Indocyanine green fluorescence imaging techniques and interventional radiology during laparoscopic anatomical liver resection (with video)

Real-Time Navigation in Liver Surgery Through Indocyanine Green Fluorescence: An Updated Analysis of Worldwide Protocols and Applications

BACKGROUND

Indocyanine green (ICG) fluorescence has seen extensive application across medical and surgical fields, praised for its real-time navigation capabilities and low toxicity. Initially employed to assess liver function, ICG fluorescence is now integral to liver surgery, aiding in tumor detection, liver segmentation, and the visualization of bile leaks. This study reviews current protocols and ICG fluorescence applications in liver surgery, with a focus on optimizing timing and dosage based on clinical indications.

METHODS

Following PRISMA guidelines, we systematically reviewed the literature up to 27 January 2024, using PubMed and Medline to identify studies on ICG fluorescence used in liver surgery. A systematic review was performed to evaluate dosage and timing protocols for ICG administration.

RESULTS

Of 1093 initial articles, 140 studies, covering a total of 3739 patients, were included. The studies primarily addressed tumor detection (40%), liver segmentation (34.6%), and both (21.4%). The most common ICG fluorescence dose for tumor detection was 0.5 mg/kg, with administration occurring from days to weeks pre-surgery. Various near-infrared (NIR) camera systems were utilized, with the PINPOINT system most frequently cited. Tumor detection rates averaged 87.4%, with a 10.5% false-positive rate. Additional applications include the detection of bile leaks, lymph nodes, and vascular and biliary structures.

CONCLUSIONS

ICG fluorescence imaging has emerged as a valuable tool in liver surgery, enhancing real-time navigation and improving clinical outcomes. Standardizing protocols could further enhance ICG fluorescence efficacy and reliability, benefitting patient care in hepatic surgeries.

Laparoscopic left hepatectomy for a patient with an absence of portal bifurcation using real-time imaging: a case report

BACKGROUND

Absence of portal bifurcation is an extremely rare anomaly that should be recognized preoperatively, especially prior to a major hepatectomy.

CASE PRESENTATION

A 45-year-old woman presented with abdominal pain, and abdominal computed tomography (CT) revealed dilatation of both the common bile duct (CBD) and intrahepatic bile duct (IHBD). Endoscopic retrograde cholangiopancreatography (ERCP) showed CBD and IHBD stones (B2 and B4). The CBD stones were removed, but the IHBD stones could not be, yet there was no evidence of malignancy at the site of IHBD stenosis. Enhanced CT revealed a dilated IHBD, while three-dimensional CT images showed the left portal vein running through the ventral side of the middle hepatic vein, which was diagnosed as the absence of portal vein bifurcation (APB). Laparoscopic left hepatectomy was successfully performed using real-time indocyanine green (ICG) fluorescence imaging.

CONCLUSION

Surgeons should be aware of the possibility of APB, a rare portal vein anomaly, before performing major hepatectomy. Real-time ICG fluorescence imaging may be helpful to ensure the precise anatomy of the liver during laparoscopic surgery.

Development of real-time navigation system for laparoscopic hepatectomy using magnetic micro sensor

BACKGROUND

We report a new real-time navigation system for laparoscopic hepatectomy (LH), which resembles a car navigation system.

MATERIAL AND METHODS

Virtual three-dimensional liver and body images were reconstructed using the "New-VES" system, which worked as roadmap during surgery. Several points of the patient's body were registered in virtual images using a magnetic position sensor (MPS). A magnetic transmitter, corresponding to an artificial satellite, was placed about 40 cm above the patient's body. Another MPS, corresponding to a GPS antenna, was fixed on the handling part of the laparoscope. Fiducial registration error (FRE, an error between real and virtual lengths) was utilized to evaluate the accuracy of this system.

RESULTS

Twenty-one patients underwent LH with this system. Mean FRE of the initial five patients was 17.7 mm. Mean FRE of eight patients in whom MDCT was taken using radiological markers for registration of body parts as first improvement, was reduced to 10.2 mm (p = .014). As second improvement, a new MPS as an intraoperative body position sensor was fixed on the right-sided chest wall for automatic correction of postural gap. The preoperative and postoperative mean FREs of 8 patients with both improvements were 11.1 mm and 10.1 mm (p = .250).

CONCLUSIONS

Our system may provide a promising option that virtually guides LH.

Detection and Real-Time Surgical Assessment of Colorectal Liver Metastases Using Near-Infrared Fluorescence Imaging during Laparoscopic and Robotic-Assisted Resections

BACKGROUND

The European Association of Endoscopic Surgery (EAES) recommends, with strong evidence, the use of indocyanine green (ICG) fluorescence imaging combined with intraoperative ultrasound (IOUS) to improve identification of superficial liver tumors. This study reports the use of ICG for the detection of colorectal liver metastases (CRLMs) during minimally invasive liver resection.

METHODS

A single-center consecutive series of minimally invasive (laparoscopic and robotic) hepatic resections for CRLMs was prospectively evaluated (April 2019 and October 2023).

RESULTS

A total of 25 patients were enrolled-11 undergoing laparoscopic and 14 undergoing robotic procedures. The median age was 65 (range 50-85) years. Fifty CRLMs were detected: twenty superficial, eight exophytic, seven shallow (<8 mm from the hepatic surface), and fifteen deep (>10 mm from the hepatic surface) lesions. The detection rates of CRLMs through preoperative imaging, laparoscopic ultrasound (LUS), ICG fluorescence, and combined modalities (ICG and LUS) were 88%, 90%, 68%, and 100%, respectively. ICG fluorescence staining allowed us to detect five small additional superficial lesions (not identified with other preoperative/intraoperative techniques). However, two lesions were false positive fluorescence accumulations. All rim fluorescence pattern lesions were CRLMs. ICG fluorescence was used as a real-time guide to assess surgical margins during parenchymal-sparing liver resections. All patients with integrity of the fluorescent rim around the CRLM displayed a radical resection during histopathological analysis. Four patients (8%) with a protruding rim or residual rim patterns had positive resection margins.

CONCLUSIONS

ICG fluorescence imaging can be integrated with other conventional intraoperative imaging techniques to optimize intraoperative staging. Rim fluorescence proved to be a valid indicator of the resection margins: by removing the entire fluorescent area, a tumor-negative resection (R0) is achieved.

Indocyanine green fluorescence image-guided laparoscopic anatomical S2/3 resection using the TICGL technique

BACKGROUND

Segment 2/3 (S2/3) resection, which can preserve more residual liver parenchyma, is a feasible alternative to left lateral sectionectomy. However, it is still challenging to perform anatomical S2/3 resection safely and precisely, especially laparoscopically. This study was designed to evaluate the safety and accuracy of the temporary inflow control of the Glissonean pedicle (TICGL) technique combined with indocyanine green (ICG) fluorescence imaging in laparoscopic anatomical S2/3 resection.

PATIENTS AND METHODS

A total of 12 patients recruited at Zhujiang Hospital of Southern Medical University from June 2021 to August 2022 were included in the study. All patients underwent ICG fluorescence imaging guided laparoscopic anatomical S2/3 resection. The TICGL technique was used to control the blood inflow of the target segment. The total time used to control the hepatic inflow of the target segment, the time of hemostasis, the amount of intraoperative blood loss, predicted resected liver volume (PRLV) and actual resected liver volume (ARLV) were used to evaluate the simplicity, safety, and accuracy of the TICGL technique combined ICG fluorescent imaging in guiding laparoscopic anatomical S2/3 resection.

RESULTS

Of the 12 included patients, 7 underwent S2 resection and 5 underwent S3 resection. The operation time was 76.92 ± 11.95 min, the intraoperative blood loss was 15.42 ± 5.82 ml, and the time of hepatic blood inflow control was 7.42 ± 2.43 min. There was a strong correlation between PRLV and ARLV (r = 0.903, P < 0.05).

CONCLUSION

The combination of the TICGL technique with ICG negative staining fluorescence imaging is a feasible approach for laparoscopic anatomical S2/3 resection.

Transhepatic arterial approaches for ICG injection to guide laparoscopic anatomical hepatectomy: A case series study

BACKGROUND

Laparoscopic anatomical hepatectomy guided by near-infrared fluorescence imaging (NIR-FI) has been utilized extensively. However, it is difficult to resect "cone units" above the third branch of the Glissonean pedicle in the right posterior lobe using the laparoscopic positive or negative staining techniques. Therefore, we undertook a new laparoscopic segmentectomy based on the concept of "cone unit" assisted by interventional radiology combined with NIR-FI.

METHODS

Laparoscopic segmentectomy guided by NIR-FI via super-selective hepatic arteriography and trans-arterial injection of ICG was carried out on 13 patients with early-stage HCC between September 2020 and January 2022.11 of cases were successful, and relevant pathological characteristics and perioperative outcomes were retrospectively analyzed.

RESULTS

Two cases failed NIR-FI out of which one case involved over-staining to the non-target segment, and in the other case, which was to undergo laparoscopic segment V resection, only the ventral segment was stained while the imaging of the dorsal segment failed. In the intraoperative conditions, the tumor safe margin was 1.1 (0.7-1.55) cm, the interventional operation time was 50 (45.5-60.5) minutes, the operation time was 280 (242.5-307.5) minutes, the blood loss was 100 (50-200) ml, the postoperative hospital stay was 5 (4.5-5.5) days. No cases converted to laparotomy, and no serious postoperative complications developed.

CONCLUSIONS

NIR-FI through super-selective hepatic arteriography and trans-arterial injection of ICG can provide a clear and lasting navigation aid for laparoscopic segmentectomy, which may have positive implication for early-stage HCC with poor preoperative liver reserves.

Indocyanine green fluorescence in gastrointestinal surgery: Appraisal of current evidence

Applying indocyanine green (ICG) fluorescence in surgery has created a new dimension of navigation surgery to advance in various disciplines. The research in this field is nascent and fragmented, necessitating academic efforts to gain a comprehensive understanding. The present review aims to integrate diverse perspectives and recent advances in its application in gastrointestinal surgery. The relevant articles were selected by using the appropriate keyword search in PubMed. The angiography and cholangiography property of ICG fluorescence is helpful in various hepatobiliary disorders. In gastroesophageal and colorectal surgery, the lymphangiography and angiography property of ICG is applied to evaluate bowel vascularity and guide lymphadenectomy. The lack of objective parameters to assess ICG fluorescence has been the primary limitation when ICG is used to evaluate bowel perfusion. The optimum dose and timing of ICG administration need to be standardized in some new application areas in gastrointestinal surgery. Binding tumor-specific ligands with fluorophores can potentially widen the fluorescence application to detect primary and metastatic gastrointestinal tumors. The narrative review outlines prior contributions, limitations, and research opportunities for future studies across gastrointestinal sub-specialty. The findings of the present review would be helpful for scholars and practitioners to explore and progress in this exciting domain of gastrointestinal surgery.

A novel method of ultrasound-guided positive staining using indocyanine green fluorescence in laparoscopic anatomical liver resection of segments VII and VIII

Background

Recently, in many Asian centers, laparoscopic anatomical liver resection (LALR) using the indocyanine green (ICG) fluorescence imaging technique has been increasingly applied in resecting hepatocellular carcinoma, even in colorectal liver metastases. However, LALR techniques have not been fully standardized, especially in right superior segments. Due to the anatomical position, prevailing positive staining using a PTCD (percutaneous transhepatic cholangial drainage) needle was superior to negative staining in right superior segments hepatectomy, while it was difficult to manipulate. Herein, we design a novel method of ICG-positive staining for LALR of right superior segments.

Methods

Between April 2021 and October 2022, we retrospectively studied patients in our institute who underwent LALR of right superior segments using a novel method of ICG-positive staining, which comprised a customized puncture needle and an adaptor. Compared to the PTCD needle, the customized needle was not limited by the abdominal wall and could be punctured from the liver dorsal surface, which was more flexible to manipulate. The adapter was attached to the guide hole of the laparoscopic ultrasound (LUS) probe to ensure the precise puncture path of the needle. Guided by preoperative three-dimensional (3D) simulation and intraoperative laparoscopic ultrasound imaging, we punctured the transhepatic needle into the target portal vein through the adaptor and then slowly injected 5-10 ml of 0.025 mg/ml ICG solution into the vessel. LALR can be guided by the demarcation line under fluorescence imaging after injection. Demographic, procedural and postoperative data were collected and analyzed.

Results

In this study, 21 patients underwent LALR of the right superior segments with ICG fluorescence-positive staining, and the procedures had a success rate of 71.4%. The average staining time was 13.0 ± 6.4 min, the operative time was 230.4 ± 71.7 min, R0 resection was 100%, the postoperative hospital stay was 7.1 ± 2.4 days, and no severe puncture complications occurred.

Conclusions

The novel customized puncture needle approach seems to be feasible and safe for ICG-positive staining in LALR of right superior segments, with a high success rate and a short staining time.

Indocyanine green fluorescence staining based on the "hepatic pedicle first" approach during laparoscopic anatomic liver resection

BACKGROUND

Indocyanine green (ICG) fluorescence staining is one of the most challenging procedures for laparoscopic anatomic liver resection (LALR). Here, we introduce a novel method based on the "hepatic pedicle first" approach that can improve the success rate of positive staining.

METHOD

The target hepatic pedicle (even for the subsegment) was dissected through the first porta until it became visible. Five milliliters of 0.025 mg/ml ICG was injected after the target hepatic pedicle (extra-Glissonian approach) or portal vein/hepatic artery (intra-Glissonian approach) was punctured successfully using scalp acupuncture under direct vision. Then, the Glissonian pedicle or vessel was clamped immediately to prevent the intrahepatic diffusion of ICG. During the operation, a fluorescence imaging model was used repeatedly to confirm the segmental boundary.

RESULTS

Finally, 24 patients underwent LALR with the "hepatic pedicle first" approach for ICG fluorescence-positive staining. In 5 patients, ICG-positive staining failed, representing a 79.17% success rate. The average staining time was 25.92 min ± 14.64 min. There were no complications associated with vessel puncture (bile leakage, hemorrhage, and thrombosis).

CONCLUSION

The "hepatic pedicle first" approach is a feasible, convenient, and safe method for ICG-positive staining, with a high success rate.

Usefulness of ethiodized oil and gelatin sponge particles for delaying the washout of indocyanine green from the liver in swine

PURPOSE

To assess the effect of ethiodized oil (EO) and gelatin sponge particles (GS) on delaying the washout of indocyanine green (ICG) from the liver in swine.

METHODS

Fifteen swine were divided into 3 groups: injection of a mixture of ICG and water-soluble contrast medium (CM) followed by embolization with GS (group A), injection of a mixture of ICG and EO (group B) and injection of a mixture of ICG and EO followed by embolization with GS (group C). The liver surface was observed using an infrared camera system during and at 1, 2, 3, and 6 h after the procedure to measure ICG contrast. Livers were removed at 6 h for histopathological examination.

RESULTS

The contrast ratio between injected and non-injected regions at 6 h was 1.45 ± 0.44 in group A, 1.89 ± 0.37 in group B, and 3.62 ± 0.76 in group C. The contrast ratio in group C was significantly greater than that in groups A and B (P = 0.032 and 0.033, respectively).

CONCLUSIONS

EO and GS delayed the washout of ICG from the liver in swine and may extend intraoperative navigation in clinical use. Indocyanine green (ICG) mixed with ethiodized oil (EO) was injected into the left hepatic artery in swine, and the artery was embolized with gelatin sponge particles (GS). We confirmed that ICG remained in the liver parenchyma up to 6 h after the procedure. EO and GS delayed the washout of ICG from the liver in swine.

Indocyanine Green Fluorescence Navigation in Liver Surgery: A Systematic Review on Dose and Timing of Administration

BACKGROUND

Indocyanine green (ICG) fluorescence has proven to be a high potential navigation tool during liver surgery; however, its optimal usage is still far from being standardized.

METHODS

A systematic review was conducted on MEDLINE/PubMed for English articles that contained the information of dose and timing of ICG administration until February 2021. Successful rates of tumor detection and liver segmentation, as well as tumor/patient background and imaging settings were also reviewed. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

Out of initial 311 articles, a total of 72 manuscripts were obtained. The quality assessment of the included studies revealed usually low; only 9 articles got qualified as high quality. Forty articles (55%) focused on open resections, whereas 32 articles (45%) on laparoscopic and robotic liver resections. Thirty-four articles (47%) described tumor detection ability, and 25 articles (35%) did liver segmentation ability, and the others (18%) did both abilities. Negative staining was reported (42%) more than positive staining (32%). For tumor detection, majority used the dose of 0.5 mg/kg within 14 days before the operation day, and an additional administration (0.02-0.5 mg/kg) in case of longer preoperative interval. Tumor detection rate was reported to be 87.4% (range, 43%-100%) with false positive rate reported to be 10.5% (range, 0%-31.3%). For negative staining method, the majority used 2.5 mg/body, ranging from 0.025 to 25 mg/body. For positive staining method, the majority used 0.25 mg/body, ranging from 0.025 to 12.5 mg/body. Successful segmentation rate was 88.0% (range, 53%-100%).

CONCLUSION

The time point and dose of ICG administration strongly needs to be tailored case by case in daily practice, due to various tumor/patient backgrounds and imaging settings.

Navigated liver surgery: State of the art and future perspectives

BACKGROUND

In recent years, the development of digital imaging technology has had a significant influence in liver surgery. The ability to obtain a 3-dimensional (3D) visualization of the liver anatomy has provided surgery with virtual reality of simulation 3D computer models, 3D printing models and more recently holograms and augmented reality (when virtual reality knowledge is superimposed onto reality). In addition, the utilization of real-time fluorescent imaging techniques based on indocyanine green (ICG) uptake allows clinicians to precisely delineate the liver anatomy and/or tumors within the parenchyma, applying the knowledge obtained preoperatively through digital imaging. The combination of both has transformed the abstract thinking until now based on 2D imaging into a 3D preoperative conception (virtual reality), enhanced with real-time visualization of the fluorescent liver structures, effectively facilitating intraoperative navigated liver surgery (augmented reality).

DATA SOURCES

A literature search was performed from inception until January 2021 in MEDLINE (PubMed), Embase, Cochrane library and database for systematic reviews (CDSR), Google Scholar, and National Institute for Health and Clinical Excellence (NICE) databases.

RESULTS

Fifty-one pertinent articles were retrieved and included. The different types of digital imaging technologies and the real-time navigated liver surgery were estimated and compared.

CONCLUSIONS

ICG fluorescent imaging techniques can contribute essentially to the real-time definition of liver segments; as a result, precise hepatic resection can be guided by the presence of fluorescence. Furthermore, 3D models can help essentially to further advancing of precision in hepatic surgery by permitting estimation of liver volume and functional liver remnant, delineation of resection lines along the liver segments and evaluation of tumor margins. In liver transplantation and especially in living donor liver transplantation (LDLT), 3D printed models of the donor's liver and models of the recipient's hilar anatomy can contribute further to improving the results. In particular, pediatric LDLT abdominal cavity models can help to manage the largest challenge of this procedure, namely large-for-size syndrome.

Super-Selective Intra-Arterial Indocyanine Green Administration for Near-Infrared Fluorescence-Based Positive Staining of Hepatic Segmentation: A Feasibility Study

BACKGROUND

Despite the increasing number of laparoscopic hepatic procedures for the resection of hepatocellular carcinoma (HCC), intraoperative tumor localization and demarcation remains challenging in comparison to open surgery. In this study, we evaluated the feasibility of positive liver segment staining through the super-selective intra-arterial indocyanine green (ICG) administration.

METHODS

Eight patients presenting with a single HCC underwent an interventional vascular procedure followed by laparoscopic surgery. A microcatheter was advanced into the hepatic artery branches perfusing the HCC followed by digital subtraction angiography and angiography computed tomography (angio-CT). Patients were then transferred to the operating room, and a laparoscopic hepatectomy was performed under ultrasound guidance. A 5 mL bolus of ICG with a concentration of .125 mg/mL was injected through the microcatheter, and a near-infrared laparoscope was used to detect the fluorescence signal to assess the correspondence between the fluorescence-based demarcation and the intraoperative ultrasound-based demarcation.

RESULTS

The duration for the angiography procedure was 32.7 +/- 5.3 min, and it took 242 +/- 118 min from the end of angiography procedure until the start of the surgical procedure. In all cases, the fluorescent liver segment was corresponding to the angio-CT findings. In 6/8 cases, fluorescence imaging was considered helpful in the identification of the resection line. In 3 patients, the resection line was changed according to the positively stained liver segment.

CONCLUSION

We successfully demonstrated the feasibility of the super-selective intra-arterial ICG administration for fluorescence-based positive staining of hepatic segmentation during laparoscopic surgery for HCC (NCT04266548).

Laparoscopic Liver Resection Enhanced by an Intervention-Guided Fluorescence Imaging Technique Using Sodium Fluorescein

BACKGROUND AND OBJECTIVES

In laparoscopic liver resections, tumor localization is a critical aspect of ensuring clear resection margins and preserving the hepatic parenchyma. In this study, we designed a fluorescence imaging technique using a new fluorophore for tumor localization.

MATERIALS AND METHODS

Immediately before laparoscopic or transthoracic liver resection, microcatheter was inserted through the hepatic artery and used to engrave the segment containing the tumor in the intervention room. Under blue light, the fluorescence of the lesion was visually confirmed, and the location was determined through intraoperative sonography. After tumor localization, liver resection was performed.

RESULTS

From February 2017 to March 2020, 24 patients underwent laparoscopic liver resection (LLR) or video-assisted transthoracic liver resection (VTLR) using intervention-guided fluorescence imaging technique (IFIT).

CONCLUSIONS

IFIT can provide some advantages in the field of LLR. In addition, in cases of VTLR for hepatocellular carcinoma in the superior posterior segment in patients with marginal liver function, IFIT is considered useful.

Laparoscopic intraarterial catheterization with selective ICG fluorescence imaging in colorectal surgery

The quality of mesorectal resection is crucial for resection in rectal cancer, which should be performed by laparoscopy for better outcome. The use of indocyanine green (ICG) fluorescence is now routinely used in some centers to evaluate bowel perfusion. Previous studies have demonstrated in animal models that selective intra-arterial ICG staining can be used to define and visualize resection margins in rectal cancer. In this animal study, we investigate if laparoscopic intra-arterial catheterization is feasible and the staining of resection margins when performing total mesorectal excision with a laparoscopic medial to lateral approach is possible. In 4 pigs, laparoscopic catheterization of the inferior mesenteric artery (IMA) is performed using a seldinger technique. After a bolus injection of 10 ml ICG with a concentration of 0.25 mg/ml, a continuous intra-arterial perfusion was established at a rate of 2 ml/min. The quality of the staining was evaluated qualitatively. Laparoscopic catheterization was possible in all cases, and the average time for this was 30.25 ± 3.54 min. We observed a significant fluorescent signal in all areas of the IMA supplied, but not in other parts of the abdominal cavity or organs. In addition, the mesorectum showed a sharp border between stained and unstained tissue. Intraoperative isolated fluorescence augmentation of the rectum, including the mesorectum by laparoscopic catheterization, is feasible. Inferior mesenteric artery catheterization and ICG perfusion can provide a fluorescence-guided roadmap to identify the correct plane in total mesorectal excision, which should be investigated in further studies.

Indocyanine green staining for intraoperative perfusion assessment

Indocyanine green (ICG) is a fluorescent iodide-based dye which is used in hepatic surgery to evaluate the biliary tree, liver perfusion, and function. While liver perfusion assessment and delineation of anatomic regions has been performed using ultrasound, ischemic demarcation, or indigo carmine/methylene blue staining, ICG staining can overcome limitations associated with these techniques, such as rapid washout, lack of precision, non-demarcation in damaged livers, and lack of intraparenchymal fidelity. ICG can be used to fluoresce target segments/tumors (Positive staining) or counterstain normal liver tissue leaving areas of interest unstained (negative staining). Moreover, ICG enhancement patterns vary for different tumors, such as colorectal liver metastases vs. hepatocellular carcinoma, providing not only help with detection but also assessment of differentiation. In the field of oncology, benefits of ICG include detection of small radiographically occult tumors, distinction between cirrhotic nodules and cancer, identification of necrotic tumors in chemotherapy-damaged livers, and determining margins when intraoperative ultrasound is inadequate. While ICG has important and expanding indications in hepatic surgery, limitations include small depth of penetrance, need for special monitors/equipment, and potential for dye spillage. ICG is well tolerated, has a small learning curve, minimally invasive surgical integration, and options of both portal vein and peripheral vein injection and hence is a safe and versatile method of anatomic liver mapping, tumor visualization, and liver graft perfusion evaluation in oncologic surgery and liver transplantation. Advancements in technique and technology associated with ICG will aid in increasing the indications in hepato-biliary surgery.

Near-Infrared Fluorescence Imaging and Photodynamic Therapy for Liver Tumors

Surgery with fluorescence equipment has improved to treat the malignant viscera, including hepatobiliary and pancreatic neoplasms. In both open and minimally invasive surgeries, optical imaging using near-infrared (NIR) fluorescence is used to assess anatomy and function in real time. Here, we review a variety of publications related to clinical applications of NIR fluorescence imaging in liver surgery. We have developed a novel nanoparticle (indocyanine green lactosome) that is biocompatible and can be used for imaging cancer tissues and also as a drug delivery system. To date, stable particles are formed in blood and have an ~10–20 h half-life. Particles labeled with a NIR fluorescent agent have been applied to cancer tissues by the enhanced permeability and retention effect in animals. Furthermore, this article reviews recent developments in photodynamic therapy with NIR fluorescence imaging, which may contribute and accelerate the innovative treatments for liver tumors.

Demarcation Line Assessment in Anatomical Liver Resection: An Overview

Anatomical liver resection (ALR) is the preferred oncological approach for the treatment of primary liver malignancies, such as hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The demarcation line (DL) is formed by means of selective vascular occlusion and is used by surgeons to guide ALR. Emerging intraoperative technologies are playing a major role to enhance the surgeon's vision and ensure a precise oncologic surgery. In this article, a brief overview of modalities to assess the DL during ALRs is presented, from the established conventional techniques to future perspectives.

[Indocyanine green fluorescence staining in liver surgery]

BACKGROUND

Indocyanine green (ICG) opens up numerous possibilities for applications in hepatobiliary surgery, due to its exclusive hepatic excretion and its fluorescence properties in the near infrared (NIR) spectrum.

OBJECTIVE

Systematic review of the literature on the application of ICG imaging in open and laparoscopic liver surgery.

MATERIAL AND METHODS

Literature review and summary of the recent scientific original articles and reviews.

RESULTS

The ICG fluorescence imaging is increasingly being used in liver surgery. It allows real-time display of the segmental anatomy of the liver. Moreover, depending on the tumor entity, direct or indirect visualization of liver tumors and metastases is also possible. The detection of bile leaks might also be facilitated. Recent experiences in liver surgery have shown that ICG imaging enables a more sensitive intraoperative detection of additional foci and probably also a higher R0 resection rate; however, the application is mainly helpful for superficial lesions, since the depth of penetration of NIR is only 8-10 mm.

CONCLUSION

Fluorescence staining using ICG is a valuable supplementary tool in modern liver surgery. It is particularly helpful in laparoscopic surgery where tactile control is eliminated and three-dimensional orientation is difficult. These disadvantages can be partially compensated by additional real-time imaging using ICG.

Evolution of photodynamic medicine based on fluorescence image-guided diagnosis using indocyanine green and 5-aminolevulinic acid

New diagnostic techniques based on photodynamic medicine, such as near-infrared fluorescence using indocyanine green (NIR-ICG) and 5-aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD), are aiding navigation tasks across various fields of surgery. Specifically, NIR-ICG is being used for the intraoperative identification of sentinel lymph nodes or blood vessels in organ resection and for blood flow evaluation in surgery. These ICG-fluorescent imaging techniques could provide an additional and potentially valuable way to identify vascular and lymphatic structures in surrounding tissue. 5-Aminolevulinic acid is a precursor of a photosensitizing substance with affinity for tumors; thus, diagnostic laparoscopy using ALA-PDD in combination should improve the accuracy of detecting peritoneal dissemination in patients with advanced gastric cancer. The ability to overlay fluorescent imaging with conventional color images in real time using ALA-PDD and NIR with ICG would be of immense benefit to surgeons, providing good visualization and detection of target lesions not seen with the naked eye. A multi-center clinical study examining the safety and efficacy of ALA-PDD during laparoscopic examination for patients with advanced gastric cancer is currently underway in the form of doctor-initiated trials, and further verification studies will be conducted. Such imaging capability could have broad potential across cancer and vascular surgery.

Robotic approach to the liver: Open surgery in a closed abdomen or laparoscopic surgery with technical constraints?

The application of the minimally invasive approach has shown to be safe and effective for liver surgery and is in constant growth. The indications for laparoscopic surgery are steadily increasing across the field. In the early 2000s, robotic surgery led to some additional improvements, such as tremor filtration, instrument stability, 3D view and more comfort for the surgeon. These techniques bring in some advantages compared to the traditional OLR: less blood loss, shorter admissions, fewer adhesions, and a faster postoperative recovery and better outcomes in case of further hepatectomy for tumor recurrence has been shown. Concerning which is the best minimally invasive approach between laparoscopic and robotic surgery, the evidence is still conflicting. The latter shows good potential, since the endo-wristed instruments work similarly to the surgeon's hands, even with an intact abdominal wall. However, the technique is still under development, burdened by important costs, and limited by the lack of some instruments available for the laparoscopic approach. The paucity of universally accepted and proven data, especially concerning long-term outcomes, hampers drawing univocal acceptance at present. Furthermore, the number of variables related both to the patient and the disease further complicates the decision leading to a treatment tailored to each patient with strict selection. This review aims to explore the main differences between laparoscopic and robotic surgery, focusing on indications, operative technique and current debated clinical issues in recent literature.

Hepatic Arterial Embolization with an Indocyanine Green-Lipiodol^® Mixture before Laparoscopic Anatomical Liver Resection

Here, we report a case of hepatocellular carcinoma detected on computed tomography and treated with laparoscopic anatomical liver resection in a 69-year-old woman who was being followed-up for hepatitis C. Intraoperative liver segmentation is necessary to accomplish laparoscopic anatomical liver resection. Therefore, the day before surgery, hepatic artery embolization was performed with an indocyanine green-Lipiodol^Ⓡ mixture and Gelpart^Ⓡ containing indocyanine green to mark the region for hepatectomy. The next day, surgeons visually confirmed the resection segments on indocyanine green fluorescence imaging and performed laparoscopic anatomical liver resection. No major complications resulted from this method. In conclusion, hepatic artery embolization with an indocyanine green-Lipiodol^Ⓡ mixture is effective and safe for liver segment identification during laparoscopic anatomical liver resection.

Laparoscopic anatomical liver resection using indocyanine green fluorescence imaging

BACKGROUND

Anatomical liver resections guided by a demarcation line after portal staining or inflow clamping of the target area have been established as essential methods for curative treatment of hepatocellular carcinoma (HCC) and have subsequently been applied to other malignancies. However, laparoscopic anatomical liver resection (LALR) procedures are very difficult to reproduce, and the confirmation of demarcation of the hepatic segment on a monitor is also challenging. Recently, indocyanine green (ICG) fluorescence imaging has been used to identify hepatic tumors and segmental boundaries during hepatectomy. Herein, we describe LALR using ICG fluorescence imaging.

METHODS

Three patients underwent pure LALR using ICG fluorescence imaging at our institute. One patient underwent anatomical partial liver resection for HCC, another underwent segmentectomy 3 for metastatic liver cancer, and the third underwent right anterior sectionectomy for HCC. To visualize hepatic perfusion and the demarcation line by negative staining using an optical imaging system, 2.5 mg ICG was injected intravenously during surgery following clamping or closure of the proximal Glissonean pedicles.

RESULTS

For all three cases, ICG fluorescent imaging clearly delineated the demarcation lines and allowed identification of intersegmental planes to some extent because the tumor-bearing hepatic region became non-fluorescing parenchyma during parenchymal transection. This allowed surgeons to recognize the direction and guide the transection of the liver parenchyma when performing LALR.

CONCLUSION

LALR using ICG fluorescence imaging is a feasible procedure for resection of the tumor-bearing hepatic region and facilitates visualization of the demarcation line and identification of the boundaries of the hepatic sections.

First Experience with Fluorescence in Pediatric Laparoscopy

Background  The use of intraoperative fluorescence images with indocyanine green (ICG) has recently been described as an aid in decision-making during surgical procedures in adults.

We present our first experiences with different laparoscopic procedures performed in children using ICG fluorescence images.

Material and Method  We have used ICG fluorescence imaging technique in varicocele ligation, two nephrectomies, cholecystectomy, and one case of aortocoronary fistula closure. All procedures were performed through a minimally invasive approach. A high definition camera equipped with a visible infrared light source and gray-scale vision technology was used.

After injection of ICG before or during the laparoscopic procedure, precise identification of vascular anatomy and bile duct architecture were easily identified. Fluorescence helped to assess blood flow from the spermatic vessels, define the variability of renal vascularization, and determine the precise location of the aortocoronary fistula. Biliary excretion of the ICG allowed the definition of the biliary tract.

Conclusion  Fluorescein-assisted images allowed a clear definition of the anatomy and safe surgical maneuvers during surgical procedures. The ICG imaging system seems to be simple and safe. Larger and more specific studies are needed to confirm its applicability, expand its indications, and address its advantages and disadvantages.

Computer vision for total laparoscopic hysterectomy

INTRODUCTION

Laparoscopic surgery is widely performed in various surgical fields, but this technique requires time for surgeons to master. However, at the same time, there are many advantages in visualizing the operative field through a camera. In other words, we can visualize what we cannot see with our own eyes by using augmented reality and computer vision. Therefore, we investigated the possibilities and usefulness of computer vision in total laparoscopic hysterectomy.

METHODS

This study was approved by the Mitsui Memorial Hospital ethics committee. Patients who underwent total laparoscopic hysterectomy at Mitsui Memorial Hospital from January 2015 to December 2015 were enrolled. We evaluated 19 cases in which total laparoscopic hysterectomy was performed by the same operator and assistant. We used the Open Source Computer Vision Library for computer vision analysis. The development platform used in this study was a computer operating on Mac OS X 10.11.3.

RESULTS

We created panoramic images by matching features with the AKAZE algorithm. Noise reduction methods improved haziness caused by using energy devices. By abstracting the color of the suture string, we succeeded in abstracting the suture string from movies. We could not achieve satisfactory results in detecting ureters, and we expect that creative ideas for ureter detection may arise from collaborations between surgeons and medical engineers.

CONCLUSIONS

Although this was a preliminary study, the results suggest the utility of computer vision in assisting laparoscopic surgery.

Real-Time Navigation Guidance Using Fusion Indocyanine Green Fluorescence Imaging in Laparoscopic Non-Anatomical Hepatectomy of Hepatocellular Carcinomas at Segments 6, 7, or 8 (with Videos)

Background

The right area and posterior area of the liver are considered relatively unfavorable portions for laparoscopic hepatectomy (LH) due to the limited gross inspection and poor tactile feedback. Fusion indocyanine green fluorescence fusion imaging (ICGFI) may be a reliable real-time navigation tool for LH. The aim of the present study was to evaluate the usefulness of ICGFI for laparoscopic non-anatomical hepatectomy in patients with hepatocellular carcinoma at the right area and posterior area.

Material/Methods

We conducted a retrospective comparison of surgical and perioperative outcomes for 21 hepatocellular carcinoma patients who had undergone LH with fusion ICGFI guidance and 21 matched patients who underwent the procedure without the guidance of ICGFI between November 2017 to August 2018.

Results

Preoperative characteristics were comparable between the groups. Tumor fluorescence images were clearly displayed in all 21 ICGFI patients, providing precise information about tumor location. Laparoscopic parenchymal transection could be performed safely and quickly through tracing the fusion ICGFI on the cutting surface. Operation time was significantly reduced in the ICGFI group. Postoperative complications were comparable between the groups. There was no positive margin in either group.

Conclusions

These preliminary data suggest that fusion ICGFI may be a useful tool that provides real-time navigation for non-anatomical LH. It may assist in the safe and accurate completion of LH for tumors located at the right posterior areas. Further studies are needed to fully clarify the advantages and disadvantages of ICGFI in LH, including short-term perioperative outcomes and long-term prognosis.

Innovative treatment for hepatocellular carcinoma (HCC)

Indocyanine green (ICG) is not new in the field of liver surgery. Early studies performed in the 1980s and 1990s revealed the value of the ICG clearance test in predicting post-hepatectomy morbidity and mortality. ICG clearance and retention tests are crucial for determining precise liver function before liver surgery and offer several benefits for safe surgery. Whereas ICG is well-known and has long history in medicine, recent progress in infrared light technology over the last decade has highlighted another feature of ICG. For example, ICG fluorescence-guided surgery may change the next generation of liver surgery. In the near future, ICG with near-infrared (NIR) light photodynamic therapy (PDT) is expected to become a new treatment method for hepatocellular carcinoma (HCC). Furthermore, several aspects of the mechanisms of ICG accumulation in HCC cells have been revealed by important basic research studies. New imaging technologies and mechanistic findings keep ICG in the spotlight. In this article, we review three recently described topics of ICG which may contribute to the development of innovative and new treatments method for HCC, fluorescence-guided surgery, mechanism of ICG accumulation in HCC cells, PDT for HCC.

Indocyanine green-based fluorescence imaging in visceral and hepatobiliary and pancreatic surgery: State of the art and future directions

In recent years, the use of fluorescence-guided surgery (FGS) to treat benign and malignant visceral, hepatobiliary and pancreatic neoplasms has significantly increased. FGS relies on the fluorescence signal emitted by injected substances (fluorophores) after being illuminated by ad hoc laser sources to help guide the surgical procedure and provide the surgeon with real-time visualization of the fluorescent structures of interest that would be otherwise invisible. This review surveys and discusses the most common and emerging clinical applications of indocyanine green (ICG)-based fluorescence in visceral, hepatobiliary and pancreatic surgery. The analysis, findings, and discussion presented here rely on the authors' significant experience with this technique in their medical institutions, an up-to-date review of the most relevant articles published on this topic between 2014 and 2018, and lengthy discussions with key opinion leaders in the field during recent conferences and congresses. For each application, the benefits and limitations of this technique, as well as applicable future directions, are described. The imaging of fluorescence emitted by ICG is a simple, fast, relatively inexpensive, and harmless tool with numerous different applications in surgery for both neoplasms and benign pathologies of the visceral and hepatobiliary systems. The ever-increasing availability of visual systems that can utilize this tool will transform some of these applications into the standard of care in the near future. Further studies are needed to evaluate the strengths and weaknesses of each application of ICG-based fluorescence imaging in abdominal surgery.