A urethral diverticulum is an outpouching of the urethral wall extending into the urethrovaginal tissue. Urethral diverticulum usually presents as a lump or mass on the anterior wall of the vagina.
Women with urethral diverticula may present as asymptomatic cases or with nonspecific urological and genital symptoms which may make the diagnosis indistinguishable from other urogenital conditions.
Classically, urethral diverticulum presents with a triad of dysuria, dyspareunia, and post-void dribbling. The commonest presentation is dysuria, which occurrs in 10-70% of cases. Conditions of dyspareunia and post-void dribbling occur in 10-70% and 25% of cases, respectively.
Other symptoms of urethral diverticulum include urinary frequency, urgency, recurrent urinary tract infections, stress or urge incontinence, and hematuria. Less common symptoms include urethral pain, suprapubic pain, nocturia, urinary retention and hesitancy, and presence of anterior vaginal swelling  . Urinary frequency and urgency are the most frequent symptoms, occurring in 40-100% of cases, while incontinence, hematuria, and repeat urinary tract infections (UTIs) occur in less than 70% of cases.
Physical examination may not be sufficient, however, it could reveal a mass in the posterior part of the urethra. On palpation, the mass may be softer and urine or pus may be expressed from the outgrowth . If the palpated mass feels hard, it is suggestive of a neoplasm of urethral diverticulum or calculus.
Neoplasms of urethra are found more commonly as adenocarcinomas. These neoplasms have been shown to be more common among black people. Furthermore, a study revealed that 6% of patients who had undergone surgery for urethral diverticulum had urethral neoplasms. Investigators have suggested that repeated injuries to the walls of the diverticulum may play a role in the development of dysplastic changes in the gland cells . Reports have shown that urethral calculus occurs in 10% of patients with urethral diverticulum. Urinary stasis and accumulation of salt in the urinary outflow tract may be responsible for the calculus formation.
Because of the non-specificity of the symptoms of urethral diverticulum, misdiagnosis often occurs. Common differential diagnoses which are initially considered include vulvovestibulitis, recurrent cystitis, vulvodynia, interstitial cystitis, and endometriosis.
A detailed history, physical examination, and appropriate investigations are sufficient to diagnose cases of urethral diverticulum. Investigations which are necessary for the diagnosis of urethral diverticulum include urodynamic studies and imaging techniques.
On physical examination, the pus or urine may be safely expressed from the urethral diverticulum by milking the urethra. Furthermore, in women, the anterior vaginal wall should be palpated for tenderness and masses.
None of the imaging techniques employed in the evaluation of patients affected by urethral diverticulum is considered definitive. There are certain merits and demerits of each technique and the choice of these to employ depends on the experience and skill of the radiologist, the availability, and cost of the technique. Available imaging modalities for investigation of urethral diverticulum include several techniques, such as, double-balloon positive-pressure urethrography (PPU), voiding cystourethrography (VCUG), magnetic resonance imaging (MRI) with or without the use of an endoluminal coil (eMRI), and ultrasonography  .
In some patients, urodynamic studies may be employed to determine the presence of urinary stress incontinence. An example of urodynamic study includes videourodynamic study which makes use of both urodynamic evaluation and cystourethrogram. This facilitates a combined and detailed evaluation of the urinary tract structure and function and reduces the need for frequent urethral instrumentation. Videourodynamic assessment may also help to distinguish true cases of stress incontinence from cases of pseudo-incontinence, which results from exertion-induced voiding of collected urine in a urethral diverticulum.
Treatment of mild or asymptomatic urethral diverticulum involves mainly a conservative approach of using prophylactic antibiotics and supportive treatment. Other suggested methods of treatment of mild or asymptomatic cases include digital decompression, urethral dilation, and periodic needle aspiration . These forms of treatment are largely supportive and not curative. There has been insufficient data on the effectiveness of these treatment methods.
Symptomatic cases can be treated with surgery and the surgical procedure performed depends on the site of the diverticulum . Urethral diverticulectomy is the treatment of choice in urethral diverticula occurring in the middle and proximal thirds of the urethra, however, urethral diverticula located in the distal third segment of the urethra are treated by marsupialization into the vagina. Generally, the definitive treatment for urethral diverticulum involves its excision through the transvaginal route . Marsupialization is best avoided as a treatment form for more proximal diverticula because of the high risk of complications such as incontinence resulting from iatrogenic injury to the urethral sphincters. Transurethral surgical techniques are considered safe for the proximal diverticula . Furthermore, pre-operative treatment of acute infections is recommended to reduce the risk of complications.
Surgical removal of a urethral diverticum, diverticulectomy, carries a success rate of 86-100%. However, this procedure may present with certain complications including recurrent diverticulum, stress incontinence, urethral stricture, and recurrent urinary tract infection. Recurrent diverticulum and urinary tract infection constitute the commonest complications of diverticulectomy.
The cause of urethral diverticula is not fully known, however, it has been hypothesized that it may be a congenital anomaly, although, they are not commonly found in children. Most investigators suggest that the urethral diverticulum is a result of prolonged recurrent infection and obstruction of the urethral and periurethral glands. This recurrent infection and inflammation result in formation of abscesses or cysts in these glands which eventually rupture into the lumen of the urethra. The ruptured cyst or abscess eventually epithelializes forming a true diverticulum in contrast to a urethrocele or a false diverticulum which has no epithelium .
Predisposing factors to urethral diverticula consist of iatrogenic factors such as injuries from urethroscopy, vaginal birth injuries, urethrotomy, and a lot of other urologic surgical procedures. These were once thought to be the direct causes of urethral diverticula. However, it has now been agreed by most investigators that main cause of urethral diverticula is repeated infection and inflammation of the urethral and periurethral glands.
Various microorganisms have been cultured from the diverticulum, examples of these include Escherichia coli and chlamydia species. In rare cases, gonococci are cultured.
Determining the definite prevalence rate of urethral diverticulum is currently difficult because of the misdiagnosis and under diagnosis that is often associated with the disease. However, the prevalence of this condition in adult females as found from autopsy reports and urethrography reports is estimated to range from 1%-5% . Another study reported an incidence rate of approximately 20 per 1,000,000 annually . Urethral diverticula are not limited to women as reports of its occurrence in men and children have been well documented.
Urethral diverticula usually occur in adults between the second to sixth decades of life . The risk factors have been noted to include female gender, periurethral procedures and instrumentation, and pelvic trauma. Furthermore, urethral diverticulum is three times more prevalent among black women as compared to white women.
The periurethral glands are tubuloalveolar glands which line the urethral wall. These glands are located in the posteriolateral aspects of the middle and the urethral wall of distal third part. Most of these glands open and drain into the distal third portion of the urethra.
When the periurethral glands are infected, their ducts may become obstructed secondary to the inflammatory changes. Recurrent infections exacerbate the obstruction and, therefore, result in the swelling of the gland and formation of a cyst or an abscess cavity . Ultimately, the abscess cavity ruptures and opens into the urethral lumen. During urination, some urine collects into the suburethral cyst and the ruptured cavity, which, in turn, enlarges into an outpouching, further epithelialized forming the urethral diverticulum.
Histologically, the diverticulum consists mostly of fibrous tissue. The chronic inflammation resulting from the repeated infections results in marked fibrosis of the diverticulum which becomes strongly adherent to adjacent tissues. The periurethral fascia remains mostly intact; however, if the urethral diverticulum becomes severely infected, it may result in invasion of the vaginal wall.
Urethral diverticula commonly affect the distal third portion of the urethra, and they rarely occur in the proximal third or anterior aspect of the urethra. Rarely, a distal urethral diverticula may arise from an obstructed urethral gland.
Urethral diverticula may vary in size and shape. Some appear spherical, others have a horseshoe shape.The width of the opening of the diverticula with the urethral lumen also varies.
Preventive measures against the development of urethral diverticula are not well established. However, prevention of such risk factors as vaginal birth trauma and urinary tract infections, and reducing the frequency of urethral instrumentation may help to reduce the incidence of urethral diverticulum formation.
Urinary diverticula could occur in the urethra or bladder in both men and women . Whereas acquired bladder diverticula are more common in men, urethral diverticula affect mostly women. Bladder diverticula are commonly associated with benign prostatic hypertrophy or any prostatic mass which causes urethral obstruction. Consequent to this urethral narrowing, the intraluminal pressure of the bladder increases in a bid to force the urine through the narrowed urethra, this ultimately results in weakness of the bladder wall especially between the bladder muscle wall fibers. These areas of weakness in the bladder eventually invaginate forming a diverticulum in the bladder wall. Bladder diverticula are usually asymptomatic and may not require treatment in contrast to urethral diverticula which are often symptomatic.
Urethral diverticula occur as a result of blockade of periurethral glands sequel to recurrent infection and inflammation of these glands. The periurethral glands are small glands which occur along the mucosa of the urethra and most of them drain into the distal third part of the urethra. Blockage of the ducts of these glands results in formation of an abscess or cyst which eventually ruptures into the lumen of urethra. Overtime, re-epithelialization occurs over the glandular opening forming a true diverticulum.
Urethral diverticulum presentation follows a classic triad of conditions like dysuria, dyspareunia, and post-void dribbling. Other symptoms include urinary frequency, urgency, hesitancy, and retention. These symptoms occur with varying frequency. Urethral diverticula may also present with urethral pain, suprapubic pain, and recurrent urinary tract infections, and hematuria.
Diagnosis of urethral diverticulum can be made via clinical evaluation and laboratory investigations. Essentially, diagnostic modalities for evaluation of urethral diverticulum include urodynamic studies and imaging techniques.
Treatment of mild and asymptomatic urethral diverticula is mostly conservative with prophylactic antibiotics and supportive care. Moderate to severe cases of urethral diverticulum are treated with surgery.
The urethra is a long tube which connects the bladder to the exterior. It is the conduit of urine from the bladder to the external environment. A diverticulum is an outpouching or a growth growing out of the wall of an organ. A urethral diverticulum is, therefore, an outgrowth on the wall of the urethra.
The cause of urethral diverticula (plural of diverticulum) is largely unknown; however, a lot of researchers have suggested that it may arise as a result of repeated infection and inflammation of small glands in the urethra. These glands are called urethral and periurethral glands. The chronic inflammation of these glands leads to their obstruction, enlargement, and finally, rupture into the urethra. Overtime, the ruptured glands become covered by new cells forming an outpouching, the diverticulum.
Urethral diverticulum is more common among women than men and it mostly occurs in adults aged 20 to 60 years. The risk factors for urethral diverticulum include frequent passage of instruments such as a catheter into the urethra and trauma to the pelvic region. Urethral diverticula are also more common among black women than white women.
Urethral diverticula may present with no symptoms at all; however, in most patients, they present commonly with pain on urination, pain during sex, and dribbling of urine after urination. Other symptoms include pain in the lower abdomen, excessive urination, inability to hold urine, bloody urine, and feeling of having urine left in the bladder after urination. There might also be a foul-smelling discharge, sometimes, released from the urethra.
Doctors can make a diagnosis of urethral diverticulum by physically examining the patient, getting details of the prevailing symptoms, and performing certain investigations. These investigations include imaging techniques which help to view the bladder and urethra, and a study which assesses the pressure and flow of urine in the bladder and urethra.
In cases where the symptoms are absent or mild, the patients are treated with antibiotics and supportive therapy to relieve the symptoms. These treatment plans are supportive and do not cure the disease.
In cases with moderate and severe symptoms, treatment plan considered is surgery. Surgery is usually a day-case surgery in which the patient goes back home on the same day. Surgery entails removal of the diverticulum and repair of the wall of the urethra, however, this procedure follows a number of complications including reappearance of the diverticulum, recurrent urinary tract infections, and involuntary urination when the lower abdomen is tense.