Urolithiasis (Kidney Stone Disease) – a chronic condition characterized by metabolic disorders that lead to the formation of stones in the kidneys and urinary tract, composed of urinary components. It is one of the most common diseases of the kidneys and urinary system. Urolithiasis accounts for 32–40% of all urological pathologies and ranks second after infectious and inflammatory diseases.
Urolithiasis can occur at any age but is most commonly diagnosed during working age (20–55 years). In children and the elderly, primary detection is very rare. Men are three times more likely to develop the disease than women, although staghorn calculi are more frequently found in women (up to 70%). In most cases, stones form in one kidney, but in 9–17% of patients the disease is bilateral.
Urolithiasis. Causes
Currently, there is no single theory explaining the causes of urolithiasis. It is a multifactorial disease with complex mechanisms and various chemical forms. The main underlying mechanism is believed to be a congenital metabolic disorder that causes the formation of insoluble salts, which crystallize into stones. However, even with a genetic predisposition, the disease will not develop without contributing factors.
According to their chemical composition, urinary stones are classified as oxalates, phosphates, urates, carbonates, and more rarely – cystine, xanthine, protein, or cholesterol stones. Typically, no more than three minerals are present in stone formation, while others appear as impurities. Stones also contain organic substances and usually have a layered structure. They may be single or multiple.
The formation of urinary stones is based on the following metabolic disorders:
- hyperuricemia (elevated uric acid levels in the blood)
- hyperuricosuria (elevated uric acid in the urine)
- hyperoxaluria (elevated oxalate levels in the urine)
- hypercalciuria (elevated calcium salts in the urine)
- hyperphosphaturia (elevated phosphate salts in the urine)
- changes in urine acidity
Some researchers emphasize external environmental factors (exogenous causes), while others focus on internal (endogenous) factors, though in most cases both interact.
Exogenous Causes of Urolithiasis:
- climate
- geological composition of the soil
- chemical composition of water and flora
- dietary and hydration habits
- lifestyle (sedentary behavior, lack of activity)
- occupational conditions (hazardous industries, hot workshops, heavy physical labor, etc.)
Diet and hydration habits – excessive intake of animal protein, salt, calcium-rich foods, oxalic and ascorbic acids, and a deficiency of vitamins A and B – play a significant role in the development of urolithiasis.
Endogenous Causes of Urolithiasis:
- infections of the urinary tract and other organs (tonsillitis, furunculosis, osteomyelitis, salpingo-oophoritis)
- metabolic diseases (gout, hyperparathyroidism)
- enzyme deficiencies or hyperactivity
- severe trauma or prolonged immobilization
- diseases of the gastrointestinal tract, liver, and biliary system
- hereditary predisposition to kidney stone formation
- gender and age factors: men are affected three times more often than women
In addition to general internal and external causes, local abnormalities of the urinary tract (such as developmental defects, accessory vessels, or strictures) play a key role in stone formation.
Kidney stones may be single or multiple (up to 5000 stones). Their size varies greatly – from 1 mm to giant stones over 10 cm and weighing up to 1000 g.
The disease can be asymptomatic or manifest as pain of varying intensity in the lumbar region or as renal colic.
Urolithiasis. Symptoms
Pain in the Lumbar Region
The pain may be constant or intermittent, dull or sharp. Its intensity, location, and radiation depend on the stone’s size and position, the degree of obstruction, and the individual anatomy of the urinary tract.
Large pelvic or staghorn stones are immobile and cause dull, persistent pain in the lumbar area. Pain is often associated with movement, vibration, driving, or physical exertion.
Renal Colic
Renal Colic (RC) – an episode of acute pain in the lumbar region caused by obstruction of the upper urinary tract. Typically, renal colic occurs when a stone migrates from the kidney’s calyx or pelvis into the ureter. The mechanism: blockage of urine outflow increases intrapelvic pressure, leading to impaired microcirculation, venous congestion, and irritation of sensory nerve receptors in the renal hilum and fibrous capsule. This results in a characteristic severe pain attack.
More detailed information about symptoms and first aid for renal colic can be found in the article Renal Colic.
Cases of Renal Colic Not Related to Urolithiasis
It should be noted that 13% of all patients with renal colic suffer from other kidney or ureteral diseases (tumors, tuberculosis, hydronephrosis, ureteral-vascular conflict, retroperitoneal fibrosis). These are often associated with the passage of blood clots, pus, or mucus obstructing the urinary tract. Colic of renal origin is considered one of the most intense types of pain and requires urgent first aid, prompt diagnosis, and treatment.
Other Associated Symptoms
Among general symptoms, signs of intoxication come to the forefront: nausea, vomiting without relief; due to intestinal paresis, gas passage becomes difficult. Depending on the site of obstruction, false urges to defecate or urinate may occur. Low-grade fever (37.1 – 37.5 ℃), decreased heart rate, and slight blood pressure elevation are possible. If a stone injures the ureteral wall or renal pelvis, urine may appear pink or red. Pain can last for several hours or even days, intermittently subsiding.
Urolithiasis. Diagnosis
The manifestations of urolithiasis may mimic those of other abdominal or retroperitoneal diseases. Therefore, a urologist must first exclude acute abdominal conditions such as appendicitis, intrauterine or ectopic pregnancy, gallstone disease, peptic ulcer, etc., sometimes in collaboration with physicians of other specialties. Consequently, establishing the diagnosis of urolithiasis can be challenging and time-consuming and includes the following steps:
1. Examination by a Urologist with detailed medical history taking to identify the etiopathogenesis of the disease and correct metabolic and related disorders for prevention and relapse prophylaxis. Key points include:
- occupation
- onset time and disease progression
- previous treatments
- family medical history
- dietary habits
- presence of Crohn’s disease, intestinal surgeries, or metabolic disorders
- medication history
- presence of sarcoidosis
- presence and course of urinary tract infection
- urinary tract anomalies or prior surgeries
- history of trauma or immobilization
2. Stone Visualization:
- Ultrasound of the kidneys and urinary tract
Image. Stone in the lower third of the right ureter
Image. Stone in the upper third of the ureter
- Plain and excretory urography or spiral CT scan
Image. Plain urography – stone in the right kidney
Excretory urography – stone in the upper third of the left ureter, obstructed left kidney
Image. Bilateral nephrolithiasis.
3. Clinical Analysis of blood and urine, including urine pH. Biochemical tests of blood and urine.
4. Urine Culture for microflora and antibiotic sensitivity testing.
5. If necessary, calcium loading tests (differential diagnosis of hypercalciuria) and ammonium chloride tests (diagnosis of renal tubular acidosis) are performed, as well as parathyroid hormone assessment.
6. Stone Analysis (if available).
7. Biochemical and radioisotope tests of renal function.
8. Retrograde ureteropyelography, ureteropyeloscopy, pneumopyelography.
Image. Antegrade ureteropyelography – stone in the left pyeloureteral segment.
9. Stone Density Measurement by Tomography (used to predict lithotripsy effectiveness and prevent possible complications).
Urolithiasis. Possible Complications
Prolonged presence of a stone without signs of spontaneous passage leads to progressive impairment of urinary tract and kidney function, eventually resulting in kidney failure.
The most common complications of urolithiasis include:
- Chronic inflammation at the stone site or within the kidney (pyelonephritis, cystitis), which may worsen under adverse conditions (hypothermia, respiratory infections), causing acute pyelonephritis or acute cystitis
- Acute pyelonephritis may lead to paranephritis, formation of renal abscesses (apostematous pyelonephritis), carbuncle or kidney abscess, papillary necrosis, and eventually – sepsis (fever), which requires surgical intervention
- Pyonephrosis – the terminal stage of purulent-destructive pyelonephritis. The kidney becomes a structure transformed by purulent melting, consisting of multiple cavities filled with pus, urine, and tissue debris
- Chronic pyelonephritis leads to rapidly progressive chronic renal failure and, ultimately, nephrosclerosis
- Acute renal failure occurs rarely, usually due to obstructive anuria in patients with a single kidney or bilateral ureteral stones
- Anemia develops as a result of chronic blood loss (hematuria) and impaired renal hematopoietic function
Urolithiasis. Treatment
Since the exact causes of urolithiasis remain unclear, removal of a stone from the kidney or urinary tract does not yet mean complete recovery. General treatment principles include two main directions: destruction and/or elimination of the calculus and correction of metabolic disorders. Additional measures include improving renal microcirculation, maintaining adequate hydration, sanitizing the urinary tract from infection and residual stones, diet therapy, physiotherapy, and sanatorium-resort treatment.
After diagnosis, determination of stone size and location, assessment of urinary tract patency and kidney function, as well as taking into account comorbidities and prior treatments, the optimal method of eliminating the stone is selected.
Methods of Stone Elimination:
- conservative treatments promoting stone passage in small calculi
- symptomatic therapy, commonly used during renal colic
- surgical removal of the stone or nephrectomy with the stone
- pharmacological litholysis
- “local” litholysis
- instrumental extraction of ureteral stones that have descended
- percutaneous stone removal through extraction (litholapaxy) or contact lithotripsy
- ureterolitholapaxy, contact ureterolithotripsy
- extracorporeal shock wave lithotripsy (ESWL)
All the above methods of treating urolithiasis are complementary rather than competitive and may be used together. The development and implementation of extracorporeal shock wave lithotripsy (ESWL), along with high-quality endoscopic technology and instruments, became revolutionary milestones in urology at the end of the 20th century. These innovations laid the foundation for minimally invasive and low-trauma urology, which continues to advance successfully across medical disciplines and has reached its peak with robotic and telecommunication technologies.
Minimally invasive methods of treating urolithiasis have fundamentally changed the mindset of urologists: regardless of the size, location, or “behavior” of the stone, the patient should – and can – be freed from it! This is entirely justified, as even small, asymptomatic calyceal stones must be removed, given the constant risk of growth and chronic pyelonephritis development.
Currently, the most widely used methods for treating urolithiasis are extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotripsy (-lapaxy) (PNL), and ureterorenoscopy (URS), which have reduced the number of open surgeries to a minimum and, in most Western European clinics, to zero.
Extracorporeal Shock Wave Lithotripsy (ESWL)
In the 1960s, scientist L.A. Yutkin developed the theory of the electrohydraulic effect, which became the basis for the method of extracorporeal shock wave lithotripsy. Shock waves are generated outside the human body and focused on the stone with a pressure of up to 1600 bar – these impacts fragment the stone.
The lithotripter breaks the stone using focused, high-intensity acoustic impulses. Acting on the stone’s heterogeneous structure, complex stress fields create cracks and destroy it.
For targeting and focusing, X-ray imaging is used, often enhanced by ultrasound guidance on many lithotripter models. Extracorporeal lithotripsy is so minimally invasive that it is performed on an outpatient basis (Lopatkin N.A. et al., 1990; Beshchliev D.A., Dzeranov N.K., 1992; Trapeznikova M.F. et al., 1992). Many studies have proven the method’s advantages not only over open surgery but also over percutaneous puncture nephrolithotripsy (Ramadan Salaheddin, 1992; Stepanov V.L. et al., 1993).
Percutaneous Nephrolitholapaxy (PNL)
Since Goodwin et al. first performed kidney puncture in 1955 and Harris et al. used a bronchoscope for nephroscopy in 1975, rapid technological advances have led to a dramatic improvement in endourological treatment methods. Today, PNL is a minimally invasive procedure for removing kidney stones and a low-trauma alternative to open surgery.
Standard percutaneous nephrolitholapaxy is performed under general anesthesia and takes from 40 minutes to 4 hours depending on stone location, size, and structure. The surgeon makes a small incision (0.5 – 1.3 cm) in the lumbar area. A needle is inserted into the renal pelvis under X-ray and ultrasound guidance for precision. The puncture tract is gradually dilated to the necessary size to insert a nephroscope, which provides optical visualization of the renal cavity. Through the nephroscope, an ultrasound or laser probe is introduced for fragmenting large kidney stones. Fragments are then removed, and a nephrostomy tube is placed to drain the kidney for the first 24 hours after surgery. In some cases, a ureteral stent is installed.
Percutaneous Nephrolitholapaxy (Postoperative Care)
After standard PNL, the patient remains in the hospital for 5–6 days. During this period, follow-up examinations are performed to detect residual stones. If present, a repeat nephroscopy is performed through the nephrostomy drain no earlier than 2–3 days after the first procedure. Once the kidney is stone-free, the tube is removed, and the patient is discharged. PNL effectiveness is over 98% for renal stones and 88% for ureteral stones.
Ureterorenoscopy. Contact Lithotripsy
Ureterorenoscopy is an endoscopic examination of the upper urinary tract performed by inserting a ureterorenoscope through the urethra, bladder, and ureteral orifices into the renal cavity. Modern rigid and flexible ureterorenoscopes are very thin (average diameter 7.5 F). At the beginning of the procedure, a guidewire is inserted to straighten the ureter, allowing the scope to advance without additional dilation. This wire facilitates scope insertion and enables ureteral stent placement at the end of surgery, completely eliminating trauma to the urinary tract.
To remove stones from the middle and lower calyces of the kidney, flexible ureteroscopes are used, which require prior installation of special sheaths (long hollow tubes). The procedure ends with placement of a ureteral stent (typically for 7–14 days) and a urethral catheter for one day. Patients are usually discharged on the second day after surgery. Outpatient surgery is also possible.
Conservative Treatment
Drug therapy for urolithiasis aims at three main goals: preventing recurrence of stone formation, stopping the growth of existing calculi, and dissolving them (litholysis). If diet therapy proves insufficiently effective, the doctor supplements it with medications. One treatment course usually lasts about a month and may be repeated as needed under laboratory and clinical supervision.
Uric Acid Stones. Treatment focuses on normalizing purine metabolism and urine acidity. Commonly prescribed medications include Allopurinol (Allupol, Purinol) for up to one month and Blemaren for up to three months.
Calcium Oxalate Stones. Therapy involves drugs that affect calcium and oxalate metabolism: Pyridoxine (Vitamin B6), Magnesium Oxide or Aspartate, Hypothiazide, and Blemaren. Treatment usually lasts no longer than one month.
Calcium Phosphate Stones. Treatment is aimed at reducing inflammation and correcting phosphate metabolism. Antibiotics (if infection is present), Magnesium Oxide or Aspartate, Hypothiazide, herbal remedies, and Methionine are prescribed. The course usually lasts up to one month.
Cystine Stones. Therapy focuses on normalizing amino acid metabolism and lowering cystine concentration in urine. Ascorbic Acid (Vitamin C), Penicillamine, and Blemaren are commonly used. Treatment may continue for up to six months.
Thus, conservative treatment of urolithiasis involves individualized medication selection and monitoring of its effectiveness. A comprehensive, physician-supervised approach helps prevent new stone formation, slow the growth of existing ones, and avoid complications without surgical intervention.
Urolithiasis. Prevention and Metaphylaxis
Preventive therapy aimed at correcting metabolic disorders is prescribed based on diagnostic findings. The number of treatment courses per year is determined individually under medical and laboratory supervision. Without prevention, within five years, half of the patients who had their stones removed by any treatment method will experience recurrence. Patient education and preventive measures should begin immediately after spontaneous passage or surgical removal of the stone.
- Lifestyle. Regular physical activity is an important part of prevention, especially for sedentary individuals. However, untrained people should avoid excessive exercise. Alcohol consumption and frequent emotional stress are not recommended. In overweight patients, reducing calorie intake significantly lowers the risk of stone formation.
- Increased Fluid Intake. This is essential for all patients with urolithiasis. When urine density is below 1.015 g/L, the risk of stone formation decreases significantly. Active diuresis promotes elimination of fine particles and sand. The optimal urine volume is at least 2 liters per day.
- Calcium Intake. For calcium oxalate stones, increased calcium consumption helps reduce oxalate excretion, decreasing the risk of crystal formation and new stones.
- Fiber Intake. Also recommended for calcium oxalate stones. The diet should include more fruits and vegetables while avoiding foods high in oxalates.
- Vitamin C Intake. Up to 4 g per day can be consumed safely. Higher doses may convert ascorbic acid into oxalic acid, increasing kidney load and oxalate excretion.
- Protein Reduction. Excessive animal protein increases calcium and oxalate excretion while lowering citrate levels and urine pH. For calcium oxalate stones, protein intake should be limited to about 1 g per kg of body weight per day.
- Thiazide Use. Prescribed for hypercalciuria (excessive calcium excretion). Common medications include hypothiazide, trichlorthiazide, and indapamide. Possible side effects: masking hyperparathyroidism, development of diabetes or gout, and erectile dysfunction.
- Orthophosphates. There are acidic and neutral forms that reduce calcium absorption and excretion while increasing pyrophosphate and citrate levels, enhancing the protective properties of urine. Indicated for hypercalciuria. Possible side effects include diarrhea, abdominal cramps, and nausea. Orthophosphates are considered an alternative to thiazides but are not used in patients with urinary stones combined with infection.
- Alkaline Citrate. Reduces urine supersaturation with calcium oxalate and phosphate, inhibits crystal growth and aggregation, and lowers uric acid concentration. Indicated for calcium stones and hypocitraturia.
- Magnesium. Recommended for calcium oxalate stones, particularly in patients with hypomagnesiuria. Possible side effects: diarrhea, fatigue, drowsiness, and central nervous system disturbances. Magnesium salts are used only in combination with citrates.
- Glycosaminoglycans. These substances inhibit calcium oxalate crystal growth and are used as adjunctive therapy in calcium oxalate stones.
Treatment of Urolithiasis at New Life Clinic
The facilities of our clinic allow us to provide advanced treatment for such a common urological condition as urolithiasis. Good health is not defined by the number of stones in the body – quite the opposite. The time has come not to collect stones, but to get rid of them. There are many ways to do so.
Our outpatient shock wave lithotripsy and minimally invasive laser lithotripsy of the kidneys and ureters using a thin endoscopic instrument make it possible to fragment and completely remove stones from the urinary tract. This allows patients to return to normal life in record time after the procedure, without any external signs of surgery.
