Houston, TX

Kidney Stones

Introduction To Kidney Stones

Different types of kidney stones, while small in size, can cause considerable discomfort and pain. These hard mineral deposits form within the kidneys and can vary in composition, leading to different types of kidney stones. Understanding the distinctions among these types is essential for effective prevention, management, and treatment. Let’s delve into the diverse world of kidney stones, exploring the various types, their origins, and the measures to mitigate their formation.

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What Are Kidney Stones?

Kidney stones are hard deposits that are made from minerals and salts that form in the urine. They are also known as renal calculi, ureteral calculi, nephrolithiasis, or urolithiasis. Kidney stones can affect any portion of the urinary tract, from your kidneys down to the bladder.

Typically, stones form when urine turns concentrated, permitting minerals to crystallize and stick to one another. 50% of patients who form a stone will have additional stones in the future. Recently, younger adults and even children are now suffering from nephrolithiasis due to changes in lifestyle and diet.

For this reason, it is important to schedule a consultation with Dr. Dhir when initially diagnosed with stone disease.

Types of Kidney Stones

Calcium Oxalate Stones

The Most Common Culprits. Calcium oxalate stones are the most prevalent type, accounting for approximately 70-80% of kidney stone cases. These stones form when the levels of calcium and oxalate in the urine become imbalanced. Oxalate is a compound found in certain foods and is also produced by the body. When excess oxalate combines with calcium, it can crystallize and develop into stones. Factors such as a diet high in oxalate-rich foods (like spinach and rhubarb), dehydration, and certain medical conditions can contribute to the formation of calcium oxalate stones.

Calcium Phosphate Stones

A Variant of Calcium Stones Calcium phosphate stones, though less common, are closely related to calcium oxalate stones. They form when there is an elevated level of calcium in the urine, often due to an underlying metabolic disorder or a high-alkaline urine pH. These stones are more likely to develop in individuals with conditions that increase urine pH, such as renal tubular acidosis. Addressing the root cause of elevated urine calcium levels is crucial in preventing the recurrence of calcium phosphate stones.

Uric Acid Stones

The Impact of Purine Metabolism. Uric acid stones constitute around 5-10% of kidney stones and are linked to the metabolism of purines, compounds found in certain foods and body tissues. Individuals who consume a diet rich in purine-containing foods, such as organ meats and seafood, may be at a higher risk of developing uric acid stones. Additionally, conditions like gout and certain genetic factors can lead to an accumulation of uric acid in the urine, fostering stone formation.

Struvite Stones

The Role of Infection Struvite stones, also known as infection stones, are relatively rare and often associated with urinary tract infections caused by specific bacteria. These stones form in an alkaline urine environment and are composed of magnesium, ammonium, and phosphate. The bacteria involved in urinary tract infections produce ammonia, which raises the pH of the urine and facilitates the formation of struvite stones. Timely treatment of urinary tract infections is vital to prevent the growth of these stones.

Cystine Stones

A Genetic Predisposition Cystine stones are uncommon and arise due to a genetic disorder called cystinuria. This condition leads to an excessive excretion of cystine – an amino acid – in the urine. As cystine is not easily soluble, it can crystallize and form stones. Cystine stones can be particularly challenging to manage and often require specialized interventions, including dietary changes and medication.

What are the Treatment Options?

Symptoms include:

Pain that occurs in waves and varies in intensity
Flank pain radiating to the lower abdomen or groin
Burning with urination or urgency to urinate
Bloody, tea-colored, or cloudy urin
Fever, chills, nausea, and/or vomiting
Stones form in the kidney and increase in size over time.

Stones in the kidney do not typically cause any symptoms or pain. Unfortunately, these stones eventually dislodge and pass down the ureter – the drainage tubes connecting the kidneys to the bladder. The ureters are quite narrow, therefore most stones over 5mm in size will get stuck.

When these larger stones get stuck and block the ureter, urine backs up in the kidneys in a condition called hydronephrosis. Hydronephrosis, with its accompanying ureteral spasms, is a very painful experience. Most women will compare it to the pain of childbirth!

What are the Causes?

There are many factors that can increase your risk for kidney stones. Genetics, diet, obesity, medical conditions such as diabetes, history of gastric bypass, as well as certain medications and vitamins are all contributory factors.

When the urine contains more substances that are crystal-forming – like oxalate, calcium and uric acid – the urinary environment is at risk for stone formation. Low urinary citrate, a urinary metabolite that protects from stone formation, can also be a deficiency leading to recurrent stones.

What are the Treatment Options?

Metabolic Expulsion Therapy (MET)

Smaller stones, usually <5mm, are treated conservatively with pain medication, drinking large amounts of fluid to pass the stone, and using an a-blocker medication (like Flomax) to aid in passing the stone into the bladder.

Surgical Management:

Large stones in the kidney are usually treated with surgery before they lodge themselves in the ureters and cause a painful ER visit. Additionally, stones larger than 5mm stuck in the ureters will also cause pain and necessitate surgery. Surgical options for kidney stones include:

Extracorporeal Shockwave Lithotripsy (ESWL): ESWL uses minimally-invasive acoustic sound waves to break up stones that form in the kidney or ureter, enabling easy passage of the resulting “stone dust” through the urine. ESWL is a one-hour procedure and patients go home the same day. Most patients can resume activities or work after 24 hours.
Ureteroscopy with Laser Lithotripsy (URS): URS with laser lithotripsy involves a thin, long flexible telescope called a ureteroscope, to internally examine the ureter and kidney for stones. Stones identified are then pulverized using a laser filament with fragments sometimes removed using a small “stone basket”. This procedure usually takes under an hour, involves no cuts or incisions, and also allows patients to go home the same day.

How do I Prevent Stones?

After a stone is passed, it is important to undergo a metabolic stone evaluation. Analysis of the stone usually identifies stones composed of calcium oxalate. Other common types identified include struvite stones and uric acid stones.

Struvite stones are associated with recurring urinary infections; uric acid stones are commonly associated in patients with gout, chronic diarrhea, or diets high in animal protein.

Dr. Dhir will also order a 24-hour urine test to identify any other mineral imbalances in the urine that could lead to future stone formation. Labs – including parathyroid hormone, uric acid, and calcium – are important to identify risk factors in the blood.

Based on the results of testing, removing calcium and vitamin C supplements, increasing fluids, reducing oxalate-rich foods, or decreasing animal protein in the diet may be recommended. Oxalate rich foods include tea, tree nuts, beets, dark leafy greens (spinach and kale), and chocolate. In certain instances, medications may be prescribed to reduce calcium levels in the urine or increase citrate in the urine to disrupt stone formation.

Dr. Dhir’s 4 Tips for Kidney Stone Prevention

As any busy urologist in Houston knows, the summer months are truly #stoneszn. Kidney stones makes up a large part of my clinical practice, but the emergency room calls for patients hospitalized with stone disease really increases once it’s hot outside. Unfortunately, in Houston this can seem like half the year.

The old adage is definitely true: passing a kidney stone can be worse than childbirth! To make things worse, stone rates are actually increasing in prevalence. New data suggest more than 10% of the US population will suffer from at least one kidney stone in their lifetime, and half of these patients will have multiple stones, or what we call chronic stone formers.

New patients in my clinic understand I have two goals: to treat their current stones and to then prevent stones in the future. The less they have to see me the better. Since prevention is key, I wanted to share my stone prevention tips and tricks with you.

Hydration, Hydration, Hydration

Summer is stone season for the simple reason that we sweat and our urine becomes more concentrated than in cooler times. Spending more time outside and exercising in the heat dehydrates us. When urine volume decreases, the urine minerals tend to concentrate, and a stone is born. Thus, hydration is the easy solution. Focus on drinking at least 2L (64 oz) daily with a goal of 3L (100 oz) if you are a chronic stone former. Simple dilution of stone-forming minerals is simple and effective.

Decrease Your Salt Intake

This tip is a bit tricky, as we all enjoy salty treats like potato chips, pretzels, deli meat, and mixed nuts to name a few. Salt is even present in our cereal and sodas so it can be difficult to avoid. Stone formers should make a diligent effort to decrease their salt loads, as high salt diets lead to high calcium levels in the urine. Avoiding fast food and planning more meals at home are some simple ways to better control the amount of salt in our diets. Most people will also benefit from a low salt diet from a heart health standpoint, as this helps lower blood pressure – think of a low salt diet as a “twofer” for your wellness goals.

Moderate Your Animal Protein

For many Texans, including myself, this is the hardest lifestyle change. Too much protein from animal sources – including red meat, fish, chicken, eggs, and seafood – can not only decrease citrate in the urine (which prevents stones) but also increase our urinary uric acid levels. This makes us much more likely to make stones. Now this does not mean abandon meat entirely, but it does indicate we must curb our “meatatarian” ways. If you have animal protein in multiple daily meals, try your best to limit this to just once a day, perhaps for dinner.

When Life Hands You Lemon, Make Lemonade

Citrate supplementation is the name of the game in stone prevention. Many of my patients are prescribed large horse pills called potassium citrate, as their metabolic workups show they are deficient in this mineral. An alternative is to naturally supplement your diet with citrate. Lemons, limes, and other fruit juices are high in natural citrate. For a low-sugar method, squeeze fresh lemons into a jar and pour a small amount in your water regularly. Diet lemonade preparations like crystal light packets also work great. If the acidity hurts your stomach, try a gentler version by drinking coconut water.

By modifying your lifestyle via the tips above, most stone formers can significantly decrease risks of future stone attacks. Of course, there are many more stone prevention recommendations that may need to be discussed given a patient’s specific metabolic issues.

If you are suffering from recurrent stone disease, I highly recommend scheduling an in-office consultation. An extensive metabolic workup is always recommended for anyone that has made a kidney stone more than once in their life.

Good luck during #stoneszn and keep those water bottles close by!

Schedule a Consultation

In cases of painful stones or recurrent urinary stones, HTX Urology is here to help! Dr. R. Robert Dhir is a highly skilled and board-certified Urological surgeon who proudly serves patients in the greater Clear Lake area of Houston, TX. His clinical focus includes leading-edge, minimally-invasive treatments of stone disease with an emphasis on prevention.

If you are interested in learning more about kidney stones and what you can do to manage this recurrent condition, please contact our office at 281-946-6462 or schedule online for your consultation today.