Urethral stone are a manifestation of urolithiasis, characterized by the presence of concretions in the urethra. The presence of stones in the urethra can cause pain, difficulty urinating up to its acute delay, weakening or changing the shape of the urine stream. Diagnosis of urethral concretions includes palpatory examination (including rectal, vaginal), urethroscopy, urethral canal augmentation, urethrography. If possible, the stones should be extracted using urethral forceps; in other cases, the concretions are pushed into the bladder and crushed or removed during urethrotomy.
Meaning
Urethral stone can be primary (i.e. initially formed in the urethra) or secondary (formed in the upper urinary tract – kidneys or bladder and descended into the urethral lumen). Specialists in the field of clinical urology are more likely to encounter secondary urethral stone.
In women, urethral concretions are much less common than in men, which is due to the peculiarities of the female anatomy: a shorter urethra, its better extensibility and a straight direction. In their chemical composition, urethral stone are similar to kidney stones – urate, oxalate, phosphate, carbonate, cystine, protein, cholesterol, etc.
Causes
Primary urethral stone are predominantly found in men. Conditions for their formation can be urethral strictures, fistulas or diverticula of the urethra, prostate adenoma, prostatitis, chronic urethritis. Concretions repeat the configuration of the part of the urethra in which they are formed and grow. Stones of the largest sizes are formed in the diverticula of the urethra.
Secondary concretions are a manifestation of urolithiasis (the presence of kidney stones or bladder). Descending from the upper urinary tract, they get stuck in the urethra, causing the corresponding symptoms. The number and shape of urethral stones can be different. Secondary concretions often get stuck at the level of the navicular fossa, sometimes in the membranous or prostatic part of the organ.
The causes of the formation of secondary stones may be errors in the food and drinking diet, dehydration; disorders of mineral metabolism in the body with hyperparathyroidism, osteoporosis, bone injuries; gastrointestinal diseases (gastritis, colitis, peptic ulcer); urinary tract infections (pyelonephritis, cystitis), etc.
Symptoms
The symptoms of urethral stone and its severity are determined by the localization, shape, size, number of concretions and the duration of their presence in the organ cavity. Obturation of the urethral lumen with a stone is accompanied by pain syndrome, difficulty urinating, dispersion and weakening of the urine stream, hematuria. When the concretion completely covers the lumen of the urethra, acute urinary retention develops. Stones of the posterior urethra cause pain when walking and sitting.
Complications
Due to the prolonged presence of the stone in the urethra, urostasis occurs in the upper urinary tract, conditions are created for hydronephrosis, urethritis, pressure sores in the urethral mucosa, the formation of urethral fistulas and paraurethral abscesses. Urethropuzure concretions partially located in the urethra and partially in the bladder can cause urinary incontinence. Sexual intercourse is painful; with constant pain syndrome, a decrease in libido and sexual dysfunction may develop.
Diagnostics
Recognition of urethral concretions is based on characteristic symptoms, palpation data, and the results of instrumental studies. In men, stones are detected by palpation of the hanging part of the urethra or perineum, and when localized in the posterior parts – during finger rectal examination. In women, a gynecological examination is carried out, during which the stone can be felt through the front wall of the vagina.
On ultrasound of the bladder, hyperechoic formation of the urethra is visualized, giving an acoustic shadow. In the general analysis of urine, micro- or macrohematuria, signs of inflammation (leukocyturia), crystalluria, often an alkaline pH level are detected.
For the purpose of differential diagnosis of concretions and foreign bodies of the urethra, imaging studies are resorted to – urethroscopy, survey urography, urethrography. The shadow of the concretion can often be seen already on the overview urograms. In X-ray contrast examination, the stone is determined as a filling defect or enhanced contrast. Endoscopic and X-ray examination of the urethra allows you to get an idea of the location, size, number of stones and predict how to remove them.
Treatment
Most often, stones located in the urethra are pushed into the bladder during urethroscopy. In this case, the next step is lithotripsy. In rare cases, stones wedged into the urethra move away on their own after the introduction of antispasmodics, water load, sedentary baths, etc.
In case of unsuccessful attempts of conservative and instrumental extraction of stones, external urethrolithotomy and removal of concretions are indicated. Surgical removal of stones from the posterior urethra is performed through an opened bladder. During the operation, an epicystostomy is applied to drain urine. At the same time or the next stage after removal of the urethral stone, surgical removal of the cause of stone formation is required – urethral stricture, diverticulum, prostate adenoma, bladder or kidney stones, etc.
Prognosis and prevention
The prognosis is favorable. Timely removal of urethral stone prevents serious complications (paraurethritis, urethritis, prostatitis, formation of fistulas and bedsores of the urethra). To exclude the possibility of repeated stone formation in the urethra, correction of eating behavior and drinking regime, elimination of the causes of urolithiasis is required. In the presence of pathologies of the urinary system, regular monitoring by a urologist is required.