Rate of Postoperative Urinary Retention After Anterior Compartment Prolapse Surgery: a Randomized Controlled Trial Comparing Early Versus Conventional Transurethral Catheter Removal

doi:10.21203/rs.3.rs-1021959/v1

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Rate of Postoperative Urinary Retention After Anterior Compartment Prolapse Surgery: a Randomized Controlled Trial Comparing Early Versus Conventional Transurethral Catheter Removal

https://doi.org/10.21203/rs.3.rs-1021959/v1

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Purpose To compare the rate of postoperative urinary retention (POUR) after anterior prolapse surgery between early transurethral catheter removal (24 hours postoperatively) and our standard practice (on postoperative day 3)

Methods We conducted a randomized controlled trial among patients undergoing anterior compartment prolapse surgery between 2020 and 2021 at a university hospital. Women were randomized into two groups. After removal, if the second void residual urine volume exceeded 150 mL, POUR was diagnosed and intermittent catheterization was performed. The primary outcome was the POUR rate. The secondary outcomes included urinary tract infection, asymptomatic bacteriuria (AB), time to ambulation, time to spontaneous voiding, length of hospitalization, and patient satisfaction.

Results Sixty-eight women were enrolled. There were no significant differences in baseline characteristics, intraoperative blood loss, operative time, anesthetic modalities, opioid use, and complications. The overall POUR rate was 29.4%. The POUR rate in the conventional group was 18.2% higher than that in the early-removal group; however, this was not statistically significant. (32.4% vs. 26.5%, RR 0.82; 95% CI: 0.39–1.72). There was no significant difference between groups for postoperative AB rate (14.7 vs. 0%, p=0.053). The early-removal group had shorter lengths of hospital stay (1 day vs. 3 days, p<0.001) and 3.8 hours earlier time to ambulation (p=0.2), without significant differences in postoperative patient satisfaction.

Conclusion Among patients undergoing anterior compartment prolapse surgery, early catheter removal was comparable in POUR rate to conventional treatment, with shorter hospitalization. Therefore, early transurethral catheter removal is preferable following anterior compartment prolapse surgery.

Clinical trial registration number thaiclinicaltrials.org, TCTR20210309003, 09 March 2021, retrospectively registered.

Obstetrics & Gynecology

Anterior compartment prolapse surgery

Pelvic organ prolapse

Postoperative urinary retention

Transurethral catheter

Early catheter removal

The prevalence of symptomatic pelvic organ prolapse (POP) is 4–12%, with an increasing trend. Rates of POP surgery are also increasing owing to aging of the population. POP is a common disease associated with pelvic floor dysfunction. POP is evaluated using the pelvic organ prolapse quantification (POP-Q) system. There are three main compartments in POP: anterior, posterior, and apical compartments. An anterior compartment prolapse has a significant effect on urinary symptoms, especially causing voiding difficulty in advanced POP because of anatomical structures. For patients with severe prolapse symptoms, surgery has been the treatment of choice. Anterior colporrhaphy (AC) and colpocleisis are the two main prolapse surgeries for anterior vaginal repair [1].

Postoperative urinary retention (POUR) is a frequent consequence of gynecologic surgery, occurring in 2.5–43% of cases, especially with surgical correction of urinary incontinence and pelvic organ prolapse [2]. Postsurgical changes in edema, inflammation, and pain are important factors in POUR. Furthermore, prolapse repair can lead to changes in the urethra–vesical junction (UVJ) that can affect voiding. Moreover, surgery in the vaginal and retropubic spaces is likely to cause disruption of the perforating nerve branches, leading to transient neuropathy, which can affect bladder sensation and micturition. Thus, to prevent this complication, indwelling bladder catheterization is routinely used. However, prolonged bladder catheterization may increase the chance of developing urinary tract infection (UTI) and may prevent ambulation, prolong hospitalization, and also adversely affect postoperative well-being [1, 2].

Whereas there is no universal definition for POUR, it is characterized by impaired bladder emptying with an elevation in residual urine volume. A stricter definition involves quantified voided volume and postvoid residual (PVR). Even with a quantified PVR, cutoff values vary in range. Generally, PVR less than 100–200 mL is considered acceptable [2-4]. There are several ways to assess PVR; the gold standard is measurement using catheterization. An alternative to catheterization is transvaginal ultrasonography [5] and a bladder scan. A non-invasive three-dimensional portable transabdominal ultrasound device is used to calculate bladder volume by imaging pockets of fluid. Its accuracy, specificity, and negative predictive value is 90%, 91.0%, and 93.1%, respectively [6]. Owing to the advantages of bladder scans, this technique is currently common in assessing PVR.

At Ramathibodi Hospital (Thailand), the bladder catheter is removed on postoperative day 3. A previous retrospective cohort study revealed that the rate of POUR after pelvic floor surgery was approximately 7% [4]. However, no randomized-controlled trials (RCTs) focusing on POUR and the optimal timing of catheter removal have been conducted.

Results of a previous RCT showed that early transurethral catheter removal at 24 hours postoperatively seemed to benefit patients undergoing vaginal prolapse surgery in terms of lower incidence of UTI and a shorter hospital stay [4]. However, the optimal timing for catheter removal following anterior prolapse surgery remains unclear. Therefore, in this study, we aimed to determine the optimal time of catheterization following anterior prolapse surgery. The main outcome was to assess the rate of postoperative urinary retention after anterior compartment prolapse surgery in a trial comparing early transurethral catheter removal (24 hours postoperatively) with our conventional practice.

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) [4], 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 [5]. 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) [7].

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 [3], 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.

Between March 2020 and February 2021, 68 women were recruited, consented, enrolled, and were randomly allocated into either the early transurethral catheter removal group (early removal group) or conventional removal group, with 34 patients in each group. No participants in this cohort were excluded; therefore, outcome data were available for all 68 women (Figure 2).

The average participant age was 66.7±9.94 years. There were no statistically significant differences in baseline characteristics (Table 1). All patients underwent AC or colpocleisis. There were no differences in terms of intraoperative blood loss, operative time, anesthetic modalities, opioid use, and complications (Table 2). The primary outcomes illustrated that POUR occurred in 20 women (29.4%), of whom 11 (32.4%) were in the conventional group and 9 women (26.5%) were in the early removal group (Figure 3). The POUR rate of the conventional group was 18.2% higher than that in the early removal group; however, this was not statistically significant (relative risk=0.82; 95% CI: 0.39–1.72). The 20 women with POUR were discharged home with a retained Foley catheter, and all of them returned to spontaneous voiding after 3 days of follow-up.

Table 1

Baseline participant characteristics
	Conventional transurethral	Early transurethral	P value
	catheter removal (n=34)	catheter removal (n=34)
Age (y), mean±SD	65.7±10.7	68.1±9.4	0.33^a
BMI (kg/m²), mean±SD	25.0±4.0	24.6±3.6	0.71^a
Vaginal parity, n (%)
0	1 (2.9%)	1 (2.9%)	1.00^c
1	3 (8.8%)	4 (11.8%)
≥2	30 (88.2%)	29 (85.2%)
Menopause, n (%)	32 (94.1%)	34 (100%)	0.49^c
Medical comorbidity, n (%)
Respiratory disease	4 (11.6%)	0	0.11^c
Metabolic disease	26 (76.5%)	28 (82.4%)	0.55^b
CVD	1 (2.9%)	6 (17.7%)	0.11^c
Current drug use, n (%)
Alpha-blocker	1 (2.94%)	0	1.00^c
Beta-blocker	2 (5.9%)	4 (11.8%)	0.67^c
Prior surgery, n (%)
Hysterectomy	5 (14.7%)	5 (14.7%)	1.00^b
Anti-incontinence surgery	1 (2.9%)	0	1.00^c
POP surgery
AC	1 (2.9%)	3 (8.8%)	0.61^c
PC	1 (2.9%)	1 (2.9%)	1.00^c
Baseline anterior vaginal prolapse, n (%)
POP-Q stage 2	5 (14.7%)	9 (26.5%)	0.49^b
POP-Q stage 3	15 (44.1%)	13 (38.2%)
POP-Q stage 4	14 (41.2%)	12 (35.3%)
Preoperative PVR (mL), median (range)	42.95 (0.45–149)	37.5 (0.97–121)	0.94^d
Preoperative asymptomatic bacteriuria, n (%)	5 (14.7%)	6 (17.7%)	1.00^c
^at-test; ^b Pearson’s χ²; ^cFisher’s exact test; ^dMedian regression.
SD, standard deviation; BMI, body mass index; CVD, cardiovascular disease; POP-Q, pelvic organ prolapse quantification; AC, anterior colporrhaphy; PC, posterior colporrhaphy; PVR, postvoid residual.

Table 2

Operative data
	Conventional transurethral	Early transurethral	p value
	catheter removal (n=34)	catheter removal (n=34)
Main operation, n (%)			0.45^c
Anterior colporrhaphy	20 (58.8%)	24 (70.6%)
Colpocleisis	14 (41.1%)	10 (29.4%)
Total colpocleisis	13 (38.2%)	10 (29.4%)
Lefort	1 (2.9%)	0
Concomitant surgery, n (%)
Vaginal hysterectomy	26 (76.5%)	25 (73.5%)	0.78^b
McCall culdoplasty	1 (2.9%)	6 (17.6%)	0.11^c
Sacrospinous ligament fixation	5 (14.7%)	2 (5.9%)	0.43^c
Laparoscopic sacrocolpopexy	0	1 (2.9%)	1.00^c
Manchester operation	0	1 (2.9%)	1.00^c
Perineoplasty	9 (26.5%)	2 (5.9%)	0.02^b
Posterior colporrhaphy	12 (35.3%)	11 (34.2%)	0.80^b
Uterosacral ligament fixation	1 (3.13%)	0	1.00^c
Intraoperative factors
Operative time (min), mean±SD	108.1±37.1	90.6±33.7	0.05^a
Blood loss (mL), median (range)	50 (10–300)	50 (10–200)	1.00^d
Intraoperative IV fluid (mL), median (range)	1002.9±342.0	869.7±379.3	0.13^d
Intraoperative urine output (mL), median (range)	300 (0–900)	300 (50–900)	1.00^d
Anesthetic modality, n (%)
General anesthesia	9 (26.5%)	13 (38.2%)	0.05^c
SB without intrathecal morphine	17 (50.0%)	20 (58.8%)
SB with intrathecal morphine	8 (23.5%)	1 (2.9%)
Opioid use (equianalgesic to IV morphine)
Intraoperative use, median (range)	0 (0–10)	0 (0–10)	1.00^d
Postoperative use, median (range)	6 (0–30)	4 (0–37.3)	0.61^d
Complications, n (%)
Vaginal hematoma	0	2 (5.9%)	0.49^c
Blood transfusion	0	1 (2.9%)	1.00^c
^at-test; ^bPearson’s χ²; ^cFisher’s exact test; ^dMedian regression.
SD, standard deviation; IV, intravenous; SB, spinal anesthesia.

There was no significant difference between groups in terms of the postoperative AB rate (14.7 vs. 0%, p=0.053). No postoperative UTI developed in any patients. The early removal group had shorter hospital stays (1 day vs. 3 days, p<0.001) and 3.8 hours earlier time to ambulation (p=0.2), with no significant differences in postoperative patient satisfaction as assessed by PGI-I scores (p=0.58); most women reported that they were “much better” (Table 3). Even though some patients experienced POUR, they were still satisfied with the outcome (80% vs. 87.5% in patients with and without POUR, respectively; p=0.465). Other postoperative complications after anterior compartment prolapse surgery were detected in the early removal group, namely, vaginal hematoma and blood transfusion. Two patients (5.9%) and 0 patients had vaginal hematoma in the early removal and the conventional group, respectively (p=0.49), and blood transfusion rates were 2.9% (1 patient) and 0 patients, respectively (p=1.00). There were no adverse events caused by the early catheter removal protocol.

Table 3

Postoperative outcomes
	Conventional transurethral catheter removal (n=34)	Early transurethral catheter removal (n=34)	P value
POUR, n (%)	11 (32.4%)	9 (26.5%)	0.60^a
Time to ambulation (h), median (range)	28 (6–60)	24.4 (15.3–28)	0.20^c
Time to spontaneous voiding (h), median (range)	1.5 (0.5–4.3)	2 (0.5–5.75)	0.06^c
Length of hospitalization (d), median (range)	3 (3–4)	1 (1–5)	<0.001^d
Patient satisfaction (PGI-I), median (range)	2 (1–4)	2 (1–3)	0.58^c
Postoperative asymptomatic bacteriuria, n (%)	5 (14.7%)	0	0.05^b
^aPearson’s χ²; ^bFisher’s exact test; ^cMedian regression; ^dWilcoxon rank-sum test.
PGI-I, Patient Global Impression Scale of Improvement; POUR, postoperative urinary retention.

In recent years, studies have aimed to establish the optimal time of catheterization to balance the rates of POUR and catheter-associated UTI. However, in a recent systematic review [8, 9], there were no strong conclusions with regard to the optimal time of removal, with considerable variation among published studies. Additionally, most previous studies were not specific to anterior compartment prolapse surgery [3, 4]. According to our results, the rates of overall, conventional, and early removal POUR were 29.4%, 32.4, and 26.5%, respectively. The conventional removal group had a higher POUR rate, which may be owing to longer operative time; however, there was no significant difference in the rate of urinary retention after anterior compartment prolapse surgery between groups. In a randomized study among patients who underwent anterior prolapse surgery with or without posterior colporrhaphy or vaginal hysterectomy, Hakvoort et al [3] showed that 40% and 9% of patients needed recatheterization if the transurethral catheter was removed on the morning after surgery and the fifth postoperative day, respectively. In that study, POUR was defined as PVR >200 mL. In another study, Gourisankar [4] revealed a significantly higher number of retentions in the early removal group (first postoperative day) than the conventional group (fourth postoperative day), with 21.4% versus 8%; odds ratio 3.10. In that study, POUR was defined as PVR >150 mL, which was similar to the present study. However, only six patients were discharged with a retained Foley catheter. After 3 days of follow-up, all of these patients returned to spontaneous voiding. These POUR rates are in contrast to the findings of our study owing to inconsistent catheter removal dates. Certain factors that might explain these variations in POUR rate are the difference in PVR cutoff values and mean measurement in considering POUR. Also, our study included patients who were older at the time of surgery and a greater number of preoperative advanced POP-Q stages compared with previous studies. Moreover, our study included all types of anterior compartment surgery, such as AC and colpocleisis, and details of concomitant surgery. Additionally, we adhered strictly to the protocol for the timing of catheter removal, 24 hours postoperatively. Furthermore, the postoperative AB rate in our study did not show significant differences between groups: 14.7 vs. 0% (p=0.053) and there were no postoperative UTIs. Patients in previous studies showed a lower risk of UTI development [2-4].

This study demonstrated that anterior compartment prolapse surgery performed as overnight surgery appears to be safe and feasible. Additionally, we observed no re-hospitalization owing to POUR. The benefits were to reduce unnecessary, costly hospitalization and the bed occupancy rate and to improve the patient turnover rate.

To our knowledge, no previous studies have assessed postoperative patient satisfaction. We used the PGI-I and found that the mean index response was “much better”, which was similar in both groups (p=0.58). Moreover, patients who experienced POUR were still satisfied, with 80% and 87.5% in POUR and non-POUR patients, respectively; p=0.465. This result may reflect good patient–doctor relationships, good surgical outcomes, preoperative counseling regarding the risk of developing POUR, and use of a noninvasive tool to measure PVR.

The strengths of this study include the randomized controlled design with no drop outs. Because our institute is a university hospital, surgeons follow standardized surgical techniques under the supervision of well-trained FPMRS staff in every case. Nevertheless, this study also has some limitations. We did not have well-allocated intraoperative anesthetic modalities and there was variation in the postoperative pain control protocol. However, these should not affect our results. Another limitation is that one researcher was unblinded to PVR measurement, which can cause observer bias. This limitation was minimized using similar bladder scans and pre-evaluation interrater reliability measures.

As for the clinical implications of our findings, POUR is a frequent consequence of transvaginal surgery. To prevent this complication, indwelling bladder catheterization is routinely used. In contrast, prolonged bladder catheterization may increase the likelihood of UTI development, prevent ambulation, prolong hospitalization, and also adversely affect postoperative well-being [1, 2].

Future researchers should consider having a well-designed anesthetic and pain control protocol. Further research is needed into 1-day pelvic floor surgery with 24-hour and 6-hour transurethral catheter removal.

In conclusion, in patients undergoing anterior compartment prolapse surgery with or without concomitant surgery, patients with early catheter removal had POUR rates comparable to the conventional group and shorter lengths of hospital stay. Shorter hospitalization supports the current policy to reduce the bed occupancy rate. Therefore, early transurethral catheter removal is preferable following anterior prolapse surgery.

Acknowledgments

The authors would like to thank Kunlawat Thadanipon, MD and Mr. Nattawut Unwanatham for their kind guidance in statistical analysis, the patients who participated in this study, the nurses, and the Female Pelvic Medicine and Reconstructive Surgery division, Department of Obstetrics and Gynecology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University.

Funding

Not applicable.

Conflicts of interest

The authors declare that they have no conflicts of interest.

Author Contribution

NC: Protocol/project development, Data collection or management, Manuscript writing/editing
AK: Data collection or management
RW: Manuscript writing/editing
KA: Manuscript writing/editing
JM: Manuscript writing/editing
OC: Protocol/project development, Manuscript writing/editing

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Hakvoort R et al (2004) How long should urinary bladder catheterisation be continued after vaginal prolapse surgery? A randomised controlled trial comparing short term versus long term catheterisation after vaginal prolapse surgery. BJOG 111:828-830.
Kamilya G et al (2010) A randomized controlled trial comparing short versus long‐term catheterization after uncomplicated vaginal prolapse surgery. J Obstet Gynaecol Res 36:154-158.
Prapaspongsa T, Manonai J (2017) Transvaginal sonographic assessment of postvoid residual urine volumes in women with pelvic floor dysfunction. Ramathibodi Med J 40:34-41.
Thanagumtorn K (2016) Accuracy of post-void residual urine volume measurement using an ultrasound bladder scanner among postoperative radical hysterectomy patients. J Med Assoc Thai 99:1061-1066.
Srikrishna S, Robinson D, Cardozo L (2010) Validation of the patient global impression of improvement (PGI-I) for urogenital prolapse. Int Urogynecol J 21:523-528.
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Rate of Postoperative Urinary Retention After Anterior Compartment Prolapse Surgery: a Randomized Controlled Trial Comparing Early Versus Conventional Transurethral Catheter Removal

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Abstract

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