Urinary catheter 'deflation cuff' formation: clinical audit and quantitative in vitro analysis

Area of Science:

• Urology
• Biomaterials Science
• Medical Device Engineering

Background:

• District nursing staff report challenges removing long-term urinary catheters (LTCs).
• A significant issue is the formation of a 'cuff' upon deflation of the self-retaining balloon, hindering removal.
• This phenomenon necessitates investigation into catheter material properties and design.

Purpose of the Study:

• To audit problems encountered by district nurses during LTC removal.
• To investigate the in vitro mechanical properties of deflated catheter balloons, specifically focusing on cuff formation and retention force.
• To identify catheter types and usage scenarios associated with removal difficulties.

Main Methods:

• A prospective audit of district nurses' experiences with urethral and suprapubic LTC removal.
• Collection of data on problem type, catheter material, and interventions.
• In vitro studies involving incubation of deflated balloons in saline at 37°C for 6 weeks.
• Suprapubic profilometry to quantify the retention force (resistance to withdrawal) caused by cuff formation.

Main Results:

• 154 patients with LTCs were included; 56% urethral, 44% suprapubic.
• 14% of patients experienced removal problems in the prior year, with 68% involving all-silicone catheters and 68% involving suprapubic catheters.
• Cuff formation was observed in 60% of problematic removals. In vitro, 10 out of 10 tested balloons formed cuffs, exhibiting retention forces ranging from 0.5-3 N.

Conclusions:

• All-silicone and suprapubic catheters are most frequently associated with difficult LTC removal.
• Suprapubic profilometry confirmed that cuff formation on all-silicone catheter balloons increases withdrawal resistance.
• Hydrogel-coated latex catheters are recommended as the primary choice for long-term urethral and suprapubic use due to fewer removal complications.