The Utility of Indocyanine Green Angiography in the Assessment of Perfusion of Gastric Conduit and Proximal Esophageal Stump Against Visual Assessment in Patients Undergoing Esophagectomy: a Prospective Study

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.

Current status of indocyanine green fluorescent angiography in assessing perfusion of gastric conduit and oesophago-gastric anastomosis

Anastomotic leak (AL) remains a significant complication after esophagectomy. Indocyanine green fluorescent angiography (ICG-FA) is a promising and safe technique for assessing gastric conduit (GC) perfusion intraoperatively. It provides detailed visualization of tissue perfusion and has demonstrated usefulness in oesophageal surgery. GC perfusion analysis by ICG-FA is crucial in constructing the conduit and selecting the anastomotic site and enables surgeons to make necessary adjustments during surgery to potentially reduce ALs. However, anastomotic integrity involves multiple factors, and ICG-FA must be combined with optimization of patient and procedural factors to decrease AL rates. This review summarizes ICG-FA's current applications in assessing esophago-gastric anastomosis perfusion, including qualitative and quantitative analysis and different imaging systems. It also explores how fluorescent imaging could decrease ALs and aid clinicians in utilizing ICG-FA to improve esophagectomy outcomes.

[ICG angiography is a safety standard in bariatric surgery]

OBJECTIVE

To examine the specific characteristics of ICG-angiography during various bariatric interventions.

MATERIAL AND METHODS

The study included 329 patients, with 105 (32%) undergoing sleeve gastrectomy (LSG), 98 (30%) undergoing mini-gastricbypass (MGB), 126 (38%) undergoing Roux-en-Y gastric bypass (RGB). Intraoperative ICG angiography was perfomed on all patients at 'control points', the perfusion of the gastric stump was qualitatively and quantitatively assessed.

RESULTS

Intraoperative ICG angiography shows that during LSG the angioarchitectonics in the area of the His angle are crucial. The presence of the posterior gastric artery of the gastric main type is a prognostically unfavorable risk factor for the development of ischemic complications. Therefore, to expand the gastric stump it is necessary to suture a 40Fr nasogastric tube and perform peritonization of the staple line. Statistical difference in blood supply at three points were found between and within the two groups of patients (Gis angle area, gastric body, pyloric region) with a p-value <0.001. During MGB, one of the important stages is applying the first (transverse) stapler cassette between the branches of the right and left gastric arteries. This maintains blood supply in anastomosis area, preventing immediate complications such as GEA failure, as well as long-term complications like atrophic gastritis, peptic ulcers, and GEA stenosis.

CONCLUSION

ICG angiography is a useful method for intraoperative assessment of angioarchitecture and perfusion of the gastric stump during bariatric surgery. This helps prevent tissue ischemia and reduce the risk of early and late postoperative complications.

Pattern of Aorto-coeliac Calcification Correlating Cervical Esophago-gastric Anastomotic Leak After Esophagectomy for Cancer: a Retrospective Study

PURPOSE

Cervical esophagogastric anastomotic leak (CEGAL) is a troublesome complication after esophagectomy and gastric pull-up. The aim of the study was to identify the preoperative clinical and radiological factors associated with increased risk of CEGAL.

METHODS

Consecutive patients whose clinical and imaging data were available and who underwent cervical esophago-gastric anastomosis following esophagectomy and gastric pull-up for esophageal cancer, between January 2013 and January 2021, were included. The patient details were collected from a prospectively maintained database. The demographic, clinical, and laboratory data including preoperative hemoglobin and serum albumin levels were recorded. Preoperative computed tomographic (CT) images were reviewed by two independent radiologists to assign vascular calcification scores for proximal aorta, distal aorta, aortic bifurcation, celiac trunk, and celiac artery branches. The primary outcome evaluated was clinically evident neck leak. Univariate and multivariate analysis of the clinical and radiological factors was performed to identify significant predictors.

RESULTS

A total of 100 patients (mean age: 54.7 years; 60 males, 40 females) were included in the study and of them, 27 developed CEGAL. Compared to the group without CEGAL, the patient group with CEGAL had significantly higher mean age (60.3 vs. 52.7 years, p < 0.01), and higher incidences of diabetes mellitus (25.9% vs 10.9%, p = 0.03), major proximal aortic calcification (29.6% vs. 6.3%, p < 0.01), and major celiac trunk calcification (22.2% vs. 6.3%, p = 0.02). Multivariate regression analysis identified age and presence of major proximal aortic calcification as independent risk factors for the development of CEGAL.

CONCLUSION

Major calcification of the proximal aorta and advanced age are independent risk factors for CEGAL after esophagectomy.

Mapping the Lymphatic Drainage Pattern of Esophageal Cancer with Near-Infrared Fluorescent Imaging during Robotic Assisted Minimally Invasive Ivor Lewis Esophagectomy (RAMIE)-First Results of the Prospective ESOMAP Feasibility Trial

While the sentinel lymph node concept is routinely applied in other surgical fields, no established and valid modality for lymph node mapping for esophageal cancer surgery currently exists. Near-infrared light fluorescence (NIR) using indocyanine green (ICG) has been recently proven to be a safe technology for peritumoral injection and consecutive lymph node mapping in small surgical cohorts, mostly without the usage of robotic technology. The aim of this study was to identify the lymphatic drainage pattern of esophageal cancer during highly standardized RAMIE and to correlate the intraoperative images with the histopathological dissemination of lymphatic metastases. Patients with clinically advanced stage squamous cell carcinoma or adenocarcinoma of the esophagus undergoing a RAMIE at our Center of Excellence for Surgery of the Upper Gastrointestinal Tract were prospectively included in this study. Patients were admitted on the day prior to surgery, and an additional EGD with endoscopic injection of the ICG solution around the tumor was performed. Intraoperative imaging procedures were performed using the Stryker 1688 or the FIREFLY fluorescence imaging system, and resected lymph nodes were sent to pathology. A total of 20 patients were included in the study, and feasibility and safety for the application of NIR using ICG during RAMIE were shown. NIR imaging to detect lymph node metastases can be safely performed during RAMIE. Further analyses in our center will focus on pathological analyses of ICG-positive tissue and quantification using artificial intelligence tools with a correlation of long-term follow-up data.

Use of Indocyanine Green Fluorescence Angiography and Prophylactic Endoscopic Stenting in Esophagectomy for Acute Esophageal Necrosis

Acute esophageal necrosis (AEN) is a rare condition with high mortality. We describe a case of an AEN accompanied with multiple esophageal perforations in a 40-year-old patient. This was addressed via emergency Ivor-Lewis-esophagectomy with intraoperative Indocyanine-Green-Angiography (ICGA) and prophylactic placement of a self-expanding metal-stent (SEMS).

[ICG lymph node mapping in cancer surgery of the upper gastrointestinal tract]

The importance of the assessment of the N‑status in gastric carcinoma, tumors of the gastroesophageal junction and esophageal cancer is undisputed; however, there is currently no internationally validated method for lymph node mapping in esophageal and gastric cancer. Near-infrared fluorescence imaging (NIR) is an innovative technique from the field of vibrational spectroscopy, which in combination with the fluorescent dye indocyanine green (ICG) enables intraoperative real-time visualization of anatomical structures. The ICG currently has four fields of application in oncological surgery: intraoperative real-time angiography for visualization of perfusion, lymphography for visualization of lymphatic vessels, visualization of solid tumors, and (sentinel) lymph node mapping. For imaging of the lymph drainage area and therefore the consecutive lymph nodes, peritumoral injection of ICG must be performed. Several studies have demonstrated the feasibility of peritumoral injection of ICG administered 15 min to 3 days preoperatively with subsequent intraoperative visualization of the lymph nodes. So far prospective randomized studies on the validation of the method are still lacking. In contrast, the use of ICG for lymph node mapping and visualization of sentinel lymph nodes in gastric cancer has been performed in large cohorts as well as in prospective randomized settings. Up to now, multicenter studies for ICG-guided lymph node mapping during oncological surgery of the upper gastrointestinal tract are lacking. Artificial intelligence methods can help to evaluate these techniques in an automated manner in the future as well as to support intraoperative decision making and therefore to improve the quality of oncological surgery.

Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations

Background

Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery.

Purpose, and Research design

Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery.

Study sample and data collection

Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed.

Conclusions

It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future.

Fluorescence-guided cancer surgery-A new paradigm

Fluorescence-guided surgery is an emerging and promising operative adjunct to assist the surgeon in various aspects of oncosurgery, ranging from assessing perfusion, identification, and characterization of tumors and peritoneal metastases, mapping of lymph nodes/leaks, and assistance for fluorescence-guided surgery (FGS). This study aims to provide an overview of principles, currently available dyes, platforms, and surgical applications and summarizes the available literature on the utility of FGS with a focus on abdomino-thoracic malignancies.