(Poster 132) Introduction of a Novel Method of Back-Fill Voiding Trial with a 3-Way Catheter

Objectives: A back-fill voiding trial is essential when assessing postoperative urinary retention (POUR). At our institution, instead of using a traditional 2-way Foley catheter, which requires manual backfilling, a 3-way catheter with a 250 ml instillation has been introduced. This study evaluates whether there is a difference in the POUR rate between the two methods before the launch of a prospective clinical trial.

Methods: This retrospective cohort study analyzed medical records of patients over 18 years who underwent a day surgery for prolapse, stress urinary incontinence, and/or gender-affirming hysterectomy between the 2 months in 2023 when the three-way catheter with automatic back-fill system was available at academic medical care with multiple surgical sites. Patients who stayed overnight and/or had bulking treatment were excluded. Patient demographics, surgical factors, anesthesia management, voiding details, and urogynecology history were collected. The primary outcome was considered successful VT (post-void residual volume of less than 150 mL for both methods). Secondary outcomes considered the POUR rate for various peri-operative variables. Statistical analyses included chi-square and t-tests for univariate comparisons, with logistic regression used to identify independent predictors of VT success.

Results: Overall, 92 patients were included, of whom 39 (42.4%) used a 3-way catheter, and 53 (57.6%) used a 2-way catheter. The patient population was, on average, 65.6 years (SD=12.9 years) and had an average BMI of 27.6 kg/m2 (SD=5.4 kg/m2). The two groups had the following differences: age, surgical center type (outpatient surgical center vs. hospital-based), preoperative administration of phenazopyridine, and the volume of local anesthetic usage (bupivacaine with epinephrine). The POUR rate was not statistically significantly different between the two groups (28.4% for two-way vs. 15.4 % for three-way; p=0.15). The volume of local anesthetic used intraoperatively was considerably higher (p < 0.001) among patients who failed the VT than those who passed. The use of phenazopyridine was also significantly associated with failing VT (p=0.0009), although it was not significant when adjusted for the VT method.

Conclusions: Our findings suggest that the POUR rate of the new back-fill system using a pre-installed 250ml saline and a two-way catheter system was not different. Based on these results, we plan on a randomized control trial to prospectively compare the POUR rate, patient satisfaction, and perioperative staff satisfaction between the traditional and the novel three-way catheter automatic back-fill system.

Legends:
Table 1 Legend:
* BMI: Body Mass Index
+ Local anesthetic used (ml): 0.5% Bupivacaine with epinephrine
^ Continuous variables are presented using mean (SD)

Table 2 Legend:
* BMI: Body Mass Index
+ Local anesthetic used (ml): 0.5% Bupivacaine with epinephrine
^ Continuous variables are presented using mean (SD)