Our recent study explored whether sonographically confirmed urethral funneling may help identify patients at increased risk of persistent incontinence after MUS. Urethral funneling—defined as the opening of the proximal urethra during Valsalva—has traditionally been interpreted as a sign associated with intrinsic sphincter deficiency and impaired urethral closure mechanisms. Despite this, its role in guiding surgical decision-making has not been clearly defined.
In a retrospective cohort of women with preoperative urethral funneling and correct postoperative sling positioning, we identified two independent predictors of persistent urinary incontinence at 24 months:
- Higher preoperative symptom severity (ICIQ-UI-SF ≥18)
- Use of the transobturator approach (TOT)
While these findings must be interpreted with caution, they raise an important clinical question: Should urethral funneling influence surgical technique selection?
The Potential Role of Pelvic Floor Ultrasound
Pelvic floor ultrasound (PFUS) has evolved from a diagnostic adjunct to a potentially strategic tool in surgical planning. It allows dynamic assessment of urethral mobility, bladder neck behavior, urethral morphology, and sling positioning. Yet, in most centers, its preoperative use does not systematically influence the choice between retropubic and transobturator approaches.
Our findings suggest that funneling may represent more than a descriptive anatomical feature. It may identify a subgroup of patients in whom a retropubic vector of support provides superior functional reinforcement compared with the more lateralized transobturator trajectory.
If confirmed, this could mark a shift from a “one-technique-fits-all” paradigm toward ultrasound-guided personalization of MUS surgery.
A Preliminary but Hypothesis-Generating Study
It is essential to emphasize that this is a preliminary, retrospective study with a limited sample size. Although sling positioning was objectively verified by postoperative ultrasound—reducing technical confounding—the design does not allow causal inference. Subgroup analyses by incontinence subtype were not feasible, and larger cohorts are required to validate these observations.
Nevertheless, the signal is clinically meaningful.
The interaction between anatomical features (such as funneling), functional severity (ICIQ-UI-SF), and surgical vector deserves prospective evaluation. Future studies should aim to:
- Confirm whether funneling independently modifies surgical response
- Compare retropubic and transobturator outcomes prospectively in this subgroup
- Explore whether funneling resolution postoperatively correlates with long-term success
- Integrate ultrasound biomarkers into predictive surgical algorithms
We believe that urethral funneling represents a promising biomarker for refining patient selection in MUS surgery. However, confirmation requires multicenter collaboration and standardized ultrasound protocols.
Hospitals and urogynecology units interested in participating in further research on ultrasound-guided surgical decision-making are warmly invited to contact our team. Collaborative prospective studies could help define whether pelvic floor ultrasound should become a routine component of preoperative stratification in stress urinary incontinence.
The future of urogynecology lies not only in refining surgical techniques, but in selecting the right technique for the right patient.
Written by: Enrique González-Díaz, MD, PhD, Pelvic Floor Unit, Complejo Asistencial Universitario de León (CAULE), León, Spain
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