The term "urethral stricture" refers specifically to anterior urethral disease — a scarring process of the urethral epithelium and the surrounding corpus spongiosum, termed spongiofibrosis. Because the posterior urethra is not surrounded by corpus spongiosum, its narrowings are not called strictures (pelvic-fracture injuries are PFUI; others are contractures or stenoses). A normal 30-Fr urethra has a 10-mm outer diameter.
Causes
- Acquired — trauma (the most common cause in developing countries; usually straddle trauma, often unrecognised until obstructive symptoms appear), iatrogenic instrumentation, lichen sclerosus (LS strictures are longer and carry a higher association with urethral cancer), and infection (gonococcal strictures, now less common; the role of Chlamydia/Ureaplasma is unclear).
- Congenital — rare; defined as a short, non-inflammatory stricture with no history or potential for trauma, in an infant before erect ambulation.
- Idiopathic — the most common cause in developed countries.
Diagnosis and Evaluation
The treatment plan depends on the stricture's location, length, depth, and density (spongiofibrosis). Patients usually present with obstructive voiding symptoms, UTIs (prostatitis, epididymitis), or retention, often after tolerating symptoms for a long time.
- Retrograde urethrography/VCUG define location and length.
- Ultrasound is the most accurate method for determining the graft length needed to repair an anterior stricture.
- MRI helps in PFUI with distorted pelvic anatomy but is not useful for anterior strictures except when urethral carcinoma is present.
Management
Four options: dilation, direct visual internal urethrotomy, urethral stent, and urethroplasty.
- Dilation — the goal is to stretch the scar without creating more scarring (bleeding means the stricture was torn, not stretched). Blind passage of filiforms is condemned. Efficacy is similar to internal urethrotomy in the short/mid term.
- Direct visual internal urethrotomy (DVIU) — incise the scar to healthy tissue so the lumen heals enlarged, usually at the 12 o'clock position (a deep distal incision risks entering the corpora cavernosa and causing ED); use normal saline irrigant. The most common complication is recurrence, and the success of later reconstruction is diminished by repeated dilations/urethrotomies.
- Urethral stent (UroLume) — must be placed only in the bulbar urethra (elsewhere it causes pain on sitting/intercourse); contraindicated after substitution urethroplasty (skin contact causes a virulent hypertrophic reaction) or with deep spongiofibrosis. (UroLume is off the market.)
- Open reconstruction (excision and primary anastomosis) — best results require total excision of the fibrosis, a widely spatulated ovoid anastomosis, and a tension-free repair in the lithotomy position; length is gained by mobilising the corpus spongiosum and detaching the bulbospongiosus from the perineal body. When the defect is too long for primary anastomosis, use a graft or flap (onlay, not tubularised). Avoid excision and primary anastomosis after prior hypospadias repair (the retrograde glanular blood supply may be absent).
- Adverse events: permanent ejaculatory dysfunction in up to 20% (semen pooling, loss of force); temporary ED in up to 20% (resolves by ~6 months, with <3–4% permanent — roughly the rate after circumcision, higher with longer reconstructions); new penile curvature (from over-aggressive distal-bulbar excision); and rare loss of libido/anorgasmia (usually psychological).
Self-Test
1. List the risk factors/causes of urethral stricture disease. Trauma (especially straddle injury), iatrogenic instrumentation, lichen sclerosus, infection (gonococcal urethritis), and idiopathic (the most common cause in developed countries).