Renal Biopsy - Types, Recovery, Risks, and Results

What Is Renal Biopsy?

A renal biopsy or kidney biopsy is a procedure that removes a small amount of kidney tissue for analysis in the laboratory. This procedure helps the physician to understand the type of kidney disease one has so that an accurate treatment plan can be worked out. A renal biopsy can also be used to determine the effectiveness of kidney treatments and detect the presence of any complications after a kidney transplant.

What Are the Types of Renal Biopsies?

There are two types of kidney or renal biopsies:

• Needle Biopsy or Percutaneous Biopsy - During a needle biopsy, the physician inserts the biopsy needle into the kidney after anesthesia is given to obtain a sample of the diseased tissue. Ultrasound or CT (computed tomography) scan might guide the needle. Most kidney biopsies use this technique.

• Open Biopsy or Surgical Biopsy - During this procedure, an incision is made in the skin after anesthesia is given, surgically removing a piece of the kidney to be tested for the disease.

Why Is a Renal Biopsy Done?

The decision to undergo a biopsy is based on the individual's signs and symptoms, test results, and other health conditions. A renal biopsy is usually done to diagnose:

• A kidney problem that cannot be identified with other techniques.

• To evaluate how fast the kidney disease is progressing.

• The damage caused by the disease.

• To assess how well the treatment is working.

• To determine the health of the transplanted kidney.

• To determine why the transplanted kidney is not working.

• To develop different treatment plans for treating kidney disease.

• The presence of blood in the urine.

• Proteinuria - The presence of excessive protein in the urine.

• If the problems are due to the presence of excessive waste products in the blood.

How Is Renal Biopsy Performed?

Two types of renal biopsies are performed. Percutaneous biopsy and open biopsy.

1. Percutaneous Biopsy -

This biopsy is performed by a doctor and takes around an hour. At the beginning of the procedure, anesthesia is administered through an intravenous line in the arm. The individual is made to lie on the stomach for the kidneys to be easily accessible. The patient has to stay in this position for around thirty minutes. Next, a local anesthetic solution is injected into the area where an incision is to be made. Next, an ultrasound or CT scan is used to direct the needle inside the kidney. This process takes around thirty to forty seconds. Slight discomfort can be felt when the tissue is being scrapped out.

Percutaneous biopsies are of two types:

• Fine Needle Aspiration Biopsy- In this procedure, the physician removes a small tissue from the kidney with the help of a small and thin needle attached to a syringe.

• Needle Core Biopsy- Needle core biopsy is required for larger tissue samples. During this procedure, the physician removes a large sample of kidney tissue with the help of a spring-loaded needle. A loud clicking or popping sound is heard when the tissue is extracted. After removing the tissue, sufficient pressure is applied at the site of tissue removal to stop any kind of bleeding. A bandage is then applied over the incision.

2. Open Biopsy -

An open biopsy is recommended depending on the patient's health conditions and medical history. This biopsy is carried out if the patient has problems with bleeding or blood clot formation or if they have only one kidney present. Open biopsy is carried out under general anesthesia. The doctor cuts the skin and surgically removes a tissue sample from the kidneys. The procedure can be performed laparoscopically as well. During this, a small incision is made with the help of a laparoscope- a thin, lighted tube to carry out the biopsy. The laparoscope has a small video camera fixed at the end that sends images of the kidney to a video monitor. With the help of laparoscopy, the physician can observe the kidney and remove a large amount of tissue through a small incision.

How Is the Recovery After Renal Biopsy?

After the procedure is completed, the patient needs time to recover. Therefore, the patient is kept under observation. The release time varies from individual to individual depending on the health, physical condition, and reaction to the procedure. During recovery, the individual is made to lie on the back or the stomach if they had a kidney transplant for around six to eight hours.

The vital signs are monitored, including blood pressure, temperature, pulse, and breathing rate.

A complete blood count (CBC) and urinalysis are carried out to check for any internal bleeding or other problem. Painkiller medications are given to reduce pain at the site of the biopsy.

Once the vitals are stable, the patient is discharged from the hospital. The discharge takes place after twelve to twenty-four hours of the procedure. It is normal to have blood in urine till one day after the biopsy. If this blood in urine lasts more than a day, the physician should report it. Bed rest for a day is advisable. Any kind of strenuous activity, such as exercises involving jogging, jumping, etc., can be avoided for two weeks after the procedure.

What Are the Risks Involved in Renal Biopsy?

A renal biopsy helps the physician diagnose kidney disease and determine appropriate treatments. Risk is involved in any surgical procedure.

The chances of getting an infection are rare but contact the physician in case if:-

• There is blood in the urine for more than one day after the biopsy.

• Difficulty in passing urine.

• Presence of fever.

• Increasing pain at the site of biopsy.

• Presence of redness, swelling, bleeding, or discharge from the biopsy site.

• Weakness.

• Damage to the internal organs while doing the procedure.

What Do the Results of Renal Biopsy Signify?

The tissue sample removed from the biopsy is sent to the laboratory for testing. The sample is analyzed under a microscope with the help of reactive dyes. Infections or abnormal conditions are also detected. The results are considered normal if the tissue is free of defects. The results are considered abnormal if there are changes in the tissue.

Abnormal results indicate-

• Kidney infection.

• A decrease in the flow of blood to the kidneys.

• Diseases of the connective tissue.

• Kidney transplant rejection.

• Kidney cancer.

• Complicated urinary tract infection.

Conclusion:

Renal biopsy is an invasive diagnostic procedure used to diagnose certain kidney diseases. There are various procedures to carry out the biopsy. The tissue sample collected is sent to the lab for testing. If a diseased tissue is found, the patient is treated for the same. A few risks and complications are involved in the procedure. However, following the doctor's instructions and resting properly helps speedy recovery.