Intermittent catheterisation (IC) is a technique for patients requiring bladder drainage, with hydrophilic-coated ICs offering advantages over uncoated catheters by reducing friction and enhancing comfort. Hydrophilic coatings, typically composed of polyvinylpyrrolidone (PVP), absorb water to create a lubricious surface. However, PVP can become mucoadhesive upon drying, potentially increasing friction during catheter withdrawal and leading to complications such as urethral microtrauma (1). To address these concerns, an alternative coating-free technology incorporating integrated amphiphilic surfactants (IAS) has been developed. This innovation provides hydrophilic properties without the drawbacks of hydrophilic PVP-based coatings.

Existing methods for assessing IC performance often lack physiological relevance and provide no insight into the risk of urethral microtrauma. To overcome these limitations, this study employs an ex vivo porcine urethral model that more accurately simulates in vivo conditions. The primary aims of this research is to;
•	Provide insights into the use of intermittent catheters and urethral microtrauma.
•	Investigate the extent of urethral microtrauma associated with different types of ICs, comparing traditional hydrophilic-coated catheters with the novel IAS technology.

A comparative analysis was conducted using commercial hydrophilic PVP-coated ICs and IAS-based ICs. Ex vivo porcine urethral tissue was used to simulate physiological catheterisation conditions. The force required for catheter withdrawal was measured using a texture analyser to assess frictional resistance. Histological sections (4 µm thick) were prepared, and immunohistochemistry was performed using primary anti-E-Cadherin rabbit antibody (1/100 dilution) and secondary Goat anti-rabbit IgG Alexa Fluor 488 antibody. Fluorescence microscopy was then employed to evaluate potential damage to the transitional uroepithelial membrane post-catheterisation.

After 120 seconds of catheter-tissue interaction (mimicking real-world use), fluorescence analysis revealed that hydrophilic PVP-coated Brand 1, Brand 2, and Brand 3 (microeyelets) exhibited uroepithelial damage levels of 3.30±0.23%, 3.52±0.74%, and 3.87±0.89%, respectively. In comparison, the IAS-based IC demonstrated a significantly lower fluorescence reduction of 5.73±1.66%.

As diminished fluorescence correlates with membrane damage, these preliminary results suggest that IAS-based ICs may exert less trauma on the urethral lining than their PVP-coated counterparts.

This study highlights the utility of ex vivo models in evaluating catheter performance under physiologically relevant conditions. The findings suggest that IAS technology could potentially reduce urethral microtrauma compared to conventional hydrophilic PVP-coated ICs. By mitigating catheter-related complications, IAS-based ICs may enhance patient comfort and improve overall quality of life for individuals requiring intermittent catheterisation. Further in vivo studies are warranted to validate these preliminary observations and confirm the clinical benefits of IAS technology in routine urological care.

Pollard D, et al. Biotribology 2022; 32:100223.