Real-time Vessel Navigation Using Indocyanine Green Fluorescence during Robotic or Laparoscopic Gastrectomy for Gastric Cancer

Current status and future trends of real-time imaging in gastric cancer surgery: A literature review

Technological advances are crucial for the optimization of gastric cancer surgery, and the success of any gastric cancer surgery is based on the correct and precise anatomical determination of the primary tumour and tissue structures. Real-time imaging-guided surgery is showing increasing potential and utility, mainly because it helps to aid intraoperative decision-making. However, intraoperative imaging faces many challenges in the field of gastric cancer. This article summarizes and discusses the following clinical applications of real-time optical imaging and fluorescence-guided surgery for gastric cancer: (1) the potential of quantitative fluorescence imaging in assessing tissue perfusion, (2) vascular navigation and determination of tumour margins, (3) the advantages and limitations of lymph node drainage assessment, and (4) identification of peritoneal metastases. In addition, preclinical study of tumour-targeted fluorescence imaging are discussed.

Intraoperative Fluorescent Navigation of the Ureters, Vessels, and Nerves during Robot-Assisted Sacrocolpopexy

In this study, we aimed to demonstrate the feasibility and safety of navigating the ureters, middle sacral artery (MSA), and superior hypogastric nerve (SHN) using indocyanine green (ICG) and near-infrared fluorescence (NIRF) imaging during robot-assisted sacrocolpopexy (RSCP). Overall, 15 patients who underwent RSCP for apical vaginal prolapse were retrospectively enrolled. All patients underwent cystoscopic intraureteric instillation of 5 cc ICG (2.5 mg/mL) before RSCP and intravenous injection of 3 cc ICG during presacral dissection and mesh fixation. In all patients, the fluorescent right ureter was clearly identified in real time. The MSA was visualized on ICG-NIRF images in 80% (13/15) of patients. The mean time from ICG injection to MSA visualization was 43.7 s; the mean duration of the arterial phase was 104.3 s. Fluorescent SHN was detected in 73.3% (11/15) of patients. The time from ICG injection to SHN fluorescence was 48.4 s; the duration of fluorescence was 177.2 s. There was no transfusion, iatrogenic ureteral injury, or bowel or urinary dysfunction. Our results indicated that intraoperative ureter, MSA, and SHN mapping using ICG-NIRF images during RSCP is a valuable and safe technique to avoid iatrogenic ureteral, vascular, and neural injuries and to simplify surgical procedures. Nonetheless, further studies are required.

Fluorescence and tracers in surgery: the coming future

The revolution that we are seeing in the world of surgery will determine the way we understand surgical approaches in coming years. Since the implementation of minimally invasive surgery, innovations have constantly been developed to allow the laparoscopic approach to go further and be applied to more and more procedures. In recent years, we have been in the middle of another revolutionary era, with robotic surgery, the application of artificial intelligence and image-guided surgery. The latter includes 3D reconstructions for surgical planning, virtual reality, holograms or tracer-guided surgery, where ICG-guided fluorescence has provided a different perspective on surgery. ICG has been used to identify anatomical structures, assess tissue perfusion, and identify tumors or tumor lymphatic drainage. But the most important thing is that this technology has come hand in hand with the potential to develop other types of tracers that will facilitate the identification of tumor cells and ureters, as well as different light beams to identify anatomical structures. These will lead to other types of systems to assess tissue perfusion without the use of tracers, such as hyperspectral imaging. Combined with the upcoming introduction of ICG quantification, these developments represent a real revolution in the surgical world. With the imminent implementation of these technological advances, a review of their clinical application in general surgery is timely, and this review serves that aim.

The introduction of fluoroscopic surgery: A report of an initial trial case

INTRODUCTION

Switching from white light to fluorescence mode is necessary to confirm the fluorescence during fluorescence-guided surgery. This case report presents the use of a syringe pump to continuously inject indocyanine green (ICG), which enabled the vessels to be visualised and the operation to be performed without switching.

PRESENTATION OF CASE

An Asian male patient in his 40s underwent an interval appendectomy following conservative treatment for appendicitis. Laparoscopic surgery was performed using the VISIONSENSE® system. Diluted ICG (25 mg/15 mL) was intravenously administered at 1 mL/min. The appendiceal artery was visualised in light green, and the intensity of the visualisation was defined relative to the tissue surrounding the dissected appendiceal artery. The superior rectal artery and the vessels within the mesentery of the small intestine were confirmed to be continuously visualised throughout the surgery. Therefore, continuous ICG angiography made it possible to operate while keeping the appendiceal artery visible in this case.

DISCUSSION

ICG angiography enabled the operation to be performed with the appendiceal artery continuously visualised. This method was developed for use in cancer surgery; however, since operations of longer duration are speculated to require larger doses of ICG, we opted to introduce this method in an initial trial for appendectomy.

CONCLUSION

The fluoroscopic surgery using a syringe pump was feasible in this first case report without switching to white light mode.

Preoperative planning and intraoperative real-time navigation with indocyanine green fluorescence in robotic liver surgery

PURPOSE

We aimed at exploring indocyanine green (ICG) fluorescence wide spectrum of applications in hepatobiliary surgery as can result particularly useful in robotic liver resections (RLR) in order to overcome some technical limitations, increasing safety, and efficacy.

METHODS

We describe our experience of 76 RLR performed between March 2020 and December 2022 exploring all the possible applications of pre- and intraoperative ICG administration.

RESULTS

Hepatocellular carcinoma and colorectal liver metastases were the most common indications for RLR (34.2% and 26.7% of patients, respectively), and 51.3% of cases were complex resections with high IWATE difficulty scores. ICG was administered preoperatively in 61 patients (80.3%), intraoperatively in 42 patients (55.3%) and in both contexts in 25 patients (32.9%), with no observed adverse events. The most frequent ICG goal was to achieve tumor enhancement (59 patients, 77.6%), with a success rate of 94.9% and the detection of 3 additional malignant lesions. ICG facilitated evaluation of the resection margin for residual tumor and perfusion adequacy in 33.9% and 32.9% of cases, respectively, mandating a resection enlargement in 7.9% of patients. ICG fluorescence allowed the identification of the transection plane through negative staining in the 25% of cases. Vascular and biliary structures were visualized in 21.1% and 9.2% of patients, with a success rate of 81.3% and 85.7%, respectively.

CONCLUSION

RLR can benefit from the routine integration of ICG fluoresce evaluation according to each individual patient and condition-specific goals and issues, allowing liver functional assessment, anatomical and vascular evaluation, tumor detection, and resection margins assessment.

Variations in the origin of the infrapyloric artery: A systematic review and meta-analysis

BACKGROUND

The infrapyloric artery (IPA) supplies the pylorus and the large curvature of the antrum. Its common origin points include the gastroduodenal artery (GDA) and right gastroepiploic artery (RGEA). The prevalence of variations in IPA origins can be of interest to gastric cancer surgeons who wish to increase their understanding of this vessel. The primary aim of this study was to perform a systematic review and meta-analysis on the origin of the IPA. The secondary aims were to assess imaging identification accuracy, to identify IPA morphological features, and to explore the relationship of IPA origin and clinicopathological characteristics.

METHODS

Electronic databases, currently registered studies, conference proceedings and the reference lists of included studies were searched through March 2023. There were no constraints based on language, publication status, or patient demographics. Database search, data extraction and risk of bias assessment were performed independently by two reviewers. The point of origin of the IPA was the primary outcome. Secondary outcomes were imaging identification accuracy, relationship between IPA origin and clinicopathological characteristics, and IPA morphological features. A random-effects meta-analysis of the prevalence of different IPA origins was conducted. Secondary outcomes were narratively synthesized given the heterogeneity of studies reporting on these.

RESULTS

A total of 7279 records were screened in the initial search. Seven studies were included in the meta-analysis, assessing 998 patients. The IPA arose most frequently from the anterior superior pancreaticoduodenal artery (ASPDA), with a pooled prevalence of 40.4% (95% CI 17.1 - 55.8%), followed by the RGEA with a pooled prevalence of 27.6% (95% CI 8.7 - 43.7%), and the GDA with a pooled prevalence of 23.7% (95% CI 6.4 - 39.7%). Cases of multiple IPAs had a pooled prevalence of 4.9% (95% CI 0 - 14.3%). The IPA was absent in 2.6% (95% CI 0 - 10.3%) of cases and arose from the posterior superior pancreaticoduodenal artery (PSPDA) in the remaining 0.8% (95% CI 0 - 6.1%). Distance between the pylorus and the proximal branch of the IPA and distance from the pylorus to the first gastric branch of the RGEA when the IPA originated from the ASPDA and RGEA were longer than when the IPA originated from the GDA. The IPA is a small vessel (<1mm), and its origin is not related to clinicopathological characteristics including patient sex, age, and tumor stage and location.

CONCLUSIONS

Surgeons must be aware of the most common origin points of the IPA. Recommendations for future study include the stratification of IPA origin according to demographic characteristics, and further investigation into IPA morphological parameters such as tortuosity, course and relation to adjacent lymph nodes, aiding the creation of a standardized classification system pertaining to the anatomy of this vessel.

Real-time vessel navigation using indocyanine green fluorescence during robotic-assisted gastrectomy for gastric cancer after coronary artery bypass grafting using the right gastroepiploic artery

Injury to the right gastroepiploic artery (RGEA) graft during gastrectomy after coronary artery bypass grafting (CABG) can cause critical coronary failure. A man in his 60s with advanced gastric cancer and a history of CABG was admitted to our hospital. His cardiac blood flow was dependent on RGEA, and a gastrectomy with RGEA preservation was necessary. Robot-assisted distal gastrectomy with real-time vessel navigation using indocyanine green (ICG) fluorescence imaging and Da Vinci Firefly technology was planned. Intraperitoneal observation revealed severe adhesions around the graft. Two milliliters ICG (2.5 mg/mL) was injected intravenously, and RGEA was visualized. An RGEA-preserving robot-assisted distal gastrectomy was successfully performed. The operation time was 279 minutes, and the blood loss was 5 mL. The postoperative course was good and there were no complications.

Tracers in Gastric Cancer Surgery

The treatment of gastric cancer mainly depends on radical gastrectomy. Determination of appropriate surgical margins and adequate lymph node (LN) resection are two major surgical steps that directly correlate with prognosis in gastric cancer. Due to the expanding use of minimally invasive procedures, it is no longer possible to locate tumors and LNs through touch. As an alternative, tracers have begun to enter the field due to their capacities for intraoperative visualization. Herein, we summarize the application of contemporary tracers in gastric cancer surgery, including isosulfan blue, methylene blue, patent blue, indocyanine green, carbon particles, and radioactive tracers. Their mechanisms, administration methods, detection efficiency, and challenges, as well as perspectives on them, are also outlined.

Safety and efficacy of preoperative indocyanine green fluorescence marking in laparoscopic gastrectomy for proximal gastric and esophagogastric junction adenocarcinoma (ICG MAP study)

PURPOSE

The incidence of adenocarcinoma of the esophagogastric junction (AEG) and proximal gastric cancer (PGC) is rising worldwide. Recently, the use of indocyanine green (ICG) tracer-guided surgery has been reported; however, its efficacy for total/proximal gastrectomy has not been clarified. We evaluated the feasibility and safety of ICG fluorescent marking for tumor localization in AEG/PGC treatment by laparoscopic surgery.

METHODS

We enrolled patients with AEG/PGC from October 2016 to March 2019 from a prospectively registered database. On the day before surgery, ICG markings were made at four locations just at the edge of the tumor by gastrointestinal fiberscope examination. Surgery was performed while viewing the fluorescence image of ICG, and the proximal portions of the esophagus and the distal portion of the stomach were resected at the edge of the area where ICG had spread.

RESULTS

We enrolled 130 patients with AEG/PGC. Overall, 107 patients were eventually included in the study: AEG n = 64 (60%) and PGC n = 43 (40%). ICG markings were detected intraoperatively in all cases, and cancer invasion into the resection lines of the esophagus and stomach, performed based on ICG fluorescence images, was negative in all cases. The median visible range of ICG fluorescence was 22.5 mm. ICG diffusion expanded 20 mm proximal for AEG. There were no adverse events associated with endoscopic ICG injection.

CONCLUSION

ICG fluorescence imaging is feasible and safe and can potentially be used as a tumor-marking agent for determining the surgical resection line for total/proximal gastrectomy in AEG and PGC treatment.

Indocyanine green (ICG) fluorescence guide for the use and indications in general surgery: recommendations based on the descriptive review of the literature and the analysis of experience

Indocyanine Green is a fluorescent substance visible in near-infrared light. It is useful for the identification of anatomical structures (biliary tract, ureters, parathyroid, thoracic duct), the tissues vascularization (anastomosis in colorectal, esophageal, gastric, bariatric surgery, for plasties and flaps in abdominal wall surgery, liver resection, in strangulated hernias and in intestinal ischemia), for tumor identification (liver, pancreas, adrenal glands, implants of peritoneal carcinomatosis, retroperitoneal tumors and lymphomas) and sentinel node identification and lymphatic mapping in malignant tumors (stomach, breast, colon, rectum, esophagus and skin cancer). The evidence is very encouraging, although standardization of its use and randomized studies with higher number of patients are required to obtain definitive conclusions on its use in general surgery. The aim of this literature review is to provide a guide for the use of ICG fluorescence in general surgery procedures.

The Use of Indocyanine Green (ICG) and Near-Infrared (NIR) Fluorescence-Guided Imaging in Gastric Cancer Surgery: A Narrative Review

Near-infrared fluorescence imaging with indocyanine green is an emerging technology gaining clinical relevance in the field of oncosurgery. In recent decades, it has also been applied in gastric cancer surgery, spreading among surgeons thanks to the diffusion of minimally invasive approaches and the related development of new optic tools. Its most relevant uses in gastric cancer surgery are sentinel node navigation surgery, lymph node mapping during lymphadenectomy, assessment of vascular anatomy, and assessment of anastomotic perfusion. There is still debate regarding the most effective application, but with relatively no collateral effects and without compromising the operative time, indocyanine green fluorescence imaging carved out a role for itself in gastric resections. This review aims to summarize the current indications and evidence for the use of this tool, including the relevant practical details such as dosages and times of administration.

Modern surgical therapy for gastric cancer-Robotics and beyond

The surgical paradigm for gastric cancer has been changed from extended surgery to minimally invasive surgery. Laparoscopic surgery is a practical method for minimally invasive surgery for early gastric cancer, and the indication is expanding to advanced gastric cancer. In recent years, robotic gastrectomy has been highlighted as a breakthrough to overcome the drawbacks of laparoscopic gastrectomy. Here, we discuss the recent updates of modern surgical therapy for gastric cancer-robotics and beyond.

New Intraoperative Imaging Tools and Image-Guided Surgery in Gastric Cancer Surgery

Innovations and new advancements in intraoperative real-time imaging have gained significant importance in the field of gastric cancer surgery in the recent past. Currently, the most promising procedures include indocyanine green fluorescence imaging (ICG-FI) and hyperspectral imaging or multispectral imaging (HSI, MSI). ICG-FI is utilized in a broad range of clinical applications, e.g., assessment of perfusion or lymphatic drainage, and additional implementations are currently investigated. HSI is still in the experimental phase and its value and clinical relevance require further evaluation, but initial studies have shown a successful application in perfusion assessment, and prospects concerning non-invasive tissue and tumor classification are promising. The application of machine learning and artificial intelligence technologies might enable an automatic evaluation of the acquired image data in the future. Both methods facilitate the accurate visualization of tissue characteristics that are initially indistinguishable for the human eye. By aiding surgeons in optimizing the surgical procedure, image-guided surgery can contribute to the oncologic safety and reduction of complications in gastric cancer surgery and recent advances hold promise for the application of HSI in intraoperative tissue diagnostics.

The oncologic safety and accuracy of indocyanine green fluorescent dye marking in securing the proximal resection margin during totally laparoscopic distal gastrectomy for gastric cancer: a retrospective comparative study

Background

Securing the proximal resection margin in totally laparoscopic distal gastrectomy for gastric cancer is related to curability and recurrence, while reducing the operation time is related to patient safety. This study aimed to investigate the role of indocyanine green (ICG) fluorescent dye marking in totally laparoscopic distal gastrectomy, whether it is an oncologically safe and accurate procedure that can be conducted in a single centre.

Methods

The data of 93 patients who underwent laparoscopic-assisted distal gastrectomy (non-ICG group) or totally laparoscopic distal gastrectomy using ICG (ICG group) between 2010 and 2020 were retrospectively reviewed. To correct for confounding factors, a propensity score matching was performed.

Results

Proximal resection margin did not vary with the ICG injection site after the propensity score matching (lower ICG, 3.84 cm vs. lower non-ICG, 4.42 cm, p = 0.581; middle ICG, 3.34 cm vs. middle non-ICG, 3.20 cm; p = 0.917), while the operation time was reduced by a mean of 34 min in the ICG group (ICG, 239.3 [95% confidence interval, 220.1–258.5 min]; non-ICG, 273.0 [95% confidence interval, 261.6–284.4] min; p = 0.006).

Conclusions

ICG injection for securing the proximal resection margin in totally laparoscopic distal gastrectomy is an oncologically safe and accurate procedure, with the advantage of reducing the operation time of gastric cancer surgery while it has the benefit of locating the tumour or clips when it is impossible to locate the tumour during surgery due to the inability to perform an endoscopic examination or when it is hard to directly palpate the tumour or clips in the operating theatre; this can be performed at a single centre.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02494-5.

Current Status and Trends of Minimally Invasive Gastrectomy in Korea

Since its introduction in the early 1990s, laparoscopic gastrectomy has been widely accepted for the treatment of gastric cancer worldwide. In the last decade, the Korean Laparoendoscopic Gastrointestinal Surgery Study group performed important clinical trials and exerted various efforts to enhance the quality of scientific knowledge and surgical techniques in the field of gastric cancer surgery. Laparoscopic gastrectomy has shifted to a new era in Korea due to recent advances and innovations in technology. Here, we discuss the recent updates of laparoscopic gastrectomy—namely, reduced-port, single-incision, robotic, image-guided, and oncometabolic surgery.

New Technique of Laparoscopic Paraaortic Lymph Node Dissection for Colorectal Cancer Using Fluorescence Navigation

BACKGROUND/AIM

According to limited current reports, therapeutic paraaortic lymph node (PALN) dissection with intensive combined therapy for colorectal cancer improves prognosis in select patients. Laparoscopic PALN dissection is a difficult technique that has not yet been established. We applied this procedure using an intraoperative fluorescence navigation technique with a near-infrared ray catheter (NIRC™) fluorescent ureteral catheter (NIRFUC).

PATIENTS AND METHODS

We evaluated the utility of laparoscopic fluorescence navigation and the short-term outcomes of 6 patients undergoing laparoscopic PALN dissection.

RESULTS

There were 3 surgeries for synchronous metastasis and 3 surgeries for recurrent metastasis. The mean surgical duration, blood loss, and postoperative hospital stay were 677 (range=518-1,090) min, 7.5 (range=3-1,600) ml, and 14 (range=9-33) days, respectively. Postoperative complications (Clavien-Dindo grade >III) occurred in 1 case.

CONCLUSION

Dissection around the ureter was navigated with a NIRFUC. Fluorescence ureteral navigation facilitated completion of the complex laparoscopic PALN dissection procedure.

Fluorescence vessel and ureter navigation during laparoscopic lateral lymph node dissection

BACKGROUND

Lateral lymph node metastasis in lower rectal cancer is considered a local disease in Japan, and guidelines suggest lateral lymph node dissection (LLND). However, laparoscopic procedures are relatively difficult. The ureter and hypogastric fascia must be dissected from the vesicohypogastric fascia to preserve the autonomic nerve and ureter. Additionally, lymph node dissection around the internal iliac artery is complex because many patterns of branching from the internal iliac artery exist. We investigated the utility of fluorescence ureter and vessel navigation using a near-infrared ray fluorescent ureteral catheter (NIRFUC) and indocyanine green (ICG).

METHODS

Fourteen patients who underwent laparoscopic LLND using fluorescence navigation were included. Eleven patients had rectal cancer, 1 had anal cancer, and 2 exhibited recurrence of rectal cancer. Eleven patients underwent NIRFUC insertion before surgery. Fluorescence vessel navigation (FVN) was performed with intraoperative ICG injections in 14 patients, with a total of 18 sides. The outcome measures were ureter navigation visibility, detection of the branch form from the internal iliac artery with FVN, differences between the fluorescence findings and anatomy of the internal iliac artery determined after LLND, and the surgical outcome.

RESULTS

In all 11 patients, the ureters were clearly identified as fluorescent before dissection around the ureter. FVN revealed the internal iliac, umbilical, and superior vesical arteries in all patients. The branch from the internal iliac artery according to the Adachi classification was revealed on 16 sides (89%). The time from intravenous ICG injection to fluorescence of the internal iliac artery was 38 (17-57) s. The time from intravenous injection to when the vessels were observed as fluorescent was 113 (65-661) s. No ureteral or vessel injuries occurred.

CONCLUSIONS

Fluorescence navigation of vessels and the ureter is feasible in laparoscopic LLND and has the potential to increase safety.

CLINICAL TRIAL REGISTRATION

Examination of fluorescence navigation for laparoscopic colorectal cancer surgery Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

[Status of minimally invasive gastrectomy : Current advancements: robotic surgery and intraoperative imaging for gastric cancer]

The surgical treatment of gastric cancer has arrived at a turning point towards the routine application of minimally invasive techniques. After the first results of prospective randomized trials from Asia confirmed the surgical and oncological safety, the latest results of international trials provided evidence for minimally invasive gastrectomy of advanced gastric cancer in a multimodal setting. A new addition in the field of minimally invasive procedures is robotic-assisted surgical techniques, which have already been implemented for these indications in many centers in Germany. The technical advantages that are applicable in the robotics setting in comparison to laparoscopy lead to a rapid dissemination of the procedure but still need to be evaluated in controlled trials. Further developments for the surgical treatment of gastric cancer are found in the field of intraoperative imaging procedures. In this field various technologies are available, such as fluorescence imaging using a near-infrared camera, which requires the use of a fluorescent agent or the hyperspectral camera system, which does not require the application of a fluorophore and merges pictures from visible and non-visible wavelengths to a functional image. It is to be expected that in the future various technological advancements can make a valuable contribution to the surgical treatment of gastric cancer in the clinical routine, especially if they support and facilitate the use of minimally invasive surgical techniques.

Real-time identification of aberrant left hepatic arterial territories using near-infrared fluorescence with indocyanine green during gastrectomy for gastric cancer

BACKGROUND

An aberrant left hepatic artery is frequently encountered during upper gastrointestinal surgery, and researchers have yet to propose optimal strategies with which to address this arterial variation. The objective of this study was to determine whether the areas perfused by an aberrant left hepatic artery can be visualized in real-time using near-infrared fluorescence imaging with indocyanine green.

METHODS

Patients with gastric adenocarcinoma who underwent minimally invasive radical gastrectomy from May 2018 to August 2019 were enrolled and retrospectively analyzed at a single-center. Patients with an aberrant left hepatic artery and normal preoperative liver function were examined. After the clamping of an aberrant left hepatic artery, indocyanine green was administered via a peripheral intravenous route during surgery. Fluorescence at the liver was visualized under near-infrared fluorescence imaging.

RESULTS

In 31 patients with aberrant left hepatic arteries, near-infrared fluorescence imaging was used without adverse events associated with indocyanine green. Six (19%) patients were reported to have an aberrant left hepatic artery upon preoperative CT imaging, while all other instances were detected during surgery. Fluorescence excitation on the liver was, on average, visible after 43 s (range, 25-65). Fluorescence across the entire surface of the liver was noted in 20 (65%) patients in whom the aberrant left hepatic artery could be ligated. Aberrant left hepatic arteries were safely preserved in 10 (32%) patients who showed areas of no or partial fluorescence excitation. Guided by near-infrared fluorescence imaging, ligation of aberrant left hepatic arteries elicited no significant changes in postoperative liver function.

CONCLUSION

Near-infrared fluorescence imaging facilitates the identification of aberrant left hepatic arterial territories, guiding decisions on the preservation or ligation of this arterial variation.

Current status of robotic gastrectomy for gastric cancer: comparison with laparoscopic gastrectomy

Robotic systems were developed to overcome limitations of laparoscopic surgery with its mechanical advantages. Along with the technical advances, robotic gastrectomy for gastric cancer is increasing. However, the evidence regarding safety and efficacy for robotic gastrectomy for gastric cancer is not mature yet. Although studies are limited, it is evident that robotic gastrectomy has a longer operation and less blood loss compared with laparoscopic gastrectomy. Studies revealed long-term oncological outcomes after robotic gastrectomy was comparable to those after laparoscopic gastrectomy. Taken together, robotic gastrectomy with systemic lymph node dissection is suggested as a safe procedure with equivalent short- and long-term oncologic outcomes to either laparoscopic or open gastrectomy for the surgical treatment of gastric cancer. However, high cost is the most significant barrier to justify robotic surgery as a routine and standard treatment for patients with gastric cancer. In the meanwhile, robotic surgery will be expansively used as long as technologic developments continue.

Global updates in the treatment of gastric cancer: a systematic review. Part 2: perioperative management, multimodal therapies, new technologies, standardization of the surgical treatment and educational aspects

Gastric cancer is the fifth malignancy and the third cause of cancer death worldwide, according to the global cancer statistics presented in 2018. Its definition and staging have been revised in the eight edition of the AJCC/TNM classification, which took effect in 2018. Novel molecular classifications for GC have been recently established and the process of translating these classifications into clinical practice is ongoing. The cornerstone of GC treatment is surgical, in a context of multimodal therapy. Surgical treatment is being standardized, and is evolving according to new anatomical concepts and to the recent technological developments. This is leading to a massive improvement in the use of mini-invasive techniques. Mini-invasive techniques aim to be equivalent to open surgery from an oncologic point of view, with better short-term outcomes. The persecution of better short-term outcomes also includes the optimization of the perioperative management, which is being implemented on large scale according to the enhanced recovery after surgery principles. In the era of precision medicine, multimodal treatment is also evolving. The long-time-awaited results of many trials investigating the role for preoperative and postoperative management have been published, changing the clinical practice. Novel investigations focused both on traditional chemotherapeutic regimens and targeted therapies are currently ongoing. Modern platforms increase the possibility for further standardization of the different treatments, promote the use of big data and open new possibilities for surgical learning. This systematic review in two parts assesses all the current updates in GC treatment.

Near-infrared fluorescence-guided surgery using indocyanine green facilitates secure infrapyloric lymph node dissection during laparoscopic distal gastrectomy

PURPOSE

We aimed to investigate the usefulness of near-infrared indocyanine green (ICG)-enhanced fluorescence guidance for infrapyloric LN dissection in laparoscopic distal gastrectomy.

METHODS

This study enrolled patients with early gastric cancer scheduled for laparoscopic distal gastrectomy. After intraoperative submucosal injection of ICG (0.1 mg/mL), LN dissection was conducted under near-infrared ICG fluorescence guidance. The operation time, bleeding events during infrapyloric LN dissection were analyzed. Cases were retrospectively 1:3 propensity-score matched to patients who underwent laparoscopic distal gastrectomy without ICG injection.

RESULTS

The mean time from midline omentectomy to exposure of the right gastroepiploic vein was significantly shorter in the ICG group (n = 20) than in the non-ICG group (n = 60) (13.05 ± 5.77 vs 18.68 ± 7.92 min; p = 0.001), and the incidence of bleeding during infrapyloric LN dissection was lower in the ICG group (20% vs 68.3%, p < 0.001). The two groups did not differ significantly regarding the number of LNs retrieved from the infrapyloric area (p = 0.434).

CONCLUSIONS

Near-infrared ICG fluorescence guidance facilitates safe and fast infrapyloric LN dissection in laparoscopic distal gastrectomy.

Oncological Robot-Assisted Gastrectomy: Technical Aspects and Ongoing Data

Robotic surgery through the da Vinci Surgical System has been widely spread for many procedures across the globe for several years. At the same time, robot-assisted gastrectomy for gastric cancer (GC) remains mostly available only in specialized centers in minimally invasive surgery and stomach neoplasm. The robotic platform has been introduced to overcome possible drawbacks of the laparoscopic approach. The safety and the feasibility of robotic radical gastrectomy have been reported in many retrospective case series and nonrandomized prospective studies. However, the superiority of robotic gastrectomy over the laparoscopic access has not yet been proven. This study aimed to report the technical aspects of robot-assisted gastrectomy for GC as well as the latest evidence on this subject.

Laparoscopic splenic hilar lymph node dissection for advanced gastric cancer: to be or not to be

The incidence of proximal gastric cancer has increased in both the East and the West. Although some novel reconstructions like double-tract or double-flap anti-reflux procedure related to proximal gastrectomy are promising, total radical gastrectomy still accounts for a significant portion of these procedures. D2 radical gastrectomy is the globally accepted standard surgical procedure for advanced gastric cancer, and lymph node (LN) dissection is considered as the critical point of radical surgery and closely related to the prognosis. The splenic hilar LNs (No. 10) are LNs that need to be removed during standard D2 surgery for proximal and total gastrectomy. Lymphadenectomy does not only provide valuable information on the prognosis of gastric cancer, but the thoroughness of the sweep itself is directly related to postoperative survival. The incidence of splenic hilar LN (No. 10) metastasis rate is not high. Although the LN metastasis pathway around the spleen is complicated, the feasibility of laparoscopic splenic hilar LN dissection in locally advanced gastric cancer has been verified. However, these results are mostly from small volume clinical studies, and the fact is that the dissection of the splenic hilar is technique-demanding even for open surgery. The rational strategy for LN dissection for surgeons is still controversial. For splenic LN dissection in radical gastric cancer surgery, whether to select individualized splenic LN dissection for those patients highly suspected of clinical metastasis or to advocate the evidence-based strategy and neglect dissection in lower risk patients to avoid over-removing of LNs, is a vital question that needs to be clarified.

The Feasibility and Safety of Preoperative Fluorescence Marking with Indocyanine Green (ICG) in Laparoscopic Gastrectomy for Gastric Cancer

BACKGROUND

Securing the surgical margin is the most essential and important task in curative surgery. However, it is difficult to accurately identify the tumor location during laparoscopic surgery for gastric cancer, and existing methods, such as preoperative endoscopic marking with tattooing and clipping, have multiple disadvantages.

AIMS

We investigated the feasibility and safety of indocyanine green (ICG) fluorescence marking for determining the tumor location during laparoscopic gastrectomy.

METHODS

We retrospectively analyzed preoperative and perioperative data from consecutive patients with gastric cancer undergoing planned laparoscopic distal gastrectomy. Data was maintained in a prospectively compiled surgical database, and patients were categorized into ICG (n = 84) or non-ICG (n = 174) groups based on whether they underwent preoperative endoscopic mucosal ICG injection. One-to-one propensity score matching (PSM) was performed to compare outcomes between the two groups.

RESULTS

We included 84 patient pairs after PSM, and there were no significant differences in preoperative patient characteristics. The ICG group had shorter procedure time (p < 0.001), lower estimated blood loss (p = 0.005), and significantly shorter postoperative hospital stay (p < 0.001). Positive resection margins were confirmed in five cases (6.0%) in the non-ICG group, whereas there were none in the ICG group (p = 0.008). Real-time confirmation was possible during laparoscopy, and the injected ICG did not affect the surgical procedure or result in adverse events.

CONCLUSION

ICG fluorescence imaging is feasible and safe and can potentially be used as a tumor-marking agent for determining the surgical resection line.

Laparoscopic Total Devascularization of the Upper Stomach and Splenectomy (Hassab's Procedure) Under Indocyanine Green Fluorescence Imaging: Initial Experience

The use of surgical treatment for refractory isolated gastric varices has decreased owing to the development of endoscopic and radiologic procedures, although surgeries are sometimes required as the final method. A 75-year-old Japanese woman was diagnosed with solitary gastric varices. Initially, intraoperative splenic artery embolization was performed using the balloon transcatheter technique under general anesthesia. Laparoscopic splenectomy was performed safely owing to preoperative splenic artery embolization. Intraoperative indocyanine green (ICG) fluorescence angiography was performed following the injection of 5 mL of ICG; the remnant stomach was observed using laparoscopic equipment with an ICG imaging system, and blood flow from the remnant gastric artery was confirmed. The blood did not pool or wash out immediately, which confirmed successful devascularization of the stomach. The total operative time was 269 minutes, and the intraoperative blood loss was 500 mL. The patient's postoperative course was good, and at 21 days after the last operation, she was discharged from our hospital in remission. Real-time fluorescence angiography with ICG is a reliable and objective technique of assessing blood flow of the stomach. Accurate, extensive devascularization in the lower esophagus and upper stomach was performed using Hassab's procedure in combination with ICG imaging.

Robotic-assisted gastrectomy for gastric cancer: a European perspective

Gastrectomy is the mainstay treatment for gastric cancer. To reduce the associated patient burden, minimally invasive gastrectomy was introduced in almost 30 years ago. The increase in the availability of surgical robotic systems led to the first robotic-assisted gastrectomy to be performed in 2002 in Japan. Robotic gastrectomy however, particularly in Europe, has not yet gained significant traction. Most reports to date are from Asia, predominantly containing observational studies. These cohorts are commonly different in the tumour stage, location (particularly with regards to gastroesophageal junctional tumours) and patient BMI compared to those encountered in Europe. To date, no randomised clinical trials have been performed comparing robotic gastrectomy to either laparoscopic or open equivalent. Cohort studies show that robotic gastrectomy is equal oncological outcomes in terms of survival and lymph node yield. Operative times in the robotic group are consistently longer compared to laparoscopic or open gastrectomy, although evidence is emerging that resectional surgical time is equal. The only reproducibly significant difference in favour of robot-assisted gastrectomy is a reduction in intra-operative blood loss and some studies show a reduction in the risk of pancreatic fistula formation.

Green indocyanine fluorescence in robotic abdominal surgery

Fluorescent imaging with indocyanine green (ICG) is an emerging technology that is gaining acceptance for being a valid tool in surgeons' decision making. ICG binds to plasma lipoproteins if injected intravenously and, when excited by near-infrared light, provides anatomic information about organs vascularization and tissues perfusion. If injected in tissues, it migrates in the lymphatic system, therefore enabling the identification of lymphatic draining pathways of different organs. In this paper we address specific applications of ICG fluorescence in robotic general surgery.

Assessment of the Completeness of Lymph Node Dissection Using Near-infrared Imaging with Indocyanine Green in Laparoscopic Gastrectomy for Gastric Cancer

Purpose

This study assessed the feasibility of near-infrared (NIR) imaging with indocyanine green (ICG) in investigating the completeness of laparoscopic lymph node (LN) dissection for gastric cancer.

Materials and Methods

Patients scheduled for laparoscopic gastrectomy for treating gastric cancer were enrolled in the study. After intraoperative submucosal ICG injection (0.05 mg/mL), LN dissection was performed under conventional laparoscopic light. After dissection, the LN stations of interest were examined under the NIR mode to locate any extra ICG-stained (E) tissues, which were excised and sent for pathologic confirmation. This technique was tested in 2 steps: infra-pyloric LN dissection (step 1) and review of all stations after proper radical node dissection (step 2).

Results

In step 1, 15 patients who underwent laparoscopic pylorus-preserving gastrectomy (LPPG) and 15 patients who underwent laparoscopic distal gastrectomy (LDG) were examined. Seven and 2 E-tissues were obtained during LPPG and LDG, respectively. From the retrieved E-tissues, 1 and 0 tissue obtained during LPPG and LDG, respectively, was confirmed as LN. In step 2, 20 patients were enrolled (13 D1+ dissection and 7 D2 dissection). Six E-tissues were retrieved from 5 patients, and 1 tissue was confirmed as LN in the pathologic review. Overall, 15 E-tissues were detected and removed, and 2 tissues were confirmed as LNs in the pathologic review. Both nodes were from LN station #6, with 1 case each in the LDG and LPPG groups.

Conclusions

NIR imaging may provide additional node detection during laparoscopic LN dissection for gastric cancer, especially in the infra-pyloric area.

Anatomical variation of infra-pyloric artery origination: A prospective multicenter observational study (IPA-Origin)

Objective

Infra-pyloric artery (IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA.

Methods

We did this prospective, multicenter, open-label, observational study at gastric surgery departments of 34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ² tests and Fisher’s tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov (No. NCT03071237).

Results

Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419 (97.7%) patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398 (95.0%) patients, including gastroduodenal artery (GDA) in 154 (36.8%) patients, anterior superior pancreaticoduodenal artery (ASPDA) in 130 (31.0%) patients, and right gastroepiploic artery (RGEA) in 114 (27.2%) patients. Fifteen (3.6%) patients were identified with multiple IPA and 6 (1.4%) patients were identified as IPA absence. The differences in the distribution of surgical approach (P=0.003) and geographic area (P=0.030) were statistically significant. No difference was shown in sex, age, gastrectomy type, tumor location, and clinical T, N and M stage.

Conclusions

Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions. Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.

Fluorescence-Guided Surgery

Surgical resection of cancer remains an important treatment modality. Despite advances in preoperative imaging, surgery itself is primarily guided by the surgeon’s ability to locate pathology with conventional white light imaging. Fluorescence-guided surgery (FGS) can be used to define tumor location and margins during the procedure. Intraoperative visualization of tumors may not only allow more complete resections but also improve safety by avoiding unnecessary damage to normal tissue which can also reduce operative time and decrease the need for second-look surgeries. A number of new FGS imaging probes have recently been developed, complementing a small but useful number of existing probes. In this review, we describe current and new fluorescent probes that may assist FGS.

Indocyanine green fluorescence angiography (ICGFA) during laparoscopic and robotic colorectal surgery- a video vignette

Anastomotic leaks are a dreaded complication of all colorectal surgery with the main factors contributing to it being tension on the anastomosis, intra-abdominal or systemic sepsis, distal obstruction, inadequate blood supply and improper surgical techniques. The leak rate of left-sided high colorectal resections can have a clinically significant leak rate from as low as 1-5% in high anterior resections to 7.9% in low anastomoses. This article is protected by copyright. All rights reserved.

Robotic surgery for the upper gastrointestinal tract: Current status and future perspectives

More than 4000 da Vinci Surgical Systems have been installed worldwide. Robotic surgery using the da Vinci Surgical System has been increasingly performed in the last decade, especially in urology and gynecology. The da Vinci Surgical System has not become standard in surgery of the upper gastrointestinal tract because of a lack of clear benefits in comparison with conventional minimally invasive surgery. We initiated robotic gastrectomy and esophagectomy for patients with upper gastrointestinal cancer in 2009, and we have demonstrated the potential advantages of the da Vinci Surgical System in reducing postoperative local complications after gastrectomy and recurrent laryngeal nerve palsy after esophagectomy. However, robotic surgery has the disadvantages of a longer operative time and higher costs than the conventional approach. In this review article, we present the current status of robotic surgery for gastric and esophageal cancer, as well as future perspectives on this approach, based on our experience and a review of the literature.