Real-Time Indocyanine Green Fluorescence Navigation in Difficult Laparoscopic Cholecystectomy

Summary

This protocol describes real-time indocyanine green fluorescence navigation for laparoscopic cholecystectomy, a safe, effective, and minimally invasive approach particularly suitable for difficult cases.

Abstract

Laparoscopic cholecystectomy (LC), with its advantages of minimal invasiveness and rapid recovery, has become the standard surgical approach for benign gallbladder diseases. However, even experienced surgeons cannot completely avoid bile duct injury (BDI), and the incidence of BDI during LC is 2-3 times higher than that of open surgery, making it the most common cause of iatrogenic BDI. Approximately 20% of BDIs require multiple surgeries, and about 0.8% eventually result in liver transplantation, significantly impacting patient safety and quality of life, while posing a major risk for medical disputes. Achieving real-time intraoperative visualization is crucial to preventing BDI, particularly in difficult cholecystectomy cases under inflammatory conditions. Real-time indocyanine green (ICG) fluorescence guidance during LC can enhance extrahepatic bile duct visualization and minimize the risk of bile duct injury. In this surgical protocol, an 83-year-old female patient, who had undergone percutaneous transhepatic gallbladder drainage (PTGBD) for acute suppurative cholecystitis 6 weeks prior, was admitted for LC. During the operation, 2.5 mg of ICG was intravenously administered 10 min before the skin incision. Twenty minutes after injection, the liver and common bile duct were clearly visualized under fluorescence imaging. As the dissection of Calot's triangle progressed, the gallbladder and cystic duct remained unstained due to stone impaction, creating a stark visual contrast. Under dynamic ICG guidance, Calot's triangle was meticulously dissected, and the cystic artery and cystic duct were sequentially ligated and divided. The gallbladder was successfully removed. The surgical field showed no bleeding, and fluorescence imaging confirmed no bile leakage, achieving visualized LC under severe inflammatory adhesions. The patient was discharged on the third postoperative day. Real-time ICG fluorescence navigation for LC is safe, effective, and minimally invasive, particularly suitable for difficult cases.

Introduction

Since German surgeon Langenbuch performed the first cholecystectomy in 1882, this procedure has become one of the most common operations in hepatobiliary surgery. With the completion of the first laparoscopic cholecystectomy (LC) by German surgeon Erich Mühe in 1985, LC has now become the standard surgical approach for benign gallbladder diseases¹. Advances in diagnostic techniques and medical equipment have driven the evolution of LC from multiport, 2D, and standard-definition systems toward single-port, 3D, and 4K high-definition systems, further enhancing its safety. Nevertheless, the incidence of bile duct injury (BDI) during LC remains as high as 0.3%-0.7%^2,3, and may be even higher in difficult LC cases, which include those with a history of abdominal surgery, acute and chronic inflammation of the gallbladder, dense adhesion of the triangular tissue of the gallbladder, suppurative cholecystitis, and atrophic cholecystitis. The main cause of BDI is the misidentification of extrahepatic biliary structures due to various factors, particularly in cases of severe gallbladder inflammation, pericholecystic tissue edema, or fibrotic adhesions resulting from recurrent inflammation. These conditions alter the tissue planes and distort the normal anatomical architecture⁴. To avoid BDI, Strasberg et al.⁵ first proposed the Critical View of Safety (CVS) strategy, an anatomical safety measure based on the dissection of Calot's triangle. This approach required that any ductal structure ligated during LC must be clearly identified, with the aim of minimizing BDI occurrence. Although CVS had become a standard component of LC procedures, it did not solve the visualization problem of extrahepatic bile ducts during the operation⁶. Intraoperative cholangiography (IOC) can provide real-time biliary imaging, enhancing the visualization of biliary anatomy and clarifying biliary tract distribution to avoid BDI. However, this procedure prolonged operative time, increased costs, and presented potential iatrogenic BDI. Furthermore, radiation exposure has prevented IOC from being routinely applied in LC, and no consensus has been reached for its application⁷.

With advancements in laparoscopic techniques, the number of patients undergoing LC for acute cholecystitis or after multiple abdominal surgeries has gradually increased. Particularly in cases of moderate to severe acute cholecystitis, surgical risks are significantly elevated⁸. Some patients who are not suitable for emergency surgery may first undergo percutaneous transhepatic gallbladder drainage (PTGBD), followed by LC after stabilization⁹. However, performing LC under chronic inflammatory changes secondary to acute inflammation, such as peritoneal adhesions, a "frozen" Calot's triangle, and thickened porta hepatis tissues, presents challenges. In recent years, indocyanine green (ICG) fluorescence navigation technology has been introduced into surgical practice, particularly in hepatobiliary surgery¹⁰. ICG is commonly used for anatomical liver resection, extrahepatic bile duct visualization, bile leak assessment at liver resection margins, and liver function evaluation. Based on the metabolic characteristics of ICG, some researchers have explored its application in LC. The extrahepatic biliary tract can be visualized under fluorescence laparoscopy to reduce the risk of BDI¹¹. For difficult LC cases with significant inflammation or post-PTGBD changes, the optimal protocol for ICG application, including dosage, timing of injection, and standardized techniques, remains controversial and lacks consensus. Further research is needed to establish the advantages of ICG fluorescence navigation in these challenging scenarios. There is a great need for videos of successful operations to guide the widespread use of such techniques in the future. ICG fluorescence navigation in a difficult laparoscopic cholecystectomy is presented here.

An 83-year-old woman was admitted to a local hospital with right upper abdominal pain and fever for one week. The pain was persistent, radiating to the right shoulder, and accompanied by chills and fever (peak temperature: 39 °C). No jaundice (scleral or cutaneous) was observed. Contrast-enhanced abdominal computed tomography (CT) revealed multiple stones in the cystic duct and gallbladder with cholecystitis. As the cholecystitis had been present for one week and was complicated by concomitant diabetes mellitus and hypertension, emergency PTGBD was performed at the local hospital, and the patient was discharged after symptom relief. One month later, admission for surgery was carried out. A PTGBD tube was fixed in the right hypochondriac region, draining a small amount of yellowish-white fluid (no obvious bile). Physical examination showed no significant abnormalities.

Laboratory findings: white blood cell count, 9.5 × 10⁹/L; neutrophils, 70%; platelets, 388 × 10⁹/L; hemoglobin, 109 g/L; alanine aminotransferase, 9.7 U/L; aspartate aminotransferase, 18.5 U/L; total bilirubin, 9.2 µmol/L. Electrolytes and coagulation function were normal. CECT showed multiple gallstones, with a drainage tube visible within the gallbladder. The gallbladder wall was significantly thickened (Figure 1A,B). The diagnosis was gallstones with cholecystitis. An ICG fluorescence-guided LC was performed after completion of the preoperative evaluation.

Protocol

This protocol follows the guidelines of the Human Research Ethics Committee of The First Affiliated Hospital of Guangzhou Medical University. Informed consent was obtained from the patients for the release of information and data related to this treatment. The reagents and equipment used are listed in the Table of Materials.

1. Patient selection

1. Use the following inclusion criteria
   1. Perform LC navigated by real-time indocyanine green fluorescence in patients with gallstones accompanied by acute or chronic cholecystitis or benign gallbladder diseases with a history of abdominal surgery. Ensure completion of standard cardiopulmonary evaluations, blood tests, and biochemical assessments. Confirm absence of contraindications for surgery or anesthesia.
   2. Perform preoperative imaging, including abdominal US and contrast-enhanced abdominal computed tomography. Perform MRCP if necessary to exclude negative common bile duct stones. Perform liver function tests, ensuring TBIL is normal and ALT is not more than 2 times the normal upper limit.
2. Use the following exclusion criteria
   1. Exclude patients with cardiopulmonary insufficiency who cannot tolerate surgery and general anesthesia, coagulopathy, or allergy to ICG.

2. Informed consent

1. Explain the laparoscopic procedure, including its methods, risks, benefits, and alternatives. Obtain informed consent.

3. Preoperative preparation, surgical position, and anesthesia

1. Preoperative preparation
   1. Perform routine laboratory tests, including complete blood count, liver function tests, and coagulation profiles.
      NOTE: Exclude surgical contraindications.
   2. Conduct imaging studies to assess vascular and bile duct variations, gallbladder inflammation status, and gallbladder stone location.
   3. Perform an ICG skin test to assess for potential allergies^12,13.
      ​NOTE: Given the previous history of seafood allergy but no documented drug allergies, and considering that the Chinese product instructions for ICG explicitly require inquiring about any history of allergy to ICG or its iodine-containing components and performing a skin allergy test prior to administration, an ICG skin test was conducted before surgery. ICG Skin Test: Intradermally inject 0.1 mL of 2.5% ICG at the lower one-third of the medial forearm and observe the wheal. Negative: Wheal subsides with no redness or swelling; Positive: Wheal develops erythema (redness) or a raised wheal (hives), diameter ≥10 mm, accompanied by itching or pseudopodia (radiating extensions).
   4. Prohibit eating for 6 h and drinking for 2 h before the operation.
2. Surgical position
   1. Position the patient on the operating table in the supine position.
   2. At the beginning of the procedure, adjust the operating table to place the patient in a head-up, feet-down (Trendelenburg) position with slight leftward tilt.
      ​NOTE: This positioning helps optimize exposure of the gallbladder and minimizes obstruction by the greater omentum.
3. Anesthesia
   1. Administer general anesthesia (following institutionally approved protocols) to ensure unconsciousness and comfort throughout surgery.
   2. Use intravenous induction agents (e.g., propofol) and muscle relaxants (e.g., succinylcholine) for intubation. Maintain anesthesia with inhaled agents (e.g., sevoflurane) and supplemental analgesics (e.g., fentanyl). Adjust depth of anesthesia to ensure adequate effect and safety.
   3. Continuously monitor heart rate, blood pressure, blood oxygen saturation, and end-tidal carbon dioxide levels.
   4. Catheter placement and medication before surgery
      1. Insert a nasogastric tube through the nose to a depth of 55 cm (catheter size, 14 F) and a urinary catheter through the urethra for drainage (catheter size, 16 F) after induction of general anesthesia.
         ​NOTE: Inserting a nasogastric tube helps reduce gastric distension interference during cholecystectomy.
      2. Administer 1.5 g of Cefuroxime sodium intravenously 30 min before skin incision for prophylactic infection prevention.
      3. Dissolve ICG (25 mg) in 10 mL of sterile water for injection. Set aside 1 mL of 2.5% ICG solution (containing 2.5 mg of ICG) for intravenous administration 10 min before skin incision.
         NOTE: Monitor for allergic reactions (e.g., rash) and vital signs throughout the procedure. If allergic manifestations occur, immediately discontinue ICG administration and initiate anti-allergic treatment. Keep vasoactive agents readily available for emergency resuscitation if required. Dispose of ICG residues in chemical waste containers.

4. Surgical technique

1. Use a four-port approach for LC. Make a 12 mm arc-shaped incision below the umbilicus and open the abdominal wall layers sequentially to access the abdomen. Insert a 12 mm trocar to establish pneumoperitoneum with insufflation pressure maintained at 12 mmHg. Introduce the laparoscope into the abdominal cavity.
2. Place another three trocars as follows: one 5 mm trocar below the xiphoid process, one 5 mm trocar at the right midclavicular line below the costal arch, and one 5 mm trocar below the costal arch along the right anterior axillary line.
   NOTE: Common surgical instruments used in LC include a fluorescence laparoscope, Harmonic scalpel, and monopolar electrosurgery devices.
3. Instrument settings
   1. Follow this for monopolar electrosurgery: Mode: Cut/Coagulation. Pure Cut: 30 W. Fulgurate Coag: 30 W.
      NOTE: During use, take precautions to prevent electrical burns. Ensure proper placement of the neutral electrode on the patient's body. Maintain a safe distance from normal tissues during activation to avoid thermal injury. Prevent accidental activation to minimize skin burns. Inspect electrode contact sites post-procedure for potential burns.
   2. Follow this for ultrasonic scalpel: Power settings: Level 3 (Low) for delicate tissues; Level 5 (Standard) for most parenchymal dissection.
      NOTE: During use, exercise caution to prevent thermal injury. Maintain adequate distance from non-target tissues to avoid inadvertent damage. As the instrument tip retains residual heat post-activation, avoid direct skin contact to prevent burns.
   3. Follow this for fluorescence endoscopic camera system: PINPOINT Camera and 10 mm 30° laparoscope. Viewing angle: 30°, field of view: 75°. System parameters: Wavelength: 805 nm; repetition rate: 20 pulses/s; maximum energy output: 2 mJ/pulse; pulse duration: 16.6 ms.
      NOTE: As the fluorescent endoscope is a thermal light source, the heat at the connection between the optical fiber and the endoscope body is high. Pay attention to thermal damage and avoid placing it directly on the patient.
4. Green fluorescence visualization and bile duct identification
   1. Dissect abdominal adhesions using monopolar electrocoagulation to reveal the gallbladder triangle (Figure 2A,B). Visualize the liver in green fluorescence 15 min after ICG injection into the peripheral vein, but not the extrahepatic biliary tract (Figure 2C).
   2. Draw a virtual line along Rouviere's sulcus, the hilar plate, and the base of liver segment IV (red dashed line). Dissect the gallbladder triangle based on this line (Figure 2D).
   3. Identify the CBD, which displays green fluorescence, 20 min after ICG injection (Figure 3A).
5. Dissection of the gallbladder triangle
   1. Retract the lymph node laterally while the assistant retracts the fundus of the gallbladder cephalad and laterally. When dissecting Calot's triangle on the gallbladder surface, encounter a tubular structure with no fluorescence. Clamp the structure with a Hem-o-lok clip as the cystic artery and transect it distally using a Harmonic scalpel (Figure 3B).
   2. Encounter another tubular structure after transection of the cystic artery. Observe no fluorescence, with sharp contrast to the common bile duct, which shows green fluorescence. Track the structure to its junction with the common bile duct. Clamp it with two Hem-o-lok clips as the cystic duct and transect distally using scissors (Figure 3C).
6. Cholecystectomy and hemostasis
   1. Dissect the gallbladder from the neck toward the fundus using a Harmonic scalpel. Transect and remove the PTGBD tube (Figure 3D).
      NOTE: PTGBD is not routinely indicated for acute cholecystitis. In this case, the disease had been present for one week before presentation and was complicated by diabetes mellitus and hypertension. Consequently, PTGBD was performed as an emergency measure to control the inflammatory response. Dispose of the PTGBD tube in a medical waste bag for centralized treatment.
   2. Remove the gallbladder in a specimen bag after transection of the cystic artery and cystic duct. Cauterize the gallbladder bed with monopolar electrocoagulation for hemostasis (Figure 3E).
7. Check for bile leakage and gallbladder removal
   1. Switch to fluorescence mode. Confirm absence of bile leakage in the operative area (Figure 3F). Place a drainage tube in the gallbladder fossa.
   2. Extract the gallbladder through the umbilical incision and suture the incision. This completes the fluorescence-guided laparoscopic cholecystectomy procedure.
      NOTE: Send the gallbladder specimen to the pathology department for histological examination. Dispose of bile and calculi in medical waste bags for centralized treatment. Discard sharps in puncture-proof containers. Place disposable surgical instruments in medical waste bags for centralized disposal. Reusable instruments must undergo decontamination, sterilization, and repackaging after cleaning.

5. Postoperative care

1. Monitoring
   1. Monitor vital signs, including heart rate, blood pressure, respiratory rate, oxygen saturation, and temperature, at regular intervals during the first 24 h.
   2. Assess abdominal drainage output, color, and volume.
   3. Observe for signs of complications such as bile leakage, bleeding, or infection.
      ​NOTE: Persistent abdominal pain, fever, or jaundice may indicate postoperative complications requiring further evaluation.
2. Pain management
   1. Administer analgesics as required according to institutional protocols.
   2. Assess pain levels regularly and adjust medications accordingly.
3. Diet and mobilization
   1. Allow oral intake of clear liquids 6 h after surgery if no nausea or vomiting is present.
   2. Advance to a soft diet within 24 h, based on tolerance.
   3. Encourage early ambulation within 12-24 h to prevent thromboembolic events and promote bowel recovery.
4. Wound and drain care
   1. Inspect incision sites daily for signs of infection or hematoma.
   2. Maintain drain patency and record daily output.
   3. Remove the abdominal drain when output is <20 mL/day of clear fluid and no evidence of bile leakage is present.
5. Discharge and follow-up
   1. Discharge the patient once oral intake, pain control, and ambulation are adequate, and no complications are detected.
   2. Schedule follow-up within 1-2 weeks for wound assessment and pathology report review.
   3. Provide education on signs of complications, such as persistent fever, abdominal pain, or jaundice, and advise immediate hospital return if these occur.

Results

The baseline characteristics and intraoperative parameters are summarized in Supplementary Table 1. The operative outcomes are summarized in Table 1. The total operative time was 90 min, with an estimated blood loss of 10 mL and urine output of 150 mL. The nasogastric tube was removed immediately after surgery. On postoperative day (POD) 1, the urinary catheter was removed. By POD 2, the abdominal drain was removed after collecting 10 mL of clear yellow fluid without evidence of blood or...

Discussion

LC is the most commonly used surgical approach for treating benign gallbladder diseases. However, LC carries the risk of BDI, particularly in cases of acute gallbladder inflammation or a history of upper abdominal surgery¹⁴. Visualizing the anatomy of the extrahepatic bile ducts is a key method to avoid BDI.ICG can assist in fluorescence imaging of the extrahepatic bile ducts.ICG is a dark green-blue dye from the tricarbocyanine family, with minimal toxicity and few adverse effects. After intraven...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Electrosurgical Generator	COVIDIEN	Force FX-8c	For blood vessel coagulation and division
ETHICON ENDOPATH  XCEL 5 mm Trocar	ETHICON	5XLT100	Provides secure, minimally invasive peritoneal access for instrument introduction during laparoscopic surgery.
ETHICON ENDOPATH XCEL 12 mm Trocar	ETHICON	12XLT100	Provides secure, minimally invasive peritoneal access for instrument introduction during laparoscopic surgery.
Fluorescence Endoscopic System(PINPOINT)	Stryker	SC9134	An endoscopic camera system wit 4K fluorescence imaging
Harmonic Scalpel	Ethicon Endo-Surgery	GEN11	For blood vessel coagulation and division
HEM-O-LOK Polymer Clip	ETHICON	544950	provide hemostasis and vessel or duct closure during laparoscopic procedures.
Indocyanine Green for Injection	Dandong Yichuang Pharmaceutical	H20055881	Intraoperative fluorescence imaging
SPSS 25.0			statistical analysis software