Objective The objective benefit of trans-vaginal mesh (TVM) on the storage function of the bladder in pelvic organ prolapse (POP) patients waits to be established. This study investigated if TVM improves the bladder storage by specifically focusing on its effects on the compliance. Design A retrospective cohort study Setting A medical center Population Female patients with voiding dysfunction who underwent TVM for prolapse stage ≥ II (POP Quantification system) and received urodynamic investigations before and after the operation. Methods: Data of pressure-flow cystometry and the derived pressure-volume analysis (PVA) were analyzed. Main outcome measures Bladder compliance, infused volume, and threshold pressure. Results Compared with the pre-operative control, TVM consistently and significantly increased the mean compliance of the filling stage (Cm; p<0.05 N=22); and further analyses demonstrated TVM increased the compliance of the late half (C2/2; p<0.01, N=22), while it exhibited insignificant effects on that of the early half (C1/2; p>0.05, N=22) of the filling stage. Moreover, without affecting the infused volume (Vinf; p>0.05, N=22), TVM decreased the threshold pressure (Pthd; p<0.01, N=22) and post-voided residual volume (Vres; p<0.05, N=13). Conclusions TVM improve storage function of POP patients via increasing bladder compliance, particularly at the late filling stage for it restored anatomical location and geometric conformation for bladder expansion. In addition, TVM also ameliorated voiding dysfunctions as it reduced urine retention, a symptom could lead to upper urinary tract damage and/or urinary incontinence.

Objective In contrast to the well-recognized benefit of trans-obturator tape (TOT) to urine continence, if the TOT-enhanced urethra resistance results in modified voiding functions in stress urinary incontinence (SUI) patients is not adequately investigated. Design and setting Urodynamic investigations were retrograde analyzed in a tertiary referral hospital. Population A total of 26 female SUI patients Methods The area enclosed by the loop trajectory (Apv) in a pressure-volume analysis (PVA) which represent the work performed in each voiding cycle was retrospectively analyzed Main outcome measures The Apv of female SUI patients before and after the TOT were analyzed. Results When compared with the pre-operative control, the Apv was significantly increased post-operatively. The TOT-enhanced Apv was accompanied by increments in the mean urethra resistance (Rv) and mean voiding pressure (Pv) but unaffected voided volume (Vv) and voiding time (Tv). Moreover, the TOT-induced Apv increase (ΔApv) displayed moderate correlations with the changes in Rv and Pv (ΔRv and ΔPv, respectively) but no correlation with the changes in Vv or Tv (ΔVv and ΔTv, respectively). Notably, the TOT-induced ΔRv displayed a strong correlation with the ΔPv. Conclusions: The thermodynamic efficacy of the bladder was enhanced after the TOT; that could be attributed to that bladder develops an elevated pressure gradient in response to the TOT-enhanced outlet resistance during urine emission. Keywords: mid-urethra sling, trans-obturator tape, stress urinary incontinence, urethra resistance, thermodynamics, pressure-volume analysis Tweetable abstract The bladder developed an elevated pressure gradient to the TOT-enhanced outlet resistance; and herein enhanced the voiding efficacy.