What is the etiology of bladder stones?

From the Guidelines

Bladder stones primarily form due to a combination of factors, including urinary stagnation, metabolic abnormalities, and dietary factors. The main causes of bladder stones include:

• Bladder outlet obstruction: Conditions like benign prostatic hyperplasia, urethral strictures, or neurogenic bladder can impede urine flow, leading to stone formation 1.
• Urinary tract infections: Bacteria can alter urine pH and promote crystal formation.
• Foreign bodies: Catheters or other objects in the bladder can act as niduses for stone formation.
• Metabolic abnormalities: Conditions like gout or hypercalciuria can increase the risk of stone formation, with studies suggesting that a higher calcium diet is associated with a reduced risk of stone formation 1.
• Dietary factors: High-sodium diets or insufficient fluid intake can contribute to stone formation, with recommendations to limit sodium intake and consume 1,000-1,200 mg per day of dietary calcium 1.
• Bladder diverticula: These pouches can trap urine, allowing minerals to crystallize. To prevent bladder stones, maintaining good hydration, treating underlying urinary tract conditions promptly, and managing any metabolic disorders is crucial. Regular urological check-ups are important for individuals at higher risk. Understanding these causes helps in developing targeted prevention and treatment strategies, with guidelines recommending increased fluid intake to achieve at least 2.5 liters of urine daily 1 and a diet with normal calcium content and low amounts of animal protein and sodium 1.

From the Research

Etiology of Bladder Stones

The etiology of bladder stones is multifactorial, involving various factors that contribute to their formation. Some of the key factors include:

• Bladder outlet obstruction, neurogenic bladder, chronic bacteriuria, presence of intravesical foreign substances, and bladder diverticula 2
• Urine stasis, infection, presence of foreign bodies, dehydration, diet, and periods of immobility 3
• Geographic and racial variation, with a higher prevalence in certain populations 4
• Supersaturation of urine with minerals, leading to crystal formation and stone growth 5, 6
• Randall's plaque, a calcium phosphate matrix found on the surface of the kidney papilla, which can serve as a nidus for stone formation 5, 6

Pathophysiology of Stone Formation

The pathophysiology of stone formation involves a complex interplay of factors, including:

• Urine supersaturation with respect to the mineral phase of the stone 6
• Histological changes in the renal papilla, including the formation of Randall's plaque 6
• Three general pathways for kidney stone formation: stones fixed to the surface of a renal papilla, stones attached to plugs protruding from the openings of ducts of Bellini, and stones forming in free solution in the renal collection system 6

Risk Factors and Complications

Risk factors for the development of bladder stones include:

• Bladder outlet obstruction, neurogenic bladder, chronic bacteriuria, presence of intravesical foreign substances, and bladder diverticula 2
• Recurrent urinary tract infections, urinary retention, and hematuria are common signs of this disorder and can lead to complications such as renal failure 2
• Complications of urinary tract stones include obstruction, pain, nausea, vomiting, and sepsis 3