A renal infarction is a vascular occlusion in the kidneys that impairs the blood flow and oxygen supply to the kidney tissue and causes the tissue to die as a result. The most common causes of this ischemic phenomenon are thrombosis and embolism. Complete renal infarctions may later require the patient to undergo dialysis, while the kidneys of partial infarctions often fully recover.
What is a renal infarction?
The physician describes the destruction of kidney tissue as a result of an embolic vascular occlusion as a renal infarction. The kidney is traversed by many arteries and is supplied with oxygen through this arterial system. If there is an occlusion in the arterial vascular system, the tissue is cut off from the blood supply and is therefore doomed to die in the long term. See etaizhou for What does Heparin-induced Thrombocytopenia Mean.
This phenomenon is also referred to as ischemia, so that a renal infarction is often referred to as an ischemic reaction. The doctor often speaks of an embolic renal infarction. In this context, embolism means an arterial blockage caused by foreign or endogenous materials. The starting point of a kidney infarction is usually the kidney capsule with its blood-carrying structures.
Sometimes a renal infarction also refers to a venous occlusion, which can result in a hemorrhagic, i.e. bleeding-related infarction of the kidneys and permanently expand the kidneys. This must be distinguished from anemic renal infarction, which does not expand the organs but deforms them with scar tissue and craters.
The doctor differentiates a renal infarction in addition to differentiating between causes, especially in the type of occlusion. Complete occlusion corresponds to absolute ischemia and, as a result, causes the kidney tissue to die off entirely. An incomplete occlusion in an arterial vessel only results in a local hypoperfusion.
The blockage of a renal artery or vein can have a variety of causes, but more than 90 percent of renal infarctions are embolisms. An embolism can occur as a result of a blood clot that has been washed in, but also fat that has been washed in or the formation of bubbles in the blood are among the embolic causes.
In cancer patients, washed-in tumor tissue can also trigger an embolism. Cholesterol emboli, in turn, arise from dissolved plaques in an arterial wall, while septic emboli arise from bacterially infected emboli. The most common cause of an embolic renal infarction, however, is a blood clot that has washed in from the aorta or the heart wall, where a thrombosis previously occurred.
This phenomenon can also be related to arteriosclerosis or vasculitis. Hemorrhagic renal infarctions, on the other hand, usually result from circulatory shock, in which case a thrombosis forms in the renal vein itself as a result of a slowdown in blood flow. Diseases of the connective tissue, vascular diseases as well as heart diseases and vascular injuries are considered to be the most important risk factors for a kidney infarction.
Symptoms, Ailments & Signs
A typical symptom of a kidney infarction is acute flank pain. Depending on the severity of the heart attack, this pain can be accompanied by severe abdominal pain. Nausea, fever and vomiting are also symptomatic. The serum may show an accompanying increase in leukocytes. Days after the kidney infarction, acute kidney failure can set in, which often manifests itself as bleeding when urinating.
If arteriosclerotic material is responsible for the infarction in the case of an embolic cause, then this material can also be deposited in other organs or parts of the body in the further course. Therefore, visual field defects or inflammations at various locations can also occur as symptoms of a kidney infarction. Partial infarcts of the kidneys in particular often remain completely symptom-free. Although functional impairments of the kidneys can also occur in the case of partial infarctions, these impairments do not have to be noticeable immediately.
Diagnosis & course of disease
The anamnesis and palpation give the doctor the first indications of a possible kidney infarction. The quality of the flank pain, in combination with a vascular disease in the patient, can already suggest a kidney infarction, for example. He often examines the serum, which may also show increased creatine and an increase in leukocytes.
Doctors usually use angiography or computed tomography to definitively diagnose a kidney infarction. In this imaging, the infarction usually shows a relatively typical picture, which also makes it possible to differentiate between partial and complete infarction. Under certain circumstances, the doctor treating you may order a sonographic examination of all arteries and veins after the diagnosis has been made, which may provide indications of previous thrombosis or show calcified vessel walls.
Examinations of the heart can also make sense in order to rule out heart function as the source of the kidney infarction. The course of the disease in the case of a kidney infarction always depends on how severe and how long the infarction actually was. The prognosis for cholesterol embolic renal infarction is generally poor. In this case in particular, the patient may need dialysis in the future. Partial infarcts of the kidneys, on the other hand, often heal completely.
The course of a kidney infarction depends on the duration and extent of the blood supply to the kidneys. In about 25 percent of cases, the infarction proceeds without any symptoms because only small areas of the kidney die off. If necrosis occurs in larger areas of the kidneys, acute kidney failure can also occur under certain circumstances. The prognosis is particularly poor in the case of a so-called cholesterol embolism, which usually results in renal failure requiring dialysis.
In the context of acute kidney failure, the end products of protein metabolism and all other urinary substances remain in the blood. In addition, the electrolyte balance gets completely messed up. The same applies to the acid-base balance. Uremia, a life-threatening intoxication condition, can develop. Uremia characterizes the increased occurrence of urinary substances in the blood, which is also referred to in Greek as “urine in the blood”.
In addition to unbearable itching, there is nausea, vomiting and black blood in the stool as a result of inflammation of the gastric mucosa and intestines. Furthermore, pulmonary edema, shortness of breath and cyanosis occur. Excessive levels of urea in the blood can cause pathological changes in the brain and other neurological disorders.
The ability of the kidneys to regenerate after acute kidney failure as a result of a kidney infarction is good. However, as already mentioned, sometimes permanent kidney damage occurs that requires dialysis. In individual cases, fatal multi-organ failure can also occur due to the secondary impairment of various organs.
When should you go to the doctor?
A kidney attack is always a reason to see a doctor as soon as possible. An emergency room is preferable, since a moderate to very severe heart attack requires acute treatment. A complete renal infarction can spell the end of the entire kidney, making seeing a doctor all the more urgent. But even a partial occlusion of a blood vessel on or in the kidney can lead to severe necrosis after a while and permanently damage or kill the kidney.
If only one functioning kidney is left or if both are affected, kidney failure will occur if timely action is not taken. The problem in this context is that minor kidney infarctions are often symptom-free and therefore only cause hidden damage. Often only the late effects are noticed.
In the case of kidney infarctions, the smallest sign of kidney damage can be taken as a reason to go to the doctor (or, if necessary, to a hospital). These include, in particular, acute and severe pain in the flanks and brownish or reddish urine. The pain in particular must also be clarified diagnostically because it indicates several diseases. For example, kidney stones, colic or inflammation can also be detected.
People who already have kidney problems, have had a transplant, or have only one (working) kidney should have any possible evidence of a heart attack checked.
Treatment & Therapy
Renal infarctions are usually treated conservatively. The administration of painkillers and the regulation of blood pressure are also part of this conservative therapy, as is systemic full heparinization. The latter measure corresponds to the administration of an anticoagulant, which is intended to dissolve any blood clots.
Depending on how severe the infarction was and how early the doctor was able to make the diagnosis, lysis therapy or emergency surgery, which may still be able to dissolve an existing embolus, are also possible. Since operations for this purpose are associated with a high risk, they are used less frequently than lysis therapies.
In lysis therapy, the doctor inserts a catheter up to the existing blood clot and releases enzymes such as urokinase to dissolve the clot. Dialysis can also be useful in acute kidney infarctions. This measure does not necessarily mean that the kidneys will not recover over time.
Outlook & Forecast
The prognosis for a renal infarction depends on the severity and duration of the reduced renal blood flow. Complete recovery of the affected kidney is possible, as is complete kidney failure. If left untreated, a kidney infarction is fatal. The prognosis for a kidney infarction in connection with a cholesterol embolism is particularly poor. The patients then usually require dialysis. However, even with temporary dialysis, kidney recovery is possible.
A good prognosis depends on prompt diagnosis and treatment of the renal infarction. If the condition is treated at an early stage, for example when the typical flank pain occurs for the first time, the complete organ infarction can possibly be prevented. The prognosis for a kidney infarction is made by the responsible specialist in internal medicine. In most cases, a nephrologist is the attending physician, who, among other things, includes the symptoms and the severity of the renal infarction to assess the course of the disease.
A kidney infarction with the subsequent need for dialysis has a negative effect on life expectancy, since dialysis, among other things, increases the risk of infection. If the course is positive, the life expectancy of the patient is not necessarily limited. The quality of life can be significantly reduced as a result of a damaged kidney.
A change in lifestyle is helpful in preventing a kidney attack. The focus of preventive measures is on reducing the risk of arterial calcification. Avoiding nicotine and a healthy diet are just as good preventive measures in this regard as avoiding alcohol, reducing weight and exercising.
Since a kidney infarction can have varying degrees of severity, dutiful aftercare makes sense. Most of those affected can take matters into their own hands by making positive changes to their habits and everyday life. In the first place here is the strengthening and complete recovery of the body.
This can be brought about with the help of various measures. An important aspect in any case is an adequate supply of oxygen and an appropriate amount of exercise that does not overtax the body. If possible, this should take place outdoors so that a healthy amount of fresh air can reach the body.
Furthermore, at least two liters of water should be drunk daily, which stimulates the activity of the kidneys again. Harmful substances such as alcohol, drugs or nicotine should be completely avoided. In addition, a balanced, low-fat and all-round healthy diet should be ensured. If necessary, overweight should be reduced in order to spare the organism unnecessarily exhausting expenditure.
Since both the physical and mental state play a role in full recovery, mental stress and stress must also be taken into account. In order to be able to effectively reduce such complaints and emerging stress, meditation, relaxation and regular rest breaks are of enormous importance.
You can do that yourself
In many patients, a kidney infarction is symptom-free for a long time. Therefore, basic precautionary measures that strengthen the organism are advisable. Sufficient oxygen supply is helpful. Regular exercise or spending time outdoors can support the activity of the heart muscle. Physical exertion or intense exertion should be avoided.
In addition, regular breaks should be taken so that the organism receives sufficient rest periods. The intake of harmful substances such as alcohol, nicotine or drugs should be completely avoided. For an optimal supply of the organism, a fluid intake of two liters per day is advisable. A fatty diet or the consumption of hard-to-digest foods should be avoided. With a healthy and balanced diet, the body receives enough nutrients to stabilize the immune system and promote general health.
Stress and hectic pace should also be reduced. Methods such as yoga, autogenic training or meditation can be used to reduce internal stress factors. The person concerned has the opportunity to do a few exercise units every day on their own responsibility and thus strengthen their inner strength. A positive attitude towards life and individual measures to improve well-being are also helpful. Since a kidney infarction can have a fatal course, a doctor must be consulted immediately in the event of symptoms or a deterioration in health, despite all precautionary measures.