The Voided Volume Transit Point (VVtrans): a novel functional biomarker for staging bladder decompensation in bladder outlet obstruction

Clinical management of lower urinary tract symptoms (LUTS) caused by bladder outlet obstruction (BOO) is hampered by its reliance on subjective symptom scores, which correlate poorly with the progressive functional decline of the bladder. This disconnect often delays intervention and risks irreversible detrusor damage. We propose the Voided Volume Transit Point (VVtrans)—the inflection point on an individual’s longitudinal voided volume (VV) versus peak flow rate (Qmax) curve where Qmax plateaus—as a non-invasive biomarker for staging bladder decompensation. Derived from multiple home-uroflowmetry measurements, a declining VVtrans value reflects the continuum of bladder remodeling from a compensated, hypertrophic state to a decompensated, fibrotic bladder with reduced functional reserve. This hypothesis is supported by physiological evidence that detrusor contractility depends on bladder volume, pathophysiological studies of BOO-induced remodeling, and the feasibility of capturing real-world voiding dynamics with home-based monitoring. If validated through prospective clinical studies , VVtrans could provide an objective measure for early diagnosis, guide the timing of intervention to preserve detrusor function, and serve as a quantitative indicator of therapeutic success. Such an approach would represent a paradigm shift towards a more precise, bladder-centric model of patient care.