- Indications for renal biopsy
- How it is done
- Preparation for renal biopsy
- Contraindications and possible complications
Renal biopsy is a medical examination in which a small sample of kidney tissue is taken in order to investigate diseases that affect the kidney or to accompany patients who have had a kidney transplant, for example. The biopsy must be performed at the hospital and the person must be kept under observation for a period of 12 hours so that the doctor can monitor the person's evolution and the amount of blood in the urine.
Before performing the biopsy, it is necessary to perform other tests, such as coagulogram and urine tests, in addition to renal ultrasound, to check for the presence of cysts, kidney shape and kidney characteristics, and thus, check if it is possible to perform the test. biopsy. The performance of this procedure is not indicated if the person has a single kidney, has signs and symptoms of infection, is hemophilic or has polycystic kidney.
Indications for renal biopsy
The nephrologist can indicate the performance of a renal biopsy when a large amount of proteins and / or blood is observed in the urine of unknown origin, in case of acute renal failure that does not improve and after kidney transplantation in order to monitor the patient.
Thus, a kidney biopsy is indicated to investigate diseases that affect the kidney and confirm the diagnosis, such as:
- Acute or chronic renal failure; Glomerulonephritis; Lupus nephritis; Kidney failure.
In addition, renal biopsy can be indicated to assess the response of the disease to treatment and to verify the extent of renal impairment.
Not every time the results change, it is necessary to perform a biopsy. That is, if the person has blood in the urine, changes in creatinine or protein in the urine in isolation and is not accompanied by hypertension, for example, biopsy is not indicated. In addition, there is no need to perform the biopsy if the reason for the kidney involvement is known.
How it is done
The biopsy should be performed at the hospital, with local anesthesia being applied to adult patients who collaborate with the procedure or sedation in children or in non-collaborative adults. The procedure takes about 30 minutes, however it is recommended that the patient remains in the hospital for 8 to 12 hours after the procedure so that the doctor can assess the person's response to the exam.
Before the procedure, ultrasound of the kidneys and urinary system is performed to check if there are any changes that compromise or increase the risk of the exam. In addition, laboratory tests are performed, such as blood culture, coagulogram and urine test to verify whether it is possible to perform the biopsy without any complications.
If everything is in compliance, the person is placed lying on his stomach and the examination is performed with the aid of the ultrasound image, which allows to identify the best place for placing the needle. The needle draws a sample of kidney tissue, which is sent to the laboratory for analysis. Most of the time, two samples are taken from different locations of the kidney so that the result is more accurate.
After the biopsy, the patient must remain in the hospital to be monitored and there is no risk of bleeding after the procedure or change in blood pressure. It is important for the patient to inform the doctor of any symptoms they present after the biopsy, such as difficulty urinating, chills, presence of blood in the urine more than 24 hours after the biopsy, fainting or increased pain or swelling of the place where the biopsy.
Preparation for renal biopsy
To perform the biopsy, it is recommended that no drugs be taken such as anticoagulants, platelet anti-aggregating agents or anti-inflammatory drugs at least 1 week before the biopsy is performed. In addition, the doctor recommends performing renal ultrasound to check for the presence of only one kidney, tumors, cysts, fibrotic or stunted kidneys that are contraindications for the exam.
Contraindications and possible complications
Renal biopsy is not indicated in the case of a single kidney, atrophied or polycystic kidneys, coagulation problems, uncontrolled hypertension or symptoms of urinary tract infection.
Kidney biopsy is low risk, and there are not many associated complications. However, in some it is possible that there is bleeding. Because of this, it is recommended that the person remains in the hospital so that the doctor can observe the presence of any sign indicating internal bleeding.
