DOse and administration Time of Indocyanine Green in near-infrared fluorescence cholangiography during laparoscopic cholecystectomy (DOTIG): a randomized clinical trial

Background: Different techniques have been proposed to reduce the incidence of the intraoperative bile duct injury during laparoscopic cholecystectomy (LC). Among these, Near-Infrared Fluorescence Cholangiography (NIFC) with Indocyanine Green (ICG) represents a relatively recent addition. At present, there is considerable variation in the protocols for the administration of ICG.

Methods: The aim of this randomized multicenter clinical trial (RCT) is to ascertain whether there are differences between the dosage and administration intervals of ICG, with a view to optimizing a good-quality NIFC during LC. Furthermore, an analysis was conducted to determine the potential impact of different factors on the outcomes of this technique. The trial was approved by the local institutional Ethics Committee.

Results: From June 2022 to June 2023, 200 patients were randomized in four arms (G1: 2.5 mg ICG > 3 h prior to surgery, G2: 2.5 mg ICG 15-30 min prior to surgery, G3: 0.05 mg/kg ICG > 3 h prior to surgery and G4: 0.05 mg/kg ICG 15-30 min prior to surgery). We found differences in the DISTURBED score between the groups (p < 0.001), suggesting that ICG administration 15-30 min before surgery was worse than administration > 3 h after LC (p = 0.02). Additionally, it was observed that body mass index (BMI), gender, ASA Classification System, previous liver and biliary disease and the type of surgery had influence on NIFC. Finally, the NIFC had an impact in intraoperative and postoperative complications, operative time and hospital length of stay.

Conclusions: The administration of ICG > 3 h improve liver background fluorescence in the NIFC during LC. There are different factors may affect NIFC results (BMI, ASA grade, previous liver disease, presence of gallbladder inflammation and type of surgery). Finally, high-quality NIFC was associated with fewer surgical complications, shorter surgical time and shorter length of hospital stay.