Kidney Stones – Prevention & Treatment with Mr Leye Ajayi

Mr Leye Ajayi is a Consultant Urological Surgeon with a specialist interest in minimally invasive surgery for urinary tract stone disease, in particular percutaneous renal surgery (PCNL), laser and lithotripsy treatment. His general urology practice focuses on andrology, rapid access prostate and haematuria (blood in urine) assessments. He is the Service Line Lead for the urology department and the clinical lead for stone disease at Royal Free NHS London. He was awarded an MD for his research into the molecular biology of prostate cancer. . He is a faculty member of the European Association of Urology Section of Uro-Technology (ESUT) and teaches and performs surgery at a number of top European Centres.

We’ve asked Mr Ajayi how kidney stones are formed, how to prevent them, and what treatment is usually recommended to remove them.

What are the kidneys?

Most people have two kidneys, one on either side of the spine underneath the rib cage. These are bean-shaped and around the size of an adult fist.

The kidneys purify the blood by filtering out waste and transferring it into your urine, so it can be removed from the body when you pee. They also make vitamins that control growth, release hormones that help regulate blood pressure, and make sure we have the right levels of sodium, potassium, and calcium in our blood.

Fun fact

The kidneys filter all the blood in the body every 30 minutes!

What are kidney stones?

Sometimes, waste minerals in the blood form crystals that collect inside the kidneys. This can happen when there is too much waste in too little water. Over time, these crystals can clump together and become a stone-like lump. Stones that remain in the kidneys often won’t cause symptoms. However, once they ‘drop’ into the ureter (the tube that connects the kidneys to the bladder), even small stones can cause intense pain.

Stones can develop in just one kidney or both, and most often affect people between the ages of 30 and 60. If a stone is very small, you could pee it out without any problems. However, if a stone grows larger, or you have multiple stones, you will need treatment to prevent a blockage in your tubes, an infection, or your kidneys not working properly.

Kidney stones can be made of different substances:

Calcium oxalate

These stones are the most common (around 80%). There are many reasons for these developing, including:

• Not drinking enough water
• Eating a diet that’s too high in protein, salt, or sugar
• Being overweight
• Having a digestive disease such as IBD, Crohn’s or Ulcerative Colitis
• Having had weight loss surgery

Uric acid

Uric acid is a waste product which forms when your body breaks down chemicals called purines. If you have high levels of uric acid, crystals form, which combine with other substances to create a stone. These stones tend to run in families, but are also linked to: 

• Chemotherapy
• Conditions such as obesity and Type 2 diabetes
• A diet high in salt and sugar
• Weight loss surgery
• Taking certain medications, such as diuretics and immune suppressants

Struvite

Struvite stones are not that common and are related to chronic urinary tract infections (UTIs). Some bacteria make the urine less acidic and more alkaline. Struvite stones can form in alkaline urine. These stones are often large and grow very fast.

Cystine

These are caused by a rare genetic disorder called cystinuria which causes a substance called Cystine to leak into your urine. Cystine is an insoluble amino acid, so it doesn’t break down, but clumps together into stones instead. These tend to be larger than other stones and will keep recurring, so this condition needs lifelong management. These stones often start forming in young adulthood, but some people will get them when they’re still children or even babies.

What are the symptoms of kidney stones?

Larger kidney stones can cause several symptoms, including:

• Severe pain that comes and goes (almost always on one side)
• Pain near the groin, pelvis, or abdomen
• Pain whilst urinating
• Blood in your pee
• Urine that smells bad or looks cloudy
• Nausea or vomiting
• Fever and chills

Treating kidney stones

At St John & St Elizabeth Hospital, we have recently invested in state-of-the-art laser technology to treat kidney stones, called Thulium Fiber laser. This is the best of its kind. We are one of the first private hospitals in the UK to invest in this cutting-edge technology.

The Thulium Fiber laser allows doctors to rapidly disintegrate stones into very fine sand (rather than small particles which is the case with other laser technology). This means less pain for the patient, a faster operating time, and a more comfortable recovery.

It also means that in the case of multiple large stones, these can be all dealt with quickly (under one hour), in one go, rather than two separate treatments. In most cases, patients will go home the same day and can be back at work as soon as the next day.

How the laser works

A kidney stones procedure using the Thulium Fiber laser, is most commonly done as an endoscopic procedure, which is performed under a short general anaesthetic. This means you will be asleep.

A long, flexible tube with a tiny light and camera, called a ureteroscope, is inserted into the urethra (the tube through which urine leaves the body). This then travels up through the natural corridors of the body, past the bladder and into the ureter. Once the stones are located, they are lasered down into fine sand. This can be done in less than an hour. The fine sand is sent off for analysis to find out the chemical composition of your stones.

After this, the surgeon may insert a tube called a stent between the kidney and urethra, which promotes healing and allows particles in the urine to leave the body more easily. The stent also allows the kidneys to drain during the healing process.

Once you wake up, the pain from the kidney stones will be gone but there will still be some discomfort (particularly if a stent has been fitted). After a couple of hours rest in hospital, you can go home, once we’re sure you’re ok. Before leaving, we will ask you to collect a pee sample.

What happens after the procedure?

If a stent has been fitted, it can make you feel like you need to pee, and it can cause some blood to appear in the urine. Men may feel pain in the penis or testicles as well.

Your doctor will prescribe medications after the procedure. Generally, these include an antibiotic to prevent infection, a pain killer, and possibly something to help with bladder spasms and stent related symptoms.

You should drink lots of water to encourage any particles to move out of the kidney. You will probably need to pee more often and urgently, so stay close to a toilet.

Most people can resume their daily routine the day after surgery.  However, if you’ve had a stent fitted, avoid high-intensity workouts until it’s been removed. Some pain medications restrict activities like driving, so make sure you read the labels carefully.

You will have a follow-up appointment with your doctor around one or two weeks post-surgery. If you have a stent, it will be removed at this point. This is done through your bladder and can be done with you awake. Sometimes, a stent will be left in longer if your surgeon feels it will help with healing. The stent can stay in for up to three months, so don’t worry if your stent is kept in longer than a week.

At this stage, your doctor will have also received the results of your stone analysis. Based on the stone’s composition, your doctor can then recommend ways to prevent future kidney stones. This could include making changes to your diet, taking supplements or medications.

Top tips for preventing kidney stones

• Stay hydrated. The number one thing you can do is to drink enough fluid, such as water. Drinking enough fluid makes it harder for chemicals to build up and become crystals. Depending on your type of stone, your doctor will recommend the right amount of fluid for you.
• Eat less salt. A diet high in salt causes calcium to build up in your urine. Too much calcium in your urine and this can lead to new stones forming.
• Include the right amount of calcium in your diet. If you’ve had calcium oxalate stones, you may be tempted to avoid calcium or oxalate-rich foods. However, this can cause more harm than good. Eating calcium and oxalate-rich foods at the same time is a better idea, as the chemicals can then bind together in the stomach and intestines before reaching the kidneys.

If you’re experiencing kidney problems, get in touch with our Urology Clinic on 020 7432 8297