Advice

Technology overview

Technology overview

This briefing describes the regulated use of the technology for the indication specified, in the setting described, and with any other specific equipment referred to. It is the responsibility of healthcare professionals to check the regulatory status of any intended use of the technology in other indications and settings.

About the technology

CE marking

The BladderScan BVI 9400 is CE marked as a Class IIa medical technology. The CE mark was received in November 2011 and is held by the manufacturer, Verathon (USA).

Description

The BladderScan BVI 9400 (Verathon) is a portable (21.9 cm × 33.6 cm; 2.36 kg) 3D ultrasound device that measures bladder volume to assess urinary retention and post‑void residual (PVR) bladder volume, to help to diagnose urological conditions and post‑operative recovery without needing urinary catheterisation.

The BladderScan BVI 9400, like other portable bladder ultrasound scanning technologies, works by sending high‑frequency sound waves into the body from a transducer probe placed on the skin of the abdomen. Some of the sound waves are reflected back towards the probe, which detects these reflected sound waves and passes the information back to the ultrasound machine. The ultrasound machine uses this information to construct a picture of a 2D 'slice' through the body.

There are 3 models of the BladderScan available in the UK (BVI 9400, BVI 6100 and BVI 3000), all of which are claimed to enable more accurate measurements than conventional 2D ultrasound. These were developed from predecessor versions of the technology. The 3000 (portable console with probe attached) and 6100 (handheld probe with built‑in display) models are intended for use in adults only. Both models use VMODE software to calculate bladder volume by transforming 2D slice images into a 3D image, which is displayed on the screen and can also be printed. The BVI 9400 uses updated patented software, NeuralHarmonics, to measure bladder volume. This also transforms 2D slice images into a 3D image and uses neural network algorithms to improve the segmentation accuracy of the structures or organ being targeted. The refined NeuralHarmonics algorithms are designed to:

  • detect, segment and measure the bladder geometry and volume

  • detect the uterus and distinguish this from measurements of the bladder.

The BVI 9400 model allows the user to set the device to 3 modes: 'small child', 'woman who has not had a hysterectomy', or 'all other patients'. The 'small child' mode (referred to as 'child mode' throughout this briefing) is intended to be used when scanning a person less than 122 cm tall and weighing less than 27 kg, generally boys and girls aged below 8 years.

The BladderScan BVI 9400 has reusable and single‑use components. The reusable components are:

  • A hand‑held probe that sends and receives ultrasound waves, automatically moving its internal transducer 360º to scan 12 planes to produce a 3D image of the bladder. The probe is attached to the console by a detachable cable and has 3 main features:

    • A scan button that is pressed to take a scan.

    • An aiming display that displays directional arrows to ensure the bladder is centred within the scanning cone.

    • A microphone that records the voice of the person operating the system.

  • A console with a colour LCD display screen. All operating controls, as well as the printer, are located on the console.

  • Lithium‑ion battery – a fully charged battery can provide about 30 examinations within a 24‑hour period. Charging time offline for an empty battery is 6 hours for a full charge.

  • A battery charger or wireless hub with AC power cord.

The single‑use components are:

  • Thermal paper roll for the printer.

  • Acoustic coupling gel.

Setting and intended use

The BladderScan BVI 9400 is intended for adults and children needing bladder volume measurements in primary and secondary care settings, including both urology and surgical wards. It is not intended for use on unborn babies or pregnant women. The BladderScan BVI 9400 does not need to be operated by a sonographer. Therefore, any healthcare professional, including healthcare assistants and nurses, can use the device, after training provided by the manufacturer.

Current NHS options

Diagnostic testing for urinary retention (UR) can include:

  • Urine dipstick to exclude any current infections or existing conditions such as diabetes.

  • Urine microbiology and cytology if indicated by a history of urinary tract infection (UTI) or haematuria.

  • If incomplete voiding is suspected or there are symptoms of recurrent UTI, post‑void residual (PVR) volume is measured. Ultrasound bladder scanning may be used for this if available.

No specific national guidelines for assessment of PVR volume in UR were found, however the UK Bladder and Bowel Foundation suggests that healthcare professionals may recommend various tests for UR, including:

  • Immediate catheterisation of people with acute UR and urinalyses to screen for haematuria and UTI, by dipstick testing or microscopic examination of the sediment.

  • Uroflowmetry to assess the flow rate of urination.

  • Urodynamic testing, which can include catheterised or ultrasound measurement of PVR volume.

  • Renal ultrasonography for people with abnormal renal function.

  • Cystoscopy to examine the inside of the bladder.

The NICE guideline on the management of lower urinary tract symptoms in men states that men with lower urinary tract symptoms who are having specialist assessment should be offered PVR volume measurement.

According to NICE's guideline on the management of urinary incontinence in women, if incomplete bladder voiding is suspected or there are symptoms of recurrent UTIs, PVR volume should be measured. If available, ultrasound bladder scanning should be used rather than catheterisation because this is more acceptable to people and has a lower incidence of adverse events.

NHS Choices (2014) states that if overflow urinary incontinence (UI) is suspected in a person in a primary care setting, PVR volume may be measured. Overflow UI, also called chronic UR, is often caused by a blockage to the urethra, such as a bladder stone. The bladder may fill up as usual, but because it does not empty properly during voiding (because of the obstruction or muscle or nerve damage) the remaining urine leaks out. Measurement is usually carried out by bladder ultrasound, but occasionally by urinary catheterisation.

When assessing lower urinary tract dysfunction in a person with neurological disease, the NICE guideline on urinary incontinence in neurological disease suggests an option of measuring the PVR volume by ultrasound, preferably using a portable scanner, and potentially taking further measurements to find out how bladder emptying varies at different times and in different situations.

The NICE guideline on urinary tract infection in under 16s states that catheter samples or suprapubic aspiration (SPA) should be used for children with UTI symptoms if it is not practical to collect urine by non‑invasive methods. Before SPA is tried, ultrasound guidance should be used to show that urine is in the bladder.

NICE is aware of the following CE‑marked devices that appear to fulfil a similar function to the BladderScan BVI 9400:

  • Bardscan II (Mediwatch [UK])

  • Cubescan BioCon‑500 and BioCon‑700 (Medline)

  • SonoSite M‑Turbo (FUJIFILM SonoSite).

Costs and use of the technology

The market average cost of the BladderScan BVI 9400 system is between £6000 and £8000, excluding VAT. The estimated average device cost of catheterisation is £2.38 per person, including the average price of a catheter (excluding long‑term catheters), a catheter insertion pack, and a drainage bag. The cost can increase to £5.59 per person, if urethral anaesthetic and a stabilisation device (such as StatLock) are used. Conventional ultrasound scanning of the bladder costs £49 per scan (less than 20 minutes, NHS reference cost 2013/14 code RA23Z).

Likely place in therapy

The BladderScan BVI 9400 would be used in a primary or secondary care setting. The BladderScan BVI 9400 is currently used in the NHS. The BladderScan BVI 9400 would be used as an alternative to catheterisation or ultrasound (including other portable bladder ultrasound scanners) to help diagnose urological conditions and assess post‑operative urine retention.

Specialist commentator comments

One specialist commentator highlighted that the BladderScan device does not diagnose urological conditions, but can provide PVR volume measurements to form part of a broader assessment. They added that a diagnosis can only be made after additional testing to determine the underlying cause.

One specialist commentator expressed concern that the BladderScan is unable to distinguish the bladder from other pelvic structures and may, therefore, also register uterine volume, and fluid from cysts and ovaries. The same specialist emphasised the importance of operator training in distinguishing between these different volumes. Another specialist commentator noted that it is difficult to mix up non‑bladder and bladder pathologies when using BladderScan.

One specialist commentator noted that postpartum bladder scanning is not recommended because it is not reliable and, in practice, catheterisation provides a more accurate measurement of PVR volume in women after delivery.

One specialist commentator suggested that the BladderScan device could be beneficial for people with multiple sclerosis or spinal injuries. These conditions can disrupt spinal nerve pathways and result in impaired bladder function and incomplete emptying of the bladder. The specialist commentator suggested that the most important investigation on which to base any planned management strategies is measurement of PVR volume, which can be carried out with portable bladder ultrasound scanning.

According to 1 specialist commentator, the scanner is easy to use, and reliable, in children. The commentator noted that the BladderScan devices are used nationally in paediatric urology departments. They explained that the difficulty in assessing PVR volume in young children relates to their small bladder volumes and less developed ability to start voids. The commentator added that it is not acceptable practice in UK paediatric units to use a catheter to formally assess PVR volume.

The lack of studies carried out in adult populations was noted by 1 specialist commentator.

Equality considerations

NICE is committed to promoting equality, eliminating unlawful discrimination and fostering good relations between people with particular protected characteristics and others. In producing guidance, NICE aims to comply fully with all legal obligations to:

  • promote race and disability equality and equality of opportunity between men and women

  • eliminate unlawful discrimination on grounds of race, disability, age, sex, gender reassignment, marriage and civil partnership, pregnancy and maternity (including women post‑delivery), sexual orientation, and religion or belief (these are protected characteristics under the Equality Act 2010).

Portable bladder ultrasound scanning may be used to assess PVR volume in people with chronic neurological conditions such as cerebral palsy or spinal dysraphism.

Bladder care is an important aspect of management in the postpartum period. Postpartum voiding dysfunction occurs in a significant number of women after giving birth. Standard bladder scanners may measure uterine debris as bladder volume. The NeuralHarmonics technology within the BladderScan BVI 9400 potentially allows more accurate non‑invasive bladder volume measurement in women who have recently given birth, because it can differentiate more accurately between the bladder and the uterus.

The BladderScan BVI 9400 is not intended for use on unborn babies or pregnant women. Pregnancy is a protected characteristic under the Equality Act 2010.