Virginia Commonwealth University School of Medicine
Introduction: Bladder wall response to stretch is measured through compliance, and during urodynamics (UDS), “filling compliance” is calculated as ?volume/?pressure. The objective of this study was to use ultrasound (US) during UDS to derive a novel provoked compliance metric in response to abdominal bladder compressions, instead of filling, and correlate this with participant characteristics and filling compliance. Methods: Individuals indicated for UDS were enrolled in a prospective IRB-approved study. Participants’ bladders were filled to ~50% capacity during UDS and filling was paused. The US probe was used to perform 5 sec compressions of the bladder 5 times to ~50% of its anterior-posterior diameter, with 5 sec between compressions. One transverse abdominal US image captured before compression and one at the maximum compression pressure were analyzed. Tracing of each transverse bladder wall image and the ImageJ circularity function (Fig 1AB) were used to quantify bladder circularity. Compression induced ?circularity/?pressure was used to calculate provoked compliance. Filling compliance was also calculated, and age and BMI data were collected. Results: Data from 31 women were analyzed in groups =60 and >60 years of age. A wider range of provoked compliance values was found in women >60 (Fig 1C, above horizontal line). Provoked compliance between 0.006 and 0.022 cm-H2O-1 was demonstrated in 12/13 (92%) of women <60 years of age, but only 5/18 (28%) of women >60 years (Fig 1C), indicating a significant association of age with provoked compliance (Fisher’s exact, p<0.05). There was no identified association between filling compliance or BMI and provoked compliance. Conclusions: Provoked compliance in response to bladder compression was quantified using a novel method, and women >60 demonstrated altered provoked compliance. Future studies connecting provoked compliance and specific types of bladder dysfunction are needed to demonstrate key relationships. SOURCE OF Funding: NIH R01DK101719, NSF REU 1852116, VCU School of Medicine Summer Research Fellowship
