Does ICG-NIRF cholangiography replace the critical view of safety in laparoscopic cholecystectomy? A prospective evaluation on biliary visualization dynamics and the impact of inflammation.

Abstract

Background: While indocyanine green near-infrared fluorescence (ICG-NIRF) cholangiography is increasingly used to facilitate real-time biliary visualization, its ability to substitute for the Critical View of Safety (CVS) as a primary anatomical endpoint remains unclear. This study aimed to characterize the intraoperative dynamics of ICG-NIRF and evaluate the impact of acute cholecystitis (AC) on its reliability.

Methods: In this prospective study of 96 consecutive patients (48 AC; 48 non-AC), biliary visualization was assessed at three milestones: T1 (dissection onset), T2 (CVS declaration), and T3 (pre-clipping). Patients received ICG (1.25 mg) at induction. Dissection followed the Tokyo Guidelines 2018 (TG18) framework using standardized subserosal-inner layer technique to achieve the CVS. The primary endpoint was the simultaneous visualization of the common bile duct (CBD), common hepatic duct (CHD), and cystic duct (CyD). Factors affecting visualization were analyzed using generalized estimating equations and multivariable regression.

Results: CVS was achieved in 93.8% of cases, whereas simultaneous three-duct NIRF visualization was achieved in only 16.7% at T1, showing significant temporal improvement by T3 (46.9%; OR 4.61, p < 0.001). Multivariable analysis identified AC as the sole independent predictor of both CBD (OR 4.48, p = 0.016) and CHD (OR 3.80, p = 0.003) non-visualization at T3, with identification failure rates increasing stepwise with TG18 severity (p = 0.001).

Conclusion: ICG-NIRF signals follow a dissection-dependent trajectory that is consistently attenuated by inflammation. Because the CVS provides anatomical certainty far beyond that of fluorescence alone, ICG-NIRF complements but does not replace the standardized dissection framework. In cases of severe AC, surgeons must prioritize meticulous surgical maneuvers over potentially unreliable fluorescence signals.