Abstract: PD60-08
Sources of Funding: None

Introduction

To highlight the dangers inherent in traumatic urethral catheterization we prospectively monitored the incidence, cost and clinical outcomes of urethral catheter related injuries. We also investigated urethral diametric strain and threshold maximum inflation pressure for rupture during inadvertent inflation of a catheter anchoring balloon in the urethra and evaluated a novel safety device to prevent trauma.

Methods

The incidence of urethral catheter related injuries was prospectively monitored at 2 tertiary referral teaching hospitals for 6 months. Recorded data included method and extent of urethral catheterization injury, number of catheterization attempts, urological management provided, additional bed days due to urethral injury and clinical outcomes after follow-up. In addition, inflation of a urethral catheter anchoring balloon was also performed in the bulbar urethra of porcine and cadaver models using 16Fr catheters (n=28). Extent of urethral trauma was characterised with retrograde urethrography. Urethral rupture was correlated with internal urethral diametric strain and maximal urethral pressure threshold values in kPa to develop a &[prime]safety threshold&[prime] pressure valve.

Results

A total of 37 iatrogenic urethral injuries were recorded. The incidence of traumatic urethral catheterization was 6.7 per 1,000 catheters inserted. Thirty (81%) patients sustained a complication Clavien-Dindo grade 2 or greater. The additional length of inpatient hospital stay was 9.4 ± 10 days (range 2 to 53). The additional cost of managing iatrogenic urethral injuries was $371,790. In porcine and cadaver models, retrograde urethrography demonstrated that urethral rupture consistently occurred at an internal urethral diametric strain greater than 40% and a maximum inflation pressure greater than 150 kPa. Based on these parameters a safety valve that reliably activated at a threshold inflation pressure of 150 kPa was developed.

Conclusions

Iatrogenic urethral catheterization injuries represent a significant cost and cause of patient morbidity. Urethral injuries will continue to occur unless urinary catheter safety mechanics are altered. Internal urethral diametric strain and threshold maximum inflation pressures are important parameters for designing a safer urethral catheter system with lower intrinsic threshold inflation pressures.

Funding

None