A Percutaneous Portal Vein Puncture Under Artificial Ascites for Intraoperative Hepatic Segmentation Using Indocyanine Green Fluorescence: A Technical Report of Laparoscopic Anatomic Liver Resection

Preliminary exploration of hepatic parenchymal near-infrared fluorescence imaging technique via retrograde biliary approach: a feasibility study (with video)

This paper explores the feasibility and principle of hepatic parenteral fluorescence imaging technology after retrograde injection of indocyanine green (ICG) through endoscopic nasobiliary drainage (ENBD). The data were collected from 53 patients with cholecystolithiasis and choledocholithiasis, from October 2022 to March 2023, diagnosed by fluorescence imaging technique retrograde biliary approach (FIT-RB). We divided the patients into two groups according to the features of liver parenchyma, the poor group (n = 34, including scattered or no imaging) and the good group (n = 19, regular uniform imaging). We compared and analyzed the perioperative results of the two groups and explored the influencing factors of the success of FIT-RB and the ICG concentration suitable for this imaging technique. The good imaging rate of the 53 enrolled cases was 35.8%. The bilirubin level before ENBD and laparoscopic cholecystectomy in the poor group was significantly higher than that in the good group (P < 0.001). The proportion of higher ICG concentrations (0.5 mg/mL) was significantly higher in the good group (P = 0.028). Our results demonstrated that the success rate of good imaging was 4.53 times higher than that of low-dose ICG (0.125 or 0.25 mg/L) cases at 0.5 mg/ml of ICG. The level of total bilirubin and direct bilirubin were negatively correlated with the imaging effect, and total bilirubin and direct bilirubin levels were important predictors of the efficacy of FIT-RB. FIT-RB is safe and feasible in patients with low site bilirubin levels. An ICG concentration of 0.5 mg/ml may be ideal for implementing this technique.

Correlation Between Indocyanine Green Fluorescence Patterns and Grade of Differentiation of Hepatocellular Carcinoma: A Western Prospective Cohort Study

Background. Most of the available evidence on the use of indocyanine green (ICG) fluorescence in clinical practice consists of articles published by surgeons of the Asian-Pacific area. We performed a prospective cohort study to assess the patterns of ICG fluorescence in Western hepatocellular carcinoma (HCC) counterparts.Methods. From April 2019 to January 2022, a total of 31 consecutive patients who underwent laparoscopic liver resection (LLR) for superficial HCC were enrolled in this prospective study. All patients underwent laparoscopic staging with both laparoscopic ultrasound (LUS) and ICG fluorescence imaging.Results. A total of 38 hepatocellular carcinomas (HCCs) were enrolled: 23 superficial (surfacing at the liver's Glissonian capsule), 5 exophytic, 5 shallow (<8 mm from the hepatic surface) and 5 deep (>10 mm from the hepatic surface). The detection rate with preoperative imaging (abdominal CT/MRI), LUS, ICG fluorescence and combined modalities (ICG and LUS) was 97.4%, 94.9%, 89.7% and 100%, respectively. The five deep seated lesions underwent ultrasound-guided laparoscopic thermal ablation. The other 33 HCCs were treated with minimally invasive liver resection. Intraoperative ultrasound patterns were registered for each single nodule resected. The ICG fluorescence pattern was classified in two types: total fluorescence (all the tumoral tissue showed strong and homogeneous fluorescence), n = 9/33 (27.3%), and non-total fluorescence (partial and rim fluorescence), n = 24/33 (72.7%). There was a statistical correlation between ICG patterns and grade of differentiation. Almost all lesions with uniform fluorescence pattern were well-differentiated HCCs (G1-G2), while partial and rim-type fluorescence pattern were more common among moderately and poorly differentiated HCCs (G3-G4) (88.9% vs 11.1%, 37.5% vs 62.5%, P = .025, respectively).Conclusions. ICG fluorescence imaging could be used to identify early the grade of HCC, ie intraoperatively, thus influencing the intraoperative treatment.

Optimal Dosage of Indocyanine Green Fluorescence for Intraoperative Positive Staining in Laparoscopic Anatomical Liver Resection

Introduction Fluorescence imaging technology, specifically utilizing indocyanine green (ICG), has emerged as a valuable tool in laparoscopic hepatectomy. In particular, laparoscopic anatomical liver resection (ALR) has benefited from the implementation of both positive and negative staining methods. A case series study reported a success rate of 53% for the positive staining method, citing potential issues regarding the proper ICG dosage needed for accurate fluorescence. Thus, it is crucial to conduct research to investigate the optimal dosage for ICG-positive staining in clinical practice to maximize the benefits of this technique. Materials and methods This retrospective study was conducted at a single center, Meiwa Hospital, and received approval from the hospital's ethics committee in accordance with the Helsinki Declaration. We reviewed the records of 264 patients who underwent open and laparoscopic hepatectomies for benign and malignant liver diseases from January 2019 to January 2023. Of these, 18 patients who underwent laparoscopic ALR with the ICG-positive staining method were evaluated. Fluorescence-emitting segmental borders were assessed immediately after puncture (first stage) and during parenchymal dissection (second stage). In the first stage, we evaluated the intensity of fluorescence emission, categorizing it as "strong" or "weak." The absence of visible fluorescence emission was considered a puncture failure. During the second stage of evaluation, from parenchymal resection to completion, we assessed the sustainability of fluorescence emission, defining it as "clear" or "contaminated." Both evaluations were subjectively judged by three surgeons at our center. The ICG quantity per targeted portal vein-bearing liver volume (mg/100 mL) was calculated for each patient, and the optimal dosage was determined using receiver operating characteristic (ROC) curve analysis. To ascertain the minimum value for adequate fluorescence emission intensity, ROC curve analysis was performed to discriminate between binary outcomes of "strong" or "weak" emission. Furthermore, to establish the maximum value for maintaining a clear fluorescence border, ROC curve analysis was conducted to discriminate between "clear" and "contaminated" during the second evaluation. Results Among the 18 successful puncture cases, the first-stage evaluation of fluorescence intensity revealed 14 punctures with "strong" intensity and four punctures with "weak" intensity. In the second-stage evaluation, 13 cases demonstrated "clear" borders, while five cases exhibited "contaminated" borders. ROC curve analysis was performed to determine the optimal ICG dose for adequate fluorescence intensity and preservation of clear borders during dissection. The analysis indicated that the appropriate ICG dose for achieving optimal intensity was 0.028 mg/100 mL (area under the curve [AUC]: 0.893), while the dose that prevented contamination of fluorescence in non-target areas until after dissection was 0.083 mg/100 mL (AUC: 0.723). Conclusions Laparoscopic anatomical resection using the positive staining method requires an optimal ICG dosage of 0.028-0.083 mg per 100 mL of liver volume. By employing this methodology, more precise and safer laparoscopic anatomical resections can be conducted, thereby enhancing the safety of the surgical procedure for patients.