Neurogenic Bladder Monitoring Using the Cystomanometer and Cystoelastometer

Summary Introduction Neurogenic bladder (NGB) patients require periodic urodynamics (UDS) to evaluate bladder function which, in turn, helps guide management. At times, bladder decompensation or hydronephrosis may develop in patients between UDS testing intervals. Increased surveillance has improved outcomes in other chronic conditions (e.g. diabetes). Two novel devices, the cystomanometer (CM) and cystoelastometer (CEM) have been developed at our institution to allow for home bladder pressure monitoring. The hand-held CM attaches to the end of any catheter and records the opening bladder pressure along with a timestamp. In addition, the CEM actively evacuates urine via a pump and records the urine volume evacuated. For safety, the pump slows and stops as it detects increasing resistance. Data is stored and transmitted wirelessly from both devices to a smart phone. A novel phone application stores, displays, and transmits data to a secure hospital server. Objective This aim of this study was to validate the function of the CM and CEM and their accuracy relative to UDS. Study design IRB approval was obtained. All NGB patients managed with intermittent catheterization undergoing routine UDS were eligible for study inclusion. At the completion of UDS, the instillation port of the 6 French dual lumen urodynamics catheter was connected to the CM or CEM. Bladder parameters were simultaneously recorded by the device and UDS during bladder emptying. Correlative statistics were calculated. Results 36 patients (30 children/6 adults; age range from 1.2-38 years [median 7.5 years]) underwent testing with the CM. Strong pressure correlation with UDS was identified (R2 = 0.89). 42 patients (30 children/12 adults; age range of 2.9-85.2 years [median 12.2 years]) underwent CEM testing. Again, strong pressure correlation was found (R2 = 0.77). CEM volume measurements were highly correlated with measured volumes ( Figure 4 , R2 = 0.98). Discussion Both the CM and CEM functioned well and transmitted the data wirelessly to a smart phone. The data from these devices was strongly correlated with simultaneous data from the UDS. A limitation is that use of these devices was by healthcare providers and therefore use by patients or their parents/caregivers at home has not been demonstrated. Conclusions The CM and CEM devices provide accurate bladder pressure and volume measurements. The potential for improved patient monitoring and care is promising. Reliability testing and the effects of such monitoring on patient outcomes remain to be determined.