Kidney Biopsy: 5 Pros and 5 Cons

Kidney Biopsy Risks: 5 Pros and 5 Cons

What is a kidney (renal) biopsy?

A kidney biopsy is an important but invasive procedure with pros and cons, which we will now go through. Its normal to be a little anxious

But what is it? It’s a procedure to take a sample of kidney tissue, about the size of a small pin, which is examined under the microscope.

It is done in a hospital, either as a day case, or you may stay one night. It requires a week of rest afterwards, including a week off work.

Why do I need a kidney biopsy?

You may need a kidney biopsy if you have:

• A significant reduction in kidney function – either short term (AKI) or long term (CKD). This is especially true if the doctors suspect a problem with the glomeruli of the kidney
• A high level of protein in the urine (proteinuria)
• A kidney transplant that is not working properly ..

.. and the diagnosis cannot be made by blood tests or ultrasound (or other) scan.

5 Pros of Kidney Biopsy

1. Accurate diagnosis: It is the gold standard for diagnosing many kidney diseases by allowing doctors to examine a small tissue sample under a microscope.
2. Have it once: For most patients only one is necessary; other tests are need regularly.
3. Guides treatment: By identifying the exact cause and type of kidney disease, the biopsy results help doctors decide the correct and most effective treatment plan. This also prevents the use of potentially unnecessary treatments which may make kidney disease worse, or have side effects.
4. Predict future: A biopsy also demonstrates disease progression. The procedure helps assess how quickly a disease is advancing and the extent of any permanent damage (e.g. fibrosis), and/or how well a treatment is working. In other words, it can predict the future for you and your kidneys.
5. Explains why transplant is not working properly: For patients with a kidney transplant, a biopsy is a key tool to determine why a transplanted kidney is not working properly, often to diagnose organ rejection or other issues (too much medication), guiding subsequent management.

5 Cons of kidney biopsy

What are the risks of a renal biopsy?

Renal biopsies are not without risk. Fortunately serious complications are extremely rare. Most risks are to do with internal bleeding after the biopsy. You will be observed very closely so any bleeding is detected and treated early.

More common risks

1. Common. Mild discomfort over the biopsy site, which can be treated with pain relief, e.g. paracetamol
2. Common. 1 in 10 chance of minor bleeding with blood in the urine may occur after a biopsy – this usually settles quite quickly
3. Quite common. 1 in 20 chance of failure of the biopsy to obtain sufficient kidney tissue to make a diagnosis. It will usually need to be repeated
4. Unusual. 1 in 50 chance of a collection of blood around the kidney (bruise-haematoma), which can cause discomfort, but usually settles on its own.
5. Rare. 1 in 100 (or less) chance of  heavier bleeding requiring the need for a blood transfusion, or an x-ray treatment (embolisation) to stop a bleeding blood vessel

Very rare risks (1 in 1000 or less)

• More severe bleeding requiring an operation including removal of the bleeding kidney, leading to ..
• Kidney dialysis – that can be permanent, or
• Death.

What increases the risk of bleeding after a renal biopsy?

Several factors are know to increase the risk of bleeding:

• Age
• Small kidneys (one or both is less than 10cm long)
• High blood pressure – especially if 150/95 or higher
• Drugs to thin the blood
• Bleeding disorders.

Note. If you have one or more of these risk factors, it is important to question your kidney doctor as to whether the risks of bleeding outweigh the possible benefits.

Should I have a kidney biopsy if I only have one kidney?

No, not usually. Having a single kidney may not increase the risk of bleeding. But if we need to remove the kidney after extreme bleeding, this is a disaster – as it will obviously put you on permanent dialysis. The doctors will need an extremely good reason to recommend a kidney biopsy in this situation.

Summary

We have described a kidney (renal) biopsy, and gone through its pros and cons. They are nothing to be frightened of. Most go well, with no complications.

Other resource

There is more information on renal biopsy written by the renal team at UHCW Coventry.