Materiały źródłowe

• #1 EAU Guidelines on Urolithiasis – Uroweb

  https://uroweb.org/guidelines/urolithiasis/chapter/bladder-stones

  Bladder stones constitute only approximately 5% of all urinary tract stones yet are responsible for 8% of urolithiasis-related mortalities in developed nations. The aetiology of bladder stones is typically multi-factorial. Bladder stones can be classified as primary, secondary, or migratory. Primary or endemic bladder stones occur in the absence of other urinary tract pathology, typically seen in children in areas with poor hydration, recurrent diarrhoea, and a diet deficient in animal protein. Secondary bladder stones occur in the presence of other urinary tract abnormalities, which include bladder outlet obstruction (BOO), neurogenic bladder dysfunction, chronic bacteriuria, foreign bodies (including catheters), bladder diverticula, and bladder augmentation or urinary diversion. In adults, BOO is the most common predisposing factor for bladder stone formation and accounts for 45-79% of vesical calculi. Migratory bladder stones are those that have passed from the upper urinary tract where they formed and may then serve as a nidus for bladder stone growth. A wide range of metabolic urinary abnormalities can pre-dispose to calculi anywhere in the urinary tract. There is a paucity of studies on the specific metabolic abnormalities that predispose to bladder stones. Bladder stones will form in 3-4.7% of men undergoing surgery for benign prostatic obstruction (BPO), 19-39% and 36-67% of motor-incomplete and motor-complete spinal cord injury patients, respectively, and 2.2% of patients with long-term catheters. It is therefore likely that patients with these conditions who form bladder stones also have an abnormal urine composition which predisposes them to bladder stone formation. The metabolic abnormalities which predispose patients to form secondary bladder stones are poorly understood. Low urine volume (poor hydration) is the most consistently demonstrable abnormality. The aetiology is most likely quite different in children than in adults. The incidence of vesical calculus formation after bladder augmentation is 2-44% in adults, and 4-53% in children. The risk of bladder stone formation in spinal cord injury, bladder augmentation or continent urinary diversion patients is reduced by performing regular bladder irrigation.

• #1 Bladder Stones – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441944/

  Bladder stones are solid calculi that are formed primarily in the urinary bladder. […] Bladder stones account for about 5% of all urinary stones and usually occur due to urinary stasis, as seen in conditions such as benign prostatic hyperplasia (BPH) or neurogenic bladder. However, they can also form in healthy individuals without anatomical defects, foreign bodies, strictures, or infections. […] Urinary stasis, such as that seen in BPH or neurogenic bladder disorder, is the primary cause of bladder calculi. […] Most of these stones are newly formed in the bladder, although some may originate in the kidneys as a calculus or a sloughed papilla. […] Bladder outlet obstruction, most commonly due to BPH, is the leading risk factor for bladder stones, accounting for 45% to almost 80% of such cases.

• #1 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Bladder stone pathogenesis is likely multifactorial with multiple lithogenic factors, including metabolic abnormalities and urinary stasis due to BOO. Thus, despite findings of differences in 24-hour urine metabolic studies between men with BOO secondary to BPH with and without bladder calculi, further prospective analyses are needed to establish an exact causal mechanism for stone formation.

• #1 Urolithiasis: Mechanism of stone formation, diagnostic modalities and treatment protocols – IJCAAP

  https://www.ijcap.in/html-article/23358

  Kidney stone pathogenesis, also known as biomineralization, is a complicated biochemical process that is still poorly understood. The biological process of renal stone development includes urine supersaturation and physicochemical alterations. A solution is said to as supersaturated if it has more dissolved material in it than the solvent could normally dissolve. Supersaturation causes solutes to precipitate in urine, which triggers nucleation and the formation of crystal concretions. In other words, crystallization happens when two ions’ concentration in a solution is higher than their saturation point. The pH and particular quantities of excess chemicals have an impact on the transition from a liquid to a solid phase. Risk factors for crystallization include low urine volume and the amount of urinary saturation with regard to the components that form stones, such as calcium, phosphorus, uric acid, oxalate, and cystine. Thus, the kinetics of a supersaturated solution which includes the rates of nucleation or crystal growth and thermodynamics, which causes nucleation, are what drive the crystallization process. Therefore, avoiding supersaturation can help prevent lithiasis.

• #1 Bladder Stones in Dogs: Causes, Symptoms, & Treatment

  https://lbah.com/canine/dog-bladder-stones/

  pH is an indicator of acidity by measuring the hydrogen ion concentration. A pH of 7 is neutral. Below 7 is acidic, above 7 is alkaline. As a general rule, dogs tend to have an acidic urine. Some uroliths have a propensity to form in acidic urine, while others tend to form in alkaline urine. Urine pH needs to be measure immediately upon voiding from the bladder for it to be accurate. […] Some uroliths form due to the presence of bacteria in the urine, so control of these bacteria is important. Bacteria are diagnosed by culturing the urine during a sterile urinalysis, or by culturing the inside of a stone after surgical removal. […] Liver shunts (Porto-Systemic Shunt- PSS) are an abnormality of blood flow to the liver. Blood that would normally flow through the liver now bypasses the liver. One of the many consequences of this disease is the formation of ammonium urate bladder stones.

• #1 The association between bacteria and urinary stones

  https://atm.amegroups.org/article/view/12906/html

  Urinary stone disease (USD) is an increasing clinical problem in both children and adults. […] Bacteria have long been recognized to contribute to struvite urinary stones; however, the role of bacteria in the development of the more common calcium oxalate (CaOx) and calcium phosphate (CaPhos) stones has not been extensively investigated. […] Whether these bacteria are causal, disease modifying or passively present remains to be determined. However, initial exploration of underlying mechanisms for this association indicate that bacteria aggregate selectively to crystals, that their presence is associated with increased clumping of crystals, and that they stimulate incorporation of proteins into the stone matrix. […] The bacterial contribution to USD formation has long been recognized. Magnesium-ammonium-phosphate (struvite) stones (a conglomeration of bacteria, crystals and protein matrix) form due to urinary tract infection (UTI) with urease-producing bacteria.

• #1 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Despite the association of urinary stasis and bladder calculi, these stones develop in only 3% to 8% of men with urinary stasis and BOO due to BPH. […] Therefore, we hypothesized that there is also an element of underlying metabolic abnormalities in the minority of patients with BOO in whom bladder calculi develop. […] Patients with bladder stones were significantly more likely to have a history of renal stone disease and gout than those in urinary retention alone. Furthermore, metabolic abnormalities on 24-hour urine supersaturation studies were more common in calculus cases. […] Gout, increased urinary uric acid supersaturation, and low urinary pH and urinary magnesium are associated with urinary stone disease in the assessment of upper urinary tract calculi. […] Therefore, these findings in patients with bladder stones suggest that metabolic abnormalities may contribute to the pathogenesis of bladder calculi.

• #1 Bladder Stones – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441944/

  Any nonabsorbable foreign body left in the bladder that is not spontaneously expelled will eventually develop layers of stone material and form calculus. […] A retained double pigtail stent can also form stone material if left in the urinary tract for a prolonged period. […] Radiation therapy, schistosomiasis, bladder augmentation surgery, urethral strictures, neurogenic or hypotonic bladder dysfunction, and bladder diverticula are additional risk factors for bladder stone formation. […] Neurogenic bladder, spinal cord injury, continent urinary diversions, and bladder augmentation surgery are well-established risk factors for bladder stone formation. […] Uric acid is the most common composition of bladder stones in adults, accounting for about 50% of cases. […] Other substances that can form bladder stones include calcium oxalate, calcium phosphate, ammonium urate, cystine, and calcium-ammonium-magnesium phosphate (also known as triple phosphate or struvite stones, which are always associated with infection).

• #1 Struvite stone – Symptoms, causes, treatment | National Kidney Foundation

  https://www.kidney.org/struvite-stones

  Struvite stones are caused by infections in the upper urinary tract. […] Struvite stones are caused by an upper urinary tract infection (UTI) from bacteria. Ammonia produced as a waste product by the bacteria can make the urine less acidic (or more alkaline). Struvite stones form when the urine becomes more alkaline. The main chemicals in a struvite stone include struvite (magnesium ammonium phosphate) and calcium carbon-apatite. These stones can grow quickly and become quite large. This can happen with few symptoms at first or little warning. […] In the case with struvite stones, surgical management requires complete stone removal, usually with a procedure such as PCNL.

• #1 Bladder Stones: Practice Essentials, Anatomy, Pathophysiology

  https://emedicine.medscape.com/article/2120102-overview

  Most vesical calculi formed de novo within the bladder, but some initially may have formed within the kidneys as a dissociated Randall plaque or on a sloughed papilla and subsequently passed into the bladder, where additional deposition of crystals causes the stone to grow. […] However, most renal stones that are small enough to pass through the ureters are also small enough to pass through a normally functioning bladder and an unobstructed urethra. In older men with bladder stones composed of uric acid, the stone most likely formed in the bladder. Stones composed of calcium oxalate usually originate in the kidney. […] In adults, vesical stones are most often composed of uric acid; these constitute more than 50% of cases. Less frequently, bladder calculi are composed of calcium oxalate, calcium phosphate, ammonium urate, cysteine, or magnesium ammonium phosphate (when associated with infection).

• #1 Urolithiasis in Small Animals – Urinary System – Merck Veterinary Manual

  https://www.merckvetmanual.com/urinary-system/noninfectious-diseases-of-the-urinary-system-in-small-animals/urolithiasis-in-small-animals

  The formation of ammonium urate calculi depends on the urine concentrations of urate and ammonium and on other poorly understood factors. […] The biologic mechanism responsible for decreased hepatic conversion of urate to allantoin lies not in reduced uricase activity but in reduced hepatic transport of urate; the rate of urate hepatic transport is approximately three times faster in breeds other than Dalmatians. […] Cystine is a relatively insoluble amino acid; therefore, in high concentration it may precipitate and form stones. […] Cystinuria is a lifelong defect of tubular reabsorption and cannot be cured. Cystine stones tend to recur within 1 yr without management to prevent recurrence, and they often recur despite attempts at prevention.

• #1 Medical Student Curriculum: Kidney Stones – American Urological Association

  https://www.auanet.org/meetings-and-education/for-medical-students/medical-students-curriculum/kidney-stones

  Uric acid is a product of purine metabolism and forms 7-10 percent of all urinary calculi. […] The most common risk factor for uric acid lithiasis is persistently acidic urine including the lack of a normal postprandial alkaline tide. […] Struvite stones are considered an infectious stone because they are formed specifically by urease producing organisms, the most common being Proteus mirabilis. […] As the bacteria that produce urease remain within the stone and in the urine, the urease they produce continues to cleave urea resulting in persistently alkaline urine. […] Most calcium stones will have a nidus or core of calcium phosphate which originally came from Randalls plaques. […] Calcium phosphate stones typically form in an alkaline pH of 7.2 or higher, which is a good reason to avoid prolonged overtreatment with urinary alkalinizing agents.

• #1

  https://link.springer.com/article/10.1007/s00240-012-0514-y

  Urinary stones consist of two phasesan inorganic (mineral) phase and an organic (matrix) phase. […] After osteopontin was identified as one of the matrix components, the biomolecular mechanism of urinary stone formation became clearer. Osteopontin expression is sporadically observed in normal distal tubular cells and is markedly increased in stone-forming kidneys. Calcium oxalate crystals adhering to renal tubular cells are incorporated into cells by the involvement of osteopontin. Stimulation of crystalcell adhesion impairs the opening of mitochondrial permeability transition pores (mPTP) in tubular cells and produces oxidative stress, apoptosis, and osteopontin expression. Macrophages phagocytose and digest a small amount of crystals, but many crystals aggregate into a mass containing osteopontin and epithelial cell debris and are excreted into the renal tubular lumen, becoming nuclei of urinary stones. This biomolecular mechanism is similar to atherosclerotic calcification. […] Osteopontin antibodies and cyclosporine A, which blocks the opening of mPTP, have markedly inhibited the expression of osteopontin and urinary stone formation in animal models.

• #1

  https://link.springer.com/article/10.1007/s00467-009-1116-y

  A third pathway suggests that crystals in the urine can become attached to a site of exposed crystalline deposits of interstitial calcium phosphate (termed Randalls plaque), following the loss of the normal urothelial covering of a renal papilla. […] Randall was convinced that interstitial plaque was a perquisite for stone formation and growth. […] The majority (approximately 75%) of CaOx stones are formed attached to sites of Randalls plaque and represents all ICSF patients. […] In all other types of kidney stone formers that we have studied, plugs were formed along the inner medullary collecting ducts and ducts of Bellini, which can serve as attachment sites for developing stones. […] These stones found attached to plugs extending from ducts of Bellini have never been found to be CaOx stones but, instead, have been apatite stones. […] In patients that have undergone intestinal bypass surgery for obesity and in cystinuric stone formers the stones appear to have formed in free solution.

• #1 Bladder stones – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/bladder-stones/symptoms-causes/syc-20354339

  Damaged nerves. Normally, nerves carry messages from your brain to your bladder muscles, directing your bladder muscles to tighten or release. If these nerves are damaged from a stroke, spinal cord injury or other health problem your bladder may not empty completely. This is known as neurogenic bladder. […] Bladder inflammation, sometimes caused by urinary tract infections or radiation therapy to the pelvis, can lead to bladder stones. […] Bladder catheters slender tubes inserted through the urethra to help urine drain from your bladder may cause bladder stones. So can objects that accidentally migrate to your bladder, such as a contraceptive device or urinary stent. Mineral crystals, which later become stones, tend to form on the surfaces of these devices. […] Stones that form in your kidneys are not the same as bladder stones. They develop in different ways. But small kidney stones may travel down the ureters into your bladder and, if not expelled, can grow into bladder stones.

• #1 Primary aldosteronism is associated with risk of urinary bladder stones in a nationwide cohort study | Scientific Reports

  https://www.nature.com/articles/s41598-021-86749-3

  We analyzed database from the Taiwan National Health Insurance to investigate whether primary aldosteronism (PA) increases the risk of bladder stones. […] In conclusion, PA is significantly associated with risk of bladder stones. […] A previous study suggests that recurrent calcium nephrolithiasis was likely associated with PA through increased hypercalciuria and hypocitraturia and that the status of hypersecretion of urinary calcium can be attenuated after adrenalectomy. […] Although bladder stones are uncommon in nephrolithiasis (estimated at 5%), such calculi are reported to result in multiple major complications such as acute urinary retention, dysuria, and even acute renal failure. […] Some evidence suggests that aldosterone plays a key role in urinary bladder function. Aldosterone could affect calcium-activated potassium (BK) channels, which are essential in regulating the function of urinary bladder smooth muscle by potassium depletion. Therefore, it is reasonable to suppose that PA is likely to be associated with urinary stone risk.

• #1 The Management of Urolithiasis

  https://www.uspharmacist.com/article/the-management-of-urolithiasis

  Urolithiasis is a complex, multifactorial process involving intrinsic factors (e.g., age, sex, heredity) and extrinsic factors (e.g., geography, climate, diet [i.e., oxalate-rich foods], mineral composition, water intake). […] The pathogenesis of urolithiasis is a complex biochemical process that is not fully understood. The formation of kidney stones is a biological process encompassing physicochemical changes and urine supersaturation. Supersaturation causes solutes to precipitate in urine, leading to nucleation and the formation of crystal concretions. The transformation from liquid to solid is affected by pH and specific concentrations of excess substances. The level of urinary saturation with respect to stone-forming constituents such as calcium, phosphorus, uric acid, oxalate, cystine, and low urine volume is a risk factor for crystallization. The crystallization process thus depends on the thermodynamics and kinetics of a supersaturated solution. Lithiasis can be prevented by avoidance of supersaturation. Most of the time, urolithiasis depends on the amount of imbalance between urinary inhibitors and promoters of crystallization.

• #1 The Management of Urolithiasis

  https://www.uspharmacist.com/article/the-management-of-urolithiasis

  In contrast, promoters are substances that facilitate stone formation by various means. These include cell-membrane lipids (e.g., phospholipids, cholesterol, glycolipids), calcitriol hormone enhancement via parathyroid-hormone stimulation, oxalate, cystine, calcium, sodium, and low urine volume. Among patients with recurrent stone formation, urinary oxalate excretion was found to be higher, whereas citrate excretion was lower. It has been suggested that an imbalance between urinary stone inhibitors and promoters is, in general, the cause of stone formation.

• #1 Bladder Stones – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441944/

  Stones composed primarily of calcium oxalate or calcium phosphate typically begin as renal calculi, becoming trapped in the bladder. […] An association between bladder calculi and cancer of the urinary bladder has been suggested, although this remains a controversial and unresolved issue. […] In children, the most common types of bladder stones are calcium oxalate, calcium phosphate, and possibly ammonium acid urate.

• #2 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Although minimal evidence exists, bladder calculi in men with benign prostatic hyperplasia are thought to be secondary to bladder outlet obstruction induced urinary stasis. […] In this comparative prospective analysis patients with bladder outlet obstruction and benign prostatic hyperplasia with bladder calculi were more likely to have a renal stone disease history, low urinary pH, low urinary magnesium and increased urinary uric acid supersaturation. These findings suggest that, like the pathogenesis of nephrolithiasis, the pathogenesis of bladder calculi is likely complex with multiple contributing lithogenic factors, including metabolic abnormalities and not just urinary stasis. […] The pathogenesis of bladder calculi has not been well studied. Historical reports of bladder calculi suggest an etiology of urinary stasis from BOO secondary to BPH. However, stasis was suggested as a causative mechanism for stone formation based more on observational associations.

• #2 Bladder calculus | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/bladder-calculus-1?lang=us

  Bladder calculi, commonly referred to as bladder stones, are urinary stones that are found primarily in the urinary bladder and comprise only 5% of all urinary tract stones. They can be divided into primary, secondary, and migratory stones: […] Secondary bladder stones are due to urinary stasis, including from: bladder outlet obstruction, neurogenic bladder, bladder diverticula, cystocele, foreign body, e.g.: indwelling Foley catheter, retained fragment from a removed Foley catheter, surgical sutures (nonabsorbable), bladder augmentation (not with gastric tissue), urinary diversion. […] Migratory stones are either a renal stone or a sloughed renal papilla that serves as a nidus for formation of a bladder stone. This type of stone is uncommon, as virtually any stone that can pass though the ureter, can also pass on through the urethra. A stone will stay stuck in the urinary bladder due to bladder outlet obstruction or bladder dysfunction (similarly to secondary stones), and may be laminated by material other than that of the original stone.

• #2 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Despite the association of urinary stasis and bladder calculi, these stones develop in only 3% to 8% of men with urinary stasis and BOO due to BPH. […] Therefore, we hypothesized that there is also an element of underlying metabolic abnormalities in the minority of patients with BOO in whom bladder calculi develop. […] Patients with bladder stones were significantly more likely to have a history of renal stone disease and gout than those in urinary retention alone. Furthermore, metabolic abnormalities on 24-hour urine supersaturation studies were more common in calculus cases. […] Gout, increased urinary uric acid supersaturation, and low urinary pH and urinary magnesium are associated with urinary stone disease in the assessment of upper urinary tract calculi. […] Therefore, these findings in patients with bladder stones suggest that metabolic abnormalities may contribute to the pathogenesis of bladder calculi.

• #2 Bladder stones – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/bladder-stones/symptoms-causes/syc-20354339

  Bladder stones are hard masses of minerals in your bladder. They develop when the minerals in concentrated urine crystallize and form stones. This often happens when you have trouble completely emptying your bladder. […] Bladder stones can develop when your bladder doesn’t empty completely. This causes urine to become concentrated urine. Concentrated urine can crystallize and form stones. […] Some infections can lead to bladder stones. Sometimes an underlying condition that affects the bladder’s ability to hold, store or eliminate urine can result in bladder stone formation. Any foreign materials present in the bladder tend to cause bladder stones. […] The most common conditions that cause bladder stones include: Prostate gland enlargement. An enlarged prostate (benign prostatic hyperplasia, or BPH) can cause bladder stones in men. An enlarged prostate can obstruct the flow of urine, preventing the bladder from emptying completely.

• #2 Bladder Stones: Practice Essentials, Anatomy, Pathophysiology

  https://emedicine.medscape.com/article/2120102-overview

  The most common factors that promote uric acid stone formations are persistently low urinary pH, dehydration leading to low urinary volume, and high uric acid production. Nitrogen atoms from urate interact with free protons to form uric acid, which is 20 times less soluble than urate and thus more prone to forming crystals. Low pH promotes the conversion of urate to uric acid. At persistently low pH, uric acid crystals can form and stabilize even at normal urinary urate concentrations. […] In patients with spinal cord injuries, bladder stones are often composed of struvite or calcium phosphate. […] Bladder outlet obstruction remains the most common cause of bladder calculi in adults. Prostatic enlargement, elevation of the bladder neck, and high postvoid residual urine volume cause stasis, which leads to crystal nucleation and accretion. This ultimately results in overt calculi.

• #2 Bladder Stones in Dogs: Causes, Symptoms, & Treatment

  https://lbah.com/canine/dog-bladder-stones/

  These bacteria also produce urease as a by-product of their metabolism. They split the urea in urine into ammonia and carbon dioxide. As this ammonia is broken down it changes the pH of the urine from its usual acid (pH less than 7) to alkaline (PH than 7). […] Excess struvite crystals in the urine set the stage for the formation of the urolith. […] The formation of an alkaline (pH greater that 7.0) urine from the diet, or from urease producing bacteria, will cause the struvite crystals to precipitate out of solution and begin the formation of a urolith. […] Urate stones are radiolucent. If they get large or covered with other minerals they might become radiopaque. Urate calculi tend to be small and occur as several stones. These stones usually form in the bladder, and when passed through the urethra, can become lodged.

• #2 Struvite stone – Symptoms, causes, treatment | National Kidney Foundation

  https://www.kidney.org/struvite-stones

  Struvite stones are caused by infections in the upper urinary tract. […] Struvite stones are caused by an upper urinary tract infection (UTI) from bacteria. Ammonia produced as a waste product by the bacteria can make the urine less acidic (or more alkaline). Struvite stones form when the urine becomes more alkaline. The main chemicals in a struvite stone include struvite (magnesium ammonium phosphate) and calcium carbon-apatite. These stones can grow quickly and become quite large. This can happen with few symptoms at first or little warning. […] In the case with struvite stones, surgical management requires complete stone removal, usually with a procedure such as PCNL.

• #2 Bladder Stones: Practice Essentials, Anatomy, Pathophysiology

  https://emedicine.medscape.com/article/2120102-overview

  Most vesical calculi formed de novo within the bladder, but some initially may have formed within the kidneys as a dissociated Randall plaque or on a sloughed papilla and subsequently passed into the bladder, where additional deposition of crystals causes the stone to grow. […] However, most renal stones that are small enough to pass through the ureters are also small enough to pass through a normally functioning bladder and an unobstructed urethra. In older men with bladder stones composed of uric acid, the stone most likely formed in the bladder. Stones composed of calcium oxalate usually originate in the kidney. […] In adults, vesical stones are most often composed of uric acid; these constitute more than 50% of cases. Less frequently, bladder calculi are composed of calcium oxalate, calcium phosphate, ammonium urate, cysteine, or magnesium ammonium phosphate (when associated with infection).

• #2 Struvite Bladder Stones in Dogs | VCA Animal Hospitals

  https://vcahospitals.com/know-your-pet/struvite-bladder-stones-in-dogs

  Bladder stones (uroliths or cystic calculi) are rock-like formations of minerals that form in the urinary bladder and are more common than kidney stones in dogs. One of the more common uroliths in the dog is composed of magnesium ammonium phosphate hexahydrate. The more common name for this type of bladder stone is struvite bladder stone. […] Struvite is a normal component of dog’s urine and will remain dissolved as long as the urine is acidic and is not too concentrated. If the urine becomes very concentrated, or if it becomes alkaline (opposite to acidic), struvite crystals will form. […] In dogs, struvite bladder stones usually form as a complication of a bladder infection caused by bacteria that produce an enzyme known as urease. This enzyme breaks down the urea that is normally present in urine, causing an excess production of ammonia; this ammonia production then causes the urine to become alkaline.

• #2 Bladder Stones – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441944/

  Stones composed primarily of calcium oxalate or calcium phosphate typically begin as renal calculi, becoming trapped in the bladder. […] An association between bladder calculi and cancer of the urinary bladder has been suggested, although this remains a controversial and unresolved issue. […] In children, the most common types of bladder stones are calcium oxalate, calcium phosphate, and possibly ammonium acid urate.

• #2 Urolithiasis in Small Animals – Urinary System – Merck Veterinary Manual

  https://www.merckvetmanual.com/urinary-system/noninfectious-diseases-of-the-urinary-system-in-small-animals/urolithiasis-in-small-animals

  The formation of ammonium urate calculi depends on the urine concentrations of urate and ammonium and on other poorly understood factors. […] The biologic mechanism responsible for decreased hepatic conversion of urate to allantoin lies not in reduced uricase activity but in reduced hepatic transport of urate; the rate of urate hepatic transport is approximately three times faster in breeds other than Dalmatians. […] Cystine is a relatively insoluble amino acid; therefore, in high concentration it may precipitate and form stones. […] Cystinuria is a lifelong defect of tubular reabsorption and cannot be cured. Cystine stones tend to recur within 1 yr without management to prevent recurrence, and they often recur despite attempts at prevention.

• #2

  https://link.springer.com/article/10.1007/s00467-009-1116-y

  A third pathway suggests that crystals in the urine can become attached to a site of exposed crystalline deposits of interstitial calcium phosphate (termed Randalls plaque), following the loss of the normal urothelial covering of a renal papilla. […] Randall was convinced that interstitial plaque was a perquisite for stone formation and growth. […] The majority (approximately 75%) of CaOx stones are formed attached to sites of Randalls plaque and represents all ICSF patients. […] In all other types of kidney stone formers that we have studied, plugs were formed along the inner medullary collecting ducts and ducts of Bellini, which can serve as attachment sites for developing stones. […] These stones found attached to plugs extending from ducts of Bellini have never been found to be CaOx stones but, instead, have been apatite stones. […] In patients that have undergone intestinal bypass surgery for obesity and in cystinuric stone formers the stones appear to have formed in free solution.

• #2 Bladder Stones in Dogs: Causes, Symptoms, & Treatment

  https://lbah.com/canine/dog-bladder-stones/

  There are several factor, usually working in combination, that lead to urolith formation: […] Urine that is saturated with excess amount of certain minerals is prone to form bladder stones. These minerals commonly include magnesium, phosphorous, calcium, and ammonia. Most stones consist of an organic matrix of protein surrounded by crystalline minerals. They start off as microcrystals that link together to form macrocrystals, continuing this process until the form a stone. […] Once a stone is form it can be a scaffold for other crystals to deposit on the outside, leading to a stone with mixed crystals as the cause. In the case the center of the stone (the nidus) can be different than the middle of the stone, which can be different than the outside of the stone. This is sometimes called a compound stone. As you can imagine this complicates treatment.

• #2 Recent advances on the mechanisms of kidney stone formation (Review)

  https://www.spandidos-publications.com/10.3892/ijmm.2021.4982

  Urinary supersaturation and crystallization are the driving force for intrarenal crystal precipitation and is mainly caused by inherited or acquired diseases associated with renal function impairment. […] A number of receptors or receptor-like features have been reported to play critical roles in crystal-cell interaction, which is recognized as the most important process for crystal retention in kidney. […] Kidney stones form at a foundation of CaP termed Randall’s plaques, which begins at the basement membranes of thin limbs of the loop of Henle on the renal papillary surface. […] An increasing number of studies have suggested that RPs are the origin of renal stones. […] These studies provide novel insight into the pathogenesis of RP-mediated kidney stone disease, while further studies are urgently anticipated to explore the mechanisms of RP formation, as well as additional roles of RP in the context of stone formation.

• #2 Cable Wire as a Nidus for Vesicolithiasis: A Case Report | RRU

  https://www.dovepress.com/cable-wire-as-a-nidus-for-vesicolithiasis-a-case-report-peer-reviewed-fulltext-article-RRU

  Bladder foreign bodies (BFBs) are an uncommon clinical occurrence, often resulting from trauma, self-insertion, iatrogenic causes, or organ migration. […] These objects can act as nidus for stone formation, leading to vesicolithiasis. […] The presence of foreign objects within the bladder creates a nidus for stone formation by inducing local inflammation, urinary stasis, and crystallization of urinary salts. […] Bladder stone formation in the presence of foreign bodies is a multifactorial process that involves both mechanical and biochemical pathways. Foreign bodies act as a nidus for stone formation by disrupting the normal urothelial environment. […] This leads to epithelial injury, increased mucous secretion, and the deposition of urinary salts, such as calcium oxalate, calcium phosphate, uric acid, and struvite, on the foreign body’s surface.

• #2 Bladder Stones: Practice Essentials, Anatomy, Pathophysiology

  https://emedicine.medscape.com/article/2120102-overview

  Bladder inflammation secondary to external beam radiation (ie, radiation cystitis) or schistosomiasis can also predispose to vesical calculi. […] Multiple risk factors predispose to bladder stones in pediatric patients undergoing bladder augmentation. […] Other etiologic factors for bladder stone formation include foreign bodies in the bladder that act as a nidus for stone formation. […] Metabolic abnormalities are not a significant cause of stone formation in patients with urinary diversions. In this group of patients, the stones are primarily composed of calcium and struvite. […] The findings suggest that multiple factors, including metabolic abnormalities, may contribute to the pathogenesis of bladder calculi in this setting. […] Rare cases of bladder calculi after radical prostatectomy have been reported. These calculi usually form on clips that have migrated into the bladder, but they may also develop as a result of urinary stasis due to bladder neck stenosis from hypertrophic scars. […] In general, if an otherwise healthy person in the United States or Europe is found to have a bladder stone, a complete urologic evaluation must be undertaken to find a cause for urinary stasis.

• #2 UrologySchool.com

  https://www.urologyschool.com/CNotes/Stones/lutstones.html

  Bladder stones that develop in the absence of any known functional, anatomic, or infectious factors. […] More common in children exposed to low-protein, low-phosphate diets. […] Lack of protein leads to a dietary phosphate deficiency, low urinary phosphate, and high levels of urinary ammonia. Due to this, the most common stone found in children from these areas is ammonium acid urate. […] Generally not associated with anatomic, functional, or infectious abnormalities. […] The incidence of bladder calculus after augmentation cystoplasty ranges from 10-52.5%. […] High risk of stone formation due to metabolic abnormalities, recurrent infections with urease-splitting organisms, prolonged urinary stasis and incomplete bladder emptying, prolonged exposure of urine to non-absorbable materials, anatomical changes following diversion, and reflux of mucous into the upper tract.

• #2 Primary aldosteronism is associated with risk of urinary bladder stones in a nationwide cohort study | Scientific Reports

  https://www.nature.com/articles/s41598-021-86749-3

  The findings suggest that PA contributed to bladder stone formation by the disease per se rather than other factors. […] Accumulating biologic evidence suggests that PA may play an important role in the development of nephrolithiasis. First, PA likely induces hypercalciuria through body volume expansion, which decreases both proximal tubule sodium and calcium absorption. Second, PA induces hypocitraturia. Potassium depletion in PA may induce proximal tubule intracellular acidosis and also cause hypocitraturia. These electrolyte disorders caused by PA itself could lead to the tubular abnormality which indirectly increases the formation of bladder stones. […] Taken together, our findings provide clinical evidence that patients with chronically persistent hyperaldosteronism eventually develop bladder stones.

• #2 Managing Urolithiasis in Dogs | Today’s Veterinary Practice

  https://todaysveterinarypractice.com/urology-renal-medicine/managing-urolithiasis-in-dogs/

  Similarly, once a stone is formed it can become a scaffold for deposition of a different type of crystal. This typically results in a compound stone, in which the shell is made of a different substance than the nidus. […] The exact mechanism of CaOx stone formation is unknown and is likely a combination of genetic, dietary, and environmental factors. […] Magnesium, phosphate, and citrate are inhibitors of CaOx stone formation; decreased urine concentrations of these substances may lead to CaOx precipitation. […] The propensity to form cystine stones diminishes with age, so medications may be discontinued in some older patients.

• #2 The Management of Urolithiasis

  https://www.uspharmacist.com/article/the-management-of-urolithiasis

  In contrast, promoters are substances that facilitate stone formation by various means. These include cell-membrane lipids (e.g., phospholipids, cholesterol, glycolipids), calcitriol hormone enhancement via parathyroid-hormone stimulation, oxalate, cystine, calcium, sodium, and low urine volume. Among patients with recurrent stone formation, urinary oxalate excretion was found to be higher, whereas citrate excretion was lower. It has been suggested that an imbalance between urinary stone inhibitors and promoters is, in general, the cause of stone formation.

• #2 Bladder stone – Wikipedia

  https://en.wikipedia.org/wiki/Bladder_stone

  Bladder stones are small mineral deposits that can form in the bladder. In most cases bladder stones develop when the urine becomes very concentrated or when one is dehydrated. This allows for minerals, such as calcium or magnesium salts, to crystallize and form stones. […] Bladder stones may occur whenever the kidneys, bladder, or ureters become inflamed, which may occur when the urine becomes too concentrated or when the body becomes dehydrated. Minerals such as calcium and magnesium crystallize into the stones, which then can cause such symptoms as lower back or abdominal pain or difficulty with urination. […] The use of urinary catheters may cause a bladder stone. Individuals who are paralyzed or are unable to adequately pass urine may require the use of small plastic tubes (catheters) placed into the bladder. The use of these tubes may lead to an infection, which irritates the bladder, resulting in stone formation. […] There is some evidence indicating that chronic irritation of the bladder by retained stones may increase the chance of bladder cancer.

• #2 Urolithiasis: Mechanism of stone formation, diagnostic modalities and treatment protocols – IJCAAP

  https://www.ijcap.in/html-article/23358

  Kidney stone pathogenesis, also known as biomineralization, is a complicated biochemical process that is still poorly understood. The biological process of renal stone development includes urine supersaturation and physicochemical alterations. A solution is said to as supersaturated if it has more dissolved material in it than the solvent could normally dissolve. Supersaturation causes solutes to precipitate in urine, which triggers nucleation and the formation of crystal concretions. In other words, crystallization happens when two ions’ concentration in a solution is higher than their saturation point. The pH and particular quantities of excess chemicals have an impact on the transition from a liquid to a solid phase. Risk factors for crystallization include low urine volume and the amount of urinary saturation with regard to the components that form stones, such as calcium, phosphorus, uric acid, oxalate, and cystine. Thus, the kinetics of a supersaturated solution which includes the rates of nucleation or crystal growth and thermodynamics, which causes nucleation, are what drive the crystallization process. Therefore, avoiding supersaturation can help prevent lithiasis.

• #3 Bladder Stones – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441944/

  Any nonabsorbable foreign body left in the bladder that is not spontaneously expelled will eventually develop layers of stone material and form calculus. […] A retained double pigtail stent can also form stone material if left in the urinary tract for a prolonged period. […] Radiation therapy, schistosomiasis, bladder augmentation surgery, urethral strictures, neurogenic or hypotonic bladder dysfunction, and bladder diverticula are additional risk factors for bladder stone formation. […] Neurogenic bladder, spinal cord injury, continent urinary diversions, and bladder augmentation surgery are well-established risk factors for bladder stone formation. […] Uric acid is the most common composition of bladder stones in adults, accounting for about 50% of cases. […] Other substances that can form bladder stones include calcium oxalate, calcium phosphate, ammonium urate, cystine, and calcium-ammonium-magnesium phosphate (also known as triple phosphate or struvite stones, which are always associated with infection).

• #3 Urolithiasis unveiled: pathophysiology, stone dynamics, types, and inhibitory mechanisms: a review | African Journal of Urology | Full Text

  https://afju.springeropen.com/articles/10.1186/s12301-024-00436-z

  Reduced urine volume raises the concentration of stone-causing compounds, which in turn promotes crystallization and stone formation, making urine volume a critical factor in the pathophysiology of urolithiasis. […] In individuals with risk factors for stone formation, such as high urinary supersaturation, low urinary volume, or low urinary pH, crystals may nucleate and aggregate into larger particles, potentially forming a stone. […] The initial stage of kidney stone formation is urinary supersaturation, which occurs when the concentration of certain substances in the urine, such as calcium, oxalate, and phosphate, exceeds their solubility limit. […] The process of crystallization occurs when urine becomes oversaturated, leading to the formation of solid crystals. […] The phenomenon of nucleation is a crucial aspect of crystal formation from a supersaturated solution. It involves the aggregation of solute molecules or ions to form a stable nucleus, which then serves as a basis for subsequent crystal growth.

• #3 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Despite the association of urinary stasis and bladder calculi, these stones develop in only 3% to 8% of men with urinary stasis and BOO due to BPH. […] Therefore, we hypothesized that there is also an element of underlying metabolic abnormalities in the minority of patients with BOO in whom bladder calculi develop. […] Patients with bladder stones were significantly more likely to have a history of renal stone disease and gout than those in urinary retention alone. Furthermore, metabolic abnormalities on 24-hour urine supersaturation studies were more common in calculus cases. […] Gout, increased urinary uric acid supersaturation, and low urinary pH and urinary magnesium are associated with urinary stone disease in the assessment of upper urinary tract calculi. […] Therefore, these findings in patients with bladder stones suggest that metabolic abnormalities may contribute to the pathogenesis of bladder calculi.

• #3 Struvite Bladder Stones in Dogs | VCA Animal Hospitals

  https://vcahospitals.com/know-your-pet/struvite-bladder-stones-in-dogs

  Bladder stones (uroliths or cystic calculi) are rock-like formations of minerals that form in the urinary bladder and are more common than kidney stones in dogs. One of the more common uroliths in the dog is composed of magnesium ammonium phosphate hexahydrate. The more common name for this type of bladder stone is struvite bladder stone. […] Struvite is a normal component of dog’s urine and will remain dissolved as long as the urine is acidic and is not too concentrated. If the urine becomes very concentrated, or if it becomes alkaline (opposite to acidic), struvite crystals will form. […] In dogs, struvite bladder stones usually form as a complication of a bladder infection caused by bacteria that produce an enzyme known as urease. This enzyme breaks down the urea that is normally present in urine, causing an excess production of ammonia; this ammonia production then causes the urine to become alkaline.

• #3 Bladder Stones: Practice Essentials, Anatomy, Pathophysiology

  https://emedicine.medscape.com/article/2120102-overview

  The most common factors that promote uric acid stone formations are persistently low urinary pH, dehydration leading to low urinary volume, and high uric acid production. Nitrogen atoms from urate interact with free protons to form uric acid, which is 20 times less soluble than urate and thus more prone to forming crystals. Low pH promotes the conversion of urate to uric acid. At persistently low pH, uric acid crystals can form and stabilize even at normal urinary urate concentrations. […] In patients with spinal cord injuries, bladder stones are often composed of struvite or calcium phosphate. […] Bladder outlet obstruction remains the most common cause of bladder calculi in adults. Prostatic enlargement, elevation of the bladder neck, and high postvoid residual urine volume cause stasis, which leads to crystal nucleation and accretion. This ultimately results in overt calculi.

• #3 Struvite Bladder Stones in Dogs | VCA Animal Hospitals

  https://vcahospitals.com/know-your-pet/struvite-bladder-stones-in-dogs

  Under these environmental conditions, struvite crystals will form and collect around any cells or debris that may have formed in the bladder because of inflammation. […] Other causes of alkaline urine can also predispose a dog to struvite bladder stones: certain kidney diseases, long-term use of diuretic drugs or antacids, and conditions that cause elevated urine pH, urinary phosphorus, or ammonia. […] Based on the results of tens of thousands of stone analyses, it was found that the number of struvite bladder stones has been declining in dogs while the number of calcium oxalate stones has been increasing. […] Struvite uroliths were noted to be more common in female dogs, while calcium oxalate uroliths are more common in male dogs. […] The only way to be sure that a bladder stone is made of struvite is to have the stone analyzed at a veterinary laboratory.

• #3 Urolithiasis in Small Animals – Urinary System – Merck Veterinary Manual

  https://www.merckvetmanual.com/urinary-system/noninfectious-diseases-of-the-urinary-system-in-small-animals/urolithiasis-in-small-animals

  Some mineral solutes precipitate to form crystals in urine; these crystals may aggregate and grow to macroscopic size, at which time they are known as uroliths (calculi or stones). […] Mechanisms involved in stone formation are incompletely understood in dogs and cats. However, three main contributing factors are 1) matrix – the inorganic protein core may facilitate initial urolith formation, 2) crystallization inhibitors – organic and inorganic crystallization inhibitors may be lacking or dysfunctional in animals with uroliths, and 3) precipitation crystallization factors – a complex relationship among urine solutes and other chemical factors in the urine can lead to conditions favoring crystallization. […] Regardless of the underlying mechanism(s), uroliths are not produced unless sufficiently high urine concentrations of urolith-forming constituents exist and transit time of crystals within the urinary tract is prolonged. For selected stones (eg, struvite, cystine, urate), other favorable conditions (eg, proper pH) for crystallization must also exist. These criteria can be affected by urinary tract infection, diet, intestinal absorption, urine volume, frequency of urination, therapeutic agents, and genetics.

• #3

  https://link.springer.com/article/10.1007/s00467-009-1116-y

  Kidney stone development is thought to require the formation of crystals in the tubular fluid, followed by crystal retention and accumulation in the kidney. […] The first hypothesis, termed the free particle model, states that crystal nuclei form by homogeneous nucleation in the lumen of the nephron under conditions of a phase change (increasing supersaturation) in the dissolved salts present in the ultrafiltrate. […] The second hypothesis, termed the fixed particle model, also requires crystal nuclei to form in the lumen of the nephron, and then adhere to the apical surface of the tubular epithelium. […] Once the crystalcell attachment step has occurred, the crystal nuclei would be fixed in position and exposed to the potentially supersaturated ultrafiltrate that would facilitate further growth of these crystals.

• #3 Cable Wire as a Nidus for Vesicolithiasis: A Case Report | RRU

  https://www.dovepress.com/cable-wire-as-a-nidus-for-vesicolithiasis-a-case-report-peer-reviewed-fulltext-article-RRU

  Over time, the accretion of these materials results in stone formation. […] Additionally, the presence of a foreign body may alter urinary flow, promoting urinary stasis, a key factor in the crystallization process. […] The interaction between the foreign body and urine constituents can lead to changes in chemical composition that favor stone formation. […] In this case, the foreign body, identified as a blue cable wire, served as a nucleus for bladder stone formation. […] Chronic irritation from the foreign body and subsequent stone development may have exacerbated the patient’s symptoms of hematuria, dysuria, and abdominal pain.

• #3 UrologySchool.com

  https://www.urologyschool.com/CNotes/Stones/lutstones.html

  The role of intestinal mucus in stone formation remains controversial. […] In contrast to renal stones, bladder stones in adults are usually composed of uric acid (in non-infected urine) or struvite (in infected urine). […] Calcium oxalate or cystine stones in the bladder suggests the ureteral passage of calculi originating in the kidney with subsequent entrapment in the bladder. […] No role of medical therapy in bladder stones.

• #3 Bladder stones – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/bladder-stones/symptoms-causes/syc-20354339

  Damaged nerves. Normally, nerves carry messages from your brain to your bladder muscles, directing your bladder muscles to tighten or release. If these nerves are damaged from a stroke, spinal cord injury or other health problem your bladder may not empty completely. This is known as neurogenic bladder. […] Bladder inflammation, sometimes caused by urinary tract infections or radiation therapy to the pelvis, can lead to bladder stones. […] Bladder catheters slender tubes inserted through the urethra to help urine drain from your bladder may cause bladder stones. So can objects that accidentally migrate to your bladder, such as a contraceptive device or urinary stent. Mineral crystals, which later become stones, tend to form on the surfaces of these devices. […] Stones that form in your kidneys are not the same as bladder stones. They develop in different ways. But small kidney stones may travel down the ureters into your bladder and, if not expelled, can grow into bladder stones.

• #3 Kidney stones: Mechanism of formation, pathogenesis and possible treatments

  https://www.pulsus.com/scholarly-articles/kidney-stones-mechanism-of-formation-pathogenesis-and-possible-treatments-4896.html

  The uneven proportion of inhibitors and promoters are responsible to the complex process of stone formation in kidneys or urolithiasis. Supersaturation of the urine with calcium and oxalate salts followed by crystalline particle formation is the major reason behind kidney stone formation with supersaturation being the driving force. The mechanism involved in the process of stone formation include nucleation of crystals fractions, growth or gathering of these crystals to a size so that they can interact with some intra-renal structure(s), confinement of these crystals inside the kidney or renal collecting system succeeded by further aggregation and/ or secondary nucleation ultimately forming the clinical stone. Calcium oxalate (CaOx) forms the major proportion of the kidney stones that is around 80%, while calcium phosphate (CaP) forms a small percentage (15%) of these stones. The crystals formed either in renal tubular fluid or in the renal interstitial fluid that is supersaturated with respect to these constituents, which in turn might be a consequence of reduced urine volume, an alteration in urine pH, mechanisms causing increased secretion of stone forming constituents such as hypercalciuria, hyperuricosuria, hypocitraturia, hyperoxaluria or a combination of these factors. The urine and presumably, the tubular fluid of stone formers are often more highly supersaturated than that of normal healthy adults, which favors nucleation and growth of crystals. Long-term accretion of additional elements, crystalline as well as organic matrix produces the clinical stone. As already explained extreme excretion of calcium or oxalate either alone or in combination as well as low volume of urine leads to an enhanced calcium oxalate supersaturation. The reciprocal actions between genetic susceptibility and environmental factors in different proportions promote both hypercalciuria and hyperoxaluria. A few genetic disorder which a rare autosomal recessive disorder, dietary routine including greater intake of oxalate and low calcium intake, potential abnormalities of anion transporters found in both gut and kidney, enhanced absorption of oxalate in the intestines other than mal absorptive diseases (enteric hyperoxaluria), changes in the normal flora of the gut thereby decreasing degradation of oxalate in the colon may cause one form of hyperoxaluria called primary hyperoxaluria types 1 and 2. Some rare genetic disorders such as adenine phosphoribosyltransferase (APRT) deficiency, cystinuria, and Dent disease, familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) and primary hyperoxaluria (PH) may lead to severe or chronic kidney stone diseases in children. The above mentioned processes in humans are influenced by several factors known as promoters and inhibitors that either support or prevent the process of stone formation thus affecting a persons ability to promote or prevent stone formation. Stone formation is facilitated by promoters while inhibitors prevent it. Among the promoters of calcium oxalate stones are high oxalate, sodium, calcium, urate, low urine pH and low urine volume while the inhibitors include organic substances such as nephrocalcin and urinary prothrombin fragment-1, osteopontin and various inorganic substances such as citrate, magnesium.

• #3 Urolithiasis (Urinary Tract Stones and Bladder Stones)

  https://patient.info/doctor/urinary-tract-stones-urolithiasis

  The most common cause of bladder stones is urinary stasis due to failure of emptying the bladder completely on urination, with the majority of cases occurring in men with bladder outflow obstruction. […] Approximately 5% of bladder stones occur in women and are usually associated with foreign bodies such as sutures, synthetic tapes or meshes, and urinary stasis, so bladder stones should always be considered in women investigated for irritable bladder symptoms or recurrent urinary tract infections. […] Patients with indwelling Foley catheters are also at high risk for developing bladder stones and there appears to be a significant association between bladder stones and the formation of malignant bladder tumours in these patients.

• #4 Bladder stones – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/bladder-stones/symptoms-causes/syc-20354339

  Bladder stones are hard masses of minerals in your bladder. They develop when the minerals in concentrated urine crystallize and form stones. This often happens when you have trouble completely emptying your bladder. […] Bladder stones can develop when your bladder doesn’t empty completely. This causes urine to become concentrated urine. Concentrated urine can crystallize and form stones. […] Some infections can lead to bladder stones. Sometimes an underlying condition that affects the bladder’s ability to hold, store or eliminate urine can result in bladder stone formation. Any foreign materials present in the bladder tend to cause bladder stones. […] The most common conditions that cause bladder stones include: Prostate gland enlargement. An enlarged prostate (benign prostatic hyperplasia, or BPH) can cause bladder stones in men. An enlarged prostate can obstruct the flow of urine, preventing the bladder from emptying completely.

• #4 Bladder stones – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/bladder-stones/symptoms-causes/syc-20354339

  Damaged nerves. Normally, nerves carry messages from your brain to your bladder muscles, directing your bladder muscles to tighten or release. If these nerves are damaged from a stroke, spinal cord injury or other health problem your bladder may not empty completely. This is known as neurogenic bladder. […] Bladder inflammation, sometimes caused by urinary tract infections or radiation therapy to the pelvis, can lead to bladder stones. […] Bladder catheters slender tubes inserted through the urethra to help urine drain from your bladder may cause bladder stones. So can objects that accidentally migrate to your bladder, such as a contraceptive device or urinary stent. Mineral crystals, which later become stones, tend to form on the surfaces of these devices. […] Stones that form in your kidneys are not the same as bladder stones. They develop in different ways. But small kidney stones may travel down the ureters into your bladder and, if not expelled, can grow into bladder stones.

• #4 Urolithiasis: Mechanism of stone formation, diagnostic modalities and treatment protocols – IJCAAP

  https://www.ijcap.in/html-article/23358

  The pathogenesis of kidney stone formation results from multifaceted physicochemical processes. Genetic, metabolic, environmental, and dietary factors play roles in urolithiasis pathogenesis, all predisposing to salt crystallization within renal tubules. Crystalluria is commonly observed in normal individuals, where crystals remain dispersed and are flushed out by urine flow. However, under certain chemical and electrical conditions, crystals can aggregate. Once aggregated, crystals adhere to epithelial surfaces, facilitating their growth and eventual formation into kidney stones. […] The process by which stones form in the kidneys involves crystal nucleation, growth, aggregation, and retention.

• #4 Driving Forces for Uric Acid Bladder Stones Identified – Renal and Urology News

  https://www.renalandurologynews.com/conference-highlights/aua-2019-coverage/recurrent-uric-acid-bladder-stones-factors/

  Urinary stasis and other factors appear to play a role in its pathogenesis. […] Uric acid supersaturation and elevated post void residuals are driving forces for uric acid bladder stone pathogenesis and is mitigated by compliance to urinary alkalinization. […] Uric acid bladder stones can be an indication of severe urinary metabolic derangements, Dr Chong told Renal Urology News. Patients with the diagnosis of uric acid bladder stones should have complete 24-hour urine studies to determine risk factors to mitigate and reduce risk of recurrent bladder stones. Urinary alkalization and reducing post-void residuals can be helpful in preventing future uric acid bladder stones.

• #4 Medical Student Curriculum: Kidney Stones – American Urological Association

  https://www.auanet.org/meetings-and-education/for-medical-students/medical-students-curriculum/kidney-stones

  Uric acid is a product of purine metabolism and forms 7-10 percent of all urinary calculi. […] The most common risk factor for uric acid lithiasis is persistently acidic urine including the lack of a normal postprandial alkaline tide. […] Struvite stones are considered an infectious stone because they are formed specifically by urease producing organisms, the most common being Proteus mirabilis. […] As the bacteria that produce urease remain within the stone and in the urine, the urease they produce continues to cleave urea resulting in persistently alkaline urine. […] Most calcium stones will have a nidus or core of calcium phosphate which originally came from Randalls plaques. […] Calcium phosphate stones typically form in an alkaline pH of 7.2 or higher, which is a good reason to avoid prolonged overtreatment with urinary alkalinizing agents.

• #4

  https://veterinarypartner.vin.com/doc/?id=4951352

  Struvite is the name given to the crystal composed of magnesium, ammonium, and phosphate. Struvite crystals are not unusual in normal urine, and their presence alone does not require treatment. Combine them with certain bacteria, however, and a stone is created. […] Stone creation is made possible by an enzyme called urease that certain bacteria, particularly Staphylococci and Proteus species, can produce. Urea is a substance seen in large amounts in urine. […] The combination of infection and inflammation caused by the ammonium creates a matrix that traps the struvite crystals and gels into an actual stone. This reaction can only take place in alkaline urine but the ammonium creates the perfect pH for stone formation. In dogs, the general rule is, if there is no infection, there are no struvite bladder stones.

• #4 Bladder Stones: Practice Essentials, Anatomy, Pathophysiology

  https://emedicine.medscape.com/article/2120102-overview

  The most common factors that promote uric acid stone formations are persistently low urinary pH, dehydration leading to low urinary volume, and high uric acid production. Nitrogen atoms from urate interact with free protons to form uric acid, which is 20 times less soluble than urate and thus more prone to forming crystals. Low pH promotes the conversion of urate to uric acid. At persistently low pH, uric acid crystals can form and stabilize even at normal urinary urate concentrations. […] In patients with spinal cord injuries, bladder stones are often composed of struvite or calcium phosphate. […] Bladder outlet obstruction remains the most common cause of bladder calculi in adults. Prostatic enlargement, elevation of the bladder neck, and high postvoid residual urine volume cause stasis, which leads to crystal nucleation and accretion. This ultimately results in overt calculi.

• #4 Kidney stones: Mechanism of formation, pathogenesis and possible treatments

  https://www.pulsus.com/scholarly-articles/kidney-stones-mechanism-of-formation-pathogenesis-and-possible-treatments-4896.html

  The uneven proportion of inhibitors and promoters are responsible to the complex process of stone formation in kidneys or urolithiasis. Supersaturation of the urine with calcium and oxalate salts followed by crystalline particle formation is the major reason behind kidney stone formation with supersaturation being the driving force. The mechanism involved in the process of stone formation include nucleation of crystals fractions, growth or gathering of these crystals to a size so that they can interact with some intra-renal structure(s), confinement of these crystals inside the kidney or renal collecting system succeeded by further aggregation and/ or secondary nucleation ultimately forming the clinical stone. Calcium oxalate (CaOx) forms the major proportion of the kidney stones that is around 80%, while calcium phosphate (CaP) forms a small percentage (15%) of these stones. The crystals formed either in renal tubular fluid or in the renal interstitial fluid that is supersaturated with respect to these constituents, which in turn might be a consequence of reduced urine volume, an alteration in urine pH, mechanisms causing increased secretion of stone forming constituents such as hypercalciuria, hyperuricosuria, hypocitraturia, hyperoxaluria or a combination of these factors. The urine and presumably, the tubular fluid of stone formers are often more highly supersaturated than that of normal healthy adults, which favors nucleation and growth of crystals. Long-term accretion of additional elements, crystalline as well as organic matrix produces the clinical stone. As already explained extreme excretion of calcium or oxalate either alone or in combination as well as low volume of urine leads to an enhanced calcium oxalate supersaturation. The reciprocal actions between genetic susceptibility and environmental factors in different proportions promote both hypercalciuria and hyperoxaluria. A few genetic disorder which a rare autosomal recessive disorder, dietary routine including greater intake of oxalate and low calcium intake, potential abnormalities of anion transporters found in both gut and kidney, enhanced absorption of oxalate in the intestines other than mal absorptive diseases (enteric hyperoxaluria), changes in the normal flora of the gut thereby decreasing degradation of oxalate in the colon may cause one form of hyperoxaluria called primary hyperoxaluria types 1 and 2. Some rare genetic disorders such as adenine phosphoribosyltransferase (APRT) deficiency, cystinuria, and Dent disease, familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) and primary hyperoxaluria (PH) may lead to severe or chronic kidney stone diseases in children. The above mentioned processes in humans are influenced by several factors known as promoters and inhibitors that either support or prevent the process of stone formation thus affecting a persons ability to promote or prevent stone formation. Stone formation is facilitated by promoters while inhibitors prevent it. Among the promoters of calcium oxalate stones are high oxalate, sodium, calcium, urate, low urine pH and low urine volume while the inhibitors include organic substances such as nephrocalcin and urinary prothrombin fragment-1, osteopontin and various inorganic substances such as citrate, magnesium.

• #4

  https://link.springer.com/article/10.1007/s00467-009-1116-y

  A third pathway suggests that crystals in the urine can become attached to a site of exposed crystalline deposits of interstitial calcium phosphate (termed Randalls plaque), following the loss of the normal urothelial covering of a renal papilla. […] Randall was convinced that interstitial plaque was a perquisite for stone formation and growth. […] The majority (approximately 75%) of CaOx stones are formed attached to sites of Randalls plaque and represents all ICSF patients. […] In all other types of kidney stone formers that we have studied, plugs were formed along the inner medullary collecting ducts and ducts of Bellini, which can serve as attachment sites for developing stones. […] These stones found attached to plugs extending from ducts of Bellini have never been found to be CaOx stones but, instead, have been apatite stones. […] In patients that have undergone intestinal bypass surgery for obesity and in cystinuric stone formers the stones appear to have formed in free solution.

• #4 The Management of Urolithiasis

  https://www.uspharmacist.com/article/the-management-of-urolithiasis

  In contrast, promoters are substances that facilitate stone formation by various means. These include cell-membrane lipids (e.g., phospholipids, cholesterol, glycolipids), calcitriol hormone enhancement via parathyroid-hormone stimulation, oxalate, cystine, calcium, sodium, and low urine volume. Among patients with recurrent stone formation, urinary oxalate excretion was found to be higher, whereas citrate excretion was lower. It has been suggested that an imbalance between urinary stone inhibitors and promoters is, in general, the cause of stone formation.

• #4 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Bladder stone pathogenesis is likely multifactorial with multiple lithogenic factors, including metabolic abnormalities and urinary stasis due to BOO. Thus, despite findings of differences in 24-hour urine metabolic studies between men with BOO secondary to BPH with and without bladder calculi, further prospective analyses are needed to establish an exact causal mechanism for stone formation.

• #5 The association between bacteria and urinary stones

  https://atm.amegroups.org/article/view/12906/html

  Urinary stone disease (USD) is an increasing clinical problem in both children and adults. […] Bacteria have long been recognized to contribute to struvite urinary stones; however, the role of bacteria in the development of the more common calcium oxalate (CaOx) and calcium phosphate (CaPhos) stones has not been extensively investigated. […] Whether these bacteria are causal, disease modifying or passively present remains to be determined. However, initial exploration of underlying mechanisms for this association indicate that bacteria aggregate selectively to crystals, that their presence is associated with increased clumping of crystals, and that they stimulate incorporation of proteins into the stone matrix. […] The bacterial contribution to USD formation has long been recognized. Magnesium-ammonium-phosphate (struvite) stones (a conglomeration of bacteria, crystals and protein matrix) form due to urinary tract infection (UTI) with urease-producing bacteria.

• #5 Bladder calculus | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/bladder-calculus-1?lang=us

  Bladder calculi, commonly referred to as bladder stones, are urinary stones that are found primarily in the urinary bladder and comprise only 5% of all urinary tract stones. They can be divided into primary, secondary, and migratory stones: […] Secondary bladder stones are due to urinary stasis, including from: bladder outlet obstruction, neurogenic bladder, bladder diverticula, cystocele, foreign body, e.g.: indwelling Foley catheter, retained fragment from a removed Foley catheter, surgical sutures (nonabsorbable), bladder augmentation (not with gastric tissue), urinary diversion. […] Migratory stones are either a renal stone or a sloughed renal papilla that serves as a nidus for formation of a bladder stone. This type of stone is uncommon, as virtually any stone that can pass though the ureter, can also pass on through the urethra. A stone will stay stuck in the urinary bladder due to bladder outlet obstruction or bladder dysfunction (similarly to secondary stones), and may be laminated by material other than that of the original stone.

• #5 Pathogenesis of Bladder Calculi in the Presence of Urinary Stasis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3777386/

  Bladder stone pathogenesis is likely multifactorial with multiple lithogenic factors, including metabolic abnormalities and urinary stasis due to BOO. Thus, despite findings of differences in 24-hour urine metabolic studies between men with BOO secondary to BPH with and without bladder calculi, further prospective analyses are needed to establish an exact causal mechanism for stone formation.

• #6 The association between bacteria and urinary stones

  https://atm.amegroups.org/article/view/12906/html

  The objective of this review is to discuss emerging evidence indicating that bacteria might contribute to CaOx and/or CaPhos USD. […] If bacteria do indeed contribute to CaOx USD, what are the potential mechanisms? One possibility is that bacteria adhere to crystals. This mechanism is supported by findings that some bacteria selectively aggregate to certain crystal types but not others and that bacteria are associated with an increased number of crystal-crystal agglomerations. […] Another way that bacteria could contribute to USD is bacterial production of citrate lyase, which could decrease the urine citrate levels that lead to supersaturated urine and crystal formation. […] Lastly, bacteria-crystal aggregates may bind to the tubular epithelium resulting in expression of stone matrix proteins in either renal tubular epithelium or inflammatory cells. […] Bacteria and USD are clinically associated because they often occur in the same patients and USD patients often have positive urine and/or stone cultures.

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