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ORGAN SYSTEMS Renal System

Urethral diverticula (UD)

Epithelised outpouchings of the urethral lumen into the surrounding periurethral connective tissue (also termed the periurethral fascia).

Epithelised outpouchings of the urethral lumen into the surrounding periurethral connective tissue (also termed the periurethral fascia).

A urethral diverticulum is a pocket or sac that forms along the urethra. Although the exact cause of urethral diverticula is not known, they are likely due to repeated infections in a periurethral gland that ultimately results in blockage. The blocked gland then likely bursts into the urethra creating the communication between the sac and the urethra. This condition is felt to be acquired rather than congenital (these are rarely if ever seen in babies). | Urethral Diverticulum – Northeast Ohio Urogynecology. (2020). Retrieved 27 November 2020, from https://www.akronurogynecology.com/urethral-diverticulum-2/

Aetiology

Congenital UDs (10% cases):

Due to a developmental defect of urethral folds on its ventral aspect leading to a segmental defect of the urethral wall, most commonly at the peno-scrotal junction. It is characterized by true epithelial lining and wall made up of full thickness urethral musculature.

Acquired UDs (90% cases):

Lined by epithelium and granulation tissue, and the UD wall lacks smooth muscle fibers.
  • Stricture
  • Infection
  • Trauma
  • Post-surgery

Pathophysiology

UD are thought to arise from repeated obstruction, infection and subsequent rupture of periurethral glands into the urethral lumen, resulting in an epithelialised cavity that communicates with the urethra.

UD is more common in women secondary to poor anatomical support of the urethra, it is a rare finding in men.

Clinical features

Most patients with UD present between the third and seventh decade of life, with a median age of 40 years, but presentation can occur at any age.

Asymptomatic presentation:

Up to 20% of patients lack symptoms, with UD being an incidental finding on imaging.

Classic triad ‘three Ds’:

Seen in only 5% cases
  1. Dysuria
  2. Dyspareunia (12–24% cases)
  3. Dribbling (post-void)

Other features:

UD present in a myriad of ways including: asymptomatic and incidentally found lesions, painful vaginal masses, bothersome LUTS, stones, or malignancy.
  • Irritative LUTS (lower urinary tract symptoms)
  • Recurrent UTIs (⅓ cases): Due to urine stasis
  • Palpable anterior vaginal wall mass (exude retained urine/debris per urethral meatus upon compression)

Diagnosis

The vague and overlapping nature of symptoms frequently delays the diagnosis of UD by 2–5 years, with the mean interval between onset of symptoms and diagnosis of 5.2 years.

Urinalysis & culture:

  • M/C organism isolated in patients with UD: E. coli

Cystourethroscopy:

Visualise location of diverticular ostium and to evaluate for other causes of irritative/obstructive voiding symptoms
Retrograde urethrogram and micturating cystourethrogram shows irregular narrow distal urethral stricture, large diverticulum in proximal bulbar with dilated posterior urethra. Bladder show saccules with Grade 1 reflux on left side and stone in left terminal ureter | Thakur, N., Sabale, V. P., Mane, D., & Mullay, A. (2016). Male urethral diverticulum uncommon entity: Our experience. Urology annals, 8(4), 478–482. https://doi.org/10.4103/0974-7796.192094

Ultrasonography (US):

Transvaginal US of a 2.3-cm saddlebag UD.

Voiding cystourethrogram (VCUG):

Preoperative, intraoperative and postoperative imaging of 1 patient with distal bulbar UD. A, preoperative VCUG. B, intraoperativeurethral ultrasound using 7.5 MHz probe before UD excision and primary anastomosis. C, postoperative VCUG reveals absence of UD without urethral stenosis or extravasation. | Cinman, N. M., McAninch, J. W., Glass, A. S., Zaid, U. B., & Breyer, B. N. (2012). Acquired male urethral diverticula: presentation, diagnosis and management. The Journal of urology, 188(4), 1204–1208. https://doi.org/10.1016/j.juro.2012.06.036

MRI:

Magnetic resonance image of a circumferential urethral diverticulum. This axial T2-weighted image shows a saddle-shaped urethral diverticulum. | El-Nashar, S. A., Singh, R., Bacon, M. M., Kim-Fine, S., Occhino, J. A., Gebhart, J. B., & Klingele, C. J. (2016). Female Urethral Diverticulum: Presentation, Diagnosis, and Predictors of Outcomes After Surgery. Female pelvic medicine & reconstructive surgery, 22(6), 447–452. https://doi.org/10.1097/SPV.0000000000000312

Differential diagnosis:

  • Vaginal wall cysts
  • Leiomyoma
  • Skene gland abnormalities
  • Gartner’s duct abnormalities
  • Urethral prolapse
  • Urethral caruncle

Management

Nonoperative management:

For UDs that could be successfully emptied with manual compression (absence of urethral obstruction)
  • Prophylactic antibiotic therapy

Surgical management:

Indications for urethroplasty included recurrent UTIs despite antibiotic therapy, obstructive voiding or a stone in the UD
  • Urethral diverticulectomy & reconstruction
  • Urinary diversion

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