The Application Value Of Detrusor Contraction Strength(WF) In Evaluating The Function Of Detrusor

Part 1: The relationship of detrusor contraction strength and PVR in bladder outlet obstruction(BOO) patients: a clinical analysisObjectives The purpose of this study was to analyze the characteristics of watts factor(WF) graph, to compare the post-void residual volume(PVR) in different WF, and to discuss the application value of WF in evaluating the function of detrusor.Materials and methods The study included a retrospective collection of 455 patients who underwent urodynamic testing in the urodynamic room of Wuhan Union Hospital from January 2013 to March 2016. The mean age of all patients was 57±17.9 years old and ranged from 18 to 87 years old. The parameters of Qmax, PVR, Pdet Qmax and WF were collected. Then summarized and analyzed the characteristics of watts factor(WF) graph. Patients without PVR were divided into group A(WF >7 W/m2) and group B(WF ?7 W/m2), and PVR in this two groups were compared by T-test statistical analysis. Patients without PVR were also divided into group C(WF >10.85 W/m2) and group D(WF ?10.85 W/m2), and PVR in this two groups were also compared by T-test statistical analysis.Results A total of 455 men were included in the study. The mean age of all patients was 57±17.9 years old and ranged from 18 to 87 years old. All the WF graphs could be divided into three types.(See Graph 2, Graph 3, Graph 4).(1) Normal graph, WF rose gradually to top and then faded before the bladder was empty. The curve ended at Y axis and the bladder was emptied completely with no PVR. The mean WFmax was 10.72 ±7.03W/m2.(N=30)(2) Higher WF, the curve started with a higher value, and declined suddenly, left an amount of PVR.(N=349)(3) WF was very low throughout micturition and resulted in a substantial volume of residual urine.(N=76) The mean PVR for group A(WF >7 W/m2) and group B(WF ?7 W/m2)were 91.93 ±116.87 ml and 135.78 ±129.0 ml respectively. There was a significant difference in PVR of this two groups(P<0.05).The mean PVR for group C(WF >10.85 W/m2)and group D(WF ?10.85 W/m2)were 87.6±104.3 ml and 110.38±131.7 ml respectively. There was also a significant difference in PVR of this two groups(P<0.05).(See Table1)Conclusion According to our results, no matter WFmax was divided by the threshold of 7 W/m2 or 10.85 W/m2, there was a significant difference in PVR of former or later two groups. Moreover, the PVR continuously increased with the decline of detrusor contraction strength. This indicates that when detrusor contraction strength is lower, the function of detrusor is quite weak and clinical doctors should pay much attention to it.Part 2: The relationship of detrusor contraction strength and BOO grades: a clinical analysisObjectives We intended to analyze the relationship between detrusor contraction strength(WF) and BOO grades, and evaluate the application value of WF in BOO patients.Materials and methods This study included a retrospective collection of 455 patients who underwent urodynamic testing in the urodynamic room of Wuhan Union Hospital from January 2013 to March 2016. The mean age of all patients was 57±17.9 years old and ranged from 18 to 87 years old. The parameters of Qmax, PVR, Pdet Qmax, WF, and bladder outlet obstruction index(BOOI) were collected. BOO was defined by the Schaefer classification and detrusor function during voiding was quantified by maximum watts factor(WFmax) obtained by pressure-flow analysis. According to Schaefer classification, patients were divided into seven groups from Schaefer 0 to Schaefer VI. All parameters in different Schaefer grades were analyzed by Kruskal-Wallis test statistical analysis.Results A total of 455 men were included in the study. The mean age of all patients was 57±17.9 years old and ranged from 18 to 87 years old. According to Schaefer classification, Schaefer 0, I, II, III, IV, V, VI included 34, 102, 87, 62, 67, 57, 46 patients respectively. There were 136(29.9%) patients without obstruction(Schaefer 0–I). There were 319(70.1%) patients with obstruction(Schaefer II–VI). The Qmax values from Schaefer 0 to VI were 16.32ml/s, 13.08ml/s, 11.86ml/s, 8.96ml/s, 7.22ml/s, 5.53ml/s, 4.89ml/s respectively(P<0.05).The PVR values from Schaefer 0 to VI were 38.79 ml, 52.39 ml, 72.7ml, 86.77 ml, 117.51 ml, 127.49 ml, 155.52 ml respectively(P < 0.05).The Pdet Qmax values from Schaefer 0 to VI were 22.47 cm H2O, 33.44 cm H2O, 45.59 cm H2O, 57.65 cm H2O, 75.12 cm H2O, 97.33 cm H2O,141.22 cm H2O respectively(P<0.05). The WFmax values from Schaefer 0 to VI were 8.19 W/m2, 9.08 W/m2, 10.74 W/m2, 11.52 W/m2, 12.46 W/m2, 13.69 W/m2, 16.36 W/m2 respectively(P<0.05). The BOOI values from Schaefer 0 to VI were-10.18, 7.28, 22.02, 39.73, 60.67, 86.28, 131.43 respectively(P<0.05).Conclusion We conclude that the Qmax continuously decreases with rising BOO grade. Parameters of PVR, Pdet Qmax, WF, and BOOI increase with rising BOO grade. When there is obstruction in the low urinary tract, the bladder contraction will increase to compensate. The BOO grades should be combined with detrusor contraction strength in evaluating the function of detrusor contraction.