Bladder stones can be divided into primary and secondary types, primarily occurring in males. Primary bladder stones are mostly caused by malnutrition and are now rare, except in some remote mountainous areas where they frequently occur in infants. Secondary bladder stones mainly result from benign prostatic hyperplasia, and their incidence has gradually increased with extended lifespans. Additionally, stones are prone to form in cases of urethral stricture, bladder diverticulum, foreign bodies (including long-term indwelling catheters), and neurogenic bladder dysfunction. Primary bladder stones are usually single and oval-shaped, while secondary bladder stones are often composed of a mixture of calcium oxalate, calcium phosphate, and uric acid, presenting as multiple smaller stones.

bubble_chart Clinical Manifestations

Typical bladder stones are commonly seen in children. During urination, the sudden obstruction of the stone at the bladder neck causes interruption of urination and severe pain. Children with this seasonal disease often hold their penis, squat, and cry, but changing their position can allow smooth urination. The friction between the bladder mucosa and the rough stone leads to bleeding, infection, and mucosal ulcers. Occasionally, severe bladder ulcers may occur, even perforating into the vagina or rectum, forming urinary fistulas. Long-term stimulation by stones and inflammation can induce bladder squamous cell carcinoma. Chronic obstruction can cause ureteral and renal pelvis dilation, hydronephrosis, and impaired renal function. Most patients usually experience frequent urination, urgency, dysuria, and terminal hematuria, often with interrupted urination. Secondary stones caused by benign prostatic hyperplasia may only present with difficulty urinating. Large bladder stones can sometimes be palpated during a digital rectal examination.

The diagnosis is easily confirmed based on medical history, clinical manifestations, and a plain urinary tract X-ray, but identifying the cause of obstruction is crucial. A metal probe inserted into the bladder through the urethra can detect stones by the sensation of friction and metallic sound upon contact. If necessary, cystoscopy during seasonal epidemics not only confirms the diagnosis but also helps identify the underlying cause of the stones.

bubble_chart Treatment Measures

For bladder stones in adults with a diameter within 3cm, transurethral lithotripsy with forceps is now commonly used, and the stone fragments are then flushed out. This method is simple and effective and can be performed on an outpatient basis. For cases with urethral stricture or stones that are hard and exceed 4cm in diameter, suprapubic cystolithotomy is preferable. If benign prostatic hyperplasia is present, it should be removed simultaneously to prevent stone recurrence. There are also reports of other methods such as extracorporeal shock wave lithotripsy, ultrasound, micro-explosion, or laser lithotripsy.

Infants and young children can prevent bladder stones by ensuring adequate nutrition from dairy products. Additionally, eliminating predisposing factors—such as actively treating obstructive conditions like urethral strictures—is important. During bladder surgery, non-absorbable sutures should not penetrate the mucosa to avoid forming a nidus for stone formation. For those with indwelling catheters, regular replacement and maintaining patency are essential.