BACKGROUND AND PURPOSE:

• Ureteral integrity using cystoscopy
  • Is recommended by AUGS following all pelvic organ prolapse surgeries
  • Can be used to following surgeries where there may be concern regarding ureteral injury
• The traditional method of increasing ureteral jet visibility in the past was indigo carmine, but recent procurement has been difficult
• Stitely et al. (Obstetrics & Gynecology, 2019) assessed the efficacy of oral riboflavin to enhance visibility in the determination of ureteric patency at cystoscopy

METHODS:

• Randomized, double blinded, clinical trial (RCT)
  • Gynecologic surgery where cystoscopy was a planned component of the procedure
  • Participants, surgeons and research team were unaware of who received intervention vs placebo  
• Patients received orally (oral capsules night before surgery) either
  • Riboflavin 400 mg
  • Placebo
• During cystoscopy: The surgeon visualized and video recorded the ureteric jets
• Primary outcome: Stronger yellow color of urine seen on cystoscopy using a 3-point scale
• Secondary outcomes included
  • Ease of ureteric jet identification (5-point scale)
  • Proportion of patients where both jets were visualized
• Statistical analysis
  • 0.75 point mean difference in the color scale
  • 80% power and 0.05 significance level
  • Minimum sample size of 60 was required (additional patients recruited to account for potential drop out)
• Charts reviewed post-surgery to determine of any ureteric injuries had occurred

RESULTS:

• 66 participants were randomized | 33 in to each study group
• Compared to placebo controls, riboflavin group had an increase in yellow urine color (P<.001)
  • Riboflavin group: Median of 2 (3-point scale)
  • Placebo: Median of 1 (3-point scale)
• Jets were more easily visualized in the riboflavin group (P<.013)
  • Riboflavin group: Median of 5 on a 5-point scale
  • Placebo group: Median of 4 on a 5-point scale
• There was no statistical difference between group in proportion of women who had bilateral ureteral patency confirmed (P=.71)
  • Riboflavin group: 91% 
  • Placebo group: 85%  

CONCLUSION:

• Authors recognized that subjective measurements used in this study
• However, strengths include RCT design
• The authors conclude that riboflavin is a safe and inexpensive option to assess ureteric jets and “should be considered for routine use’

Learn More – Primary Sources:

Oral Riboflavin to Assess Ureteral Patency During Cystoscopy

Related ObG Topics:

Which Surgeries are Most Likely to Lead to Urinary Tract Injury?

Best Method of Evaluating the Ureters When Indigo Carmine is Not Available?

When to Consider Intraoperative Cystourethroscopy?