3.5 TVM decreases residual volume
Finally, we investigated if TVM-increased bladder compliance is associated with impaired voiding efficacy in POP patients by analyzing the residual volume in response to TVM. In 13 out of the 22 POP patients, their pre-operative PVA displayed more infused volume than voided volume, indicating an amount of post-voided residual volume (Vres) in the bladder (Figure 2C PRE). Without markedly affecting the volume difference between the top and the bottom borders, TVM shifted the loop downward, indicating the Vres was decreased post-operatively (Figure 2D POST). The TVM-decreased Vres was confirmed by statistical analyses showing that when compared to the pre-operative control, TVM consistently decreased Vres in most patients (Figure 4E; 11 out of 13, 85%) and significantly decreased the mean value of Vres of the patient (Figure 4F p<0.05 N=13), implying rather than impaired voiding efficacy, TVM brought about improved bladder emptying signifying improved voiding efficacy.