Urethral Stricture

07.07.2020

A urethral stricture occurs predominantly in males. The cause is chronic inflammation related to infection or trauma. Urethral stricture occurs because of scarring of the wall that, instead of being elastic, becomes rigid and retracted, obstructing the lumen. The diagnosis is suspected when the urinary stream is poor. The treatment depends on the site, on the length and on the depth of the scar.

Symptoms and clinical manifestation of urethral stricture

The main symptom of urethral stricture is the poor urinary stream. Urinary frequency and urgency are due to bladder adaptation to obstruction. To empty completely against the obstruction, the bladder increases its contractility. This, reducing bladder capacity, results in urgent and frequent urination. Patients with urethral stricture also demonstrate UTI, epididymitis, post-void residual urine volume or decreased force of ejaculation. Additionally, patients may present with urinary spraying or dysuria

Diagnosis

Patients with symptomatic urethral stricture (poor urinary stream) has a reduced peak flow rate (uroflowmetry). The confirmation is made with urethroscopy or retrograde urethrography. Urethroscopy identifies a urethral stricture, but does not delineate the location and length of strictures. Retrograde urethrography with or without voiding cystourethrography allows for identification of stricture location in the urethra, length of the stricture, and degree of lumen narrowing. All of this stricture characteristics are important for subsequent treatment planning. Post-traumatic urethral stricture is common in the bulbar urethra, is usually short and limited scarring.

Treatment

The main factors to consider in decision making include: 

  • stricture aetiology
  • location
  • severity
  • prior treatment
  • comorbidity
  • patient preference.  

The best treatment for short bulbar stricture (< 2 cm) is the direct visual internal urethrotomy. It is the less invasive, the operative time is short and the recovery is fast. The postoperative catheterization time is a surgeon's decision. Usually, after no complicated procedures, the catheter is left in place for 72 hours. The main drawback of internal urethrotomy is the late recurrence that might occur after 3-6 months in up to 20% of patients. Strictures longer than 2 cm or recurrent strictures should be treated by urethroplasty (overlap anastomosis or onlay procedures with buccal mucosa as preferred graft).

The anterior urethra has poor results in terms of recurrence if treated by internal urethrotomy, despite its length. For this reason, the preferred treatment is urethroplasty. That can be done in one stage, in two stages or multi-stage. In these procedures, the damaged urethra is replaced by a graft. The best graft is oral mucosal (buccal mucosa). If it is no possible to use it, penile fasciocutaneous flap is a good alternative.

Differently, the stricture of the terminal portion of the urethra (fossa navicularis) at the tip of the penis should be treated, as the strictures of the bulbar urethra, with dilatation or incision. Urethroplasty can be considered in case of failure (recurrence) that occurs in 20% of patients.

The primary contracture of the bladder neck, refractory to alpha-blocker treatment, is usually treated with an incision that can be made with diathermic or laser energy. Vesicourethral strictures after prostate resection or anastomosis in Radical Prostatectomy are best treated with diathermy or laser incision. The vaporization of the obstructing scar seems to be crucial to obtain the best results. Holmium or Thulium laser have some advantage because of their effective vaporization.

The urethral dilation may be considered in all urethral stricture as second-choice treatment, when the other procedures cannot be done or in selected patients as adjuvant treatment after internal urethrotomy or urethroplasty in order to maintain the urethral patency after the procedure.

The perineal urethrostomy (perineostomy) is a good option when complex and extended anterior urethral strictures are not suitable for stable treatment (multiple recurrences) or in high-risk patients for anaesthesia.

Overlap anastomosis (or augmented anastomosis) is the best treatment for bulbar traumatic strictures less than 2 cm.

Post-operative care

In non-complicated internal urethrotomy, the post-operative catheterization may last 72 hours. After urethroplasty, the urinary catheter should be placed following urethral stricture intervention to divert urine from the site of intervention and prevent urinary extravasation. Moreover, a urethral catheter is thought to be optimal as it may serve as a stent around which the site of urethra intervention can heal. The length of urinary catheterization is widely variable and depends on the surgeon preferences (2-3 weeks). Urethrography or voiding cystography is performed two to three weeks following open urethral reconstruction to assess for complete urethral healing.

As a followup, after the operation, the patient should be monitored to identify symptomatic recurrence following direct visual internal urethrotomy or urethroplasty.  

Complications

Erectile dysfunction, as measured by the International Index of Erectile Function (IIEF) may occur transiently after urethroplasty with the resolution of nearly all reported symptoms approximately six months postoperatively. Meta-analysis has demonstrated the risk of new-onset erectile dysfunction following anterior urethroplasty to be ~1%. The significant Erectile Dysfunction rate after overlap anastomosis seems to be due to interruption of the cavernosal nerves or to the damage of the nerves because of trauma.

Ejaculatory dysfunction manifested as the pooling of semen, decreased ejaculatory force, ejaculatory discomfort and decreased semen volume has been reported by up to 21% of men following bulbar urethroplasty. The reason for Ejaculatory dysfunction is the weakness of the dissected bulbo-cavernous muscle to access the bulbar urethra.

Reference

American Urological Association (AUA) Guideline on male urethral stricture. Approved by the AUA Board of Directors, April 2016