Implementation of a policy of universal cystoscopy at the time of hysterectomy for benign indications: A retrospective comparative study

Lower urinary tract injury (LUTI) is a serious complication of major gynaecologic surgery. Although intra‐operative cystoscopy can facilitate timely diagnosis and treatment of LUTI, the optimal approach to cystoscopy at the time of benign hysterectomy remains debatable.


INTRODUCTION
Lower urinary tract injury (LUTI) is a rare but recognised complication of hysterectomy. The risk of such injuries varies widely in the published literature; however, recent analyses using large population databases report a 1.8% overall urinary tract injury rate and 0.78% ureteral injury rate. 1,2 These injuries are one of the main causes of significant morbidity after hysterectomy, especially when diagnosis and treatment are delayed. 3 Cystoscopy is a low-risk low-cost procedure that can improve intra-operative detection of LUTIs, 3 allowing for immediate repair, thus reducing complications due to delayed diagnosis. With up to 75% of urinary tract injuries occurring during uncomplicated hysterectomies without identifiable risk factors, universal cystoscopy allows detection of otherwise unsuspected injuries being missed with selective or no cystoscopy. 4 The main arguments against universal cystoscopy is the overall low prevalence of urinary tract injuries, additional surgical time and cost involved with cystoscopy. 5 Even with a high sensitivity, 3 universal cystoscopy can still miss some injuries, potentially those caused by delayed thermal effect or defects too small to be visually identified. 6 On the other hand, it has been suggested that some injuries are asymptomatic and will spontaneously resolve, hence universal cystoscopy can lead to overdiagnosis and unnecessary interventions that may pose additional risks to patients. 7 There is no consensus regarding the optimal approach to cystoscopy at the time of hysterectomy for benign indications. While the American College of Obstetricians and Gynecologists (ACOG) guidelines recommends routine cystoscopy to be considered at the time of laparoscopic total hysterectomy and high-risk procedures (such as prolapse repairs and continence procedures), 8,9 there are no specific recommendations regarding hysterectomies performed for other benign indications or operative routes. With limited local published data and guidelines, the approach to cystoscopy at the time of hysterectomy remains inconsistent among gynaecologists in Australia.
At our institution, a policy of universal cystoscopy at the time of benign hysterectomy was introduced in September 2019. The primary aim of this study was to investigate whether implementation of this policy was associated with an increase in intra-operative detection and decrease in the rates of LUTI. The secondary aim was to evaluate the adherence rate to this policy.

MATERIALS AND METHODS
This is a retrospective cohort study of all hysterectomies performed for benign indications at the Nambour General Hospital from 1 November 2016 to 31 March 2017 and Sunshine Coast University Hospital (the Gynaecology Unit relocated to a newly built hospital location during the study period) from 1 April 2017 to 31 March 2021. The start date was selected as this is when electronic medical records were initiated at the institution, and the end date reflects the time when data collection began. The Sunshine Coast University Hospital Gynaecology Unit is a large regional teaching unit in Australia, led by ten general obstetriciangynaecologists who perform hysterectomies by various operative routes in routine and complicated cases.
A policy for universal cystoscopy to be performed at the time of all hysterectomies was implemented at our institution on 30 September 2019. Prior to that, cystoscopy was selectively per- Continuous variables with a normal distribution were analysed using Student's t-test while those non-normally distributed were assessed with Mann-Whitney U-test. Categorical variables were analysed using Fisher's exact test. The outcomes were compared between the two groups using multivariate logistic regression models. P-values <0.05 were considered significant. Demographic and peri-operative characteristics of both groups are shown in Table 1. There were no significant differences in BMI and length of stay. Mean age of patients, rates of abdominal hysterectomy and estimated blood loss were increased in the post-policy group compared with the pre-policy group. There were more hysterectomies performed for fibroids, and fewer per- The overall rate of LUTI was 1.9%, with each case of injury corresponding to one patient. The pre-policy group had a LUTI rate of 2.2% and the post-policy group had a rate of 1.5%.
Taking into account the LUTIs that were identified with direct visualisation prior to performing cystoscopy, there was no significant difference in the cystoscopy detection rates between groups.
In the pre-policy group, cystoscopy detected three of the four remaining LUTIs and in the post-policy group, cystoscopy detected one of the two remaining LUTIs.
Peri-operative characteristics of the cases with LUTI in both groups are reported in Table 3. Cystoscopy was performed in 85.7% of LUTI cases in the pre-policy group and in all the cases of the post-policy group. Intra-operative bladder injury, in particular cystostomy, was the most common LUTI in both groups. There were no significant differences between groups in terms of types of LUTI, route of hysterectomy, surgical time and primary surgeon.

DISCUSSION
This is the first Australian study examining the effects of an institutional policy of universal cystoscopy at the time of benign  The overall prevalence of LUTI associated with benign hysterectomy in our study was consistent with that published in contemporary literature. Although earlier studies which looked at selective cystoscopy at time of hysterectomy reported much lower rates of LUTI, less than 1%, 7,11 these are likely underestimated due to very low rates of cystoscopy use and lack of longterm post-operative follow-up. 5 The LUTI detection rate using cystoscopy in our study was slightly lower than previously reported at 83-97%. 3,4,12 Of note, in the case of the delayed LUTI in the post-policy group ( Table 4, suggest that universal cystoscopy for laparoscopic hysterectomy would achieve cost efficacy when either the ureteral injury rate alone exceeds 0.25%, bladder injury rate exceeds 1.1% or overall LUTI rate exceeds 0.80%. 15 The different decision analysis models, variation in data used, as well as changes in clinical practice over the decade (such as surgical approach to hysterectomy and treatment of LUTI), has likely contributed to these disparate findings.
No doubt, an analysis using local data would be warranted to accurately evaluate the cost-effectiveness of universal cystoscopy at the time of benign hysterectomy in Australia.
There were several significant differences in the perioperative characteristics of the pre-and post-policy groups. More