Kidney and Urinary Tract Stone Treatment

Kidney and urinary tract stones are hard masses that form in the renal pelvis or urinary channels when minerals such as calcium, oxalate, and uric acid, which are dissolved in the urine, crystallize for various reasons. This condition, defined as urolithiasis in the medical literature, is a mechanical problem that can obstruct urine flow at any point in the urinary system. These crystalline structures, which arise as a result of disturbances in the body’s mineral and fluid balance, can be effectively removed with modern urological approaches without damaging kidney tissue. The professional management of this health problem, which directly affects quality of life, includes not only removing the existing stone through surgical and/or medical methods but also preventing the formation of new stones through scientific protocols.

What Are Kidney and Urinary Tract Stones and Where Do They Form in Our Body?

The human body, just like a magnificent factory, constantly produces waste substances, and it is the responsibility of our kidneys to filter and remove these wastes from our blood. The kidneys form urine by filtering the blood. Urine is actually a complex fluid containing hundreds of different chemicals in water. If the amount of water consumed is too low or the body somehow tries to excrete too many minerals, these substances in the urine cannot remain in liquid form and begin to precipitate. Just as sugar settles at the bottom after a while when you add too much sugar to a glass of water, minerals in the urine can similarly accumulate on the inner surface of the kidney. These grains of sand, initially too small to be seen with the naked eye, adhere to each other over time and form stones that reach millimetric and sometimes even centimetric sizes.

These hard structures do not always remain fixed inside the kidney. They can move downward along with the direction of urine flow. The course of the disease and the degree of discomfort it causes the patient vary completely according to the location of the stone in the body. Sometimes a very large stone remains silently in the kidney for years without moving, while a stone as small as a lentil may enter a narrow channel and completely stop urine flow.

The areas where kidney and urinary tract stones form and become lodged are as follows:

• Renal pelvis
• Lower kidney chambers (Lower renal calyx)
• Middle kidney chambers (Middle renal calyx)
• Upper kidney chambers (Upper renal calyx)
• Areas where the chambers in the kidney balloon out (Renal diverticulum)
• Upper urinary channel (Upper ureter)
• Middle urinary channel (Middle ureter)
• Lower urinary channel (Lower ureter)
• Urinary bladder
• External urinary channel (Urethra)

Why Are Kidney and Urinary Tract Stones So Common in Türkiye?

The geography, climate, and environmental factors of the region where a person lives have an incredibly significant effect on the development of kidney stone disease. When looking at the map, there is a “stone belt” where this disease is much more common in certain parts of the world, and Türkiye is located within this belt. Therefore, it is certainly not a coincidence that at least two out of every ten people in our country experience this disease at some point in their lives. Climatic conditions are among the most fundamental reasons for these high rates. Especially in regions where summers are very hot and long, people unknowingly lose enormous amounts of fluid through sweating. If this fluid loss is not replaced by drinking enough water during the day, the kidneys try to retain water in the body and excrete very little, dark-colored, concentrated urine. This concentrated urine provides the perfect environment for stone formation.

In addition to the climate, our dietary habits also accelerate this process. A lifestyle in which salt consumption is very high, animal protein is consumed abundantly, but the habit of daily water intake remains poor constantly strains the kidneys. Genetic inheritance, in other words familial predisposition, also has a major role; individuals with a family history of stone disease are much more likely to experience this problem than others. Especially in regions where consanguineous marriages are common, rare genetic kidney stone diseases that begin in childhood are unfortunately also encountered more frequently. This condition, which used to be much more common in men, is now rapidly increasing among women as well due to changing dietary habits and the rise of sedentary lifestyles.

The factors that increase the frequency of kidney and urinary tract stones in our country are as follows:

• Hot climate conditions
• Insufficient water consumption
• Excessive sweating
• Genetic predisposition
• Sedentary lifestyle
• Consanguineous marriages
• High salt consumption
• Obesity

Through What Mechanism Do Kidney and Urinary Tract Stones Develop?

Understanding how stones form in our body is also the key to understanding how we can prevent this disease. The most important condition that triggers crystallization in the urinary tract is urine reaching the level of “supersaturation.” There is always a delicate balance in the urine between stone-forming substances and protective substances that prevent stone formation. While substances such as calcium, oxalate, and uric acid are on the stone-forming side of the scale, substances such as citrate and magnesium are on the protective side. Protective substances are natural shields that prevent microscopic crystals in the urine from sticking to each other. If these protective substances are deficient in a person’s urine due to congenital reasons or dietary mistakes, stone-forming minerals rapidly combine and begin to grow.

In addition, the acidity or alkalinity of urine, namely its pH value, is also very critical. When urine becomes too acidic, different minerals tend to crystallize, while when it becomes too alkaline, completely different minerals tend to crystallize. Therefore, a person’s metabolic structure, the types of food consumed, and the chemical balance of the urine collectively initiate or stop the stone formation process.

The inorganic and organic substances that play a role in the formation of kidney and urinary tract stones are as follows:

• Calcium
• Oxalate
• Phosphate
• Uric acid
• Cystine
• Struvite
• Citrate
• Magnesium

What Are the Common Types of Kidney and Urinary Tract Stones?

Although kidney stones are generally thought of as a single type of mass in society, there are actually stone types with completely different characteristics depending on the chemical substances they contain. Distinguishing between these types is extremely important in terms of preventing the patient from passing stones again in the future and choosing the correct treatment method. For example, calcium oxalate stones, the most common type, are generally quite hard, easily visible on X-rays, and sometimes difficult to break. This type of stone is found in approximately eighty percent of patients and is generally based on insufficient fluid intake combined with genetic predisposition.

Uric acid stones, on the other hand, have a completely different story. These stones, which are absolutely invisible on X-rays and can only be detected on tomography, develop when the urine is highly acidic. They are generally seen in people who consume excessive amounts of animal protein or who have gout. The most favorable feature of these stones in medicine is that they can be dissolved inside the body without surgery, simply by using certain medications that make the urine alkaline. However, this process is related to the size of the stone. Therefore, very large stones are not always expected to dissolve by administering medication treatment. Another different type is struvite stones. These develop entirely due to chronic urinary tract infections and can grow very rapidly, completely filling the kidney like a deer’s antler. Cystine stones are entirely the result of a congenital genetic disease, and their chemical structure, which works like a suspension system, causes them to be resistant to shock wave treatment. Patients with these stones are diagnosed at a very young age and frequently require surgical procedures due to stone disease.

The best-known types of kidney and urinary tract stones are as follows:

• Calcium oxalate
• Calcium phosphate
• Uric acid
• Struvite
• Cystine

Why Is the Pain of Kidney and Urinary Tract Stones So Severe and What Are the Symptoms?

When kidney stones are mentioned, the first thing that comes to mind is that famous, unforgettable, unbearable pain. Most patients describe this pain as the most severe pain they have ever experienced in their lives. So how can a stone only a few millimeters in diameter cause pain severe enough to make a person writhe? Contrary to the common belief in society, the cause of the pain is not the stone scratching or causing bleeding in the walls of the urinary channel. The actual cause of the pain is an increase in pressure within the system of which the kidney is a part, resulting entirely from mechanical disruption of urine flow. The kidney continues to produce urine without stopping. However, when a stone moving through the channel suddenly blocks the pathway, the produced urine cannot flow downward toward the bladder and begins to accumulate inside the kidney. This accumulation causes the thin renal capsule surrounding the kidney, which is incredibly rich in nerves, to stretch like a balloon. The actual source of those terrible pain signals sent to the brain is this sudden stretching of the capsule.

The pain usually begins suddenly and comes in waves. The location where the pain is felt also varies according to the position of the stone. If the stone is higher up, the pain is felt in the back and lower back, but as the stone begins to move downward through the urinary channel, it spreads toward the front of the abdominal cavity, the groin, and even the genital area. Meanwhile, because the excessive stress in the kidney also triggers the autonomic nervous system, the nervous system that works outside a person’s control, the gastrointestinal system is affected as well, and severe nausea and vomiting attacks are added to the picture. Seeing blood in the urine due to irritation caused by the stone in the channel is also extremely common.

Some of the complaints experienced by patients during attacks of kidney and urinary tract stones are as follows:

• Severe lower back pain
• Pain radiating to the groin
• Nausea
• Vomiting
• Blood in the urine
• Frequent urge to urinate (in stones close to the bladder)
• Burning during urination (in stones close to the bladder)
• Pain radiating to the genital area (in stones close to the bladder)

Which Methods Are Used to Diagnose Kidney and Urinary Tract Stones in Emergency Departments?

In a patient presenting to the hospital with agonizing pain, the first thing that must be done is to quickly and definitively distinguish whether this pain is actually caused by a stone or by another problem such as appendicitis or gallbladder disease. Thanks to advances in medical technology, the diagnostic process today proceeds quite rapidly, reliably, and clearly. In the first stage, ultrasonography is generally preferred because it contains no radiation, works entirely with sound waves, and causes no harm to the patient. Ultrasound immediately shows swelling in the kidney (urine accumulation) and confirms the presence of the stone through the dark shadow created by sound waves striking the stone. This method is always the first and safest option for pregnant women and children.

However, in order to create a definitive treatment plan, the exact location of the stone, its size measured in millimeters, and its internal density must be known in great detail. In addition, some stones, such as those located in the urinary channel, may not be visible on ultrasound; at this point, computed tomography, the gold standard of modern medicine, comes into play. Non-contrast tomography is most commonly used in stone disease. This imaging, performed in less than one minute, can also create a three-dimensional map of the urinary tract. Tomography clearly shows even a 1-millimeter grain-of-sand-sized stone in the system, including uric acid stones that are invisible on X-rays. In addition, thanks to the density value measured by the device, the hardness of the stone can be known in advance, allowing us to predict the success of subsequent extracorporeal stone-breaking or surgical procedures.

Most of the medical tests used in the diagnosis of kidney and urinary tract stones are as follows:

• Ultrasonography
• Non-contrast and/or contrast-enhanced computed tomography
• Intravenous pyelography (rarely used today)
• Plain urinary system X-ray
• Complete urinalysis
• Kidney function blood tests
• Certain blood tests that screen for infection and stone predisposition
• Urine culture

How Should the First Medical Intervention Be Performed During an Attack of Kidney and Urinary Tract Stones?

During a kidney stone attack, which we call renal colic, the patient has only one wish: for the pain at that moment to stop as soon as possible. Therefore, the main objective of the emergency approach is to relieve the patient by breaking the mechanism of pain. First, simple painkillers and special medications that reduce fluid pressure inside the kidney and relieve spasms in the urinary channel are used. When necessary, antibiotics with anti-inflammatory effects or certain powerful narcotic painkillers may also be used. Even medications called alpha blockers, which are sometimes used for prostate enlargement, may be used to widen the urinary channels, accelerate urine flow, and reduce pressure.

There is a very common and unfortunately frequently made mistake in society: trying to force a patient experiencing a pain attack to drink liters of water or administering liters of intravenous fluid. However, the channel is already completely blocked by a stone. If you force more water into a pipe behind a closed tap, the pipe reaches the point of bursting. Similarly, overloading a blocked kidney with fluid increases urine production, further raises the already extremely high pressure inside the kidney, and can make the patient’s pain unbearable. Therefore, during an attack, the patient should be given only the amount of fluid needed for basic requirements, and forced water consumption should definitely be avoided.

The emergency treatment steps applied during a kidney and urinary tract stone attack are as follows:

• Establishing intravenous access
• Maintenance intravenous fluid support
• Painkiller or narcotic injections
• Antispasmodic medications
• Anti-nausea medications
• Stomach protectors

Can Small Kidney and Urinary Tract Stones Be Passed Using Medication Alone?

Not every kidney stone requires immediate placement on an operating table or a shock wave device, which is incorrectly known among the public as a laser device or sound wave treatment. Anatomically, our body has an excellent drainage system capable of expelling stones up to a certain size on its own. In particular, a very large proportion of stones measuring 5 millimeters or less pass spontaneously without any medical intervention with appropriate guidance and abundant fluid intake. However, when the stone size exceeds 6 millimeters, the likelihood of these stones becoming lodged in the channel and causing severe pain increases. For patients in this group, “medical expulsive therapy” may be a treatment option.

Interestingly, alpha blockers, a special group of medications originally developed to make urination easier for prostate patients, are used in this treatment. These medications have an excellent relaxing effect on the smooth muscles located in the lower part of the urinary channel. When the medication is used, the aim is to relieve spasms and contractions in the walls of the channel, which may help the tunnel widen slightly and make it easier for the stone to progress toward the bladder. This process generally covers a maximum period of 3 to 4 weeks. If the stone does not pass during this period, if severe pain cannot be controlled, or if swelling develops in the kidney at a level that may cause permanent damage, other treatment methods should be initiated without delay.

The characteristics of stones that have a relatively high likelihood of passing with medication and may be observed are as follows:

• Stones smaller than five millimeters
• Stones up to a maximum of ten millimeters
• Stones located close to the lower part of the urinary channel
• Stones with smooth surfaces
• Stones that have not caused infection
• Stones that do not impair kidney function

How Are Kidney and Urinary Tract Stones Broken Using External Shock Waves?

The idea of eliminating stones without the need for surgical intervention and without making any incision or opening in the patient’s body created a major revolution in medicine years ago. In this method, called SWL (Shock Wave Lithotripsy treatment), high-energy shock waves are generated by a special device outside the patient’s body. Because there is a sound in the environment, patients also refer to them as sound waves. These waves pass through the skin, muscles, and other soft tissues without causing any damage and release their energy only when they strike a hard object, namely the stone. This focused energy repeatedly strikes the stone, aiming to crush it until it becomes small granules or millimetric fragments. In the days following the procedure, patients pass these crushed particles through their urine.

This method is generally a first option for patients with stones located inside the kidney or urinary channel, mostly smaller than 2 centimeters and not very dense, regardless of location. However, like every technology, it also has limitations. Stones found to be very hard on tomography may resist these sound waves and fail to break. If the patient is very overweight, the shock waves may not pass through the thick fatty tissue and reach the stone with sufficient power. In addition, if the stone is located in the lower chambers of the kidney or in chambers with narrow openings, even if it breaks, the fragments may remain at the bottom of the kidney because they cannot climb against gravity into the channel or pass through the narrow areas. It is also not a good treatment choice for pregnant patients because it may harm the baby, or for patients using blood thinners because it may cause serious bleeding. Similarly, it is not preferred in patients with infection because it may cause the infection to enter the bloodstream and lead to serious health problems. In such cases, other minimally invasive surgical methods should be considered.

The situations that make shock wave treatment of kidney and urinary tract stones difficult and in which it should not be preferred are as follows:

• Severe obesity
• Very hard stone structure
• Location in the lower chamber of the kidney
• Anatomical narrowing in the urinary tract
• Pregnancy
• Active urinary tract infection
• Bleeding disorders and use of blood-thinning medication

How Is Minimally Invasive Kidney and Urinary Tract Stone Surgery Performed with Laser Technology?

In cases where sound waves are insufficient or when stones remain lodged in the urinary channel, flexible camera instruments and laser systems, one of the finest examples of advanced medical technology, come into play. This procedure, performed entirely through natural pathways without making any opening in the body, is called Retrograde Intrarenal Surgery (RIRS). The instruments used in this procedure are called flexible ureteroscopes. After the patient is anesthetized, these extremely thin, flexible fiber-optic camera systems, whose tips can bend in every direction like a snake, are advanced through the urinary opening, moved upward along the urinary channel, and entered into the kidney, making it possible to visually identify stones even in the most remote chambers of the kidney.

When the stone is encountered, a laser fiber passed through this extremely thin instrument is brought into contact with the stone. Although it varies according to the chemical structure of the stone, the laser energy can generally break it into small fragments or turn it into dust within a short time. These fragments are then grasped and removed using microscopic opening and closing nets called “baskets.” The greatest advantages of minimally invasive laser kidney stone surgery include generally mild postoperative pain, a low risk of tissue damage, and the fact that most patients can be discharged on the day of the procedure or the following day and return to their daily lives. The emergence of disposable devices that do not carry the concern of breaking or malfunctioning, instead of reusable devices that were repeatedly sterilized in the past, makes it possible to push the technique even in difficult stones and increase success. In addition, newly developed vacuum systems have made it possible to suction out all stone fragments from the body.

The advantages of minimally invasive laser surgery for kidney and urinary tract stones are as follows:

• No incision in the body
• Rapid return to daily life
• Ability to break very hard stones
• Ability to perform the procedure even in patients using blood thinners due to the low risk of bleeding
• Access to all kidney chambers
• Low pain level
• Short hospital stay

Which Surgical Method Is Used to Remove Very Large Kidney and Urinary Tract Stones?

Sometimes stones grow so insidiously inside the kidney for such a long time that they fill all the renal pelvises and chambers, taking on the shape of a tree branch or deer’s antler. Because turning huge stone masses larger than 1.5 cm in the lower chamber of the kidney and over 2 centimeters in all other locations into dust using laser alone may take a long time, and because there is a possibility of infection developing in the body from the kidney during this process, RIRS is generally not preferred for large stones. The standard and safest method for these large-volume stones is a procedure performed by creating an opening from the back, called Percutaneous Nephrolithotomy surgery. In this procedure, a thin tunnel only as thick as a pencil is created from the patient’s back toward the kidney.

Through this small tunnel, the kidney is entered using special camera-equipped instruments, and those huge stones are rapidly broken using pneumatic or ultrasonic lithotripters or a laser device. The fragmented stones are then removed through the same opening in a short time using a vacuum system, special forceps, or by allowing them to flow out on their own. This surgery, which could previously involve significant bleeding, has become quite safe today due to the reduction in instrument diameters and the increase in knowledge and skill. The smaller the instruments become, the less damage is caused to kidney tissue, and the faster the patient’s recovery process becomes. With this method, the kidney can be completely cleared of very large stone burdens quickly and in a single session. This procedure can be performed in the prone or supine position. Since a flexible ureteroscope can also be used when performed in the supine position, success is much higher in these combined surgeries, known as Endoscopic Combined Intrarenal Surgery, especially for complicated and high-volume stones.

The types of kidney and urinary tract stone surgery performed by creating an opening on the side of the body close to the back are as follows:

• Standard percutaneous
• Mini percutaneous
• Ultra-mini percutaneous
• Micro-percutaneous

How Is the Treatment of Kidney and Urinary Tract Stones Planned in Pregnant Women and Children?

Pregnancy is a very sensitive period during which countless hormonal and anatomical changes occur in the expectant mother’s body. The growth of the baby in the womb causes the uterus to enlarge and naturally puts external pressure on the urinary channels. While this physiological condition already creates mild swelling in the kidneys, the situation becomes quite complex if a stone is also present. In order to protect the baby from radiation, X-rays or tomography are not used unless absolutely essential except in special circumstances; diagnosis is made either with ultrasound or MRI. Since these methods provide indirect information, the physician’s experience is important in diagnosis. The aim of treatment is definitely not to harm the baby. Therefore, instead of treatments such as shock wave therapy and percutaneous nephrolithotomy, placing a temporary soft plastic tube in the channel to ensure urine flow or eliminating the stone through a laser-assisted procedure called RIRS relieves the kidney and may allow the main procedure to be postponed until after delivery when necessary.

Stone disease in children requires a much more different and meticulous approach compared with adults. If a stone has formed in a child, there is a much greater likelihood that an inherited enzyme deficiency, a structural disorder of the kidneys and urinary tract, or a metabolic disorder lies behind it rather than environmental factors. Therefore, every stone case in children must be investigated from multiple dimensions. It is vitally important not to damage those small and delicate developing kidneys during surgery. When surgery is required, the aim is to resolve the problem carefully using specially designed miniature cameras and laser systems that are much thinner and more delicate instead of standard instruments.

The main factors examined when investigating kidney and urinary tract stones in children are as follows:

• Familial genetic inheritance
• Congenital kidney anomalies
• Urinary tract infections
• Metabolic enzyme deficiencies
• Dietary habits
• Daily fluid intake amount

Which Tests Should Be Performed to Prevent the Formation of Kidney and Urinary Tract Stones?

The greatest misconception that physicians and patients frequently fall into during stone treatment is thinking that the disease is over when the stone is completely removed from the kidney or expelled from the body. However, surgical intervention only eliminates the current result; it does not correct the actual cause that formed the stone, namely the abnormal chemical balance in the body. If this underlying disorder is not identified and corrected, stones will continue to form repeatedly in a very large proportion of patients over the following years. We call the preventive medicine strategies applied to break this vicious cycle and prevent recurrence a detailed metabolic evaluation.

The most valuable test applied especially for high-risk patients, such as young stone patients, those with a frequent family history of the disease, individuals with both kidneys prone to stones, or those with a single kidney containing a stone, is the “24-hour urine analysis.” After a stone-free period of approximately one month, the patient is asked to collect all urine produced over a full day in a special container. The amounts of calcium, uric acid, oxalate, citrate, and magnesium in this urine are measured in the laboratory. In this way, we can clearly determine what is being excessively excreted in the patient’s urine and which protective substance that prevents stone formation is deficient. According to this patient-specific biochemical map, a completely individualized dietary program and preventive medication treatments, if necessary, are initiated.

The patient groups considered at high risk for kidney and urinary tract stones are as follows:

• Those who develop stone disease in childhood or at a young age, especially before the age of 20–25
• Those with recurrent stone disease
• Those with stones in both kidneys
• Patients with a single kidney
• Those with a family history of recurrent or chronic stone disease
• Those who have undergone gastrointestinal surgery or have intestinal absorption disorders
• Those who frequently experience urinary tract infections or are diagnosed with infection stones
• Those with a special stone type such as cystine, uric acid, or infection stones
• Those diagnosed with kidney calcification/nephrocalcinosis
• Those with metabolic diseases such as hyperparathyroidism, gout, obesity, metabolic syndrome, or renal tubular acidosis
• Those with congenital or acquired anatomical abnormalities of the urinary tract
• Those who remain immobile for a long time or have neurological conditions such as spinal cord injury

What Should Be Considered in Nutrition to Prevent the Recurrence of Kidney and Urinary Tract Stones?

No matter how successful medications or surgeries are, the ultimate solution and strongest protection against kidney stone disease lie in the patient’s lifestyle and kitchen. Completely reorganizing dietary habits is the first step in protecting kidney health. At the heart of this process, unquestionably, is water consumption. Spreading fluid intake throughout the day and ensuring that the urine color always remains pale yellow or clear like water continuously flushes the kidneys and prevents crystals from precipitating. Water should be considered like a medication and consumed at regular intervals, not only when thirsty.

In addition, salt consumption is the greatest hidden enemy of kidney stones. Every extra grain of salt added to food pushes calcium that would otherwise be reabsorbed from the kidneys into the blood toward the urine. Increased calcium in the urine directly means a new stone. Another major dietary mistake is completely removing foods such as milk, yogurt, and cheese from the diet with the belief that calcium causes stones. On the contrary, calcium obtained from food remains in the intestines, binds oxalate, the other building block of the stone, and allows it to be excreted in the stool. One of the common mistakes made by patients with calcium stones is completely eliminating calcium-containing foods. However, calcium obtained through the diet binds oxalate in the intestine and reduces oxalate absorption. If calcium intake is unnecessarily reduced too much, more oxalate may be absorbed from the intestine, and this may increase oxalate excretion in the urine, thereby raising the risk of calcium oxalate stones. Therefore, what should be done is not to completely eliminate calcium, but to maintain adequate and balanced calcium intake while avoiding excessive consumption of foods rich in oxalate.

Foods rich in oxalate do not have to be completely prohibited; however, especially in patients who frequently form stones or who are found to have high oxalate levels in the urine, the portions of these foods should be reduced and, if possible, consumed together with calcium-containing foods.

In addition, frequent consumption of sugary and carbonated beverages, especially cola-type drinks and foods high in sugar, may also have a negative effect on stone formation. High salt consumption, excessive animal protein intake, insufficient water intake, and excess weight are also important factors that increase the risk of stone disease. Obesity and metabolic syndrome may increase the risk of uric acid and calcium stones in particular by affecting the acid-base balance of the urine and the excretion of certain minerals. Therefore, abundant fluid intake, reducing salt, balanced nutrition, weight control, and regular physical activity are among the fundamental preventive approaches for stone patients.

Foods rich in oxalate that may trigger the formation of kidney and urinary tract stones are as follows:

• Spinach
• Chard
• Beetroot
• Cocoa / Chocolate
• Black tea
• Nuts (Hazelnuts, Walnuts, Almonds, Cashews)
• Okra
• Certain legumes

Frequently Asked Questions