Cystourethroscopy facilitates anatomical assessment of the bladder and the urethra. The precise role of cystourethroscopy in the evaluation of female urinary incontinence is controversial.  It may be more useful in assessing residual sphincteric function in males with postprostatectomy incontinence who are considering surgical treatment of their condition.  Specifically, surgeons may recommend a sling as opposed to an artificial sphincter in more mild cases of incontinence in which residual sphincter function is intact. [3, 4]
On the other hand, cystoscopy helps detect bladder lesions and identify other pathologies. These may include foreign bodies (eg, suture, mesh material from prior surgery for prolapse or incontinence), bladder cancer, and bladder stones —conditions that would otherwise remain undiagnosed if only urodynamic studies are performed. A visual inspection of the urethra can also establish a diagnosis of urethral stricture or identify urethral diverticulum. Such conditions may contribute to incontinence and irritative voiding symptoms.
In general, cystoscopy is indicated for patients with persistent irritative voiding symptoms, hematuria, postoperative incontinence, voiding dysfunction, and suspicion of a urethral diverticulum or fistula. Obvious causes of bladder overactivity, such as cystitis, stone disease, and tumor, can be easily diagnosed. This information is important in determining the etiology of the incontinence and thus influences treatment decisions.
A flexible cystoscope rather than a rigid cystoscope is routinely used for diagnostic cystourethroscopy. A flexible cystoscope has excellent optics and enhances patient comfort during the cystoscopic examination, especially if performed in the office setting. Careful urethroscopy is also routinely performed to assess the structure and function of the urethral sphincter mechanism and to rule out urethral pathologies.
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In general, the patient is positioned in the dorsolithotomy position, the genitals are prepared and draped in a sterile manner, and a copious amount of lubricant is applied to the urethral meatus and cystoscope. All patients with risk factors for surgical infections should receive antibiotic prophylaxis prior to simple cystourethroscopy according to the American Urological Association guidelines on antimicrobial prophylaxis.  Likewise, all patients undergoing cystourethroscopy with any form of intervention should also be given prophylaxis.
The irrigant flow is then turned on and the cystoscope is inserted carefully into the urethral meatus. Care is taken to insert the scope through the urethra in an atraumatic manner with the aid of direct visualization. Once the bladder neck is traversed and bladder entered, the bladder can then be drained of urine or urine can be obtained for culture and analysis. Systematic inspection of the bladder is then performed with a moderate volume of irrigant solution instilled and should include both inspection of the bladder neck and bladder dome via scope flexion. Care should be taken to look for bladder pathology (eg, mucosal lesions, foreign bodies, structural changes of the bladder wall, openings to diverticula or fistulae). The ureteral orifices should be identified bilaterally.
Upon satisfactorily inspecting the bladder, irrigation should be started again to facilitate urethral inspection. The scope should be gradually withdrawn through the bladder neck and urethra, taking care to view the urethral mucosa and structure as the lumen collapses past the end of the scope. Maneuvers to assess sphincter function, such as Valsalva and voluntary sphincter contraction, can be performed. The patient should then be cleaned, the drapes should be removed, and the patient should be shown to the nearest toilet to void, if needed.
Comparisons of cystourethroscopy and multichannel urodynamic studies show the latter to be more sensitive and specific in diagnosing stress incontinence and detrusor overactivity. Yet, cystourethroscopy can facilitate important anatomic and functional assessments of the lower urinary tract that can lead to diagnoses not evident on urodynamics. Thus, in combination with urodynamics, cystourethroscopy can aid in making a correct diagnosis.
A fixed, rigid, nonfunctioning urethral sphincter can be found in severe cases of intrinsic sphincter deficiency. Neurologic injury can also produce such a presentation. Rounding of the urethra or the presence of bladder trabeculations (ie, thick, bandlike cords of detrusor muscle, often with interspersed shallow diverticulum or cellules) during bladder filling may indicate a diagnosis of detrusor overactivity.  Otherwise, in males, such bladder findings are most suggestive of outlet obstruction, usually due to prostatic enlargement.
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A retrospective study of 84 patients in a referral urogynecology practice illustrated the potential importance of cystourethroscopy in evaluating incontinence, as 19% of the cases had a cystourethroscopic finding that changed clinical management.  These included intravesical sutures, urethral diverticula, bladder cancer, and cystitis glandularis. In addition, a number of patients had urethroscopic findings that contributed to the ultimate diagnosis of intrinsic sphincter deficiency. Bladder neck fronds and polyps or cystitis cystica can indicate prior or chronic inflammation. Findings including urinary tract fistulas, diverticular openings, and functional ureteral abnormalities can be also visualized with cystourethroscopy.
In most cases, cystourethroscopic findings support urodynamic diagnoses. Thus, cystourethroscopy complements urodynamic testing and may enhance its diagnostic accuracy. Additionally, patients in this population diagnosed with malignant or premalignant lesions may not always have the classic symptoms of pain and hematuria. Likewise, other commonly associated characteristics and risk factors, such as advanced age, urinary urgency, and detrusor overactivity, may not be present. Thus, cystourethroscopy also can aid in diagnosing other urologic conditions.
Other adjunctive tests, such as fluoroscopy and videourodynamics, can provide further anatomic assessment of the lower urinary tract. However, these methods are more costly and less readily available in clinical practice. More research is needed to further define the role of cystourethroscopy in the evaluation of urinary incontinence, but it remains a helpful diagnostic procedure that complements urodynamic testing.
Dynamic Retrograde Urethroscopy
In this technique, the cystoscope is first introduced into the bladder and the bladder is filled to 250 mL with irrigant solution. The flow of the irrigant is then turned off and the cystoscope is withdrawn to the mid urethra. The activity of the urethral sphincter mechanism is observed at rest and with Valsalva maneuvers.
Patients with stress urinary incontinence due to urethral hypermobility whose urethra is otherwise normal have a closed bladder neck at rest and intact voluntary guarding reflex. Patients with stress incontinence due to intrinsic sphincter deficiency have an open bladder neck at rest and impaired voluntary guarding reflex. A reassessment of the full length of the urethra with irrigant running is also generally performed to observe for evidence of urethral pathology.
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