The Added Value of Home-Uroflowmetry: Analyzing an Individuals' VV-Qmax Curve and Inflection Point
Gunter De Win1, Matthew Peters2, Jasper Pauwels2
1Faculty of Medicine and Health Sciences, University of Antwerp, 2610 Antwerp, Belgium; Department of Urology, Antwerp University Hospital, 2650 Edegem, Belgium; Antwerp Surgical Training, Anatomy and Research Centre (ASTARC), Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Adolescent Urology, Department of Urology, University College London Hospitals, London, UK.
Objective:
To analyze individual VV-Qmax plots based on multiple home uroflowmetries and compare these with cross-sectional nomograms.
Methods:
Healthy volunteers (16-69 years) without lower urinary tract symptoms (LUTS) were asked to take a Minze Homeflow™ device home to register 25 uroflows. Participants reporting urinary tract disorders, malignancy, or medication affecting bladder function were excluded. Dysfunctional voiding curves or participants with less than 15 acceptable flows were also excluded. For each individual, a VV-Qmax scatterplot was visually evaluated, and a segmented regression was performed to determine the volume at which inflection occurred.
Results:
One hundred forty-five participants were enrolled. Thirty-eight were excluded based on medical history or LUTS, another 3 because the minimum amount of acceptable flows was not reached. This resulted in 104 participants (40 M/64 F) and 2498 acceptable uroflows with intra-individual differences based on voided volume, urge, and time of the day. Individual VV-Qmax plots derived from multiple measurements do not align with the published nomograms based on cross-sectional data. The VV-Qmax curve for an individual demonstrates that Qmax increases with rising voided volumes up to a specific transitional voided volume (VVtrans) of 253 mL (in men) and 214 mL (in women), after which Qmax remains stable despite further increases in voided volumes.
Conclusion:
A single uroflowmetry is insufficient to represents an individuals' voiding pattern. An individuals' VV-Qmax curve may give a better picture and can identify a new parameter, VVtrans, which might be a reflection of a patient's bladder function and urethra patency. Further evaluation and application in clinical LUTS scenarios are needed.
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