Development and first-in-human testing of FLUME urinary catheter with protected tip and relocated drainage holes

Evaluation of a catheter design which protects its tip with the retaining balloon when inflated, and has eyeholes at the base of the balloon to improve drainage.

Preclinical tests included assessment of retaining balloon performance, and microbiological blockage. Clinical testing evaluated short-term use and safety in hospital (stage 1) or the patient's usual residence (stage 2).

The retaining balloon supported static loads of 0.7kg, with reduced trauma when modelling forced evulsion. In vitro time to blockage with P. Mirabilis was significantly slower for FLUME compared with latex Foley catheters, but not the silicone Foley. Stage 1 testing (10 patients) confirmed balloon inflation, drainage, retention and removal, with no serious adverse events caused by catheterisation; one balloon failed to inflate, one patient could not be catheterised. Of five patients at stage 2, one had the catheter for 28 days without complication, one experienced spontaneous balloon deflation (14^th day) and three needed early removal (blood clot, bypassing, difficulty connecting the drainage bag). Bacterial profiles of two FLUME catheters retained at least 2 weeks matched the Foley catheters. Acquired catheter colouration (two FLUME, one Foley) was not associated with biochemical change in the material.

FLUME catheter performed well in preclinical blockage and balloon tests. Tests in 15 patients confirmed basic function and additional training was not needed for staff familiar with Foley catheterisation. Clinical issues commonly seen with catheters included failed catheterisation, clot blockage and bypassing. In addition, an unintended balloon deflation and a failure of bag connection occurred.

This article describes a new catheter design which aims to improve patient comfort and safety, and maximise bladder drainage, by protecting the bladder from the exposed catheter tip and by locating the drainage holes better. Various tests were done to check the catheter retaining balloon was safe and how well the catheter did when exposed to bacteria that could block it. The catheter was also used in people for the first time, to check it could be put in safely and functioned as intended. The results showed the FLUME catheter did well in the balloon and blockage tests. Tests in 15 patients confirmed basic function and showed placement was easy for staff familiar with conventional catheters. There were some clinical issues typical of urinary catheters and some possible improvements were identified.