Description

• A narrowing of the anterior urethral lumen caused by scarring of the corpus spongiosum (spongiofibrosis)
• A narrowing of the posterior urethra is not a stricture. It is better termed a distraction defect, stenosis, or contracture depending on the etiology.
• A stricture can be located at any point along the anterior urethra, which is subdivided into meatus, fossa navicularis, penile, and bulbar urethra.
• Strictures in each location can have different etiologies and treatments.

Epidemiology

Incidence

• Strictures occur in up to 0.6% of the population (1).
• The cause of strictures can be idiopathic, iatrogenic, inflammatory, or traumatic (2).
• Idiopathic or iatrogenic strictures are the most common types followed by traumatic and inflammatory (2).
• Inflammatory strictures secondary to gonorrhea were more common in the past but have become less prevalent due to effective antibiotic treatment.
• The prevalence of strictures increases with age (1).
• The bulbar urethra is the most common location for a stricture (2).

Etiology and Pathophysiology

• Scarring of the corpus spongiosum can be caused by trauma, inflammation, or previous surgery.
• Urethral trauma is often caused by a straddle injury, which leads to a spongiofibrosis and dense stricture in the bulbar urethra.
• Inflammatory strictures are commonly caused by gonorrhea or lichen sclerosus (LS), previously referred to as balanitis xerotica obliterans (BXO) (2).
• Gonorrhea causes urethritis that can lead to strictures if untreated.
  • Inflammation in the urethral glands of Littré in the distal penile and bulbar urethra can lead to scarring of the corpus spongiosum and urethral narrowing.
• LS is an inflammatory condition of unknown etiology (3).
  • Presents with whitish plaques on the prepuce, glans, and penile shaft, which can be treated and cured with circumcision if caught in this early phase.
  • Biopsy of suspicious lesions can confirm the pathologic diagnosis.
  • LS can progress to meatal stenosis and eventually panurethral stricture disease if left untreated.
• Iatrogenic strictures are most commonly from urethral catheterization or transurethral surgery. Less commonly, they may be secondary to hypospadias repair (2).
• Radiation to the urethra, although uncommon, can lead to eventual stricture formation.

Pediatric Considerations
Meatal stenosis is a common pediatric diagnosis seen in circumcised boys. One theory is that irritation from friction on the meatus after circumcision leads to inflammation and scar formation.

Genetics
No genetic risk factors are known.

Risk Factors

• Urethral trauma
• Catheterization
• Transurethral surgery (i.e., transurethral resection of the prostate or TURP)
• Hypospadias or other urethral surgery
• Unprotected sexual intercourse
• Untreated gonococcal urethritis

General Prevention

• Appropriate catheterization technique
• Prevention of sexually transmitted infections

Commonly Associated Conditions

• Urinary tract infections (UTIs)
• If severe luminal narrowing or complete obliteration of the urethral lumen occurs, urinary retention and acute renal failure may develop.
• Bladder stones
• Loss of bladder contractility could develop if left untreated for many years.