Tweetable abstract
The bladder developed an elevated pressure gradient to the TOT-enhanced outlet resistance; and herein enhanced the voiding efficacy.
This study was registered in ClinicalTrials.gov (NCT05255289)
INTRODUCTION
Weakness in muscle and/or tissue surrounding the urethra results in stress urinary incontinence (SUI) characterized by involuntary urine leakage on effort, physical exertion, sneezing, or coughing.1 SUI is a common problem affecting women’s daily life in physical, social, and hygienic aspects.2Conservative options, such as strengthening of the pelvic floor musculature3 and bladder training,4are prescribed for SUI patients; and for those who have failed conservative therapies, a mid-urethral sling is a preferred treatment recommended.5 In 1996, the first mid-urethral sling, tension-free vaginal tape, was launched;6 and subsequently, the trans-obturator tape (TOT) was developed in 2001.7 For TOT exhibits a satisfied cure rate and a relatively diminishes invasiveness,8,9 it is increasingly accepted as a treatment of choice worldwide in the last decade.10
The procedure of TOT positions a narrow band of synthetic tape under the urethra;11 and together with the scar tissue that grows following the sling implantation, the tape adds-on an exogenous urethra resistance to maintain the continence during urine storage.12 Notably, in contrast to the well-recognized therapeutic benefit of the enhanced resistance to the bladder continence during urine storage,13 if the voiding function of the bladder adapts to the TOT-enhanced outlet resistance has not been adequately investigated.14-16 Particularly, to the best knowledge of ours, there is so far no study exploring if the thermodynamic efficacy of the bladder is modified following the TOT. Because an insufficient work output in response to an enhanced loading caused by the TOT-enhanced resistance could be a risk factor leading to un-compensated bladder functions,17 we investigated the change in the thermodynamic efficacy of the bladder in response to the TOT to clarify the potential adaptation of the bladder to the enhanced outlet resistance.
Interestingly, a recent study demonstrated the pressure-volume analysis (PVA) of voiding cycles specifically assays the voiding work of the bladder and thereby quantifies the thermodynamic efficacy of bladder emptying.18 We hence explored the potential modifications in the thermodynamic efficacy of the bladder in response to the TOT using the PVA.