How should a bladder stone be diagnosed and managed, including size-based treatment options and preventive measures?

Bladder Stone Treatment

Bladder stones should be treated with endoscopic transurethral cystolithotripsy as the preferred first-line approach, with the underlying cause of stone formation (bladder outlet obstruction, foreign bodies, or metabolic abnormalities) addressed simultaneously or immediately after stone removal. 1, 2

Diagnostic Evaluation

Initial Imaging

• Ultrasound is the primary diagnostic tool for detecting bladder stones, with 88% specificity for renal/bladder stones 3
• Plain KUB radiography (44-77% sensitivity) helps differentiate radiopaque from radiolucent stones and aids in follow-up 3
• Non-contrast CT is the gold standard when diagnosis is uncertain, providing detailed information on stone density, internal structure, and composition 3, 4

Laboratory Assessment

• Obtain urine dipstick and culture before treatment to identify and treat urinary tract infections 3, 1
• Blood tests should include creatinine, uric acid, ionized calcium, sodium, potassium, CBC, and CRP 3
• Stone composition analysis is essential for all patients to guide metabolic therapy and prevent recurrence 1, 5
• Perform 24-hour urine collection within 6 months of diagnosis to identify metabolic abnormalities 1

Treatment Algorithm by Stone Size and Clinical Context

Small to Moderate Stones (<3 cm)

Transurethral cystolithotripsy is the preferred treatment, offering minimal invasiveness with high efficacy 2, 6

Technical options include:

• Holmium:YAG laser lithotripsy allows stone fragmentation under local anesthesia in selected patients 6, 7
• Pneumatic or ultrasonic lithotripsy are effective alternatives 6
• Any associated foreign bodies (sutures, mesh, synthetic tapes) should be removed or cut flush with bladder mucosa during the same procedure 2

Large Stone Burden (>3 cm)

• Percutaneous endoscopic cystolithotripsy is preferable to avoid urethral injury and facilitate complete stone removal 2, 6
• Open suprapubic cystolithotomy should be considered when endoscopic approaches fail or stone burden is massive 2

Special Consideration: Extracorporeal Shock Wave Lithotripsy (ESWL)

• ESWL is simple, effective, and well-tolerated for bladder stones 2
• Caveat: Ancillary procedures are required in a significant number of patients, limiting its role as primary therapy 2

Management of Underlying Causes

Primary Bladder Stones

Address metabolic abnormalities and dietary factors 1:

• Increase fluid intake to achieve ≥2 liters of urine output daily 1
• Maintain normal dietary calcium intake while limiting sodium to ≤2,300 mg/day 1
• Reduce animal protein intake 1
• For calcium oxalate stones with hypercalciuria: offer thiazide diuretics 1
• For calcium stones with hypocitraturia: prescribe potassium citrate 30-100 mEq/day 1

Secondary Bladder Stones

Identify and correct the anatomical or functional bladder pathology causing urinary stasis before or during stone removal 1:

• In men with bladder outlet obstruction, concomitant prostate surgery has traditionally been recommended, though recent observational studies question this dogma 6
• For stones associated with foreign bodies: remove or resect the offending material; if transurethral treatment fails, consider partial mesh resection via cystotomy 2
• In patients with neurogenic bladder or urinary diversion, consider aggressive prophylaxis including urease inhibitors (acetohydroxamic acid) due to high recurrence risk 3

Infection Management

Critical principle: In cases of infection-related stones or active UTI:

• Collect urine for culture before and after any intervention 3
• Administer culture-directed antibiotics before definitive stone treatment 1
• Perioperative antibiotic prophylaxis is mandatory for all patients undergoing endourological treatment 3
• Single-dose prophylactic antibiotic before the procedure is sufficient for most patients 3

Prevention of Recurrence

Stone Analysis-Guided Therapy

Bladder stone composition predicts kidney stone composition in 70% of patients with multi-site calculi, suggesting metabolic abnormalities play a significant role 5

Follow-Up Protocol

• Obtain 24-hour urine collection within 6 months of initiating medical therapy to assess treatment response 1
• Perform periodic imaging to monitor for recurrence, with frequency based on stone activity and underlying risk factors 1
• For struvite/carbonate apatite stones: prophylactic or suppressive antibiotic therapy should be considered due to recurrent UTI risk 3

Common Pitfalls to Avoid

• Never perform blind basketing (stone extraction without endoscopic visualization) 8
• Do not delay treatment of bladder outlet obstruction in secondary stone formers, as this perpetuates stone formation 1
• Avoid assuming all bladder stones are due to obstruction alone—metabolic evaluation is essential 5
• In women, always investigate for foreign bodies (sutures, synthetic mesh) as the incidence is increasing with pelvic floor surgery 2