Pathogenesis (development of disease)
Urethral stricture is caused by scarring transformation of the urethra (urethra).
According to the localization, urethral stricture can be classified as follows:
- Bulbar urethral stricture (between the sphincter and the beginning of the mobile penis; portion of the urethra fixed to the pelvic floor) – the most common form of urethral stricture, with approximately 50%; usually caused by trauma.
- Penile urethral stricture (in the mobile part of the penis) – circa 30% of cases.
- Urethral stricture in the area of the fossa navicularis (ampullary dilation of the male urethra (urethra), located in the area of the glans penis just before the meatus urethrae externus (external urethral orifice); urethral segment in the area of the glans) – circa 20% of cases.
- Urethral stricture in the area of the posterior urethra (“posterior urethra” = course through the prostate/prostatic urethra and the pelvic floor muscles/membranous urethra) – very rare; it occurs in the context of injuries (e.g. traumatic urethral tear) or after radiotherapy (radiation therapy) in the context of prostate cancer (prostate cancer).
Etiology (causes)
Behavioral causes
- Cycling (3-fold more common than in noncyclists).
Disease-related causes
Skin and subcutaneous (L00-L99).
- Lichen sclerosus et atrophicus – chronic inflammatory progressive connective tissue disease of the skin; circa five percent of cases.
Infectious and parasitic diseases (A00-B99).
- Bacterial urethritis (inflammation of the urethra) – up to 20% of cases; usually untreated gonorrhea.
Genitourinary system (kidneys, urinary tract – sex organs) (N00-N99).
- Bacterial urethritis (inflammation of the urethra) – usually an untreated gonorrhea.
- Balanitis xerotica obliterans (BXO) – chronic inflammatory inflammation of the glans penis (glans), the cause of which is unknown.
Injuries, poisoning and other consequences of external causes (S00-T98).
- Urethral avulsion in the setting of a pelvic fracture (pelvic fracture).
Other causes
- Iatrogenic (urethral stricture caused by medical procedures) – in about 45% of cases:
- Brachytherapy – form of radiotherapy in which the radiation source is introduced directly into the tumor.
- Permanent catheterization, traumatic
- Correction of hypospadias (malformation of the urethra).
- Prostatectomy (removal of the prostate gland).
- Transurethral urinary bladder surgery (surgery performed on the urinary bladder through the urethra), such as TUR-P (transurethral resection of the prostate); up to five percent of cases
- Cystoscopy (cystoscopy of the bladder).
- Idiopathic (urethral strictures without an identifiable cause) – up to 30% of cases; it is often a longer history of minor trauma (eg, cycling).
- Trauma (injury)
