Innovation for Pelvic Health

To many involved with the routine assessment of voiding and storage dysfunction, urodynamics involves the measurement of long-established parameters of bladder pressures and uroflow rates. Initially, voiding assessment was simply “eyeball” urodynamics. From those simple observations to the use of the hydrostatic water column, urodynamics moved from qualitative measurements to something more quantitative.

 The strip chart recorder provided a permanent record of the pressure and flow measurements. Additionally another dimension of the measurements allowed the clinician to register real bladder contractions because the strip chart plotted the trends quite faithfully.

 Two clever hydro-dynamic engineers initiated the juxtaposition of pressure and flow data popular and the obstructive impedance index was born. Today, the use of such calculations as urethral resistance factor (URA), bladder work (WF), passive urethral resistance (PURR), classification of bladder outlet obstruction (CHESS) and others are used to quantify the degree of bladder outlet obstruction (BOO) using computer methods.

 Retrieval of pressure/flow data has evolved but what has not changed is the measurement method of the data itself. A catheter is still required to get the pressure information (much to the discomfort to the patient). It is true that catheter development has progressed and technologies such as electronic and air-charged catheters are a testament to industry looking to make any advancement in this field. But how do we advance beyond measuring pressures in such an invasive way?

 Urodynamics alone will not attract enough attention from mainstream science to encourage innovation without some lateral technological adaptation. The air-charged catheter came from intra-uterine pressure measurement technology. The electronic catheter came from the cardiac pressure sensing world. Similar successful adaptations can be achieved in the future if one pays close attention to what is happening in other fields of science and industry.

 Let’s not forget one of the biggest adaptations in the last 20 years—the use of the standard computer to control, record and display data in a meaningful and processed manner. Without the compact and cost-effective personal computer, we might still be in the strip chart era! Gone are the manual calibrations and manual post-procedure calculations. Computer automation has enhanced the recording and reporting functions of urodynamics testing.

The paperless approach also means that in increasingly more hospitals and offices, those reports also pass directly to EMR systems without killing any trees.

But as the title of this article suggests –— where are the advancements beyond pressures going to come from?

 Hemodynamic measurements using near infrared spectroscopy (NIRS) is a nascent technology being applied to bladder muscle monitoring, and it shows much promise for evaluating BOO conditions in males. This technology was borrowed to a large degree from vascular pulse oximetry.

Other areas where NIRS can be useful are being explored. Imagine a realtime bladder condition monitoring method that does not involve a catheter! This is the holy grail of urodynamics. So far, the laser technology used in Laborie Medical’s Tetra NIRS solution is the most intriguing realtime measurement modality to be introduced into the research community in recent years.

 If you don’t want to use a laser to look at oxyhemoglobin, then perhaps an external pressure cuff concept (borrowed from standard blood pressure cuff principles) is more to your liking? Some patients may find that the thought of an occlusion cuff (or pressure condom) placed around the penis, a little disconcerting but perhaps it is better than experiencing catheter intubation.

 Better yet, what happens if you can diagnose the bladder condition by indirect measurement such as evidence of morphological changes in the bladder wall due to urethral obstruction? Ultrasound has been successfully demonstrated to indicate such conditions whether looking at the detrusor wall thickness or intravesical prostatic position (IPP). To the same end, some have looked at measuring the total bladder mass to obtain some important information about the bladder without resorting to the catheter. And while we look for better ways to measure the pressure, perhaps we should consider that some measurement techniques will actually glean NEW information about the bladder that the plain old catheter cannot provide?

 Not convinced that such technologies will make a practical impact in the clinic? If the most promising technologies are not developed beyond the single-center research mode, certainly nothing significant will come of them. Controlled, reproducible, multi-center trials help to develop consensus on what works and what does not. As an equipment company that serves the research community to a significant degree, Laborie has seen many variations and interpretations on how new technologies are applied. Perhaps that is why we also see varying degrees of success being reported in the journals. In an ideal world, Laborie would have an infinite budget and we would certainly sponsor many clinical trials to advance promising technologies. The unfortunate reality is that device manufacturers are not like pharmaceutical companies: budgets are tight and limited. The best that we can manage would be to invest in the consistent instrumentation configurations for the hardware, software and testing protocols. Making those configurations available to all our clients who share an interest in validating and/or collaborating with us on our exciting research projects would be a great service to the science.

 The medical community has successfully and repeatedly demonstrated that consistent site-to-site reproducibility of trial results begins with the careful and methodical attention to detail for the equipment, protocol and training.

 Needless to say, the art and science of urodynamics is begging for new and fascinating techniques applied to lower urinary tract diagnosis so that progress can be made. For the comfort and for better access to the patient, for the additional and new insights we can offer to the clinicians, such work on new technologies is a must or one day, the practice of urodynamics will disappear.