Role of ICG in Acute Cholecystitis During Laparoscopic Cholecystectomy

The message for surgeons:

ICG clearly improves visualization.

Whether it independently prevents bile duct injury remains less certain.

That is an important distinction when counselling surgeons about the technology.

ICG in the difficult acute gallbladder

This may actually be the most logical application.

Consider:

• Severe acute cholecystitis
• Dense adhesions
• Contracted gallbladder
• Impacted neck stone
• Mirizzi-type anatomy
• Short or parallel cystic duct
• Distorted Calot’s triangle
• Gangrenous gallbladder
• Previous episodes of cholecystitis
• Unexpected anatomy
• Difficult identification of the cystic duct

In these situations, the question is not:

“Can ICG replace dissection?”

The better question is:

“Can ICG give me additional anatomical information before I make the next irreversible move?”

That is where fluorescence potentially adds the greatest value.

Practical intraoperative workflow

Step 1 — Administer ICG

Intravenous administration is the most commonly used approach.

However, dose and timing are not completely standardized.

A randomized dose-finding study evaluated administration approximately 30 minutes before surgery and found that 0.1 mg provided favourable bile duct-to-liver fluorescence ratios compared with higher doses in its specific imaging system and protocol. (PubMed)

Therefore, surgeons should follow the dose, concentration, timing and imaging-system recommendations of the specific ICG product and fluorescence platform rather than universally adopting one published dose.

Step 2 — Start with white light

ICG should not replace conventional anatomical orientation.

Begin with:

White light → exposure → decompression → traction → anatomical landmarks

Then switch to fluorescence.

Step 3 — Map the biliary anatomy

Before significant dissection, identify:

CBD → CHD → cystic duct → gallbladder

The fluorescence image should be interpreted together with the white-light anatomy.

Step 4 — Dissect toward CVS

The surgeon should continue to obtain the Critical View of Safety.

ICG can help answer:

• Is this structure the cystic duct?
• Where is the CBD?
• Is the CBD running close to the operative field?
• Is the suspected cystic duct actually entering the gallbladder?
• Has inflammation distorted the expected anatomy?

The “ICG pause” before clipping

A useful practical concept is to introduce an ICG safety pause immediately before clipping or dividing the cystic duct.

Ask three questions:

1. What is this structure?

2. Where is the CBD/CHD?

3. Do the fluorescence anatomy and surgical anatomy agree?

If they do not agree:

STOP.

Do not proceed simply because the structure “looks like” the cystic duct.

This is particularly relevant in severe inflammation, where the consequences of a mistaken assumption can be catastrophic.

What ICG cannot do

ICG has important limitations.

It does NOT:

• Demonstrate the Critical View of Safety by itself
• Replace careful dissection
• Reliably identify structures buried under thick inflammatory tissue
• Replace intraoperative cholangiography when ductal stones or detailed ductal anatomy need evaluation
• Reliably identify vascular anatomy
• Guarantee prevention of bile duct injury
• Replace bailout procedures when CVS cannot be achieved

The fluorescence signal can also be affected by liver background fluorescence, excessive ICG dose, timing of administration, obesity, inflammation and tissue thickness.

ICG versus conventional IOC

This is an important practical distinction.

ICG fluorescence

Advantages

• No X-ray
• No cystic duct cannulation
• Real-time imaging
• Rapid
• Repeatable
• Can be used before dissection
• Provides continuous visual guidance

Conventional intraoperative cholangiography

Advantages

• Provides a ductal contrast study
• Better assessment of ductal continuity
• Can demonstrate filling defects
• Can provide more comprehensive biliary anatomy

The 2025 SAGES guideline conditionally favours IOC over ICG fluorescence imaging for benign biliary disease, reflecting the current certainty of evidence rather than suggesting that ICG is clinically useless. (PubMed)

Therefore:

ICG and IOC should be viewed as complementary technologies rather than interchangeable techniques.

What does WSES recommend?

The position of the emergency-surgery community is particularly relevant to acute cholecystitis.

The WSES international consensus position paper states that ICG cholangiography can enhance visualization of the biliary tree, guide dissection toward CVS and potentially improve confidence during emergency laparoscopic cholecystectomy.

Importantly, the panel recommends ICG cholangiography during laparoscopic cholecystectomy for acute cholecystitis when equipment and expertise are available, while acknowledging that the underlying evidence is moderate/low level. (PubMed Central (PMC))

This is therefore a strong recommendation with an evidence base that is not equivalent to high-quality RCT evidence—an important nuance.

A practical algorithm

Acute cholecystitis → Laparoscopic cholecystectomy

↓

Administer ICG according to local protocol

↓

White-light anatomical assessment

↓

Near-infrared fluorescence mapping

↓

Identify CBD/CHD + cystic duct

↓

Progressive dissection

↓

Critical View of Safety

↓

ICG + white-light confirmation

↓

Clip and divide cystic duct

↓

If CVS cannot be achieved → STOP

↓

Consider bailout strategy

• Subtotal cholecystectomy
• Fundus-first approach in selected circumstances
• Conversion when appropriate
• Intraoperative cholangiography
• Additional imaging/consultation according to the clinical situation

The most important surgical principle

ICG should be an adjunct, not a permission slip.

A fluorescent cystic duct does not automatically mean that the anatomy is safe.

The surgeon must still establish the relationship between:

Gallbladder → cystic duct → CHD → CBD

and obtain the Critical View of Safety before division.

If the anatomy remains unclear despite fluorescence:

Do not dissect harder. Change the strategy.

That may mean subtotal cholecystectomy, conversion, IOC or another bailout technique.

Expert takeaway

The role of ICG in acute cholecystitis is best understood as real-time anatomical augmentation.

It can:

✔ Improve visualization of extrahepatic bile ducts

✔ Provide anatomical information before and during dissection

✔ Potentially shorten identification of biliary structures

✔ Be particularly useful in difficult/inflamed Calot’s triangle

✔ Avoid radiation and cystic duct cannulation

But:

✘ It does not replace Critical View of Safety

✘ It does not guarantee prevention of bile duct injury

✘ It cannot reliably resolve every difficult anatomy

✘ Current randomized evidence has not conclusively demonstrated reduction in bile duct injury

Bottom line

In acute cholecystitis, ICG is best viewed as an additional pair of eyes—not as a substitute for surgical judgment.

The strongest current evidence supports its ability to improve biliary visualization, while evidence for reducing clinically important outcomes such as bile duct injury remains evolving.

For the surgeon facing a severely inflamed Calot’s triangle, however, the practical value may be considerable:

See the anatomy → understand the anatomy → achieve CVS → confirm before dividing.

And when anatomy remains uncertain:

ICG should make the surgeon more cautious—not more confident.

That may ultimately be its greatest contribution to safer emergency laparoscopic cholecystectomy.

Key PubMed references

1. Calabrese EC, et al. SAGES 2025 guidelines for fluorescence image-guided surgery using indocyanine green. Surg Endosc. 2025;39:7935-7957. PMID: 41249539. (PubMed)
2. Kumar SK, et al. SAGES guidelines for the use of intraoperative imaging of the common bile duct. Surg Endosc. 2025. PMID: 41044285. (PubMed)
3. Pimentel T, et al. Indocyanine green fluorescent cholangiography in laparoscopic cholecystectomy: systematic review and meta-analysis with trial sequential analysis of randomized controlled trials. Surgery. 2025;181:109149. PMID: 39891966. (PubMed)
4. Seretis C, et al. Routine use of ICG to enhance operative safety in emergency laparoscopic cholecystectomy: a randomized controlled trial. PMID: 35194663. (PubMed)
5. Huang Y, et al. Real-time fluorescent cholangiography with indocyanine green in laparoscopic cholecystectomy: randomized controlled trial to establish optimal ICG dose. Surg Today. 2023. PMID: 35920936. (PubMed)
6. Dip F, et al. Does near-infrared fluorescent cholangiography with indocyanine green reduce bile duct injuries and conversions to open surgery? Surgery. 2021. PMID: 33478756. (PubMed)
7. Pesce A, et al. Utility of fluorescent cholangiography during laparoscopic cholecystectomy: a systematic review. World J Gastroenterol. 2015;21:7877-7883. PMID: 26167088. (PubMed)
8. WSES. Indocyanine green fluorescence-guided surgery in the emergency setting: international consensus position paper. (PubMed Central (PMC))
9. WSES. 2020 guidelines for detection and management of bile duct injury during cholecystectomy. (PubMed Central (PMC))
10. Tang K, et al. Evaluating the safety and efficacy of ICG fluorescence imaging for difficult laparoscopic cholecystectomy: systematic review and meta-analysis. Am Surg. 2026;92:1374-1383. PMID: 41289059. (PubMed)