Introduction:
This protocol outlines a randomized phase IV clinical trial designed to compare the efficacy of two different doses of indocyanine green (ICG) used in near-infrared fluorescent cholangiography during laparoscopic cholecystectomy (LC)-the current gold standard treatment for symptomatic cholelithiasis. Despite its effectiveness, LC is still associated with significant risks, particularly bile duct injury (BDI), a severe complication that this study aims to mitigate.
Phase: Phase IV Study design: Multicenter, randomized, open-label, parallel-group clinical trial (modified intention-to-treat).
Objectives:
Primary objective:
* To analyze differences between treatment groups (standard dose 2.5 mg >3h preoperative vs reduced dose 0.25 mg immediate preoperative 15-30 min) during laparoscopic cholecystectomy in:
* Visualization of extrahepatic biliary structures
* Degree of visualization
* Degree of background liver fluorescence interference
* Perceived utility of the technique
Secondary objectives:
* Influence of BMI, biliary pathology type, surgery type, prior inflammation, surgical difficulty, previous instrumentation, and laparoscopic imaging system on results
* Intraoperative and postoperative complication rates
* 30-day mortality
* Impact on operative time and hospital stay
* Correlation between subjective and objective fluorescence assessment (ducts-to-liver fluorescence ratio) Population: Patients ≥18 years indicated for laparoscopic cholecystectomy (elective, early or urgent deferred).
Main inclusion criteria:
* Age ≥18 years
* Signed informed consent
* Indication for laparoscopic cholecystectomy (symptomatic cholelithiasis, gallbladder polyps with surgical indication)
Main exclusion criteria:
* Age <18 years
* Pregnancy or lactation
* Chronic kidney disease (stage >IIIb)
* ICG or iodinated contrast allergy
* Functional thyroid disease
* Emergency non-deferrable surgery
* Open approach
* Suspicion of gallbladder carcinoma
* Inability to understand the study Investigational product: Indocyanine green (ICG), intravenous administration
This multicenter study involves two hospitals in Castilla y León, Spain, and plans to enroll 122 adult patients meeting specific clinical criteria for LC. Participants will be randomized into two treatment arms and will receive ICG accordingly:
* Group 1: 2.5 mg >3h before surgery
* Group 2: 0.25 mg 15-30 min before surgery Fluorescence will be assessed both subjectively by the surgical team and objectively through digital image analysis using specialized software to calculate the bile duct-to-liver fluorescence ratio (RFBH).
Endpoints:
* Rates and degree of biliary structure identification pre- and post-dissection
* Perceived utility of cholangiography
* Liver background fluorescence interference
* Ducts-to-liver fluorescence ratio Duration: 12 months recruitment + 1 month follow-up = total 13 months Countries: Spain Ethics: The study will be conducted in accordance with ICH-GCP, EU Clinical Trials Regulation No 536/2014, and applicable national regulations.
Beyond comparing the diagnostic performance of two dosing strategies, this study seeks to provide evidence supporting a more practical and logistically feasible approach for implementing ICG fluorescence cholangiography in routine surgical practice, without compromising diagnostic accuracy or patient safety.