Urinary stones primarily manifest as difficulty urinating, straining during voiding, which may be dribbling, sometimes with interrupted urine flow and urinary retention. Urination may cause significant pain radiating to the glans penis. Posterior urethral stones cause pain in the perineum and scrotum.Penile stones may present as palpable masses at the site of pain, and forceful urination may expel the stone. Complete obstruction leads to acute urinary retention. Infected cases may exhibit purulent urethral discharge. Female urethral diverticulum stones primarily cause lower urinary tract infection symptoms: frequent urination, dysuria, nocturia, pyuria, hematuria, and notably, dyspareunia. Urethral discharge may occur.In male urethral diverticulum stones, besides urethral discharge and dysuria, a gradually enlarging, firm mass may appear beneath the penis. This mass exhibits marked tenderness but no urinary obstruction symptoms. Not all urolithiasis patients are suitable candidates for extracorporeal shock wave lithotripsy (ESWL).Extracorporeal shock wave lithotripsy (ESWL) has specific indications and contraindications. Generally, lithotripsy may be used for stone removal in the following situations: ESWL is the standard method for treating kidney stones ≤2 cm in diameter or ≤300 mm² in surface area. Kidney stones ≥2 cm in diameter and staghorn calculi are recommended for percutaneous nephrolithotomy (PNL) or combined ESWL.
ESWL is the preferred treatment for upper ureteral stones ≤1cm in diameter. For upper ureteral stones between 1-1.5cm, options include ESWL, ureteroscopy (URS), or PNL. Upper ureteral stones ≥1.5cm are suitable for PNL (above the L4 level), laparoscopic stone removal, or open surgical stone removal.For mid-to-lower ureteral stones ≤1.5 cm in diameter, ESWL and URS are options; ≥1.5 cm stones may be treated with laparoscopic lithotripsy or open surgery. Bladder stones may also undergo extracorporeal shock wave lithotripsy, though methods differ, with transurethral endoscopic lithotripsy being the primary approach.
Urethral stones are generally unsuitable for ESWL; treatment may employ endoscopic approaches similar to those for bladder stones.
Lithotripsy is contraindicated in the following conditions: 1. Unresolved urinary tract obstruction distal to the stone; 2. Patients with bleeding disorders; 3. Uncontrolled infection at the stone site; 4. Impaired cardiac, hepatic, or renal function;5. Pregnant women; 6. Patients with excessive obesity affecting focal localization; 7. Patients with kyphosis; 8. Patients with renal artery sclerosis, etc.
Urinary stones are not immediately expelled after lithotripsy. This is because the lithotripter is not a "stone expeller"; it lacks expulsion capability and only fractures stones into small fragments that can pass through the urinary tract.The successful passage of fragments depends on multiple factors, including renal urine output, ureteral patency and propulsive capacity, and fragment size. Therefore, physicians often administer diuretics, ureteral dilators, or ureteral motility enhancers post-treatment to facilitate stone expulsion and shorten the passage time.