Introduction: Mid-urethral sling (MUS) immediate postoperative management is not widely standardized. Our Unit protocol for outpatient MUS with general anesthesia is to remove the bladder catheter intraoperatively. Afterwards, the voiding function is assessed with the measurement of the spontaneous voiding volume (SVV) and the post-void residual volume (PVR).

During this year of the COVID-19 pandemic, except during the months of the first wave, the surgical activity of Urogynaecology has been around 80% of the pre-pandemic times. This has been possible thanks to an exceptional opportunity for our team to operate in a small hospital linked to our main university hospital, in which COVID patients were not attended. Since the end of June 2020, patients in waiting list for stress urinary incontinence (SUI) surgery were selected according to their profile of risk factors for COVID-19, and informed about the possibility to be operated in this small hospital by the same surgeons and with the same surgical device to correct SUI. If they agree and consent, selected patients would be operated with some different elements: operating rooms, nursing team and anesthesiologists. Due to the anesthesia protocol of this centre, all patients received regional anaesthesia. This type of anaesthesia has been identified as a risk factor for acute postoperative urinary retention (PUR) following outpatient MUS surgery (1). However, in a cohort of patients after same-day outpatient vaginal pelvic floor surgery was no difference noted between anaesthesia types (2). Other risk factors for PUR include elevated PVR on preoperative functional tests, concomitant pelvic organ prolapse (POP) surgery, elevated body mass index and advanced age (3). Although PUR is typically a transient complication, it increases women discomfort and the risk of urinary tract infections.

Despite the different type of anaesthesia, we decided to apply the same protocol for outpatient MUS with general anesthesia and the intraoperative removal of the bladder catheter with subsequent voiding assessment was performed in all patients. Our hypothesis was that the regional anesthesia will not increase the risk of PUR.

The aim of this study was to describe early postoperative complication rate related with bladder function, after MUS surgery with regional anesthesia.

A case series study was designed with patients who underwent MUS surgery from June 2020 to March 2021, all them prospectively evaluated. We excluded women with risk factors for acute (PUR) following outpatient MUS surgery: age >80 years, concomitant POP surgery or detrusor underactivity demonstrated on pressure/flow measurement at preoperative urodynamics.

The bladder catheter was removed intraoperatively. The first SVV was measured, as well as the PVR (by ultrasound or catheterization). A significant PVR was considered when was >1/3 of SVV (minimum SVV: 150 ml). A 2nd attempt was given after a first voiding trial failure. In women with significant PVR, a continuous bladder catheter was maintained 24-48h after surgery, with the posterior voiding trial assessment. One week and one month after surgery, uroflowmetry with PVR measurement were performed in women normal postoperative PVR.

In order to check the safety of this protocol, the rate of the following complications was calculated: VD with bladder catheterization/PUR, urinary tract infections, bladder/urethral lesions.

During the study period, a total of 223 urogynecological surgeries have been performed by our team, being 116 MUS. POP concomitant surgeries were performed in 32 patients, being one of the exclusion criteria of the present analysis. From the 84 patients with isolated surgery related to MUS (Table 1), 28 women with>80 years old or detrusor underactivity were also excluded. Therefore, the catheter was finally removed intraoperatively in 56 /84 patients (66.7%).

The total complication rate was 20.2% (n=17). The most frequent complication was urinary tract infection (7.1%, n=6). Bladder perforation in 3 cases during TVT surgery and urethral lesion occurred in 3 patients during sling excision, all them were detected intraoperative, and these 6 patients required an opened bladder catheter during 1 week.

A significant PVR (>1/3 of SVV with a minimum of SVV of 150 ml), was detected in 5 patients (5.9%), but only one of them needed discharge home with bladder catheter (1.2%).

The complication rate after MUS surgery with regional anesthesia observed in our series, after intraoperative bladder catheter removal, is acceptable.

In a cohort of selected patients without preoperative PUR risk factors, only 1 in 56 women needed discharge home with bladder catheter after intraoperative removal, which seems that regional anesthesia has not a great impact in the immediate voiding function.

However, our results should be interpreted with caution due to the low sample size and the non-controlled design of the study.

Intraoperative bladder catheter removal after MUS surgery under regional anesthesia seems to be safe and with an acceptable complication rate.

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