Current diagnostic standards for stress urinary incontinence (SUI), such as bladder neck descent (BND), Urethral Rotation Angle (URA), and Retrovesical angle (RVA), are descriptive parameters that fail to identify the true structural and biomechanical state of the supporting tissues. We propose that SUI is the result of a sequential failure of urethral supports that can be quantified through vectorial analysis. These failures are categorized as:
Rotational Stability Failure.
Functional Insufficiency of the Anterior Support.
Dysfunctional Synergy.

Aim: To justify the rationale for the V-MAP (Vectorial Mobility Assessment of the Pelvic floor) protocol as a superior diagnostic tool that utilizes dynamic vectors to transition from descriptive anatomy to precision medicine based on the functional state of the tissue.

The V-MAP protocol is based on functional transperineal ultrasound (TPUS) using the machine Mindray i9,  to monitor the behavior of the internal Urethro-Vesical Junction (UVJ) relative to the pubis, which serves as a more anatomically stable anchoring point. Two fundamental vectorial parameters are defined:UPD (Urethro-Pubic Distance): A radio-vector measured from the postero-inferior border of the pubic symphysis to the UVJ.UPA (Urethro-Pubic Angle): The angular or vectorial displacement of the UVJ during a maximum Valsalva maneuver. Using Fung’s Theory of Viscoelasticity, the UPD Strain is calculated as the percentage of elongation relative to the resting state: (Strain% = (UPD Valsalva - UPD rest)/UPD rest) x 100. This formula allows us to map the tissue transition from elastic stretching to permanent plastic deformation or structural rupture.

The V-MAP model establishes a critical diagnostic threshold known as the "25/33 Rule":

The 25% Rule (Laxity): A UPD strain ≥ 25% identifies the "Yield Point," where the UVJ support system leaves the elastic zone and enters a plastic zone of permanent microstructural damage.

The 33% Threshold (Rupture): A UPD strain ≥ 33% represents the "Ultimate Strain" limit, correlating with macroscopic rupture or avulsion of the support system's anchorage.

Based on this logic, six SUI phenotypes are proposed based on the interaction between UPD and UPA. These phenotypes allow for the classification of patients according to their specific failure mode: from isolated urethro-pubic support instability to "Vectorial Dissociation" (critical failure of both vectors).

Vectorial analysis demonstrates that urethral mobility is an orbital phenomenon rather than a simple vertical descent (BND) or static angular change (URA/ARV). Unlike conventional measurements that often show overlap between continent and incontinent patients, the V-MAP protocol clarifies these "grey zones." A patient may exhibit marked hypermobility yet remain biomechanically competent if the UPD strain remains below 25%. Conversely, patients with minimal linear descent may present irreversible structural failure if they exceed the 33% threshold. V-MAP measures not just the magnitude of movement, but the actual condition of the suspensory apparatus.

The V-MAP protocol provides the first biomechanical map of pelvic support failure. By categorizing patients into six specific phenotypes, surgeons can move away from a "one-size-fits-all" approach and select personalized surgical strategies (suburethral threads, plications, or suspension slings) tailored to the detected tissue failure mode, optimizing success rates and repair longevity.

Fung, Y. C. (1993). Biomechanics: Mechanical Properties of Living Tissues. Springer-Verlag
Di Pietto, L., et al. (2009). Urethral angle and bladder neck mobility in women with SUI. Urologia Journal
Dietz, H. P. (2010). Pelvic floor ultrasound. Ultrasound Obstet Gynecol