What Is Urethral Stricture?

When the urethra is damaged by various causes, scar tissue forms and contracts during the healing process, causing the urethral lumen to narrow or even become completely obstructed. The lining epithelium thins and partially undergoes metaplasia into stratified squamous epithelium. The propria layer becomes discontinuous, and the vascular sinusoidal structure of the corpus spongiosum is largely replaced by fibrous connective tissue, which intermingles with the spongy tissue without a clear boundary. The result of all these changes is urethral stricture.

Urethral stricture is one of the most common conditions in urological surgery. In recent years, with the development of industries such as transportation and construction, as well as the increasing use of intraurethral instruments and surgical procedures, its incidence has been rising in both developed and developing countries. Common causes of urethral stricture include congenital, inflammatory, traumatic, iatrogenic, and idiopathic factors.

Because the male urethra is longer than the female urethra and differs in anatomical position and tissue structure, it is more susceptible to trauma and infection. Coupled with social factors, the condition predominantly affects adult men.

1. Causes of Urethral Stricture

Urethral stricture can be classified as either spastic or organic.

Spastic urethral stricture is a temporary phenomenon caused by contraction of the external urethral sphincter. Contributing factors may include urethritis, urethral calculi, intraurethral instrumentation, or abnormal sexual activity. Spastic strictures can generally be managed with comprehensive treatment, including removal of contributing factors, warm sitz baths, sedatives, analgesics, and antispasmodics.

Organic strictures can be classified into three categories based on etiology:

① Congenital urethral stricture, such as meatal stenosis or urethral valves.

② Inflammatory urethral stricture, which may result from gonorrhea, tuberculosis, or nonspecific infections. The stricture pattern tends to be complex and the degree of narrowing is often severe. After early infection control, treatment primarily involves urethral dilation. Additionally, indwelling catheterization may also cause urethral stricture.

③ Traumatic urethral stricture is the most common type, resulting from severe urethral injury with inadequate or delayed initial management.

Pathologically, the degree, depth, and length of the stricture vary considerably. Typically, there is only a single stricture, though gonococcal strictures may be multiple. Strictures may become secondarily infected, leading to urethral diverticula, periurethral inflammation, prostatitis, or epididymo-orchitis. If urinary obstruction persists long-term, it may eventually result in hydronephrosis, renal impairment, and uremia.

2. Clinical Presentation of Urethral Stricture

Symptoms of urethral stricture vary depending on its degree, extent, and progression. The main symptoms are as follows:

First, difficulty urinating, with urinary retention in severe cases. Initially, patients experience straining to void, prolonged urination time, and a split urinary stream. Gradually, the stream becomes thinner and the range shorter, eventually progressing to a dribbling pattern. When the detrusor muscle contracts but cannot overcome urethral resistance, residual urine volume increases, potentially leading to overflow incontinence or urinary retention.

Second, urethral stricture is often accompanied by chronic urethritis. It may lead to secondary bladder infections, stones, or epididymo-orchitis. The proximal urethra dilates above the stricture, and urinary stasis may lead to recurrent urinary tract infections, periurethral abscesses, urethral fistulae, prostatitis, and epididymitis. The resulting obstruction can cause hydronephrosis and recurrent urinary infections, ultimately leading to declining renal function or even uremia.

Third, chronically increased intra-abdominal pressure may lead to complications such as hernias, hemorrhoids, and rectal prolapse.

3. Diagnostic Examinations for Urethral Stricture

1. Urethral Palpation and Scrotal/Anal Examination

All patients with traumatic urethral stricture should undergo routine anal, rectal, and prostate examinations. Significant upward displacement of the prostate suggests a higher stricture location or a longer stricture segment. Proctoscopy can determine the presence, size, and location of a urethrorectal fistula.

2. Urethral Sound Examination

Urethral sounding can determine the location, degree, and length of the stricture.

3. Urethrography

This examination is an important basis for selecting the treatment method.

4. Urethral Ultrasound

This offers the advantage of clearly distinguishing the layers of the urethral lumen, corpus spongiosum tissue, and periurethral tissues, allowing precise estimation of stricture length while avoiding repeated X-ray exposure from contrast studies.

5. Urethral MRI

Magnetic resonance imaging (MRI) has diagnostic reference value for urethral strictures following pelvic fractures.

6. Others

Urinary tract infections are often associated with abnormal urinalysis and bacteriological findings, which are significant for guiding antibiotic selection.

4. Treatment of Urethral Stricture

Current treatment methods for urethral stricture primarily include urethral dilation, internal urethrotomy, laser therapy, urethral stent placement, and open urethral reconstruction including end-to-end anastomosis and substitution urethroplasty. The choice of treatment should be individualized based on the stricture's etiology, location, length, complications, and prior surgical history to develop a personalized treatment plan for each patient.

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The medical information provided here is for reference only and should not be used as a basis for clinical diagnosis or treatment.