| disease | Urethral Stones |
Urethral stones are mostly caused by kidney, ureter, or bladder stones that become lodged in the urethra during downward passage, leading to medical consultation. They commonly occur in children aged 1 to 10 years. Ninety percent of cases are male, with stones often impacted in the prostatic urethra, navicular fossa, or external urethral orifice.
bubble_chart Clinical Manifestations
Stones impacted in the urethra cause difficulty in urination, thinning of the urinary stream, or dribbling, and sometimes acute urinary retention may occur. The site of the stone exhibits significant pain and tenderness; stones in the anterior urethra may present as palpable nodular masses, and occasionally, part of the stone may be visible protruding from the external urethral orifice. In cases where urethral stones are complicated by infection, local pain intensifies, purulent discharge is observed at the urethral orifice, and bladder irritation symptoms also worsen. Secondary stones in urethral diverticula may not present obvious symptoms of urinary obstruction, but there may be discharge at the urethral orifice, and stones can be palpated below the penis. Some patients may feel a sac-like diverticulum that fills with pressure during urination.
Stones in the anterior male urethra can be palpated in the penis or perineum, while posterior urethral stones may be detected rectally. In females, urethral stones can be palpated along the anterior vaginal wall. Posterior urethral stones require X-ray imaging for definitive diagnosis. Occasionally, urethrography, probing with a metal urethral sound to locate the stone, or direct visualization via urethroscopy may be necessary.
For small stones near the urethral orifice, a large amount of liquid paraffin can be injected to attempt extrusion, or mosquito forceps or sharp tweezers can be used to grasp and remove them. Alternatively, the tip of a probe can be bent into a hook shape to try and extract the stone. However, for larger stones, repeated forceful attempts to extrude them should be avoided to prevent extensive injury to the urethral mucosa. Stones impacted at the external urethral orifice or in the navicular fossa may sometimes require incision of the external urethral orifice for removal. Stones in the posterior urethra can be pushed back into the bladder using a urethral probe and then crushed with transurethral mechanical lithotripsy forceps or removed via suprapubic cystotomy. Stones within a urethral diverticulum should be excised along with the diverticulum. For stones tightly impacted in the anterior urethra that cannot be removed or pushed back into the bladder, a straight incision can be made along the side of the penis, pulled toward the center, and the urethra incised to extract the stone. The incision should then be closed in layers with absorbable sutures to prevent postoperative urinary fistula formation. Occasionally, large dumbbell-shaped stones in the prostatic urethra and bladder neck may require cystotomy to slowly loosen and remove the stone intact. Due to prolonged impaction in the posterior urethra, urinary incontinence may occur after stone removal.
