Bladder analysis: an improved experience

It is estimated that the main cause of Lower Urinary Tract Symptoms (LUTS), a common complaint of the ageing male, is Benign Prostatic Hyperplasia (BPH) (enlarged prostate). In 2009, a report published in the UK,1 stated that a third of the 9.4 million men aged over 50 experience symptoms suggestive of BPH. The National Institute for Health and Clinical Excellence (NICE) says that 3.2 million men in the UK present with clinical BPH. Age is an important risk factor for LUTS and its prevalence increases with age. Despite the availability of effective prescription therapies, many men with storage and/or voiding LUTS may not be receiving appropriate treatment in UK general practice, the International Journal of Clinical Practice has reported.2 Benign Prostatic Enlargement (BPE) causes narrowing of the urethra where it passes through the prostate, leading in turn to Bladder Outlet Obstruction (BOO) and Lower Urinary Tract Symptoms (LUTS). The Gold Standard diagnostic test for investigating BOO’s, is known as a Pressure-Flow Study (PFS). However, this invasive test is expensive, time-consuming and requires skilled analysis and interpretation of results. The alternative is the non-invasive cuff test which provides a rapid means of investigating men with LUTS. The technology measures both the urinary flow rate of a patient and the pressure their bladder generates to produce this flow. A specialised cuff, placed around the shaft of the penis, is temporarily inflated to obstruct flow. The cuff pressure required to interrupt voiding then provides a measure of bladder pressure. The combination of maximum flow rate and cuff pressure can be used to determine whether BOO is present or not. This test is intended to compliment standard pressure flow studies and current diagnostic options available to patients.

Impact on policy

NICE guidance3 suggests that the consequences of poorly managed LUTS can lead to serious complications of the urogenital tract. Without effective diagnostic pathways, unnecessary treatment, including surgery, is currently being offered to certain patients suffering from LUTS, placing a huge and potentially unnecessary burden on the NHS. Expenditure in this area will also continue to escalate due to the ageing population. The effective management of patients with voiding symptoms through a time efficient diagnostic (cuff) test can, therefore, inform whether surgery or further investigation for bladder outlet obstruction is required. This will contribute to lowering the burden that these symptoms are currently placing on the NHS. This could also reduce the need for invasive urodynamics and the morbidity associated with invasive techniques could also be avoided. However, there are significant challenges associated with the successful implementation of non-invasive testing for the management of LUTS. For this reason two centres have been involved in a noninvasive bladder analysis system adoption study commissioned by the NHS Technology Adoption Centre (NTAC). Both have implemented the non-invasive cuff test into routine clinical practice, with the aim of evaluating its diagnostic potential and accuracy, patient acceptability and its position in the diagnostic pathway. The clinical implementation lead at the North Bristol NHS Trust is Mr Marcus Drake, consultant urologist. North Bristol NHS Trust provides hospital and community health-care to the residents of Bristol area, South Gloucestershire and North Somerset. It is the largest teaching Trust in the South West and treats over 250,000 patients per year. The urology and urodynamic departments are actively involved in research and have close links with the University of Bristol, University of the West of England and the University of Bath. The Bristol Urological Institute (BUI) based at Southmead Hospital was established in 1993 to support and develop urological research, with particular emphasis on urological cancers and on the problems of urinary incontinence. The project aim of the BUI was to assess the benefits and barriers to implementation of the technology and sought to identify ways in which this noninvasive diagnostic test could be implemented into current diagnostic pathways. Through direct application of the test to patients in the clinical setting, diagnostic algorithms have been developed to guide use of the cuff test and maximise the diagnostic accuracy of the technology. Leeds Teaching Hospitals NHS Trust was also involved in the study, with the clinical implementation lead here being undertaken by consultant urologist, Mr Neil Harris. This Trust is among the biggest in the UK and includes the largest teaching hospital in Europe (St James’s University Hospital). The Trust provides acute hospital services for the population of Leeds and the surrounding area and acts as a regional centre for a number of specialist services such as cancer and cardiac surgery. In total the Trust employs around 14,000 staff across six main sites, treating well over a million patients every year with a budget of around £930 m. St James’s University Hospital is both a secondary and tertiary referral centre for urology and services are delivered in dedicated facilities known as the Paul Sykes Centre. The facilities incorporate specialised urodynamic services that deliver a range of investigations to patients. At Southmeads Hospital in Bristol 60 men were recruited to the study and had non-invasive cuff tests performed. All successfully completed the penile cuff test, with 92% of tests yielding interpretable results. As such, the initial results suggest that clinicians can safely consider a result of obstruction on the non-invasive cuff-test as a reliable indicator when treating patients suspected of BOO. Additionally, one-fifth of men in whom a diagnosis of “obstructed” was missed by the cuff test, are not misdiagnosed as they will be automatically sent for invasive urodynamics. The small amount of time taken, and minimal trauma associated with the test, means that a minority of patients having two investigations is outweighed by the significant number of men avoiding the need for invasive urodynamics. At St James’s University Hospital 61 cuff tests were performed as part of the investigation and many positive outcomes were found. The test compared well with invasive urodynamics, in that where both investigations were successfully completed 25% of patients diagnosed as obstructed by pressure-flow studies were all classified as obstructed by the cuff test. In addition, the patient feedback showed a unanimous preference for the cuff test over catheterbased pressure flow studies.