A kidney infarction is when an artery or vein in the kidney is blocked by a blood clot and kidney tissue dies as a result. In many cases, a kidney infarction is asymptomatic, but it can also develop into a dangerous emergency.
Below you will find further information and selected specialists for a kidney infarction.
The kidneys are traversed by many arteries and veins and are therefore heavily supplied with blood. If a blood clot (or even washed in fat or an air bubble) is washed along with the blood, it can block an artery or vein in the kidney (embolism). If this blockage affects an artery, part of the kidney is no longer supplied with blood. If the artery is completely blocked, the affected tissue dies.
Illustration of a calcified constriction in an artery (top), which is blocked by a blood clot (bottom)
If a vein is blocked, blood stagnates in the kidney tissue. The used blood cannot flow out and as a result no oxygen-rich blood can flow in. In this case too, tissue is not adequately supplied and sooner or later dies.
The severity of the symptoms depends primarily on the extent of the kidney infarction. In many cases, only small areas of the kidney are affected, in which case there are often no symptoms at all. In this case, the kidney infarction usually becomes apparent later due to impaired kidney function.
If a larger blood vessel is blocked, the failed blood supply affects more extensive parts of the kidney or, in the worst case, even the entire kidney. This often results in severe and prolonged pain in the flank. This may be accompanied by fever, vomiting, nausea, abdominal pain and high blood pressure.
In 90 percent of cases, an embolism is responsible for a kidney infarction. In this case, a clot enters the kidney with the blood and gets stuck in a blood vessel.
In rarer cases, a thrombosis in a renal artery is responsible for the infarction. This causes a tear or narrowing in a renal artery. A local blood clot then forms there.
However, other foreign bodies in the blood are also possible, for example tumor tissue in cancer patients, cholesterol crystals, washed-in fat or bubbles in the blood. However, the effect is the same for all causes: The blood can no longer flow properly (or at all) to or from the kidney.
Risk factors for a kidney infarction are
The first signs of a kidney infarction can often be found by describing the symptoms and palpating the abdomen and flanks. The doctor will also inquire about other illnesses that could be risk factors for a kidney infarction.
Blood and urine tests can be helpful, but are unfortunately usually unspecific. Possible signs may be an increase in white blood cells or serum creatinine (a metabolic product that allows conclusions to be drawn about kidney function). An ultrasound examination (possibly with Doppler sonography) can usually show a lack of blood flow in the kidney.
Computed tomography or angiography (imaging of the blood vessels) may also be necessary to diagnose a kidney infarction with certainty. It must be differentiated from a kidney tumor, a kidney cyst, renal colic, a urinary stone disease and pyelonephritis.
In most cases, kidney infarcts are treated with medication. Painkillers relieve the acute symptoms, antihypertensives regulate blood pressure, heparin inhibits blood clotting and ideally dissolves small existing blood clots.
If there is an underlying disease, this must also be treated.
In the case of a severe kidney infarction, surgical removal of the blood clot or lysis therapy is also an option. However, surgical removal is associated with high risks and is therefore rarely carried out. In lysis therapy, the doctor inserts a catheter into the affected blood vessel and applies a medication directly to the blood clot. This dissolves the clot so that the blood can flow freely again.
If kidney function is severely impaired, dialysis may be necessary after the infarction to temporarily take over the kidneys' functions.
The course of a kidney infarction depends heavily on the extent of the infarction and the duration of the circulatory disorder. The longer tissue has not been sufficiently supplied with blood, the greater the risk that it will die. In the case of an extensive infarction, there is a risk that the affected kidney (or even both kidneys) cannot be saved. In most cases, however, the kidney infarction is not so severe that extensive or even complete recovery is possible. Even if temporary dialysis is necessary, the kidneys can then resume their function.
Rapid diagnosis and treatment are crucial for a good prognosis. If you experience sudden, severe flank pain, you should therefore consult a doctor as soon as possible.
