Urethral diverticulum

Transperineal and endovaginal ultrasound for evaluating suburethral masses: comparison with magnetic resonance imaging

OBJECTIVE

To evaluate the utility of pelvic floor ultrasound (US) in the detection and evaluation of suburethral masses, using magnetic resonance imaging (MRI) as the reference standard.

METHODS

This was a retrospective analysis of US and MRI scans of all women with a suburethral mass on clinical examination at a single urogynecology clinic over a 13-year period (February 2007 to March 2020). All women were examined using two-dimensional transperineal US (2D-TPUS) with or without three-dimensional endovaginal US (3D-EVUS). All patients underwent unenhanced T1-weighted and T2-weighted MRI, which was considered the reference standard in this study. Presence of a suburethral mass and its size, location, connection with the urethral lumen and characteristics were evaluated on both pelvic floor US and MRI. Agreement between pelvic floor US and MRI was assessed using intraclass correlation coefficients (ICC; 3,1).

RESULTS

Forty women suspected of having a suburethral mass on clinical examination underwent both MRI and US (2D-TPUS with or without 3D-EVUS). MRI detected a suburethral mass in 34 women, which was also detected by US. However, US also identified a suburethral mass in the remaining six women. Thus, the agreement between US and MRI for detecting a suburethral mass was 85% (95% CI, 70.2-94.3%). The ICC analysis showed good agreement between MRI and 2D-TPUS for the measured distance between the suburethral mass and the bladder neck (ICC, 0.89; standard error of measurement (SEM), 3.64 mm) and excellent agreement for measurement of the largest diameter of the mass (ICC, 0.93; SEM, 4.31 mm). Good agreement was observed between MRI and 3D-EVUS for the measured distance from the suburethral mass to the bladder neck (ICC, 0.88; SEM, 3.48 mm) and excellent agreement for the largest diameter of the suburethral mass (ICC, 0.94; SEM, 4.68 mm).

CONCLUSIONS

2D-TPUS and 3D-EVUS are useful in the imaging of suburethral masses. US shows good-to-excellent agreement with MRI in identifying and measuring suburethral masses; therefore, the two modalities can be used interchangeably depending on availability of equipment and expertise. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. - Legal Statement: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Urethral Diverticulum following Polypropylene Mesh Midurethral Slings: A Literature Review

Aims

It is currently unknown whether an association exists between polypropylene mesh and urethral diverticulum formation following placement of polypropylene midurethral slings (MUS) for the treatment of stress urinary incontinence (SUI). We aimed to examine the literature associating MUS with the occurrence of urethral diverticula.

Methods

Multiple online research databases, including PubMed, Google Scholar, EBSCOhost, and the Cochrane Library, were searched, from January 2019 to February 2019, for evidence related to the occurrence of urethral diverticula following polypropylene MUS procedures.

Results

Four case reports were published demonstrating the occurrence of urethral diverticula following the use of polypropylene mesh for surgical treatment of SUI. Subjects of these cases were menopausal and had an elevated body mass index (BMI), recurrent urinary tract infections (UTIs), autoimmune conditions, or prior pelvic floor surgeries. A thorough urologic workup, including imaging prior to sling placement, was not always performed.

Conclusion

No clear association exists between polypropylene MUS placement and subsequent urethral diverticulum formation. Factors that diminish polypropylene mesh biocompatibility include elevated BMI, menopause, recurrent UTIs, prior pelvic surgeries, and preexisting medical conditions. Symptoms associated with urethral diverticula should prompt a complete urologic workup prior to MUS placement.

Urethral diverticulum and urolithiasis in a female guinea pig (Cavia porcellus)

CASE DESCRIPTION A 5-year-old sexually intact female guinea pig was evaluated because of mild dysuria and a subcutaneous mass located cranioventral to the urogenital openings. CLINICAL FINDINGS Non-contrast-enhanced CT and surgical exploration of the distal aspect of the urethra revealed a urethral diverticulum with an intraluminal urolith. Analysis revealed that the urolith was composed of calcium carbonate and struvite. TREATMENT AND OUTCOME The urolith was surgically removed and ablation of the urethral diverticulum was attempted. Approximately 3 months later, the guinea pig was reevaluated for masses in the perineal region, and positive-contrast urethrocystography revealed 2 uroliths present in the same diverticulum. Uroliths were manually expressed with the patient under general anesthesia. Approximately 2 weeks later, urethroplasty was performed to create an enlarged stoma with the diverticulum, thereby preventing urine from pooling in the diverticulum and potentially reducing the risk of future urolith formation. The urethroplasty site healed well with no reported complications or evidence of urolith recurrence 6 months after surgery. CLINICAL RELEVANCE Urolithiasis is common in guinea pigs, and urethral diverticulum and intraluminal urolith formation should be considered as a potential differential diagnosis for a subcutaneous mass along the distal aspect of the urethra. Creation of a urethral stoma from a urethral diverticulum via urethroplasty achieved a successful outcome in this patient.