Hypothesis / aims of study
Polypropylene mid-urethral tape (MUT) procedures are the most effective treatment for stress urinary incontinence. (1) Complications of chronic pain and dyspareunia are known to be associated with MUT. (2) Translabial ultrasound scanning (TLUS) can reliably assess the location of MUT. (3) TLUS is offered by some centres as part of the evaluation for potential MUT related complications, the exact role of this in planning management has not been defined. The aim of this study is to describe the findings of TLUS in a population of women referred with chronic pain following MUT.
Study design, materials and methods
Data were collected for women who presented with chronic pain following MUT and had a TLUS, between April 2016-February 2019. Scans were performed by one of two operators with relevant competencies. Data were recorded for the route of the MUT, time since procedure, findings and management. Scans schematically reported parameters of tape location, diameter, proximity to longitudinal smooth muscle, tape orientation at rest and on strain. Images were taken in sagittal and coronal planes and any defects in the course of the MUT were noted. Relevant clinical and demographic data were recorded.
Data were analysed using descriptive statistics.
Data from 78 women were evaluated. The average age was 51.7 years, and average time from surgery to presentation was 6.79 years. 37 tapes were retropubic , 35 were transobturator , 3 single incision slings; 3 had undergone 2 MUT procedures (2 of these had removal of the initial tape).
43/78 tapes were found to be away from the longitudinal smooth muscle of the urethra. 8 were proximally placed and 35 distally placed on the urethra. 21/78 were found to be sited in the mid-urethral portion. In 2 tapes it was not possible to determine position in relation to the urethra, due to previous excisions. The tape location was not commented on in 12 cases.
8 scans were suggestive of proximity to the longitudinal smooth muscle; one of these tapes was found to be within the urethra at cystourethroscopy. 4 tapes appeared twisted, and 1 appeared prominent. Average tape diameter was 6.34 mm (95% CI 5.95- 6.73).
13 women had previous partial excisions for mesh exposure, and this was correctly identified at TLUS as a defect in the relevant portion of the course of the MUT. No women had defects in the course of the MUT, unless they had previous excision. 5 scans were suggestive of urethral perforation; 3 of these were confirmed at cystourethroscopy. 2 patients had a small urethral perforation at urethroscopy with a normal appearance on TLUS. TLUS to detect perforation in this cohort had a sensitivity of 60% and specificity of 97.2%.
Interpretation of results
Adequate images of the course of the MUT were identified in all cases, with all those with previous excision correctly identified. No defects of the course of the MUT were found in those without previous excision. This suggests that TLUS is useful in mapping the course of MUT and may help surgeons minimise dissection during excision.
The study found that tapes associated with pain were narrower than at the time of insertion. This may be due to increase fibrosis. However, a control group is required to further investigate this finding.
In our study, we found that the finding of exposure was specific, however with a lower sensitivity. Not all cases went onto have a cystourethroscopy, and so these numbers may be different in reality. As this was a retrospective study, involving only a case group, i.e. those with the complication of pain, it is difficult to infer the exact diagnostic role of TLUS.