What is Cystoscopy in a World Without Indigo Carmine?
Cystoscopy in a World Without Indigo Carmine refers to the practice of performing cystoscopy, a diagnostic procedure used to examine the bladder, without the use of Indigo Carmine. Indigo Carmine is a dye that has been traditionally used in medical procedures to highlight certain structures.
What are the Risks of Cystoscopy in a World Without Indigo Carmine?
Performing cystoscopy without the use of Indigo Carmine, a dye traditionally used to enhance visualization during this procedure, presents several risks and challenges. Risks may include:
Compromised visualization of the urinary tract structures.
Difficulty identifying lesions, tumors, or other abnormalities within the bladder or urethra.
Increased risk of unrecognized ureteral obstruction or injury during surgical procedures.
Risk of inadvertent bladder perforation during diagnostic or therapeutic procedures.
Inability to clearly delineate the margins of a tumor.
Delayed diagnosis of conditions like interstitial cystitis, bladder cancer, or other urinary tract disorders.
Surgeons might need more time to perform procedures.
Use of alternative dyes like methylene blue.
Additional costs and resource burdens on healthcare systems.
Video Transcript: Cystoscopy in a World Without Indigo Carmine
In light of the current and prolonged shortage of indigo carmine, this video will review all methods available to detect ureteric patency during intraoperative cystoscopy during gynaecological surgery.
Gynaecological surgery carries risk of ureteric injury due to the proximity of the reproductive organs to the urinary tract. These surgeries account for 75% of the iatrogenic ureteric injuries and cause significant morbidity from unrecognised injuries.
The visual inspection alone of ureteric peristalsis has low sensitivity for detection of ureteric injury. In one study the rate of ureteric injury during hysterectomy was 1.7% with only 12.5% of these detected with visual inspection alone. Many studies have focused on intraoperative cystoscopy as a means to diagnose ureteric injury during gynaecological surgery.
Administration of IV indigo carmine has been the mainstay of assessing ureteric integrity.
Numerous studies have demonstrated much higher rates of detection of ureteric injuries when indigo carmine was used during cystoscopy, compared to surgeries without cystoscopy.
Indigo carmine is well tolerated and has a rapid onset of action. Bright blue ureteric jets are seen minutes after administration as demonstrated in this video. Indigo carmine, while expensive, was the main marker dye used until an unavailability of raw materials and manufacturing delays led to a shortage back in 2014.
No anticipated return date is currently available. This unavailability may be a permanent reality that forces gynaecologists to seek alternate methods of detection for ureteric integrity.
In this video we will review alternate methods available. Advantages and disadvantages will be discussed. Additional tips will also be provided.
The options for cystoscopy without dye include 10% dextrose, normal saline, and sterile water.
We begin here with a video of 10% dextrose. This option is readily available and used in many institutions. It allows for the visualisation of ureteric jets because of the difference in viscosity as demonstrated in this video.
Ureteric jets can be very difficult to visualise.
A recent publication suggests increasing to 50% dextrose as a way to mitigate this. Visualisation alone does not rule out injury along the entire length of the ureter.
Here we have a cystoscopy with sterile water. This medium is also readily available and inexpensive. Here we see a strong ureteric jet. Again, in this situation we have uncertainty about the integrity of the ureteric jet along its entire course. This can be mitigated by not only observing the jet, but also looking at the velocity. Sluggish jets may alert clinicians to partial obstruction injuries.
Methylene blue is another agent that can be used to confirm ureteric jets. It is the second most common dye and results in blue jets being visualised as demonstrated here. Few studies exist that examine this method. One of the main disadvantages is that the urine jets can be only lightly or inconsistently stained.
There has been studies that suggest there can be long delays to excretion in the urine and this has the negative consequence of lengthening operating time while the surgeon waits for the coloured jets. Methylene blue is also a monoamine oxidase inhibitor, and the clinician must consider the possibility of serotonin syndrome if given in those patients on SSRIs, SNRIs, and monoamine oxidase inhibitors.
A promising new agent that has recently been reported is sodium fluorescein. This organic compound has been used extensively in ophthalmology as a colouring agent.
Sodium fluorescein results in bright yellow ureteric jets as visualised here. Sodium fluorescein is readily available in most hospitals. It has a quick onset of action being seen within three to five minutes of administration. The ophthalmology data suggests it is tolerated well even at much higher doses such is standard in that discipline.
Minimal data is currently available in gynaecology patients. Optimal dosage appears to be 0.25 ml to 0.5 ml of the 10% solution.
And lastly, here we have our oral colouring agents. Currently available are vitamin B complex and phenazopyridine. Vitamin B results in yellow jets as demonstrated in this video. One study was identified for use of each of these. Both are relatively inexpensive and well tolerated.
There are certain disadvantages. Vitamin B is inconsistent in dying of jets. In the one study mentioned above, only 70% of patients had bilateral yellow jets seen.
Phenazopyridine is no longer manufactured in Canada and only available from compounding pharmacies. This obviously limits its use and for this reason we were unable to obtain a video of cystoscopy with it.
In addition, the oral agents can only be used in situations where cystoscopy is planned preoperatively as the medications must be given orally prior to surgery.
In conclusion, we know that gynaecological surgery carries a significant risk of ureteric injury and unrecognised injuries can have serious consequences. Intraoperative cystoscopy has been studied as a means to screen for these injuries and prevent negative sequelae.
Many options for marker dyes exist and the practicing gynaecologist must be aware of all options especially in light of the current shortage we have of the most widely accepted dye available, indigo carmine. Sodium fluorescein appears to be a very promising agent and requires further studies.
We hope this video gives you useful information so an informed decision can be made the next time you are performing intraoperative cystoscopy.