Clinical Presentation and Diagnostic Evaluation of Male Urethral Stricture

Abstract

Primary diagnosis of urethral strictures mostly relies on the presence of certain risk factors in the context of bladder outlet obstruction, that lead to further investigation. Findings on physical examination, patient-reported assessments, uroflowmetry, and post-void residual determination can raise suspicion of a stricture, but are not sufficient for diagnostic confirmation. Definitive diagnosis of urethral narrowing is based on cystoscopy, while staging, characteristics determination, and surgical planning is typically made using retrograde/voiding urethrogram. Evidence supporting the use of urethral ultrasound for anterior strictures has been growing considerably and may be even considered as surrogate for urethrogram in some specific settings. More recently, both urethral magnetic resonance, along with urethral computed tomography have proven to be helpful for complex cases of pelvic fracture urethral injuries, fistulas, and posterior urethral strictures.

Regarding follow-up studies after surgical repair, it has been recommended to use periodical patient-reported outcome measurements including not only voiding features, but also sexual, overall satisfaction, and quality of life fields, since, besides voiding function, urethroplasty may impact on several aspects of patients’ daily life. Currently, a comprehensive tool incorporating all these aspects does not exist yet. Additionally, uroflowmetry and post-void residual measurement should be performed on a regular basis. Nonetheless, cystoscopic evaluation should be done around 3 months and between 12 and 18 months postoperatively, because some recurrences may not be detected by the above-mentioned assessments. If a stricture recurrence is detected, then urethrogram is mandatory for staging and further surgical planning.

Appendices: Clinical Presentation and Diagnostic Evaluation of Urethral Stricture

1.1 Appendix 1

1.2 Appendix 2

Procedure Description for RUG/VCUG

Materials. Antiseptic solution to prep and sterile field should be available for draping. Our recommendation is to use a 60 ml syringe with a catheter tip adaptor and a long gauze to wrap and hold the penis. Alternatives are to utilize a 6-12F Foley’s catheter or a Brodny’s clamp. Inner sheath of intravenous catheter may be useful for meatal strictures. Intraurethral anesthetic lubrication is not recommended. Approximately 30–60 ml of water-soluble contrast (e.g., diatrizoate meglumine or iohexol). A tray should be available if VCUG is planned. Leaded gloves and apron for the staff are required.

Positioning. Subjects (specially their pelvis) should be placed obliquely at 20°–45° on a radiolucent stretcher, with the bottom hip flexed at 45°–90° and the top leg stretched down. Whether to use a right- or left-oblique positioning, is totally upon surgeon’s preference, as long as he/she stands on the opposite side of the screening arm. When positioning is correct, a scout film should show the lower obturator fossa completely closed, this prevents a potential underestimation of bulbar strictures length.

Fluoroscopy and Normal Findings. Scout film can detect stones, urethral or ureteral stents, staples or brachytherapy seeds. The long gauze is placed gently wrapping the penis, just below the corona, stretching it to get an optimal estimation of the urethral length. Contrast is then slowly injected under continuous fluoroscopy, demonstrating urethral distensibility, while saving sequential pictures. The goal is to see contrast passing through both the stricture and the membranous urethra, at least. Bladder filling for VCUG can be achieved by either RUG instillation or through a SPC (when placed beforehand).

Normal findings on RUG are: a uniform and smooth but narrower penile urethra transitioning to a wider bulbar urethra in an S-shaped fashion at the penoscrotal (penobulbar) junction; a bulbar tapering into membranous urethra forming a symmetrical cone which continues as a 1–2 cm long faint strand, representing the membranous urethra; then, an oval filling defect corresponding to the verumontanum is seen, along with a slight widening at the prostatic urethra; finally, the most proximal narrow segment before the bladder is the bladder neck. Under normal conditions, the posterior urethra will not be distended by RUG. Sometimes, Littre’s (penile) and Cowper’s (bulbomembranous) glands are seen on normal RUG, but they are usually seen secondary to obstruction. A filling defect at the proximal bulbar urethra due to a contraction of an anterior part of the bulbospongiosus muscle (compressor nudae) can be confused with a USx.

If voiding is achieved, normal findings on VCUG are: bladder neck, and prostatic and membranous urethra are open. Anterior urethra is poorly partially distended and delineation is suboptimal for a proper interpretation.

Tips and Troubleshooting. If the catheter-tip adaptor does not pass through a meatal/fossa stricture during RUG, it can be replaced by an intravenous sheath or one may use a 6-8F pediatric cystoscope or even a ureteroscope. When a subject is not able to void in the context of a bulbomembranous or posterior stenosis/PFUI during VCUG, the bladder neck status (regarding either function or anatomy) cannot be appropriately evaluated, so that, an attempt to ascendingly pass a 6-8F pediatric cystoscope can be done. If available, it might be necessary to perform an antegrade flexible cystoscopy through a SPC tract along with a RUG, simultaneously. If there is no previous tract, an 18F SPC might be placed, so antegrade cystoscopy could be done 3–5 weeks later, to better define the defect length and bladder neck status (incompetence, fibrosis, tethering or non-relaxing). Some simple non-evidence-based maneuvers may be attempted in case of psychological inhibition to void, e.g., to fill the bladder until the need to void is triggered, to open a water faucet, to play relaxing music, to turn the room’s lights off, and/or to place the patient in a standing position (but still obliquely). In patients with a known BPH, alfa-blockers may be initiated >7 days before VCUG. Information about posterior urethra/bladder neck may be critical in surgical planning and predicting postoperative continence after reconstruction.

1.3 Appendix 3

Procedure Description for SUG

Materials. Same preparation than used for RUG is made. Typically, SUG is performed with a linear transducer between 5 and 15 mHz. Urethra is slowly and steadily distended with 20–100 ml of sterile saline or jelly injected using the same materials and in the same fashion as in RUG, excluding air bubbles.

Positioning. Unlike in RUG, either a normal supine, a frog-legged or a low-lithotomy position is used, depending on the stricture length and location.

SUG Scanning. Under cephalad stretching, towards the pubic bone, multiple transverse and longitudinal scans on the ventral penile surface can be taken until length, caliber, location, spongiofibrosis, and coexistent pathology are identified. The same is repeated at the penoscrotal junction (trans-scrotally) for proximal penile and bulbar USx.