety of kidney malformations. Fortunately, most of them are harmless and don't require therapy.

Absence of an organ (agenesis)

First of all, with the malformations of the kidney, the changed ones number of the kidneys. Usually humans have two kidneys. If there is only one kidney, this is called unilateral (= one-sided) agenesis (= absence of an organ), if there are no kidneys, it is one bilateral (= bilateral) agenesis. An additional kidney is also possible. A Aplasia on the other hand denotes an incomplete development of the kidney.

Double kidney

This is a kidney with two pelvic calyx systems (the urine collected after passing through the kidney and transferred into the ureter).

Pelvic kidney

For example, the kidney may be in a different location than the usual (ectopic kidney), i.e. often too deep Compared to the normal position below the diaphragm from about the twelfth thoracic vertebra to the third lumbar vertebra.

Horseshoe kidney

This occurs when the kidneys merge at the lower end as they develop. This is often symptom-free, but it can too Urinary flow disorders and thus to be recurrent Infections to lead.


The causes of the malformations are genetically conditioned. That means that these diseases are partly inherited are or through random mutations can arise in the genome.


Most are malformations of the kidney Incidental findingwhich does not result in any further treatment. Complaints that therefore lead to a doctor are rare, but can be caused by increased kidney inflammation and associated Flank pain demonstrate.

Cystic kidney disease

A far more problematic malformation than one, for example Pitcher or horseshoe kidney are cystic kidney diseases (cysts are generally cavities that are filled with fluid) in which the kidney is interspersed with cysts and thereby disrupt the structure and thus also the function of the kidney. This malformation often leads to kidney failure, which progresses slowly or quickly depending on the disease. There are different types that are affected by the Potter classification and take into account both genetic and clinical conditions.

Potter I manifests itself already in newborns or toddlers. Here are both kidneys affected and also the liver. The disease is so severe that those affected die in childhood.

Potter II is characterized by unilateral kidney involvement. The liver is not affected here. The patients usually reach a higher adult age.

Potter III has the most cystic kidney disease best forecast. As with Potter I, both kidneys and liver are affected. However, the disease is milder and usually only manifests itself in adulthood.

At Potter IV are less that Cysts The reason for the renal failure, but rather a massive congestion in the renal pelvis caused by a narrowing. This already leads to problems during pregnancy. An indication of the disease can be found in the sonography to be too low Amniotic fluid volume be.

Cystic kidney diseases are to be distinguished from cysts that can develop in the course of life and are usually completely harmless if they do not exceed a certain size. If the cyst has increased in size, there is a risk of the cyst bursting.


The diagnosis of malformations of the kidney can be made by chance in an ultrasound (Sonography) can be asked with completely different questions. In the case of more serious malformations of the kidney such as the cystic kidney disease The consequences of kidney failure (e.g. imbalance in minerals or acid and base balance, or high blood pressure, etc.) draw attention to the suspicion of a kidney problem. Changes such as cysts are clearly visible through an ultrasound. Other options include running an elimination program. A contrast agent is given into the vein, which is then filtered through the kidney so that the filling of the kidney and ureter can be made visible through several x-rays. Can also be a Cystoscopy (Urethrocystoscopy) help with the diagnosis of malformations.


Especially with the cystic kidney diseases is a early detection the disease or malformation necessary to treat kidney failure. In the course of this, the kidneys are regularly examined by ultrasound. A further deterioration in kidney function is also indicated by the determination of kidney values ​​in the laboratory. In addition, substances such as non steroidal Anti-inflammatory drugs (NSAIDs) such as Ibuprofen, Aspirin® (ASS) and Diclofenac Be avoided. Hypertension should be medicated early on ACE inhibitors such as ramipril. In the case of end-stage renal failure (i.e. the kidney finally fails and urinary poisoning occurs (Uremia), The result is a severe impairment of the nervous system, which can go as far as a coma) dialysis procedures must be used. A cure is only through one Kidney transplant possible.In Potter I and III, liver function should also be monitored.