Why does blood flow stop?
The kidney receives blood through one large artery, which inside the organ is divided into segmental branches. If the lumen is blocked, the tissue area is left without oxygen and dies within a few hours. Most often, the cause is an embolus brought by blood flow from the left side of the heart due to atrial fibrillation or valve pathology. Less commonly, local thrombosis due to atherosclerosis, arterial wall dissection, vasculitis or trauma are to blame. Separately, heart attacks are distinguished due to thrombosis of the renal vein, when the outflow of blood is disrupted.
- Embolism from the heart with atrial fibrillation
- Thrombosis due to atherosclerosis of the renal artery
- Arterial wall dissection
- Vasculitis and autoimmune vascular diseases
- Thrombophilias and coagulation disorders
- Trauma to the lumbar region and complications of interventions
Symptoms
The classic manifestation is sudden intense pain in the side or lower back, which does not depend on the position of the body and is not relieved by usual means. Nausea, vomiting and fever are often associated. About half of patients experience blood in their urine, sometimes only during laboratory testing. A sharp rise in blood pressure is characteristic: the ischemic kidney releases substances that constrict blood vessels. Small heart attacks can be almost asymptomatic and are discovered by chance.
- Sudden pain in the side, lower back, or abdomen
- Nausea and vomiting
- Temperature rise
- Blood in urine
- Increase in blood pressure
- Decreased urine output with bilateral lesions
How is it different from renal colic?
Renal colic with a stone also causes severe pain in the side with blood in the urine, so it is difficult to distinguish between them based on complaints. Clues include age, the presence of arrhythmia or a prosthetic valve, the absence of a stone on ultrasound and CT without contrast, as well as a noticeable increase in the LDH enzyme in the blood. With colic, the pain is usually wave-like, with periods of subsidence; with a heart attack, it is more constant. The question is put to rest by a computed tomography scan with contrast, which shows a wedge-shaped area without blood supply.
- Colic - wave-like pain, heart attack - constant
- With a heart attack, there is often a source of embolism in the heart
- Absence of stone on imaging
- An increase in LDH is characteristic of a heart attack
- The final answer comes from a CT scan with contrast.
Diagnostics
The main method is multislice computed tomography with intravenous contrast: it shows the area where blood does not flow and the condition of the blood vessels. Doppler ultrasound helps assess blood flow, but small segmental infarctions are not always visible. The tests determine creatinine, LDH, urinalysis and coagulation parameters. A mandatory step is to search for the source of the embolism: ECG, 24-hour rhythm monitoring and echocardiography. In young patients, the blood coagulation system is additionally examined.
- MSCT of the kidneys with contrast
- Dopplerography of renal vessels
- LDH, creatinine, urinalysis
- Coagulogram
- ECG and rhythm monitoring
- Echocardiography to find the source of the thrombus
Treatment and prevention of recurrences
Treatment is carried out in a hospital. The basis is anticoagulant therapy, which prevents thrombus growth and new embolisms, as well as adequate pain relief and pressure control. In the early stages of a large lesion, endovascular intervention is discussed to restore blood flow. Further prevention depends on the cause: for atrial fibrillation, constant anticoagulant therapy is required, for atherosclerosis, control of lipids and pressure is required. It is extremely dangerous to stop prescribed blood thinning medications on your own.
- Hospitalization and observation
- Anticoagulants as prescribed by a doctor
- Pain relief and blood pressure control
- Endovascular restoration of blood flow in selected cases
- Continuous therapy for atrial fibrillation
- Control cholesterol, blood pressure, quit smoking
- Monitoring kidney function after discharge
