Urethral diverticulum (UD) is a medical condition characterized by the formation of a sac-like pouch that develops along the urethra. This condition is observed far more frequently in women than in men, typically presenting between the ages of 30 and 70. Because its manifestations often mimic other common urinary tract issues, UD is frequently overlooked or misdiagnosed for extended periods. Increased awareness and sophisticated imaging techniques are helping to improve the detection rate.
Defining the Condition
A urethral diverticulum is an outpouching of the urethral lining that protrudes outward into the surrounding tissue, often toward the anterior vaginal wall in women. This abnormal pouch usually connects to the main urethral channel through a small opening, known as an ostium. Most diverticula are found along the middle or distal sections of the urethra.
During urination, urine flows into this pouch through the ostium, where it becomes trapped and stagnant. This retention creates a localized reservoir that can accumulate urine, pus, mucus, or cellular debris. The presence of this fluid-filled sac adjacent to the urethra leads to the development of symptoms and complications.
Identifying the Symptoms
The clinical presentation of a urethral diverticulum is highly variable, contributing to the difficulty in achieving a timely diagnosis. Many patients experience non-specific lower urinary tract symptoms that are often mistakenly attributed to other conditions, such as bladder infections.
One characteristic complaint is post-void dribbling, which is the involuntary leakage of urine minutes after voiding. This happens when pooled fluid within the diverticulum slowly drains out. Recurrent urinary tract infections (UTIs) are also common due to the constant presence of stagnant, infected urine in the pouch.
Patients frequently report painful urination (dysuria) and discomfort during sexual intercourse (dyspareunia). A clinician may also detect a tender, palpable mass located beneath the urethra in the anterior vaginal wall. The size of the diverticulum does not always correlate with symptom severity.
Understanding the Underlying Causes
The vast majority of urethral diverticula are acquired rather than congenital. The most accepted theory centers on the periurethral glands, specifically the Skene’s glands, located near the end of the urethra.
When the ducts of these glands become obstructed, often due to recurrent infection, they can swell and form a retention cyst or an abscess. If pressure builds, the abscess can rupture inward into the urethral lumen. This rupture creates a permanent communication between the abscess cavity and the urethra, establishing the sac-like structure of the diverticulum.
Less commonly, UD may result from a congenital defect or trauma sustained during childbirth. Continuous exposure to urine prevents the opening from healing, allowing the pouch to persist and repeatedly fill. This cycle of obstruction, infection, and rupture explains the history of chronic urinary problems.
Diagnostic Procedures
The evaluation for a urethral diverticulum begins with a medical history and physical examination, where a physician may attempt to palpate the anterior vaginal wall. Pressing on a tender, suburethral mass during this exam can sometimes result in the expression of pus or retained urine from the urethral opening, providing a strong clinical suspicion of UD.
To definitively confirm the diagnosis and map the anatomy, imaging studies are required. Magnetic Resonance Imaging (MRI), particularly T2-weighted sequences, has become the gold standard for visualization due to its superior soft-tissue contrast. MRI clearly shows the size, location, and extent of the diverticulum, providing a roadmap for surgical intervention.
Another technique is the Voiding Cystourethrogram (VCUG), a specialized X-ray performed while the patient is urinating. The VCUG involves instilling a contrast dye into the bladder and urethra, which may then fill the diverticular pouch. However, VCUG requires the ostium to be open for the dye to enter, making it less sensitive than MRI.
Management and Treatment Options
The approach to managing a urethral diverticulum depends on the presence and severity of symptoms. Small diverticula discovered incidentally that cause no distress may require only conservative management, involving observation and regular monitoring.
For patients experiencing significant symptoms such as recurrent infections, pain, or post-void dribbling, surgical excision, known as diverticulectomy, is the definitive treatment. This procedure is performed through a transvaginal approach and involves dissecting and removing the entire diverticular sac while preserving the integrity of the urethra.
The surgical goals include complete removal of the pouch, watertight closure of the defect in the urethral wall, and reinforcement of the surrounding tissue with multiple layers of sutures. Following surgery, a urinary catheter is left in place for one to two weeks to allow the urethral repair to heal without urine exposure.
While diverticulectomy is effective, potential complications include the formation of a urethrovaginal fistula (a connection between the urethra and the vagina) or new-onset stress urinary incontinence. The risk of recurrence after a successful repair is low.