Approach Considerations
Once a diagnosis is suspected based on history and physical examination findings, endoscopic and radiologic studies help to localize the diverticulum. Urine culture should be performed to exclude coexisting urinary tract infection (UTI). When possible, culture of expressed fluid from the diverticulum should be obtained, as this aids in appropriate antibiotic selection.
Imaging Studies
The principal imaging studies used in the workup of urethral diverticula are voiding cystourethrography (VCUG) and magnetic resonance imaging (MRI). Ultrasonography (US) can also be used; in addition to its relative noninvasiveness and low cost, a particular benefit of US compared with MRI is in differentiating a septated urethral diverticulum from multiple urethral diverticula. [16] A limitation of US is that it is operator dependent.
Infrequently used techniques that may have utility in selected cases include intravenous pyelography (IVP), computed tomography (CT) urography, and retrograde urethrography using a double-balloon catheter.
Voiding cystourethrography
The most helpful plain film radiologic study is properly performed VCUG. This study aids in defining the location, size, and number of diverticula present. The study should be performed under fluoroscopic control with the patient sitting or standing in an oblique position. The presence of filling defects within the diverticulum may suggest the possibility of urethral calculi or a tumor.
The main limitation of VCUG is that it relies on the patient’s ability to void during the study. If the patient is unable to void, the urethra may not become opacified and a diverticulum that is present may not be seen.
Magnetic resonance imaging
MRI has emerged as the criterion standard in diagnostic imaging for urethral diverticula, as it reveals the extent and location of the diverticula. [10] In patients with strongly suspect symptoms, MRI demonstrates the diverticulum with the highest sensitivity and specificity of any of the imaging modalities. Furthermore, planar technology allows the exact ostium to be identified prospectively in many cases and can give the operating surgeon a “roadmap” to guide the operative intervention. [17, 18] T2-weighted MRI can identify the diverticulum and its extent and proximity to the bladder neck and other structures. While contrast administration is not required, it may help differentiate and enhance adjacent pathology, such as cancer.
Ultrasonography
US imaging of urethral diverticula can be performed using transabdominal, endovaginal, transperineal, translabial, or transrectal techniques. [19] US can provide precise measurements of the size of the lesion, the number of loculations, and the orientation and location with respect to the urethra. In some cases, US can be used to visualize the connection between the diverticulum and urethra. Also, US can be used to help differentiate solid from cystic suburethral masses, identify stones within diverticula, and visualize intraluminal masses.
Of the various US techniques for examining potential diverticula transabdominal US generally is agreed to be suboptimal, especially with small (< 2 cm) lesions. Transvaginal US has been useful for some, but not all, investigators; direct compression of the urethra and diverticulum may be a problem. The transrectal approach has many strong advocates, with improved visualization of the periurethral area cited as one substantial advantage.
Transperineal or translabial US is performed by placing the imaging probe between the labia minora and directly on the external urethral meatus. This may be the route of choice with distal diverticula, although the transrectal approach actually may allow probe placement closer to the lesion in cases of proximal urethral diverticula.
Compared with other ultrasound routes, translabial ultrasound provides superior imaging of the urethral rhabdosphincter. On 3D/4D translabial ultrasound, visualization of a gap in the hyperechoic urethral rhabdosphincter circle formed between the cyst and urethral lumen in the axial plane is a diagnostic sign of urethral diverticulum. [20, 21]
Intravenous pyelography and CT urography
Urethral diverticula have been noted incidentally on IVP relatively infrequently. Postvoid radiography from an IVP may reveal a collection of contrast below the urinary bladder consistent with urethral diverticulum.
While IVP is not recommended as a routine imaging study to document urethral diverticulum, it is useful when ectopic ureterocele is suspected. CT urography may be a better modality since it offers more planes of view; however, no studies to date have confirmed it should be used routinely in the evaluation of suspect diverticula.
Retrograde urethrography using a double-balloon catheter
This technique has been popular in the past but has fallen out favor because retrograde positive-pressure urethrography is technically difficult to perform and is usually painful. However, this procedure may be performed under general anesthesia, if desired. This procedure has largely been replaced by MRI. Retrograde urethrography using a double-balloon catheter may be useful if a suspected diverticulum cannot be observed on VCUG.
Procedures
Urodynamics
Consider urodynamic studies in patients with symptoms of stress urinary incontinence or overactive bladder. Patients with overactive bladder may require anticholinergic therapy to control irritative voiding symptoms.
Cystoscopy
Cystourethroscopy is often performed using a short beaked female urethroscope with a 0° lens. Alternatively, flexible cystoscopy or a urethrotome sheath may be used. Constant water flow and bladder neck occlusion during urethroscopy allows the entire urethra to be distended to enhance visualization. Simultaneous digital compression of the urethral diverticulum may cause active drainage of pus into the urethral lumen, allowing identification of the communication site. Localization of the ostium before surgery is of particular importance, as this guides closure of the ostium during diverticulectomy.
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The urethral diverticulum is shown as spherical mass at the distal urethra.
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Voiding cystourethrogram reveals contrast pooling in a urethral diverticulum. The urethral diverticulum is located well away from the bladder neck at the distal urethra.
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The anterior vaginal wall and the periurethral fascia have been dissected off, exposing the urethral diverticulum.
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The urethral diverticulum has been excised sharply. Foley catheter is visible through the neck of the diverticulum.
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The urethral diverticulum is closed in 3 layers with nonoverlapping suture lines. The vaginal wall is closed.
