What this Trial Is About

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.

Comparison Between Standard and Reduced Doses of Indocyanine Green in Fluorescence Cholangiography During Laparoscopic Cholecystectomy.