A new urinary catheter to improve bladder drainage: first-in-human testing of the Flume catheter

The current long-term catheter (LTC) Foley design is a firm-tipped tube, with an inflatable retention balloon, below which the eyeholes enter the drainage lumen.

The physical relationship of the components in the bladder can encourage direct trauma of the bladder wall and incomplete urine drainage, which may contribute to discomfort, blockage and urinary tract infection.

The Flume catheter design rearranges the components, so the eyeholes are at the bladder base and the tip is shielded when the balloon is inflated.

Since the Flume has just half the length of a Foley residing within the bladder, this should reduce discomfort from bladder spasms as well as enhancing drainage.

We have undertaken laboratory tests, which confirmed more effective drainage, and improved duration of use in vitro compared to the main Foley-design catheters currently used in the NHS. Placement, retention and connections use the same approaches as the Foley design, so will be familiar to users.

The research proposed will undertake first-in-human testing of the Flume design (Phase 1; to establish its safety, acceptability and possible efficacy).

The project will yield data needed for design of a subsequent definitive clinical trial (Phase 3; subject to separate funding application), aiming to compare quality of life and adverse events for users of the new Flume catheter compared to the standard Foley Catheter.

This proposed project will evaluate QoL and adverse events, develop the ICIQ-LTCqol as a primary outcome for a future randomised trial, and collect data to aid planning a Phase 3 trial (namely feasibility measures such as recruitment, retention and data completeness, and data to aid health economic planning).

The plan of investigation is as follows; 1.

To evaluate short term use of the Flume catheter in 10 patients in hospital peri-operatively; to check ability to place a catheter during planned elective surgery on the lower urinary tract, and to remove it on schedule per operation requirements prior to discharge. Patient and healthcare professionals will complete questionnaires about placement/ removal/ problems/ other comments.

A stop-go decision will be taken at the conclusion. 2.

To evaluate 15 LTC users using a Flume catheter instead of a Foley catheter for one month at their usual residence (“home”), with close follow up (weekly phone call/ nurse visit). A stop-go decision will be taken at the conclusion.

Patients will complete adverse event/ experience logs and outcome measures (ICIQ-LTCqol and Patient Global Impression of Improvement (PGI-I)) at baseline and after one month.

Healthcare professionals will complete a questionnaire about placement and removal of the Flume catheter, and adverse events. Patients will undergo qualitative interviews about their experiences. 3.

To evaluate 40 LTC patients using a Flume catheter instead of a Foley catheter for up to three months at home (initial phone call/ nurse visit at one week, then monthly until the scheduled date of their Foley LTC change, weekly subsequently). A stop-go decision will be taken at the conclusion.

Patients will complete adverse event/ experience logs, and outcome measures (ICIQ-LTCqol, PGI-I, EQ-5D-5L) at baseline and at the time of their catheter change. A sample of patients will undergo qualitative interviews about their experiences. Timing of application of outcome measures is tabulated in the Supporting Documentation section.

If this work shows that the Flume catheter is acceptable, then funding will subsequently be sought for a Phase 3 trial.

The Phase 3 trial would determine whether the novel Flume design (shielding the catheter tip and enhancing drainage) delivers key NHS benefits of improved QoL, reduced adverse events and health economic savings.