Retrograde Intrarenal Surgery for Kidney Stones

Overview

What are kidney stones?

Kidney stones form when waste substances in the urine like minerals, acid or salts build up and crystallise to form hard stones in the kidneys.Stones can vary in size, ranging from tiny grains to larger stones that may block the flow of urine.

What causes kidney stones?

You are more likely to get kidney stones if you:

• Do not drink enough water
• Take certain medicines
• Have certain medical conditions
• Eat too much salt or animal protein
• Have a family history of kidney stones

Signs and symptoms

Small kidney stones may not cause any symptoms and can pass out in the urine without causing pain.

Larger kidney stones may cause:

• Pain in the back or side of the tummy
• Severe pain that comes and goes
• Nausea or vomiting
• Blood in the urine
• Pain or burning while passing urine
• Fever and chills if there is an infection

What treatments should I expect?

Treatment depends on the size and location of the kidney stone.

Treatment options may include:

• Drinking plenty of fluids to help small stones pass naturally
• Medicines to relieve pain or help the stone pass
• Shock wave lithotripsy (SWL): Uses sound waves to break the stone into smaller pieces
• Percutaneous nephrolithotomy (PCNL): Removes large or complex kidney stones through a small cut in the back
• Retrograde intrarenal surgery (RIRS): A thin tube (uteroscope) is used to break a stone using laser energy

Retrograde intrarenal surgery (RIRS)

What is RIRS and when is it done?

Retrograde Intrarenal Surgery (RIRS) is a minimally invasive procedure used to treat kidney stones. It uses a thin flexible tube with a tiny camera (ureteroscope) to reach the kidney and a laser to break the stone into small pieces.

RIRS may be recommended if you have:

• Kidney stones up to > 2 cm in size
• Stones located in a difficult-to-reach part of the kidney
• Kidney stones that have not been successfully treated with shock wave therapy (SWL)
• Certain medical conditions, such as a bleeding disorder, that make other procedures less suitable

Procedure

Step-by-step overview

• You will be given medicine to make you sleep during the procedure (general anaesthesia)
• A thin guidewire (a soft wire used to guide the instruments) is gently passed through the urinary passage into the kidney using X-ray guidance (live X-ray images)
• A a small hollow tube (ureteric access sheath) is placed to help the instruments reach the kidney and protect the ureter (the tube that carries urine from the kidney to the bladder)
• A thin, flexible tube with a tiny camera (flexible ureteroscope) is passed through the sheath into the kidney
• The kidney stone is located and broken into small pieces using a laser (a special light beam)
• The stone pieces are removed through the sheath or allowed to pass naturally in the urine
• A temporary small soft tube (ureteric stent) may be placed to help urine drain from the kidney while it heals

Recovery and aftercare

• Most patients go home the same day or after one overnight stay
• You can usually return to your normal activities soon, as advised by your doctor.
• If a small tube that helps urine drain is placed, your doctor will tell you when it should be removed.
• Drink plenty of fluids, unless your doctor advises otherwise
• You may need a follow-up scan to check that all the kidney stones have been removed

Benefits and risks of RIRS

Benefits

• No cuts (incisions) are made on the body
• Can treat stones in difficult-to-reach areas of the kidney
• Low risk of bleeding
• High chance of removing the stones completely, depending on their size and location
• May be suitable for selected patients when other treatment options are less suitable
• Short hospital stay and faster recovery than more invasive surgery

Possible risks

As with any surgery, there are potential risks,

• Bleeding
• Urinary tract infection
• Mild pain or discomfort from a temporary ureteric stent
• Small stone fragments may remain and require another procedure
• Temporary blood in the urine

Myths and facts

Myth 1: RIRS involves making cuts on the body

Fact: RIRS is performed through the natural urinary passage without making any cuts or incisions.

Myth 2: All kidney stones can be treated with medicines.

Fact: While small stones may pass naturally, larger stones or stones causing symptoms may require procedures such as RIRS.

Myth 3: Laser treatment damages the kidney.

Fact: The laser is carefully used to break the stone into small pieces while minimising damage to surrounding tissues.

Myth 4: A ureteric stent is permanent.

Fact: A ureteric stent is usually temporary and is removed after your kidney has healed.

Myth 5: Once a kidney stone is removed, it will never come back.

Fact: Kidney stones can return. Drinking enough water and following your doctor's advice can help reduce the risk.

References

1. Cleveland Clinic. Kidney Stones. [Online] Available from: https://my.clevelandclinic.org/health/diseases/15604-kidney-stones. Accessed on: 14 July 2026.
2. National Health Service. Kidney stones. [Online] Available from: https://www.nhs.uk/conditions/kidney-stones/. Accessed on: 13 July 2026.
3. Inoue T, Okada S, Hamamoto S, et al. Retrograde intrarenal surgery: Past, present, and future. Investigative and clinical urology. 2021;62(2):121.
4. Retrograde intrarenal surgery. [Online] Available from: https://urologycentre.com.sg/urological-procedures/kidney-health/rirs-retrograde-renal-surgery/. Accessed on: 13 July 2026.