What is the treatment approach for a patient with a urinary tract (UT) stone?

Treatment Approach for Urinary Tract Stones

For patients with urinary tract stones, the treatment approach should be based on stone size, location, and patient factors, with both shock wave lithotripsy (SWL) and ureteroscopy (URS) being acceptable first-line treatments for stones requiring removal, though URS yields significantly higher stone-free rates. 1

Initial Assessment and Diagnosis

• Ultrasound is the primary diagnostic tool for suspected urinary tract stones with 45% sensitivity and 94% specificity for ureteral stones 1
• Non-contrast CT is the standard for acute flank pain after ultrasound, providing detailed information on stone location, burden, density, and anatomy 1
• Basic laboratory evaluation should include urine dipstick, creatinine, uric acid, ionized calcium, sodium, potassium, blood cell count, and C-reactive protein 1
• Stone analysis should be performed for all first-time stone formers to guide treatment and prevention strategies 1

Management Based on Stone Size

For Stones <10 mm:

• Observation with periodic evaluation is an option for initial treatment if symptoms are controlled 1
• Medical expulsive therapy (MET) with alpha-blockers is recommended, especially for stones >5 mm in the distal ureter 1, 2
• Patients should have well-controlled pain, no clinical evidence of sepsis, and adequate renal functional reserve 1
• Follow-up with periodic imaging studies is essential to monitor stone position and assess for hydronephrosis 1

For Stones >10 mm:

• Although observation or MET could be attempted, most cases will require surgical intervention 1
• Both SWL and URS are acceptable first-line treatments 1
• URS provides better stone-free rates but has slightly higher complication rates 1

Pain Management

• NSAIDs (diclofenac, ibuprofen, metamizole) are first-line analgesics for renal colic 1, 2
• NSAIDs reduce the need for additional analgesia compared to opioids 1, 2
• Opioids are recommended as second-choice analgesics when NSAIDs are contraindicated or insufficient 2
• If opioids are required, agents other than pethidine are preferred (hydromorphone, pentazocine, or tramadol) 2

Surgical Intervention Options

Shock Wave Lithotripsy (SWL):

• Non-invasive option with fewer complications but lower stone-free rates 1
• Routine stenting is not recommended as part of SWL 1
• If initial SWL fails, endoscopic therapy should be offered as the next treatment option 1

Ureteroscopy (URS):

• Higher stone-free rates with a single procedure but slightly higher complication rates 1
• First-line therapy in patients with uncorrected bleeding diatheses or those requiring continuous anticoagulation/antiplatelet therapy 1
• Safety guidewire should be used during the procedure 1

Special Situations:

• In cases of sepsis and/or anuria in an obstructed kidney, urgent decompression via percutaneous nephrostomy or ureteral stenting is required before definitive treatment 1
• If purulent urine is encountered during endoscopic intervention, the procedure should be aborted, appropriate drainage established, antibiotic therapy continued, and urine culture obtained 1

Stone Dissolution Therapy

• Uric acid stones require alkaline urine (pH 6.0-7.0) for dissolution, with potassium citrate as first-line therapy 3
• Cystine stones require alkaline urine (pH around 7.0) to increase solubility 3
• Struvite stones (infection stones) require acidification for dissolution 3

Prevention of Recurrence

• Increased fluid intake (2-3 liters per day) and dietary modification are key strategies for preventing stone recurrence 4
• Follow-up with 24-hour urine collection is necessary to monitor adherence and metabolic response 3

Important Caveats

• Blind basketing (stone extraction without endoscopic visualization) should never be performed due to risk of ureteral injury 1
• Antimicrobial prophylaxis should be administered prior to stone intervention based on prior urine culture results and local antibiogram 1
• Open/laparoscopic/robotic surgery should not be offered as first-line therapy except in rare cases of anatomic abnormalities, large or complex stones, or those requiring concomitant reconstruction 1
• When residual fragments are present, especially if infection stones are suspected, endoscopic procedures should be offered to render the patient stone-free 1