key: cord-0879301-sb7fu3zg
authors: Zakhari, Andrew; Paek, Wusun; Chan, Wilson; Edwards, Darl; Matelski, John; Solnik, M. Jonathon; Murji, Ally
title: Retrograde bladder filling after laparoscopic gynecologic surgery: a double-blind randomized controlled trial
date: 2020-10-03
journal: J Minim Invasive Gynecol
DOI: 10.1016/j.jmig.2020.09.019
sha: cb6bacdb1f9af97a0f01367e6644d27fb93049ca
doc_id: 879301
cord_uid: sb7fu3zg

Objective To evaluate whether retrofilling the bladder upon completion of elective laparoscopic gynecologic surgery for benign indications has an effect on the timing of the first post-operative void and timing of discharge from hospital. Design Double-blind randomized controlled trial Setting Single academic surgical day hospital Patients Patients undergoing outpatient laparoscopic gynecologic surgery, excluding hysterectomy or pelvic reconstructive surgery. Interventions Upon completion of surgery, patients were randomized to either retrograde filling of the bladder with 200 mL of saline prior to catheter removal or standard care (immediate catheter removal). Patients and PACU nurses (outcome assessors) were both blinded. Measurements The primary outcome was the time to first void. Secondary outcomes were time to hospital discharge, post-operative urinary tract infection and patient satisfaction. Main Results Over a 3 month period, 47 patients were approached on the day of surgery, 42 consented and were randomized (21 to intervention and 21 to control). There were no significant differences in baseline demographics between groups. The median time to first void was significantly shorter for patients in the intervention arm compared to controls (104 ± 75min vs 162 ± 76min, p<0.001). Retrofilled patients were discharged faster from PACU compared to controls (155.0 ± 74min vs 227 ± 58min, p=0.001). There were no urinary tract infections in either group and the proportion of satisfied or very satisfied patients was high (93.8% vs. 88.2%, p=0.512). Conclusion Retrograde filling the bladder after outpatient laparoscopic gynecologic surgery is a safe, effective method that significantly reduces length of hospital stay.

Retrograde bladder filling after gynecologic laparoscopy safely expedites first void and hospital discharge. Interventions Upon completion of surgery, patients were randomized to either retrograde filling of the bladder with 200 mL of saline prior to catheter removal or standard care (immediate catheter removal). Patients and PACU nurses (outcome assessors) were both blinded.

The primary outcome was the time to first void. Secondary outcomes were time to hospital discharge, post-operative urinary tract infection and patient satisfaction.

Over a 3 month period, 47 patients were approached on the day of surgery, 42 consented and were randomized (21 to intervention and 21 to control). There were no significant differences in baseline demographics between groups. The median time to first void

Postoperative urinary retention following routine gynecologic surgery ranges from 0% to 21%, with even higher rates seen with pelvic reconstructive procedures (1) (2) (3) . While predicting postoperative urinary retention is challenging, there are many recognized risk factors including incontinence/prolapse surgery, bladder dissection, excision of deeply infiltrating endometriosis, prolonged operative time, and perioperative narcotic use (4) (5) (6) (7) .

Early identification of urinary retention dictates that patients must void prior to discharge following uncomplicated day surgery. This may lead to increased time in the post-anesthesia care unit (PACU) and delayed discharge, as patients typically awake to an empty bladder, having been catheterized throughout their procedure. Ensuring safe and efficient discharge from the PACU not only minimizes unnecessary use of valuable healthcare resources, but also reduces patient exposure to the healthcare setting, which can be of particular importance in the context of social distancing during the COVID-19 pandemic.

Retrograde bladder filling in the operating room prior to urinary catheter removal is a simple and safe intervention which has been shown to decrease time to first void postoperatively, and time to discharge from PACU following laparoscopic hysterectomy (8) .

However, the benefit of this intervention in patients undergoing other laparoscopic procedures in gynecology has not been investigated. Evidence of the efficacy and safety of this proposed intervention could significantly impact patient flow and optimize healthcare resource utilization.

Our objective was to evaluate whether retrofilling the bladder upon completion of elective laparoscopic gynecologic surgery for benign indications had an effect on the timing of the first post-operative void and timing of discharge from hospital.

We performed a double-blind randomized controlled trial (RCT) between January 10 th 2020 and April 27 th 2020 at a single academic outpatient hospital in Toronto, Canada. All procedures were performed by one of six fellowship-trained gynecologic surgeons, with the assistance of a fellow in advanced gynecologic surgery. Institutional Review Board approval was granted (Women's College Hospital Research Ethics Board), and the trial protocol was registered online at clinicaltrials.gov (NCT04198285). Eligible patients were approached by one of three fellows on the day of surgery and written informed consent was obtained.

We included women scheduled to undergo elective outpatient gynecologic laparoscopy who were able to provide informed consent. Exclusion criteria were: scheduled pelvic reconstructive procedures (eg, prolapse, incontinence, or vaginal reconstructive surgery), hysterectomy, laparoscopic nerve detrapments, pregnancy, past history of neuromuscular disorders (eg. multiple sclerosis), known voiding dysfunction, urinary incontinence, recurrent urinary tract infections (UTIs), genito-urinary malformations, and patients taking anticholinergic medications. Finally, patients who experienced an intraoperative bladder injury were also excluded, given the need for an indwelling urinary catheter postoperatively.

Block randomization in groups of four was performed using a computer generated random number generator. Sequentially numbered, opaque envelopes were used to assign patients to either the intervention or control arm, and were only opened upon completion of the surgery in the operating room, but prior to extubation and transfer to PACU.

Baseline characteristics were collected for all patients including age, ethnicity, smoking status, and underlying medical comorbidities such as cardiovascular disease, respiratory disease, and prior surgical interventions. Total perioperative narcotic and benzodiazepine use was collected for all patients, as well as total operative time and total intraoperative intravenous fluid volume received.

All patients undergoing gynecologic laparoscopy at our center are routinely catheterized with a foley catheter left to straight drainage for the duration of surgery. In the intervention group, upon completion of the procedure and prior to patient extubation, 200mL of normal saline was retrograde instilled into the bladder through the foley catheter prior to catheter removal by the surgical team in the operating room. This volume of saline was chosen as prior reports indicate the normal sensation to void occurs around 200mL. (9, 10) In the control group, the foley catheter was removed upon completion of the procedure, as is our routine practice. Both the patients and outcome assessors (PACU nursing team) were blinded to the intervention, as was the statistician analyzing the results.

The primary outcome was the time to first void, calculated from time of arrival to PACU to first successful void. A successful void was defined as any voided volume greater than 100mL. If a void was less than 100mL, then a bladder scan was performed and if it showed a residual volume of less than 100mL remaining in the bladder, this also constituted a successful void. A failed voiding trail was when a patient voided less than 100mL and had greater than 100mL residual on bladder scan. The voiding algorithm is presented in greater detail in Appendix 1.

Time and volume of first void was recorded, as was voiding success, failure, and additional interventions determined by a pre-defined custom voiding algorithm (Appendix 1).

Secondary outcomes were total time spent in PACU (calculated from arrival to PACU to discharge), post-operative complications including unexpected medical visits, UTIs within the first post-operative week, as well as overall patient satisfaction. The PACU nursing team, who were blinded to the intervention, were solely responsible for reporting the primary outcome and determining discharge from PACU. The nursing team at our ambulatory surgical center is comprised of a relatively small and consistent group who were readily engaged in this study's postoperative voiding protocol as an adjunct to the standard recovery orders.

Patients were contacted by phone by a blinded team-member at one week postoperatively to ensure that no unexpected complications arose within the first postoperative week such as UTIs, unplanned return to hospital or emergency room. Screening for UTI was done by asking symptom related questions and whether medical attention was sought out for these symptoms, followed by investigation of urine analysis/culture if available. Patient satisfaction with the experience in PACU was also measured over the phone using a 5-point Likert scale.

Based on the existing literature, we calculated that with 20 subjects per arm we would be able to detect a 10% difference between groups in the time to first void with 99% power and a 5% type I error rate (8) . Descriptive data was reported as proportions for categorical data and medians with interquartile ranges (IQR) or means with standard deviations (SD) for continuous variables. Comparisons between the two groups was completed with Student's t-test for normally distributed continuous variables and Wilcoxon's rank sum test for skewed data. Chisquare and Fisher's exact test were used for categorical variables. A time to event analysis was performed for first void and PACU discharge. Significance was set at p<0.05. An intention to treat analysis of the data was performed. 

A total of 47 eligible patients were approached during the study period (January to March 2020), 42 of whom consented to participate (see Figure 1 ). After randomization, an equal number of patients were allocated to intervention (N=21) and control (N=21) groups. There were no significant differences in baseline patient characteristics between the two groups.

Surgical characteristics were also similar, with the most common procedure being laparoscopic oophorectomy. Intra-operative administration of narcotics, benzodiazepines and intra-venous fluids were similar between groups, as was total operative time and post-operative narcotic consumption. Table 1 shows patient and surgical characteristics for both intervention and control arms.

The median time to first void was significantly shorter for patients in the intervention arm compared to the control arm (104 ± 75min vs 162 ± 76min, p<0.001, Table 2 Figure 2 , showing a significant divergence between groups (p=0.0001 and p=0.008 respectively). In the post-operative setting, there were no differences between the two groups in terms of total narcotic use.

A total of five patients failed to void entirely, two in the intervention group and three in the control group, detailed in Table 3 . Among these five, two were discharged home with a foley catheter and passed an outpatient trial of void on post-operative day 1 (one retrofill patient, one control patient). Two patients were protocol violations sent home without a foley catheter and given careful instructions to return if unable to void (both control patients) and recovered without complication when assessed at time of routine post-operative visit. One patient was catheterized and remained admitted in the hospital for social reasons (retrofill patient), and passed a trial of void the following morning.

Completion rates for post-operative follow up surveys was similar between the two groups (retrofill 76% (16/21), control 81% (17/21)). There were two patients who had unexpected hospital visits, one from each arm, both of whom presented for abdominal pain which self-resolved. There were no reported UTI's in either group. Overall, the majority of patients reported that they were either satisfied or very satisfied with their experience in PACU (93.8% vs. 88.2%, p=0.512).

In this randomized controlled trial, we found that retrofilling the bladder in the operating room with 200mL of NS prior to urinary catheter removal following laparoscopic gynecologic surgery was associated with significantly shorter time to first void in PACU and an earlier discharge from hospital, with a median difference of 58min and 72min respectively. There were no differences in peri-operative complications, readmission, and both groups reported high patient satisfaction. Delays in discharge due to inability to void following outpatient laparoscopy may be avoided with this simple intervention. Earlier discharge from hospital can also result in improved patient flow, contributing to a reduction in use of healthcare resources and subsequent cost savings.

Strengths of our study include its randomized nature and the consistent blinding of not only patients, but also outcome assessors. We encountered minimal loss to follow up and very few protocol violations. The two groups were comparable in terms of baseline characteristics, and although the majority of patients were Caucasian (approximately 60%), there was nonetheless diverse ethnic representation in the groups. The study was conducted at a single institution, and all procedures were performed by a small group of similarly trained subspecialists in gynecologic surgery, ensuring a generally comparable surgical exposure to patients. Standardization of post-operative surgical care at the ambulatory hospital by a core group of nursing staff also ensures that both groups received similar PACU care.

However, these findings must be interpreted within the context of the study design.

There were multiple exclusion criteria established to eliminate potentially confounding variables, which resulted in a homogeneous study population who were at low risk of urinary retention.

Consequently, our results may not be generalizable to a more medically and surgically diverse patient demographic. There was no formal testing of bladder function preoperatively to detect occult voiding dysfunction or to evaluate bladder capacity. While this information would have been valuable, it would be unlikely for any significant voiding dysfunction to exist without the patient's knowledge, and differences between groups are unlikely due to randomization. Furthermore, identifying which patients require a trial of void after surgery and which do not remains largely unknown and often left to surgeon judgement. A retrospective cohort study of nearly 5000 patients undergoing various same-day gynecologic surgeries found no difference in readmission rates and post-operative urinary retention in patients with and without an order to void prior to discharge (12) . However, the fact that they did not account for procedure type was a key limitation. For instance, the combination of laparoscopic and vaginal surgeries (including pelvic reconstructive procedures) and cancer surgeries (where extensive lymphadenectomy or aggressive dissections may have occurred) may directly impact postoperative voiding dysfunction. Further study aimed at evaluating which patients (based on patient and surgical characteristics) could be safely discharged without a trial of void after surgery is required.

Patients undergoing elective outpatient gynecologic laparoscopy (excluding hysterectomy and pelvic reconstructive surgery) who undergo bladder retrofilling in the operating room are able to void quicker and are discharged from hospital faster compared to current standard of care. Retrograde bladder filling should be considered as a safe addition to recovery protocols that can enhance recovery after surgery.

MJS has no disclosures to report AM sits on the speaker bureau and advisory board for Abbvie, Allergan, Bayer, and Hologic, and the advisory board for Pfizer, outside the submitted work Abbreviations: BZD = benzo, MME = morphine milligram equivalent ***Due to the inherent complexity of converting remifentanil to MME, this narcotic was excluded from total MME comparison Other: Diagnostic laparoscopy with or without tubal dye test, cervico-isthmic cerclage 

Immediate Foley removal after laparoscopic and vaginal hysterectomy: determinants of postoperative urinary retention

Bladder dysfunction after gynecologic laparoscopic surgery for benign disease

Postoperative urinary retention following vaginal mesh procedures for the treatment of pelvic organ prolapse

Laparoscopic identification of pelvic nerves in patients with deep infiltrating endometriosis

Prevention and management of postoperative urinary retention after urogynecologic surgery

Predictors of postoperative urinary retention in outpatient minimally invasive hysterectomy

Urinary Retention After Hysterectomy and Postoperative Analgesic Use

Effect of Postoperative Partial Bladder Filling After Minimally Invasive Hysterectomy on Post Anesthesia Care Unit Discharge and Cost: A Single-Blinded Randomized Controlled Trial

Bladder sensation

Frequency-volume charts: A tool to evaluate bladder sensation

Diagnostic accuracy of retrograde and spontaneous voiding trials for postoperative voiding dysfunction: a randomized controlled trial

Patient Discharge without an Order to Void in the Outpatient Gynecologic Surgery Setting

We would like to acknowledge the dedicated PACU nurses who were instrumental in conducting this study.

AZ reports honoraria from Hologic, outside the submitted work WSP has no disclosures to report WC has no disclosures to report DE has no disclosures to report JM has no disclosures to report