We conducted a randomized controlled trial at the Urogynaecology Clinic, Female Pelvic Medicine and Reconstructive Surgery (FPMRS) division, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand, a tertiary care center, between March 2020 and February 2021. The study protocol was approved by the Committee on Human Rights Related to Research Involving Human Subjects, Faculty of Medicine, Ramathibodi Hospital, Mahidol University (COA. MURA2020/357).
Patients were recruited from the Urogynaecology Clinic of Ramathibodi Hospital. Women were eligible for enrollment if they were scheduled for anterior compartment prolapse surgery, with or without concomitant surgery, and agreed to participate in the study. Other inclusion criteria were no urinary incontinence or neurologic disorders, not a candidate mid-urethral sling surgery, no preoperative urinary retention (PVR > 150 mL) , and no preoperative UTI. Women who refused to participate or had intraoperative bladder injuries or ureteral injuries were excluded.
On the day of admission (the day before surgery), patients were personally informed about the risks and advantages of being enrolled, prior to the randomization process. Demographic data and medical history were collected. POP-Q data were evaluated by a surgeon. Preoperative PVR was measured using transvaginal ultrasonography and calculated using the following formula: postvoid residual volume=(height×width×depth)×0.7 . Clinical symptoms and signs of UTI were recorded and urinalysis with urine culture was performed in all patients to exclude UTI. Patients were randomly assigned to the early transurethral catheter removal (24 hours postoperatively) or conventional removal (day 3 postoperatively) protocol on the day of surgery (Figure 1). Randomization was computer generated, with 1:1 group allocation in blocks of four. The randomization was concealed by a research assistant not involved in trial enrollment using consecutively numbered opaque envelopes, which were opened at the end of the procedures.
Preoperative antibiotic prophylaxis was administered in every patient within 60 minutes before the skin incision. Two grams of intravenous cefazolin was the antibiotic of choice, unless the patient had drug allergies. Local infiltration of 0.5% xylocaine with adrenaline (1:200,000) was used to facilitate dissection. Then, either AC or colpocleisis was performed. In the AC procedure, a midline incision was made in the anterior vaginal wall, extending from the vaginal apex to the bladder neck, not beyond the urethra. The procedure was performed by a trained senior resident in obstetrics and gynecology, under the supervision of FPMR staff in all cases.
When the catheter was removed, micturition was recorded and PVR was measured immediately using a bladder scanner (model BioCon-700, South Gloucestershire, UK). Postvoid bladder scanner standardized measurements were performed three times by two trained residents, with the average volume from six attempts recorded. Urine samples were sent for urinalysis and culture just before catheter removal. POUR was diagnosed with a second PVR exceeding 150 mL. Once POUR was detected, intermittent catheterization was done. In case a fourth PVR still exceeded 150 mL, the patient was discharged and the transurethral catheter was retained for a period of 3 days, followed by a visit to the outpatient department. The patients in both groups were scheduled for follow-up for 4 weeks after discharge. Before discharge, patient satisfaction was assessed using the Patient Global Impression Scale of Improvement (PGI-I) .
The primary outcome in this study was the rate of postoperative urinary retention in each group. The sample size was derived from a previous study by Hakvoort et al , using two independent proportions and a sample of 68 patients (34 patients in each group) for a 95% confidence interval (CI), 80% power, and 5% probability of type I error, and 10% data loss.
The secondary outcomes were the rates of postoperative UTI and asymptomatic bacteriuria (AB), mean time to ambulation, mean time to voiding, and mean length of hospital stay. The presence of AB was defined as quantitative urine culture yielding at least 105 colony-forming units of an identified single microorganism. UTI was microbiological evidence of serious bacteriuria and pyuria, in addition to symptoms such as dysuria, increased bladder sensation, or fever. The time to ambulation was defined as the interval between the completion of surgery and the time when the patient could stand up and walk, supported by a nurse or another person. Time to normal voiding was defined as the time interval between catheter removal and spontaneous voiding. The length of hospital stay was defined as the time interval between the completion of surgery and hospital discharge. Finally, PGI-I scores were used to assess patients’ overall satisfaction after prolapse surgery. There were seven possible responses (scored 1–7): 1) very much better, 2) much better, 3) a little better, 4) no change, 5) a little worse, 6) much worse, and 7) very much worse. The satisfaction level was defined as PGI-I 1 and 2.
Stata/IC16 was used for statistical analysis (StataCorp LLC, College Station, TX, USA). Intention-to-treat analysis was conducted by an independent statistician. For continuous data, the statistical analysis was performed using the Student t-test and median regression. Additionally, categorical data were compared using the chi-squared test and Fisher’s exact test, as appropriate. A value of p<0.005 was considered statistically significant.