ICS standard for digital exchange of urodynamic study data

Can multicentre urodynamic studies provide high quality evidence for the clinical effectiveness of urodynamics? ICI-RS 2019

Aims

Lower urinary tract (LUT) function can be investigated by urodynamic studies (UDS) to establish underlying functional abnormalities in the LUT. A multicentre registry could present an opportunity to improve the scientific evidence base for UDS. During the International Consultation on Incontinence Research Society (ICI‐RS) meeting in Bristol, United Kingdom 2019, an expert panel discussed the potential of a multicentre urodynamic registry to improve the quality of urodynamic output.

Methods

the potential importance of a multicentre urodynamic registry, parameter inclusion, quality control, and pitfalls during a registry roll‐out were reviewed and discussed.

Results and Conclusions

The clinical utility, evaluation, and effectiveness of UDS remain poorly defined due to a lack of high quality evidence and large study populations. Therefore, the ICI‐RS proposes formation of a urodynamic panel for future roll‐out of a registry. The inclusion of basic parameters was discussed and the essential parameters were defined as well as the potential pitfalls of a registry roll‐out. The discussion and recommendations in this paper form the base for future urodynamic registry development.

Functional regeneration of supraspinal connections in a patient with transected spinal cord following transplantation of bulbar olfactory ensheathing cells with peripheral nerve bridging

Treatment of patients sustaining a complete spinal cord injury remains an unsolved clinical problem because of the lack of spontaneous regeneration of injured central axons. A 38-year-old man sustained traumatic transection of the thoracic spinal cord at upper vertebral level Th9. At 21 months after injury, the patient presented symptoms of a clinically complete spinal cord injury (American Spinal Injury Association class A-ASIA A). One of the patient's olfactory bulbs was removed and used to derive a culture containing olfactory ensheathing cells and olfactory nerve fibroblasts. Following resection of the glial scar, the cultured cells were transplanted into the spinal cord stumps above and below the injury and the 8-mm gap bridged by four strips of autologous sural nerve. The patient underwent an intense pre- and postoperative neurorehabilitation program. No adverse effects were seen at 19 months postoperatively, and unexpectedly, the removal of the olfactory bulb did not lead to persistent unilateral anosmia. The patient improved from ASIA A to ASIA C. There was improved trunk stability, partial recovery of the voluntary movements of the lower extremities, and an increase of the muscle mass in the left thigh, as well as partial recovery of superficial and deep sensation. There was also some indication of improved visceral sensation and improved vascular autoregulation in the left lower limb. The pattern of recovery suggests functional regeneration of both efferent and afferent long-distance fibers. Imaging confirmed that the grafts had bridged the left side of the spinal cord, where the majority of the nerve grafts were implanted, and neurophysiological examinations confirmed the restitution of the integrity of the corticospinal tracts and the voluntary character of recorded muscle contractions. To our knowledge, this is the first clinical indication of the beneficial effects of transplanted autologous bulbar cells.

Transplantation of autologous olfactory ensheathing cells in complete human spinal cord injury

Numerous studies in animals have shown the unique property of olfactory ensheathing cells to stimulate regeneration of lesioned axons in the spinal cord. In a Phase I clinical trial, we assessed the safety and feasibility of transplantation of autologous mucosal olfactory ensheathing cells and olfactory nerve fibroblasts in patients with complete spinal cord injury. Six patients with chronic thoracic paraplegia (American Spinal Injury Association class A-ASIA A) were enrolled for the study. Three patients were operated, and three served as a control group. The trial protocol consisted of pre- and postoperative neurorehabilitation, olfactory mucosal biopsy, culture of olfactory ensheathing cells, and intraspinal cell grafting. Patient's clinical state was evaluated by clinical, neurophysiological, and radiological tests. There were no adverse findings related to olfactory mucosa biopsy or transplantation of olfactory ensheathing cells at 1 year after surgery. There was no evidence of neurological deterioration, neuropathic pain, neuroinfection, or tumorigenesis. In one cell-grafted patient, an asymptomatic syringomyelia was observed. Neurological improvement was observed only in transplant recipients. The first two operated patients improved from ASIA A to ASIA C and ASIA B. Diffusion tensor imaging showed restitution of continuity of some white matter tracts throughout the focus of spinal cord injury in these patients. The third operated patient, although remaining ASIA A, showed improved motor and sensory function of the first spinal cords segments below the level of injury. Neurophysiological examinations showed improvement in spinal cord transmission and activity of lower extremity muscles in surgically treated patients but not in patients receiving only neurorehabilitation. Observations at 1 year indicate that the obtaining, culture, and intraspinal transplantation of autologous olfactory ensheathing cells were safe and feasible. The significance of the neurological improvement in the transplant recipients and the extent to which the cell transplants contributed to it will require larger numbers of patients.

International Continence Society guidelines on urodynamic equipment performance

These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice.

Urodynamic assessment of urinary incontinence

Context

Urodynamic evaluation in the assessment of women complaining of urinary incontinence remains controversial with recent UK National Institute of Health and Clinical Excellence guidance maintaining that it is unnecessary prior to surgery for women with a primarily stress leakage. Other experts contend it should be part of routine preoperative assessment since it establishes a diagnosis, allows more careful patient counseling and predicts surgical outcome.

Objectives

To summarize current literature to define the evidence level on which these conflicting opinions are based.

Materials and Methods

A systematic literature search was performed and retrieved publications summarized in a narrative evidence review using both original papers and previous reviews.

Results

Five hundred and one primary research papers and 65 previous reviews were retrieved. The findings were summarized in a narrative comprising overview, description of methods of bladder and urethral pressure measurement, and a summary of the literature concerning four key questions.

Conclusion

The level of evidence was low regarding answering each of the questions posed, preventing firm conclusions. Urodynamic findings do correlate with relevant symptoms and, to some extent, with symptom severity, giving reasonable diagnostic accuracy. There is no reliable evidence that preoperative urodynamic diagnosis improves outcome from surgery for stress incontinence although it is likely to facilitate preoperative discussion. Tests to differentiate sphincter deficiency and urethral hypermobility are not currently recommended due to poor validity and reproducibility. This along with the current use of mid-urethral tapes as the universal primary surgical procedure means differentiation is not a necessity. Preoperative diagnosis of detrusor overactivity does not appear to worsen surgical outcome in women with a primary symptom of stress leakage. Large, well-designed prospective studies are now underway to provide a definitive answer to these questions.

The Immediate and 6-mo Reproducibility of Pressure–Flow Studies in Men with Benign Prostatic Enlargement

OBJECTIVES

Urodynamics is an objective method of diagnosing bladder outlet obstruction (BOO) in men. This study examined the immediate and 6-mo reproducibility of this investigation.

METHODS

Urodynamics was performed in men as part of a multinational, multicentre, double-blind, placebo-controlled drug trial. Each patient had two fill/void cycles both at baseline and 6 mo. The BOO index (BOOI) and bladder contractility index (BCI) were calculated for each cycle and data analysed to look for changes in immediate and 6-mo reproducibility between the two fill/void cycles.

RESULTS

A total of 114 patients had urodynamics at baseline. In the immediate term, although there was a small but statistical fall in both the BOOI and BCI, with cycle one figures greater than those in cycle two, 81% and 79% of patients remained in the same BOOI and BCI category, respectively. At 6 mo, the differences were not statistically different with 70% of patients remaining unchanged in their BOOI category in cycle one and 71% in cycle two; 65% remained unchanged in their BCI category in cycle one and 74% in cycle two. No patient with a BOOI > 65 changed category in the second investigation, and only 5 of 103 first cycles with a BOOI > or = 50 changed category to equivocal obstruction.

CONCLUSIONS

Urodynamics has good reproducibility when looking at the BOOI and BCI, indicating that a second study is not necessary in most patients and one investigation is sufficient for an accurate diagnosis on which treatment options can be based.

Pressure-flow studies in patients with benign prostatic hyperplasia: a study comparing suprapubic and transurethral methods

AIM

To compare the use of the suprapubic puncture method versus the transurethral method in pressure-flow studies in patients with benign prostatic hyperplasia.

METHODS

Twenty-three men with benign prostatic hyperplasia underwent both suprapubic and transurethral pressure-flow studies during a single session. Standard pressure-flow variables were recorded in all patients with both methods, enabling calculation of obstruction using commonly used grading systems, such as the urethral resistance algorithm, the Abrams-Griffith (AG) number and the Schaer linear nomogram.

RESULTS

There were statistically significant differences between the methods in the mean values of maximum flow rate (P < 0.05), detrusor pressure at the maximum flow (P < 0.01), urethral resistance algorithm (P < 0.01), AG number (P < 0.01) and maximum cystic capacity (P < 0.01). Of the men in the study, 10 (43.5%) remained in the same Schaer class with both methods and 18 (78.3%) in the same AG number area. Using the transurethral method, 12 (52.2%) men increased their Schaer class by one and 1 (4.3%) by two. There were also differences between the suprapubic and transurethral methods using the AG number: 4 (17.4%) men moved from a classification of equivocal to obstructed and 1 (4.3%) from unobstructed to equivocal.

CONCLUSION

The differences between the techniques for measuring intravesical pressure alter the grading of obstruction determined by several of the commonly used classifications. An 8 F transurethral catheter significantly increases the likelihood of a diagnosis of bladder outlet obstruction when compared with the suprapubic method.

Bladder volume sensitivity of isovolumetric intravesical pressure

AIMS

Recently, methods have been introduced for non-invasively measuring the isovolumetric bladder pressure. This pressure can also be measured invasively using a stop test. In itself, the isovolumetric pressure is a measure of urinary bladder contractility, by combining it with maximum urinary flow rate it can be used to diagnose infravesical obstruction. We have studied the (possible) volume dependence of this pressure in order to enhance the accuracy of this type of measurements and to explore its physiological background and possible diagnostic relevance.

MATERIALS AND METHODS

In 1,020 healthy subjects, recruited for an ongoing longitudinal study of changes in bladder contractility secondary to prostatic enlargement, we measured the isovolumetric bladder pressure using the condom catheter method. In each subject, voiding was repeatedly interrupted. The resulting pressure-volume relations were normalized and averaged.

RESULTS AND CONCLUSIONS

There is an optimum bladder volume for isovolumetric pressure measurements, averaging 264 +/- 122 ml (mean +/- SD). Measurements should be taken at or above the optimum volume. At volumes below the optimum volume, the pressure decreases by approximately 5% for each 10% of volume decrease. At bladder volumes smaller than 247 ml pressure readings in 50% of subjects are suboptimal. The optimum volume for isovolumetric pressure generation is only marginally related to voiding diary parameters. Probably it represents mechanical properties of the bladder, whereas voiding diary parameters more likely represent neurophysiological properties. However, the optimum volume does not reflect the optimum (smooth) muscle length for force generation of the bladder wall: during normal voiding bladder smooth muscle always operates at a suboptimal length for force generation.

Trying to predict 'dangerous' bladders in children: the area under the curve concept

OBJECTIVE

Children with neurological and non-neurological lower urinary tract dysfunction normally undergo video urodynamics. One reason is to try to diagnose 'dangerous' bladders. Currently, bladder compliance is used to predict 'dangerous' bladders; however, in children there are no standardized methods of measurement and thus no 'cut-off' values. Compliance may also be normal even though high-pressure detrusor overactivity waves may exist during the filling phase of urodynamics. We tried to determine whether measuring the area under the detrusor pressure curve (AUC) during the filling phase of urodynamics would be a useful parameter in predicting 'dangerous' bladders.

PATIENTS AND METHODS

Children referred to the urodynamics unit at Southmead Hospital, a tertiary referral centre, from 2000 to 2004 were investigated. Although 130 patients were identified, only 15 patients had raw data which were analysable using the available computer software.

RESULTS

There was no correlation between the AUC and predicting 'dangerous' bladders possibly due to limitations in the computer software.

CONCLUSION

Although the study did not reveal any correlation between the AUC and 'dangerous' bladders, it revealed the limitations of the available computer software in determining AUC, and highlighted the need for new standardized software and multinational, multi-centre trials to look into the concept of AUC. There is also a need for the International Continence Society to standardize methods and terminology in predicting 'dangerous' bladders.