Fernando Dip, MD, Mario Nahmod, MD, Pedro Ferraina, MD, Raul Rosenthal, MD, Steven Wexner, MD. Training Center and Experimental Surgery Jose de San Martin Clinical Hospital, Buenos Aires, Argentina; Department of Colorectal Surgery , Department of Minimal Invasive, Metabolic and Bariatric Surgery, Cleveland Clinic Florida US.
BACKGROUND: Due to it’s unique properties, sodium fluorescein has being used for medical applications such as diagnostic ophthalmology and intravenous angiography. Despite being excreted via the renal system it has never been used to aid in the intraoperative visualization of the ureters. The goal of our study was to assess the real-time visualization of ureters using intravenous sodium fluorescein under the stimulus of a 530 nm wavelength light.
MATERIALS AND METHODS: Nine, 250 gm Wister rats were administered an intravenous dose of 0.01 ml of sodium fluorescein. Anesthesia was performed with an intraperitoneal dose of ketamine-xylazine. A laparotomy was immediately performed following the administration of the dye. The retroperitoneum was exposed and observed under an alternating white xenon and a 530 nm excitation light with an objective to visualize the organs captured within the fluorescence of the compound (sodium fluorescein). All rats were euthanized at the completion of the procedure.
RESULTS: Utilizing xenon light, the kidneys and urinary bladder were visualized. The light was then changed to a 530 nm wavelength mode making possible to visualize the location and orientation of the ureters along with its peristaltic movements. Fluorescence imaging of the ureters was noted 5-10 minutes after the kidney’s were visualized. In addition, the vascular structures in close proximity to the ureters were identified as well.
CONCLUSION: Intravenous administration of sodium fluorescein enables intraoperative fluorescence visualization of the ureters in a rat model. This imaging modality might be applied in clinical settings to prevent ureteral injury when performing urologic or other pelvic procedures.