Intraurethral catheter placement does not change the external circumferential measurement of the urethra during AUS placement: A prospective observational trial.

Aims: Measuring the urethral circumference accurately during artificial urethral sphincter (AUS) placement is an important technical aspect to optimize the selection of cuff size. Differing methods exist for this step with some experts recommending measurement with no urethral catheter in place. In this prospective observational trial, we compared urethral measurements with and without an indwelling catheter to determine if the presence of a catheter affects the circumferential measurement.

Methods: With IRB approval, we prospectively collected data on consecutive cases of transperineal male AUS implantation. Urethral circumference was measured with no urethral catheter (0 French [Fr]), 12Fr, and 16Fr Foley catheters in the urethra. The final measurements and cuff size chosen were recorded. A comparison was made between each measurement using Spearman's correlation coefficient.

Results: A total of 54 patients were included, the majority of whom (92.6%) underwent AUS placement for postprostatectomy incontinence. The three urethral circumference measurements were highly correlated (0Fr vs 12Fr, ρ = 0.96, P < .001, mean difference 1 mm) (0Fr vs 16Fr, ρ = 0.94, P < .001, mean difference 2 mm) (12Fr vs 16Fr, ρ = 0.96, P < .001, mean difference 1 mm). Patients with a history of radiation had a lower mean urethral circumference than those who had never been radiated (4.78 cm vs 5.3 cm, P = .01).

Conclusions: Urethral circumference measurement during AUS implantation is not influenced by the presence of a 12 or 16Fr Foley catheter when compared to no catheter in the urethra. Measurement of the urethral circumference can, therefore, be accurately performed with or without a catheter in place, depending on the surgeon's preference.