Options to Evaluate Ureter Patency at Cystoscopy in a World Without Indigo Carmine

Indigo carmine dye for detecting urinary track damage during vaginal surgery

OBJECTIVE

Unrecognized ureteral and bladder injury increase morbidity and mortality in gynecologic surgery. The primary objective of this study is to analyze the efficiency of a systematic intra-venous (IV) injection of carmine indigo to detect bladder injury in gynecologic vaginal surgery for benign disease. The secondary objective is to analyze the cost and use of carmine indigo.

STUDY DESIGN

A retrospective, monocentric study was conducted in a tertiary hospital between January 2018 and October 2021. All patients undergoing a vaginal surgery of hysterectomy for benign disease or anterior prolapse were systematically included. Patients can be systematically included by the automatic coding of surgery. After anesthesia, during the patient's installation, an intravenous injection of 5 mL of intravenous indigo carmine (Carmyne®) diluted in 100 mL of physiological serum was systematically administered by the anesthesia team. Intraoperative cystoscopy was performed only in cases of suspected associated ureteral injury.

RESULTS

We recorded 443 vaginal hysterectomies for benign disease and 95 vaginal anterior prolapse surgeries. There were 6 (1,4%) bladder injuries during vaginal hysterectomies and 1 (1,1%) bladder injury during vaginal prolapse surgery. All bladder injuries were diagnosed intraoperatively. No ureteral injury was diagnosed in this series of patients. No complication related to IV indigo carmine injection was found. In this tertiary hospital, 1085 ampoules of carmine indigo were ordered during the same period, approximatively 270 per year. The total cost to the gynecology and obstetrics department was 19,600 euros, or about 4,900 euros per year. Half of the carmine indigo was used in vaginal surgery and half in laparotomy, caesarean section and endometriosis surgery for suspected bladder or ureteral injury.

Indigo Carmine: Between Necessity and Concern

Dyes, such as indigo carmine, have become indispensable to modern life, being widely used in the food, textile, pharmaceutical, medicine, and cosmetic industry. Although indigo carmine is considered toxic and has many adverse effects, it is found in many foods, and the maximum permitted level is 500 mg/kg. Indigo carmine is one of the most used dyes in the textile industry, especially for dyeing denim, and it is also used in medicine due to its impressive applicability in diagnostic methods and surgical procedures, such as in gynecological and urological surgeries and microsurgery. It is reported that indigo carmine is toxic for humans and can cause various pathologies, such as hypertension, hypotension, skin irritations, or gastrointestinal disorders. In this review, we discuss the structure and properties of indigo carmine; its use in various industries and medicine; the adverse effects of its ingestion, injection, or skin contact; the effects on environmental pollution; and its toxicity testing. For this review, 147 studies were considered relevant. Most of the cited articles were those about environmental pollution with indigo carmine (51), uses of indigo carmine in medicine (45), and indigo carmine as a food additive (17).

Comparing vitamin B2 versus 5% dextrose in water for optimal ureteric jet visualisation at the time of pelvic reconstructive surgery: A randomised controlled trial

OBJECTIVE

To compare preoperative vitamin B2 versus intraoperative cystoscopy distension using 5% dextrose in water (D5W) for ureteric jet visualisation during pelvic reconstructive surgery.

DESIGN

Double-blinded, randomised controlled trial.

SETTING

Three tertiary hospitals in Toronto, Canada.

POPULATION

Adult women undergoing pelvic reconstructive surgery.

METHODS

Patients were randomised to receive 100 mg of vitamin B2 preoperatively versus bladder distension with D5W intraoperatively.

MAIN OUTCOMES

The primary outcome was the rate of accurate detection of bilateral ureteric jets during cystoscopy. Secondary outcomes included the time elapsed until visualisation, use of intravenous furosemide or fluorescein to assist with visualisation, surgeon satisfaction, and positive urine culture 1 week after surgery.

RESULTS

The intervention was completed by 236 patients (vitamin B2 n = 117, D5W n = 119). Preoperative characteristics were similar across groups. Accurate detection of both ureteric jets was high in both groups (vitamin B2 97.4% vs. D5W 90.8%, p = 0.051). The vitamin B2 group had significantly lower use of fluorescein rescue compared with the D5W group (3.4% vs. 11.8%, respectively, p = 0.025). Surgeon satisfaction while using vitamin B2 was significantly higher (p < 0.001). There were no significant differences in the time elapsed until visualisation, the use of furosemide, or the incidence of positive urine culture at 1 week after surgery.

CONCLUSIONS

Both preoperative vitamin B2 and intraoperative cystoscopy distension with D5W are highly available and inexpensive methods to detect ureteric jets with high accuracy at the time of pelvic reconstructive surgery. Vitamin B2 was shown to have lower rates of fluorescein rescue for visualisation and higher rates of surgeon satisfaction.

Cost-effectiveness of agents used for evaluation of ureteral patency during intraoperative cystoscopy in gynecologic and urogynecologic surgery

BACKGROUND

Intraoperative evaluation of ureteral patency is often performed in gynecologic and urogynecologic surgery. Many agents are used to help assess the patency, each with its own associated cost, ease of use, and adverse reactions. Some agents, such as dextrose, are used as an instillation fluid to create a viscosity difference and aid the visualization of a ureteral jet. Others, such as oral phenazopyridine or the intravenous use of sodium fluorescein and indigo carmine, cause a color change of the urine to directly aid the visualization of ureteral jets. Recently, numerous studies have examined the efficacy and surgeon satisfaction of these agents. The studies have also emphasized certain options as associated with a lower cost. However, there have not been any cost studies comparing these agents.

OBJECTIVE

To compare the cost-effectiveness of the following 4 agents that are commonly used in assessing ureteral patency intraoperatively: oral phenazopyridine, dextrose instillation, intravenous sodium fluorescein, and intravenous indigo carmine.

STUDY DESIGN

We constructed a decision-analytic model to compare cystoscopy using oral phenazopyridine, dextrose instillation, intravenous sodium fluorescein, and intravenous indigo carmine. Failure to see efflux resulted in work-ups for ureteral obstruction. The probabilities were obtained from published studies, and the probability of successfully seeing efflux ranged from 0.92 with oral phenazopyridine to 0.99 with intravenous indigo carmine. The costs of the agents, adverse effects, and ureteral obstruction work-ups were obtained from the University of North Carolina at Chapel Hill Department of Pharmacy, the Healthcare Cost and Utilization Project 2016 database and the FAIR Health Consumer database. The cost of a ureteral obstruction work-up used in our model ranged from $9755 for intraoperative evaluation with retrograde pyelograms and stents to $29,034 for hospitalization. Our primary outcome was the incremental cost-effectiveness ratio per unnecessary work-up for ureteral obstruction avoided. Sensitivity analyses were performed to identify the key uncertainties.

RESULTS

Oral phenazopyridine, followed by an intravenous agent if needed, had a mean cost of $110 per patient. Dextrose averaged $151 more per patient, with only a slight improvement in avoiding unnecessary ureteral obstruction work-ups and a higher cost associated with adverse reactions (incremental cost-effectiveness ratio, $62,000). Intravenous agents cost approximately $1000 more per patient and were less effective at preventing unnecessary work-ups. Sensitivity analyses did not identify any thresholds that would significantly change the outcomes.

CONCLUSION

Our model suggests that oral phenazopyridine and dextrose instillation are the least expensive and the most effective agents to aid in the visualization of ureteral patency during intraoperative cystoscopy, although dextrose is associated with higher costs owing to a higher rate of adverse reactions (primarily urinary tract infections). Intravenous sodium fluorescein and indigo carmine are historically popular first-choice agents. However, they were found to be more expensive and less effective as primary agents in our model and should likely be reserved for use as secondary agents in the event that the visualization of ureteral jets is unclear with the initial use of phenazopyridine or dextrose.

A Review on the Etiology, Prevention, and Management of Ureteral Injuries During Obstetric and Gynecologic Surgeries

Iatrogenic ureteral injuries are a rare but serious complication of some gynecological and obstetric procedures with both high morbidity and legal implications. The incidence varies widely depending on the type and extent of the surgeries with about 70% unrecognized intraoperatively. When recognized intraoperatively and promptly managed, the prognosis is good. Ureteral injuries recognized postoperatively come with dire consequences for the patients and are litigation prone. Due to the proximity of the lower half of the ureters to the pelvic organs, 50% of the cases of injuries to the ureter occur within the jurisdiction of gynecological and obstetric practice. A good knowledge of the etiology, predisposing factors, appropriate surgical skills, proper identification of the course and deviation of the ureters, and intraoperative recognition of inadvertent damage to the ureter and its vasculature is required by all obstetricians and gynecologists to reduce the incidence of ureteral injuries by at least 50%. This review aims to add to what is already known, particularly among obstetricians and gynecologists practicing in resource-constrained settings.

Urine staining intensity and observation of intraoperative ureteral jets among oral agents

INTRODUCTION AND HYPOTHESIS

To determine if administration of a standard 400 mg oral dose of riboflavin (vitamin B2) was comparable to phenazopyridine (pyridium) for evaluating ease of visualization of ureteral jets at the time of cystoscopy.

METHODS

A three-arm double-blinded, randomized controlled study was performed consisting of thiamine as placebo, phenazopyridine, and riboflavin. Agents were administered the morning of surgery prior to surgical procedure. The primary outcome was the ease of visualization of the ureteral jets based on a grading of urine stain intensity on a 7-point color scale, where 1-2 were minimal yellow staining, 3-4 were moderate yellow staining, and 5-7 defined as intense yellow staining. Analysis of covariance (ANCOVA) was used with pairwise comparison to characterize urine stain intensity as a continuous variable among the three groups controlling for age, BMI, creatinine, and time from ingestion of medication to first cystoscopy.

RESULTS

Eighty-four subjects were randomized with a mean ± SD age of 46.25 + 11.36 and BMI of 32.46 + 6.59. Riboflavin did have moderate or intense staining in 57% of cases; however, there was no significant difference between urine staining intensity compared to placebo (p = 0.21). There was a statistically significant increased urine staining intensity for phenazopyridine compared to placebo (p = 0.001) and for phenazopyridine compared to riboflavin (p = 0.001).

CONCLUSIONS

Phenazopyridine provided statistically significantly greater urine staining compared to both riboflavin and placebo and should be considered primarily for ease of ureteral jet visualization.

The effect of preoperative phenazopyridine on short-term urinary retention following urogynecologic surgery

INTRODUCTION AND HYPOTHESIS

Previous studies have found that administration of phenazopyridine decreased short-term urinary retention following surgery but other more recent trials have shown mixed results. This study sought to investigate the potential benefit of preoperative administration of oral phenazopyridine in relation to the prevention of short-term urinary retention following urogynecologic surgery.

METHODS

This is a retrospective cohort study of a convenience sample of women undergoing urogynecologic surgery from June 2016 to March 2019. Following surgery, subjects underwent a standardized retrograde voiding trial. The data had previously been gathered from a prior prospective trial at our institution (Kesty et al. Int Urogynecol J 31(9):1899-1905, 11). Chart review was performed to determine whether patients that received 200 mg of preoperative oral phenazopyridine to better visualize ureteral efflux during cystourethroscopy were more or less likely to pass their postoperative voiding trial. Bivariate statistical analysis was performed as well as a multivariate logistic regression model.

RESULTS

A total of 165 subjects were included in the final analysis; 100 who did not receive preoperative phenazopyridine and 65 who did receive phenazopyridine. There was no statistical difference between voiding trial pass rates following urogynecologic surgery between those who did not receive preoperative phenazopyridine compared to those who did [77% (77/100) and 82% (53/65), respectively, p = 0.37)]. The multivariate logistic regression model demonstrated no difference in postoperative voiding trial pass rates among those who received preoperative phenazopyridine compared to those who did not (OR 1.7, 95% CI: 0.53, 5.8).

CONCLUSIONS

Preoperative administration of oral phenazopyridine does not decrease short-term urinary retention following urogynecologic surgery.

Patch Testing With Carmine 2.5% in Petrolatum by the North American Contact Dermatitis Group, 2011-2012

BACKGROUND

Carmine is a natural red dye that may cause allergic contact dermatitis.

OBJECTIVE

The aim of this study was to analyze patch test reactions to carmine (2.5% in petrolatum) and characterize carmine-positive patients.

METHODS

This study conducted a retrospective analysis of North American Contact Dermatitis Group data compiled between 2011 and 2012.

RESULTS

Of 4240 patients patch tested to carmine, 132 (3.1%) had reactions with a final interpretation of "allergic" (positive). Carmine-positive patients were significantly more likely to be female (77.7% vs 68.3%; P = 0.0237) and have a final primary diagnosis of allergic contact dermatitis (74.8% vs 47.2%; P < 0.0001). As compared with carmine-negative patients, carmine-positive patients were significantly more likely to have involvement of all facial sites combined (48.1% vs 29.9%; P < 0.0001) and the lips (7.6% vs 3.6%; P = 0.0166). At final reading, most carmine reactions were weak (+; 64.9%). Approximately half (53.4%) were currently clinically relevant; identified sources were primarily personal care products (77.1%), especially makeup (31.4%) and lip products (8.6%).

CONCLUSIONS

Weak patch test reactions to carmine should be interpreted with caution. Allergic contact dermatitis to carmine should be suspected in women with facial and/or lip dermatitis, especially those using carmine-containing cosmetics.

Cystoscopy at the time of incontinence and prolapse surgery

PURPOSE OF REVIEW

This article provides an update on the use of cystoscopy at the time of prolapse and incontinence surgery.

RECENT FINDINGS

Iatrogenic lower urinary tract injury is a known complication of antiincontinence procedures and surgical repair of pelvic organ prolapse. Intraoperative cystoscopy improves detection of lower urinary tract injuries in women undergoing pelvic floor surgery. The pelvic surgeon has a number of agents available to aid in the cystoscopic visualization of ureteral efflux. When injuries of the urinary tract are identified and treated intraoperatively, there is decreased morbidity, lower healthcare costs, and a lower risk of litigation than when detection is delayed. Therefore, many organizations, including the American College of Obstetricians and Gynecologists (ACOG), the American Urogynecologic Society (AUGS), and the American Urological Association (AUA) recommend cystoscopy at the time of pelvic floor surgery.

SUMMARY

Cystoscopy should be universally employed at the time of prolapse and incontinence surgery, except in instances of isolated repair of the posterior compartment.

CO2 Cystoscopy for Evaluation of Ureteral Patency

Gynecologic surgery is associated with various perioperative complications, especially urinary tract injuries. Intraoperative cystoscopy plays an important role in allowing assessment of the bladder to ensure the absence of injuries. Verification of the urinary jets from the ureters is a fundamental step that is not always easy to accomplish. Dyes are frequently used, but these are not always available and are associated with adverse effects. The present study aimed to demonstrate the use of CO₂ as a medium for distension during cystoscopy. A total of 47 patients underwent CO₂ cystoscopy after laparoscopic hysterectomy (n = 26) or bladder endometriosis nodule resection (n = 21). In all patients, the ureteral jets were readily identified, leaving no doubt as to their patency. The median interval between the onset of cystoscopy and the view of jetting from both ureteral ostia was 145 seconds (range, 80-300 seconds). All cystoscopies were normal, and no patient had any signs of accidental urinary tract injury in the follow-up period. Two patients experienced mild urinary tract infection. This cystoscopy technique using CO₂ is fast, easy, safe, and efficient. We recommend bladder distension with CO₂ as a reasonable alternative technique when cystoscopy is required during gynecologic procedures.

Dextrose Instillation as an Alternative Agent to Observe Ureteral Efflux During Pelvic Reconstructive Surgery

OBJECTIVE

To evaluate the use, cost, postoperative urinary tract infection (UTI) rates, and complications of dextrose instillation during cystoscopy.

METHODS

The medical records of patients who underwent cystoscopy during pelvic reconstructive surgery between June 2016 and June 2017 were reviewed. Patients were divided into two groups: patients who had one ampule of dextrose 50% (D50) directly instilled and patients who did not have D50 instilled during cystoscopy. Preoperative demographics, UTI rates, and postoperative complications were compared. Pharmaceutical cost and availability were reported by the pharmacy at our institution.

RESULTS

Out of 63 patients identified, dextrose instillation was used in 20 patients and no dextrose was used in 43 patients. Each ampule of D50 cost $2.18 and there were no problems with supply shortage. As D50 was directly instilled into the bladder, there was immediate visualization of ureteral efflux at the time of surgery. Three patients (15%) in the dextrose group and 10 patients (23%) in the nondextrose group developed postoperative UTIs. There was no statistically significant difference in postoperative UTI rates between the two groups (p = 0.43) and there were no differences in postoperative complications.

CONCLUSION

Dextrose is a safe, cost-effective, readily available agent that provides instantaneous visualization of ureteral efflux without an increased risk of postoperative UTI.

American Urogynecologic Society Consensus Statement: Cystoscopy at the Time of Prolapse Repair

Injury to the urinary tract is a known risk of surgical repair of anterior and apical pelvic organ prolapse. Cystoscopy at the time of surgical prolapse repair is a low-risk procedure that can identify genitourinary tract injury by inspecting the bladder and urethra as well as by visualizing the ureters and ureteral efflux. There are several techniques to assist with visualization of ureteral efflux. Identifying injury intraoperatively may allow for mitigation of the morbidity of the injury. Universal cystoscopy should be performed at the time of all pelvic reconstructive surgeries, with the exception of operations solely for posterior compartment defects.