Kidney infarction

Kidney infarction is a fairly rare variant of ischemic kidney disease (an extremely rare urological disease). For its occurrence, a sudden and complete cessation of blood flow along a relatively large arterial kidney vessel is necessary.

With partial preservation of blood flow or with slowly increasing occlusion, other syndromes develop: vasorenal hypertension, chronic renal failure with different rates of progression, etc.

[1], [2], [3], [4], [5], [6], [7]

Causes of the infarction of the kidney

Kidney infarction can develop due to arterial thrombosis or arterial embolism (more often). The source of arterial emboli in most cases is a parietal thrombus of the left atrium or ventricle.

Kidney infarction, as a rule, is a complication of a number of cardiovascular diseases:

• infective endocarditis;
• atrial fibrillation;
• heart defects (especially mitral);
• atherosclerosis;
• myocardial infarction;
• nodular periarteritis.

Kidney infarction can occur in patients with ascending aortic thrombosis, as well as those who underwent renal artery surgery.

Kidney infarction can be caused by medical-diagnostic renal arteriography (embolism of the renal artery or its branches with a kidney tumor, arteriovenous fistula, bleeding). In the outcome of a kidney infarct, nephrosclerosis develops and the kidney function decreases.

[8], [9], [10], [11], [12]

Symptoms of the infarction of the kidney

Symptoms of myocardial infarction depend on the extent of the lesion. With a small heart attack, symptoms may be absent. A larger infarct of the kidney is manifested by sharp pains in the lumbar region and an admixture of blood in the urine, possibly a decrease in diuresis. In the resorptive syndrome, subfibrility is normal, which is usually observed on the 2nd-3rd day. Arterial hypertension may develop as a result of ischemia of perifocal with respect to the tissue necrosis zone.

[13], [14]

Forms

Infarction of the kidney according to the pathological anatomical classification is classified as ischemic with a corolla of perifocal hemorrhages. In form, it is a cone directed by the base to the capsule of the kidney. Enlargement of the kidney with occlusion of the renal artery is insignificant.

[15], [16], [17], [18], [19],

Diagnostics of the infarction of the kidney

Since the infarction of the kidney is attributed to rare diseases with extremely nonspecific symptoms, a detailed history is of paramount importance. It should be the most thorough way to ask the patient about all his accompanying diseases, about the drugs that he takes. Pay attention to some characteristic details. Sharp pains in the lumbar region in a short time after the restoration of sinus rhythm in a patient with atrial fibrillation may be due to a heart attack of the kidney, especially if antiarrhythmic therapy was not preceded by a long reception of anticoagulants. The same can be said about patients with mitral insufficiency, which is characterized by flickering or fluttering of the atria. Infectious endocarditis of the left heart divisions naturally causes embolism along a large circle.

Recently, in hospitals are increasingly falling ill with opiate addiction, which is administered intravenously, as a result of which they develop a specific endocarditis. For the endocarditis of drug addicts, the tricuspid valve is more common, but in conditions of reduced immunity the process can spread to other valves. Heavy atherosclerosis is often complicated by thrombosis. When collecting anamnesis in such a patient, the fact of irregular reception of anticoagulants or antiaggregants is of particular importance, since interruptions in their reception can provoke thrombosis. The same can be said about the individuals who underwent surgery on the arteries, in this case kidney.

Physical methods can reveal soreness in the projection of the affected kidney, a positive symptom of effleurage, a visible admixture of blood in the urine, a decrease in diuresis, an increase in body temperature.

Laboratory diagnosis of a kidney infarction

The general analysis of urine is characterized by proteinuria and hematuria, which can be of any severity - from a slight increase in "unchanged" erythrocytes to profuse bleeding.

In the general analysis of blood within 2-3 days, moderate leukocytosis is characteristic.

Biochemical methods can reveal an increase in the concentration of C-reactive protein, an increase in the level of lactate dehydrogenase (LDH) in serum and urine (the latter is specific for kidney infarction).

Hematuria of unclear etiology is an indication for cystoscopy. Isolation of blood-colored urine along one of the ureters allows one to determine the side of the lesion, and also unambiguously exclude glomerulonephritis.

A coagulogram is necessary in the shortest possible time to evaluate hemocoagulation. Without a coagulogram, the appointment of anticoagulants or hemostatic drugs is highly undesirable.

[20], [21]

Instrumental diagnosis of a kidney infarction

Ultrasonography of kidneys with dopplerography is a study of fundamental importance mainly because of its comparative availability for most urological clinics around the clock. It allows a non-invasive way to assess the state of the kidneys and trunk renal vessels.

It is possible to confirm the diagnosis of a kidney infarction with CT or MRI with the introduction of appropriate contrast agents. At the same time, a wedge-shaped part of the parenchyma that does not accumulate contrast is detected.

Angiography is the "gold standard" for the diagnosis of lesions of the renal arteries. However, the value of computer and angiographic techniques is severely limited by the impossibility of realizing them in a round-the-clock mode. Therefore, in most cases, dopplerography is avoided.

Differential diagnosis

Differential diagnosis of a kidney infarction is complicated. In the first place, it is necessary to exclude renal colic. And the absence of stones does not exclude it. It is quite possible renal colic and as a result of the clot of blood. The most important argument against renal colic is the lack of expansion of the cup-and-pelvic system, which indicates the preservation of the passage of urine in the ureters. The second most important and frequent diagnosis for discussion is the aortic aneurysm stratification. It is with this disease that a very intense pain, acute violation of blood supply to the kidneys, hematuria, etc., is regular. Aortic aneurysms in most cases are diagnosed in elderly patients with severe prevalent atherosclerosis and high blood pressure; are accompanied by extremely intense pain. Thus, the diagnosis of a kidney infarction is the last place as a diagnosis of an exception, since its probability is extremely small without a characteristic cardiovascular anamnesis. 

Treatment of the infarction of the kidney

All patients with suspected renal infarction are advised by a urologist or a vascular surgeon. If the clinical picture is ambiguous, it may be necessary to consult a nephrologist.

All persons with suspected heart attack of a kidney need emergency hospitalization.

All patients, especially with hematuria, are shown a strict bed rest.

Drug treatment of kidney infarction

With severe pain, anesthesia is indicated. In case of a heart attack with ischemic pain, the use of narcotic analgesics is indicated. In this situation it is better to immediately assign the strongest drugs: fentanyl, morphine, omnolone, since others are usually ineffective.

In hematuria, haemostatic therapy with sodium etamzilate is indicated. In the absence of hematuria and a short period from the moment of cessation of blood flow, it is possible to use thrombolytics such as streptokinase, which can lead to restoration of kidney function, but even with minor hematuria, this therapy is contraindicated.

To correct the violation of the coagulating system of blood, direct anticoagulants are shown: heparin sodium 5000 ED 2-3 times a day, enoxaparin sodium (kleksan) 1 mg / kg 2 times a day. The duration of treatment is usually 8-10 days with the subsequent transfer to oral medications.

[22], [23], [24], [25], [26], [27], [28], [29]

Operative treatment of myocardial infarction

With a small period that has elapsed since the occlusion of the renal artery, it is possible to restore blood flow by promptly removing the thrombus or embolus, and if necessary, angioplasty can be performed later. Profuse hematuria, resistant to conservative hemostatic therapy, total kidney infarction, poorly amenable to correction of arterial hypertension, developed as a result of a previous infarction of the kidney serve as indications for nephrectomy.

Further management

A patient with a kidney infarction is shown a long (practically lifelong) intake of antiaggregants: acetylsalicylic acid 100 mg once a day after meals. Reserve drugs are ticlopidine 1250 mg 2 times a day and clopidogrel 75 mg once a day.

With a special propensity for thrombosis additionally or as a monotherapy, indirect coagulants can be prescribed: warfarin 5-7.5 mg once a day under the control of MHO (target level of MHO 2.8-4.4 in monotherapy and 2-2.5 when combined with antiaggregants).

Prevention

Infarction of the kidney can be prevented, if it is to prevent and adequately treat these diseases. To prevent the progression of atherosclerosis, including renal arteries, it is possible to prescribe medications that lower cholesterol levels - statins, fibrates, cholestyramine (cholestyramine). In the conditions of the present atherosclerotic vascular lesion, antiplatelet agents such as acetylsalicylic acid, ticlopidine, clopidogrel are also shown. Ticlopidine (ticlid) and clopidogrel (hydrofluoric acid) are indicated in conditions of high probability of thrombosis, especially if its consequences really threaten life (for example, coronary stents, artificial pacemaker), and if it is impossible to prescribe acetylsalicylic acid for some reason (aspirin bronchial asthma, exacerbation of peptic ulcer).

[30], [31], [32], [33], [34], [35], [36]