Over the past two decades, midurethral slings (MUS) have become the gold standard for treatment of women with stress urinary incontinence (SUI). It is estimated that 3.7 million MUS's have been implanted worldwide between 2005-2013 [1]. Some of the advantages of MUS include shorter recovery time and reduced blood loss compared to other surgical alternatives for treatment of SUI leading to its increased popularity among surgeons [2-4].

Immediate postoperative urinary retention following MUS is a challenge for both patients and caregivers. Urinary retention after pelvic reconstructive surgery requiring indwelling catheter or clean intermittent catheterization (CIC) usage occurs in approximately 15-60% of patients postoperatively (5-7). Currently, there is no consensus on the most efficient and precise way to detect postoperative urinary retention following outpatient female pelvic reconstructive surgery to accelerate the discharge process and avoid over or under diagnosis of retention (6-8).

Current methods to evaluate postoperative urinary retention include both “passive” and “active” voiding trials. During a passive voiding trial, patients are given time to allow for spontaneous bladder filling postoperatively (awaiting urge to void), are permitted to void and then the voided volume is compared to post void residual (PVR) volume as measured by bladder scan. During an active voiding trial, the bladder is retrofilled with a set amount of sterile water (ie. 300mL), the catheter is removed, the patient is permitted to void, and the voided volume is compared with a bladder scan PVR volume. “Passing” a voiding trial has previously been defined as voiding equal or greater than ⅔ the residual volume, whereas others characterize “passing” as voiding at least 200mL and voiding a greater volume than the post-void residual volume (9). Typically, patients who fail their voiding trial are discharged home with an indwelling catheter to prevent detrusor injury from bladder overdistention (10).

Many women consider being discharged home with a Foley catheter or the need for CIC to be a surgical complication and describe catheter use as the worst aspect of their surgery (6,11). Indwelling catheters are the leading cause of hospital-acquired urinary tract infections (UTIs), are often a source of embarrassment and inconvenience for patients, and often require additional office visits and healthcare utilization (8).

To date there is lack of consensus and conflicting data regarding the optimal method to assess immediate postoperative urinary retention. The primary objective of this study was to evaluate the rate of immediate postoperative urinary retention detection after passive versus active voiding trial following treatment with MUS for SUI. We hypothesize that standardized postoperative active voiding trials would decrease the failure rate and need for home catheterization and also provide faster discharge time. This was based on the fact that an active VT may help avoid bladder overdistention compared to a passive VT due to decreased patient sensation and enables control of the amount of fluid within the bladder at the time of the VT. Furthermore, actively filling the bladder may lead to performing the VT sooner, possibly leading to earlier discharge. Secondary objectives were to assess risk factors associated with VT failure in our patient population.