The Efficacy of Fluorescent Cholangiography Using the Spy Scope™ System, a Randomized Control Trial

Danny A Sherwinter, MD. Maimonides Medical Center

 

BACKGROUND: Intraoperative cholangiogram (IOC) has been shown to be helpful in delineating biliary anatomy and may prevent main duct injury during laparoscopic cholecystectomy. Despite these benefits, the need for ionizing radiation and injection of contrast directly into the biliary system has prevented IOC from becoming routine. Fluorescent cholangiography using an intravenously injected fluorophore and near infrared (NIR) imaging provides similar anatomical detail without the drawbacks of radiographic cholangiography.
To date, NIR imaging systems have been cumbersome, requiring the surgeon to halt dissection and switch modes, or even switch cameras to obtain the fluorescent cholangiographic views. The laparoscopic image, and therefore the context necessary to accurately interpret the cholangiographic images is lost and the operative flow interrupted.
The Spy system (Novadaq, Ontario) is a NIR fluorescence based laparoscopic system that has the novel capability of acquiring both NIR and white light images simultaneously. It can then superimpose the fluorescent cholangiogram on the standard white light laparoscopic image in real-time.
METHODS: The Spy scope consists of a high definition (HD) 10mm endoscopic camera and light source designed to concurrently acquire high resolution visible and NIR fluorescence images. Furthermore, it is equipped with a combined display mode that merges the NIR image as an overlay on the HD image. Indocyanine green (ICG) was used as the fluorophore.
38 patients undergoing laparoscopic cholecystectomy were enrolled in this study, 19 were randomized to receive 1cc of ICG injected intravenously 30-60 min prior to beginning the procedure and 19 were randomized to the control group. The Spy system was used as the sole imaging system in all cases. At the completion of the cases, the operative surgeons were asked to assess visualization, safety, operative technique, resident autonomy and teaching value on a five-point Likert Scale. Objective parameters such as operative time and time to identification of the major structures were also evaluated.
RESULTS: No difference in mean operative times was noted between the ICG and control groups (52.4 and 46.1 minutes respectively) but mean time to identification of the key anatomical structures (14.2 and 19.7 minutes respectively) was significantly reduced. Based on surgeon questionnaire responses, the Spy scope did not significantly improve the safety of the procedure or the ability of the surgeon to identify important structures but did provide the surgeon with the confidence to allow trainees greater operative autonomy.
CONCLUSION: The results of this study are encouraging and indicate that although the Spy system doesn’t supplant the critical view technique it speeds recognition of key structures by providing real-time contextualized cholangiographic images without being obtrusive or interrupting the operative flow. It may be especially helpful for surgeons early in the learning curve to help in identifying anatomy and preventing injury.

 


Session Number: SS10 – Novel Technologies & Operations
Program Number: S062

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