A urethral diverticulum has been defined as an out pouching of the urethral tissue into the urethro-vaginal space. The lining of the diverticulum is the same as urethral mucosa.
Frequency of Urethral Diverticula
The exact frequency of urethral diverticula cannot be determined as most of the cases remain asymptomatic and hence get missed. Urethral diverticula are far more common in females, especially in those suffering from chronic genitourinary problems like recurrent urinary tract infections, post-void dribbling of urine and dyspareunia.
In the rare cases, when urinary diverticula are found in males, they are associated with congenital anomalies of the urinary tract or trauma during surgery.
Although urethral diverticulum can appear at any age, the most commonly affected are women in the age group of 30 to 50 years.
Origin and Progression of a Urethral Diverticula
Urethral diverticula are believed to originate from para-urethral glands. Obstruction and infection of these glands may lead to their inflammation. The glands get enlarged, form a retention cyst and then an abscess. The abscess may rupture back into the urethra or through the peri-urethral connective tissue into the space between the vaginal wall and this connective tissue.
Stones may form inside the urethral diverticulum in 1.5% to 10% of cases. They are usually composed of calcium oxalate or phosphate. The most probable reason for formation of stones is stagnation of urine inside the diverticulum.
Constant injury of the mucosal tissue lining the urethral diverticulum may lead to hyperplastic and neoplastic changes inside it. 5% of all urethral cancers develop inside the urethral diverticula. Of these, 60% are adenocarcinomas, 30% are transitional cell carcinomas in nature, while 10% are composed of squamous cells.
Signs and Symptoms of Urethral Diverticula
The signs and symptoms of urethral diverticula vary from patient to patient. They may also depend on the time when the diagnosis is made. When the condition is diagnosed early, most of the symptoms pertain to urination and include dysuria, increased frequency of micturition and post-void dribbling. When the condition is identified late, the symptoms may include low pelvic pain and dyspareunia. Recurrent infection or neoplastic changes may also lead to hematuria which is seen in 10% to 25% of all cases of urethral diverticulum.
Physical Findings in Case of Urethral Diverticula
The physical findings may also vary from patient to patient. While they may be completely absent in one patient, they may be marked in the other patient. Important physical findings may include:
- Palpable mass on the anterior vaginal wall
- Purulent discharge from the urethral opening upon compression
- Sub-urethral tenderness
Treatment of Urethral Diverticula
Treatment is usually indicated only when the condition is symptomatic. However, in case a filling defect is noticed during imaging studies, it is a sign for intervention as it may indicate the presence of stones or development of malignancy within the diverticulum.
Medical Treatment for Urethral Diverticula
Treatment of urethral diverticula basically involves surgery. The role of medical intervention is limited to treatment of recurrent urinary tract infections before taking up the patient for surgery. Medical treatment can also be considered in patients who are unwilling or unfit for surgery.
Surgical Treatment of Urethral Diverticula
Surgical intervention depends upon the exact location of the urethral diverticulum.
- In cases where the diverticulum empties into the distal one third of the urethra, simple marsupialization of the diverticular sac may solve the purpose.
- If the diverticulum opens distal to the urethral rhabdo-sphincter, the diverticular sac is exteriorized after incising the posterior urethral wall.
- If the diverticulum opens into the middle or proximal one third of the urethra, total excision or ablation is the preferred treatment of choice.