Kidney infarction

Renal infarction is a rather rare variant of ischemic kidney disease (an extremely rare urological disease). For it to occur, a sudden and complete cessation of blood flow through a relatively large arterial renal vessel is necessary.

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

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

Causes kidney infarction

Renal infarction may develop as a result of arterial thrombosis or arterial embolism (more frequently). The source of arterial emboli in most cases is a mural thrombus of the left atrium or ventricle.

Renal infarction is usually a complication of a number of cardiovascular diseases:

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

Renal infarction may occur in patients with ascending aortic thrombosis, as well as those who have undergone renal artery surgery.

Renal infarction may be caused by diagnostic and therapeutic renal arteriography (embolism of the renal artery or its branches in case of a kidney tumor, arteriovenous fistulas, bleeding). As a result of renal infarction, nephrosclerosis and decreased renal function develop.

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

Symptoms kidney infarction

Symptoms of renal infarction depend on the extent of the lesion. With a small infarction, symptoms may be absent. A larger renal infarction is manifested by sharp pains in the lumbar region and blood in the urine, and a decrease in diuresis is possible. Subfibrillation is normal within the resorptive syndrome, which is usually observed on the 2nd-3rd day. Arterial hypertension may also develop due to ischemia of tissues perifocal to the necrosis zone.

[ 13 ], [ 14 ]

Forms

Renal infarction according to pathological-anatomical classification is classified as ischemic with a rim of perifocal hemorrhages. In shape, it is a cone, directed by the base to the capsule of the kidney. The enlargement of the kidney with occlusion of the renal artery is insignificant.

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

Diagnostics kidney infarction

Since renal infarction is a rare disease with extremely non-specific symptoms, a detailed anamnesis is of primary importance. The patient should be asked most thoroughly about all of his or her concomitant diseases and medications. Pay attention to some characteristic details. Sharp pain in the lumbar region shortly after the restoration of sinus rhythm in a patient with atrial fibrillation may be caused by renal infarction, especially if antiarrhythmic therapy was not preceded by long-term use of anticoagulants. The same can be said about patients with mitral insufficiency, which is characterized by atrial fibrillation or flutter. Infective endocarditis of the left heart naturally produces embolism in a large circle.

Recently, people with drug addiction to intravenous opiates have been increasingly admitted to hospitals, as a result of which they develop specific endocarditis. Endocarditis in drug addicts is more often characterized by damage to the tricuspid valve, but in conditions of reduced immunity, the process can spread to other valves. Severe atherosclerosis is often complicated by thrombosis. When collecting anamnesis from such a patient, the fact of irregular intake of anticoagulants or antiplatelet agents is of particular importance, since interruptions in their intake can provoke thrombosis. The same can be said about people who have undergone surgery on arteries, in this case, renal.

Physical methods can reveal pain in the projection of the affected kidney, a positive percussion symptom, visible blood in the urine, decreased diuresis, and an increase in body temperature.

Laboratory diagnostics of renal infarction

A general urine analysis reveals proteinuria and hematuria, which can be of any severity - from a slight increase in "unchanged" red blood cells to profuse bleeding.

A general blood test shows moderate leukocytosis over 2-3 days.

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

Hematuria of unclear etiology is an indication for cystoscopy. The release of blood-stained urine through one of the ureters allows one to determine the side of the lesion, as well as to clearly exclude glomerulonephritis.

A coagulogram is required as soon as possible to assess hemocoagulation. Without a coagulogram, prescribing anticoagulants or hemostatic drugs is highly undesirable.

[ 20 ], [ 21 ]

Instrumental diagnostics of renal infarction

Kidney ultrasound with Dopplerography is a fundamentally important examination mainly due to its relative availability for most urological clinics around the clock. It allows for a non-invasive assessment of the condition of the kidneys and main renal vessels.

It is possible to confirm the diagnosis of renal infarction using CT or MRI with the introduction of appropriate contrast agents. In this case, a wedge-shaped area of the parenchyma that does not accumulate contrast is revealed.

Angiography is the "gold standard" for diagnosing renal artery lesions. However, the value of computer and angiographic methods is severely limited by the impossibility of their real implementation around the clock. Therefore, in most cases, Dopplerography is used.

Differential diagnosis

Differential diagnostics of renal infarction is complicated. First of all, it is necessary to exclude renal colic. Moreover, the absence of stones does not exclude it. Renal colic is also quite possible due to the passage of a blood clot. The main argument against renal colic is the absence of dilation of the renal pelvis, which indicates the preservation of the passage of urine through the ureters. The second most important and frequent diagnosis for discussion is dissection of the aortic aneurysm. It is with this disease that extremely intense pain, acute impairment of blood supply to the kidneys, hematuria, etc. are typical. Aortic aneurysms in most cases are diagnosed in elderly patients with severe widespread atherosclerosis and high blood pressure; they are accompanied by extremely intense pain. Thus, the diagnosis of renal infarction is in last place as a diagnosis of exclusion, since its probability is extremely low without a characteristic cardiovascular history.

Treatment kidney infarction

All patients with suspected renal infarction should consult a urologist or vascular surgeon. In case of ambiguous clinical picture, a consultation with a nephrologist may be required.

All individuals with suspected renal infarction require emergency hospitalization.

All patients, especially those with hematuria, are advised to stay on strict bed rest.

Drug treatment of renal infarction

In case of severe pain, pain relief is indicated. In case of infarction with ischemic pain, narcotic analgesics are indicated. In this situation, it is better to immediately prescribe the strongest drugs: fentanyl, morphine, omnolone, since others are usually ineffective.

In case of hematuria, hemostatic therapy with sodium etamsylate is indicated. In the absence of hematuria and a short period of time after the cessation of blood flow, thrombolytics such as streptokinase may be used, which may lead to restoration of kidney function, but even with minor hematuria, such therapy is contraindicated.

Direct anticoagulants are indicated to correct disorders of the blood coagulation system: sodium heparin 5000 U 2-3 times a day, sodium enoxaparin (clexane) 1 mg/kg 2 times a day. The duration of treatment is usually 8-10 days with subsequent transfer to oral medications.

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

Surgical treatment of renal infarction

If a short period of time has passed since the occlusion of the renal artery, it is possible to restore blood flow by surgical removal of the thrombus or embolus, and, if necessary, angioplasty can be performed later. Profuse hematuria resistant to conservative hemostatic therapy, total renal infarction, poorly corrected arterial hypertension that developed as a result of a previous renal infarction are indications for nephrectomy.

Further management

A patient who has had a renal infarction is prescribed long-term (almost lifelong) administration of antiplatelet agents: 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.

In case of a special tendency to thrombosis, indirect coagulants may be prescribed additionally or as monotherapy: warfarin 5-7.5 mg once a day under the control of INR (target INR level 2.8-4.4 in monotherapy mode and 2-2.5 when combined with antiplatelet agents).

Prevention

Renal infarction can be prevented by engaging in prevention and adequate treatment of these diseases. To prevent the progression of atherosclerosis, including renal arteries, it is possible to prescribe drugs that lower cholesterol levels - statins, fibrates, cholestyramine (cholestyramine). In conditions of existing atherosclerotic vascular lesions, antiplatelet agents are also indicated - acetylsalicylic acid, ticlopidine, clopidogrel. Ticlopidine (ticlid) and clopidogrel (plavik) are indicated in conditions of high probability of thrombosis, especially if its consequences are truly life-threatening (for example, coronary stents, artificial cardiac pacemaker), and also 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 ]