Assessment of the blood supply using the indocyanine green fluorescence method and postoperative endoscopic evaluation of anastomosis of the gastric tube during esophagectomy

Does Indocyanine Green Utilization during Esophagectomy Prevent Anastomotic Leaks? Systematic Review and Meta-Analysis

Background: Indocyanine Green (ICG) is a promising technique for the assessment of gastric conduit and anastomosis perfusion during esophagectomy. ICG integration may be helpful in minimizing the risk of anastomotic leak (AL). Literature evidence is sparse, while the real effect of ICG assessment on AL minimization remains unsolved. The aim of this systematic review and meta-analysis was to compare short-term outcomes between ICG-guided and non-ICG-guided (nICG) esophagogastric anastomosis during esophagectomy for cancer. Materials and Methods: PubMed, MEDLINE, Scopus, Web of Science, Cochrane Central Library, and ClinicalTrials.gov were queried up to 25 April 2024. Studies that reported short-term outcomes for ICG versus non-ICG-guided (nICG) anastomosis in patients undergoing esophagectomy were considered. Primary outcome was AL. Risk ratio (RR) and standardized mean difference (SMD) were utilized as effect size measures, whereas to assess relative inference we used 95% confidence intervals (95% CI). Results: Overall, 1399 patients (11 observational studies) were included. Overall, 576 (41.2%) underwent ICG gastric conduit assessment. The patients' ages ranged from 22 to 91 years, with 73% being male. The cumulative incidence of AL was 10.4% for ICG and 15.4% for nICG. Compared to nICG, ICG utilization was related to a reduced risk for postoperative AL (RR 0.48; 95% CI 0.23-0.99; p = 0.05). No differences were found in terms of pulmonary complications (RR 0.83), operative time (SMD -0.47), hospital length of stay (SMD -0.16), or 90-day mortality (RR 1.70). Conclusions: Our study seems to indicate a potential impact of ICG in reducing post-esophagectomy AL. However, because of limitations in the design of the included studies, allocation/reporting bias, variable definitions of AL, and heterogeneity in ICG use, caution is required to avoid potential overestimation of the ICG effect.

Usefulness of fluorescence imaging with indocyanine green for evaluation of bowel perfusion in the urgency setting: a systematic review and meta-analysis

INTRODUCTION

Fluorescence imaging with indocyanine green (ICG) has been extensively utilized to assess bowel perfusion in oncologic surgery. In the emergency setting, there are many situations in which bowel perfusion assessment is required. Large prospective studies or RCTs evaluating feasibility, safety and utility of ICG in the emergency setting are lacking. The primary aim is to assess the usefulness of ICG for evaluation of bowel perfusion in the emergency setting.

MATERIALS AND METHODS

The manuscript was drafted following the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA). A systematic literature search was carried out through Pubmed, Scopus, and the ISI Web of Science. Assessment of included study using the methodological index for nonrandomized studies (MINORS) was calculated. The meta-analysis was carried out in line with recommendations from the Cochrane Collaboration and Meta-analysis of Observational Studies in Epidemiology guidelines, and the Mantel-Haenszel random effects model was used to calculate effect sizes.

RESULTS

10 093 papers were identified. Eighty-four were reviewed in full-text, and 78 were excluded: 64 were case reports; 10 were reviews without original data; 2 were letters to the editor; and 2 contained unextractable data. Finally, six studies 22-27 were available for quality assessment and quantitative synthesis. The probability of reoperation using ICG fluorescence angiography resulted similar to the traditional assessment of bowel perfusion with a RD was -0.04 (95% CI: -0.147 to 0.060). The results were statistically significant P =0.029, although the heterogeneity was not negligible with a 59.9% of the I2 index. No small study effect or publication bias were found.

CONCLUSIONS

This first metanalysis on the use of IGC fluorescence for ischemic bowel disease showed that this methodology is a safe and feasible tool in the assessment of bowel perfusion in the emergency setting. This topic should be further investigated in high-quality studies.

Blood flow evaluation of reconstructed gastric tube in esophageal surgery using near-infrared imaging and retrospective time-intensity curve analysis

PURPOSE

Near-infrared fluorescence imaging using indocyanine green (ICG-NIFI) can visualize a blood flow in reconstructed gastric tube; however, it depends on surgeon's visual assessment. The aim of this study was to re-analyze the ICG-NIFI data by an evaluator independent from the surgeon and feasibility of creating the time-intensity curve (TIC).

METHODS

We retrospectively reviewed 97 patients who underwent esophageal surgery with gastric tube reconstruction between January 2017 and November 2022. From the stored ICG videos, fluorescence intensity was examined in the four regions of interest (ROIs), which was set around the planned anastomosis site on the elevated gastric tube. After creation the TICs using the OpenCV library, we measured the intensity starting point and time constant and assessed the correlation between the anastomotic leakage.

RESULTS

Postoperative leakage occurred for 12 patients. The leakage group had significantly lack of blood flow continuity between the right and left gastroepiploic arteries (75.0% vs. 22.4%; P < 0.001) and tended to have slower ICG visualization time assessed by the surgeon's eyes (40 vs. 32 s; P = 0.066). TIC could create in 65 cases. Intensity starting point at all ROIs was faster than the surgeon's assessment. The leakage group tended to have slower intensity starting point at ROI 3 compared to those in the non-leakage group (22.5 vs. 19.0 s; P = 0.087).

CONCLUSION

A TIC analysis of ICG-NIFI by an independent evaluator was able to quantify the fluorescence intensity changes that the surgeon had visually determined.

Evaluation of tissue blood supply during esophagectomy using fluorescent diagnostics and diffuse scattering spectroscopy in visible region

BACKGROUND

The success of the surgical treatment of a tumor or obstruction of the esophagus with subsequent anastomosis application depends on the level of blood supply to the stitched tissues. Intraoperative assessment of blood flow is widely used in medicine and can be used as a diagnostic method that affects the outcome of surgery and reduces the frequency of postoperative complications for the patient.

METHODS

In this work, the assessment of blood supply during esophageal resection operations was carried out using two techniques sequentially: fluorescent diagnostics with indocyanine green and measurement of hemoglobin oxygen saturation by diffuse scattering spectroscopy in the visible wavelength range. The first method was used to assess the integrity of the vascular network structure in the area of anastomosis and blood flow through the sutured tissues, the second one - for local assessment of hemoglobin oxygen saturation in the investigated area.

RESULTS

Conducted clinical study involved the participation of nine patients with malignant neoplasms (six cases) or esophageal obstruction (three cases). The presence of postoperative complications was compared with the measurement results. Anastomosis failure was observed in only one patient. According to the results of the study, with the use of the investigated method of assessing blood supply, there is a tendency towards a decrease in the frequency of anastomosis leaks (11.1 % compared with 21.4 %).

CONCLUSIONS

Therefore, fluorescent diagnostics with indocyanine green and measurement of hemoglobin oxygen saturation using diffuse scattering spectroscopy were affirmed as methods that allow increasing the safety of surgical procedures by assessing the risk of postoperative complications, including anastomosis failures.

Surface microdialysis measures local tissue metabolism after Ivor Lewis esophagectomy; an attempt to predict anastomotic defect

Anastomotic defect (AD) after esophagectomy can lead to severe complications with need for surgical or endoscopic intervention. Early detection enables early treatment and can limit the consequences of the AD. As of today, there are limited methods to predict AD. In this study, we have used microdialysis (MD) to measure local metabolism at the intrathoracic anastomosis. Feasibility and possible diagnostic use were investigated. Sixty patients planned for Ivor Lewis esophagectomy were enrolled. After construction of the anastomosis, surface MD (S-MD) probes were attached to the outer surface of the esophageal remnant and the gastric conduit in close vicinity of the anastomosis and left in place for 7 postoperative days (PODs). Continuous sampling of local tissue concentrations of metabolic substances (glucose, lactate, and pyruvate) was performed postoperatively. Outcome, defined as AD or not according to Esophagectomy Complications Consensus Group definitions, was recorded at discharge or at first postoperative follow up. Difference in concentrations of metabolic substances was analyzed retrospectively between the two groups by means of artificial neural network technique. S-MD probes can be attached and removed from the gastric tube reconstruction without any adverse events. Deviating metabolite concentrations on POD 1 were associated with later development of AD. In subjects who developed AD, no difference in metabolic concentrations between the esophageal and the gastric probe was recorded. The technical failure rate of the MD probes/procedure was high. S-MD can be used in a clinical setting after Ivor Lewis esophagectomy. Deviation in local tissue metabolism on POD 1 seems to be associated with development of AD. Further development of MD probes and procedure is required to reduce technical failure.

Application of indocyanine green (ICG)-guided surgery in clinical practice: lesson to learn from other organs-an overview on clinical applications and future perspectives

Indocyanine green (ICG) fluorescence-guided surgery is a modality of intra-operative navigation that might support the surgeon with enhanced visualization of anatomical structures in real time. Over the last years, it has emerged as one of the most promising and rapidly developing technical innovations in surgery. The most popular current clinical applications include fluorescence cholangiography, bowel anastomotic perfusion assessment, fluorescence-guided lymphography for sentinel lymph-node identification and guided lymphadenectomy and the possible use in oncological surgery for the identification and localization of tumors and the diagnosis and treatment of peritoneal carcinosis. This paper provides an overview of the multiple fields of applications of ICG fluorescence-guided surgery in visceral and oncological surgery, discussing indications summarizing most recent and significative available literature and giving technical notes of use.

Predictive impact of the thoracic inlet space on ICG fluorescence blood flow speed in the gastric conduit wall and anastomotic leakage after esophagectomy

PURPOSE

The thoracic inlet space might influence the blood vessel perfusion in the gastric conduit. The purpose of this study was to clarify the impacts of the thoracic inlet space on blood vessel perfusion in the gastric conduit and anastomotic leakage after esophagectomy.

METHODS

One hundred and forty-two esophageal cancer patients underwent esophagectomy followed by gastric conduit reconstruction via the retrosternal route. The blood flow speed in the gastric conduit was measured using indocyanine green fluorescence before and after reconstruction. Parameters at the thoracic inlet space were measured using CT. We then investigated the correlation between these two parameters and whether they could predict anastomotic leakage after esophagectomy.

RESULTS

Blood flow speed in the gastric conduit was slower after reconstruction than before reconstruction (P < 0.001). The incidence of anastomotic leakage (n = 23) was higher among patients with a delayed blood flow speed before reconstruction (n = 27) than among those with a non-delayed blood flow speed before reconstruction (n = 115) (P < 0.001). Among the patients with a non-delayed blood flow speed before reconstruction, the thoracic inlet area (TIA, sternum-tracheal distance × clavicle head distance) was positively correlated with the blood flow speed after reconstruction (P = 0.023) and was identified as an independent predictor of anastomotic leakage (P < 0.001).

CONCLUSION

A narrow TIA was associated with a delayed blood flow speed in the gastric conduit after reconstruction and was capable of predicting anastomotic leakage in the patients with a non-delayed blood flow speed before reconstruction.

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.

Safety and efficacy of indocyanine green near-infrared fluorescent imaging-guided lymph nodes dissection during radical gastrectomy for gastric cancer: A systematic review and meta-analysis

Background

Indocyanine green (ICG) fluorescence imaging has been a new surgical navigation technique for gastric cancer. However, its clinical value should still be evaluated further. In this meta-analysis, we investigated the safety and efficacy of ICG near-infrared fluorescent imaging-guided lymph nodes (LNs) dissection during radical gastrectomy.

Methods

Studies comparing ICG fluorescence imaging with standard care in patients with gastric cancer were systematically searched from PubMed, Embase, Web of Science, and Cochrane Library through August 2021. The current meta-analysis was performed according to the preferred reporting items for systematic review and meta-analysis guidelines. A pooled analysis was performed for the available data regarding the number of LNs dissection, the number of metastatic LNs dissection, other operative outcomes, and postoperative complications. R software version 4.2.0 and Stata 16.0 software were used for the present meta-analysis.

Results

This analysis included 12 studies with a total of 1365 gastric cancer patients (569 in the ICG group and 796 in the non-ICG group). The number of retrieved LNs in the ICG group was significantly higher (weighted mean difference [WMD]=7.67, 95% confidence intervals [CI]: 4.73 to 10.62, P<0.05) compared to the non-ICG group with moderate heterogeneity (P<0.001, I2 = 70%). The number of metastatic LNs, operative time, and postoperative complications were all comparable and without significant heterogeneity. Additionally, ICG near-infrared fluorescent imaging was associated with reduced intraoperative blood loss (WMD=-10.28, 95% CI: -15.22 to -5.35, P<0.05) with low heterogeneity (P=0.07, I2 = 43%).

Conclusions

ICG near-infrared fluorescent imaging-guided lymphadenectomy was considered to be safe and effective in gastrectomy. ICG was used to increase the number of LNs harvested while reducing intraoperative blood loss without increasing operative time or postoperative complications.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021291863.

Application of Indocyanine Green Enhanced Fluorescence in Esophageal Surgery: A Mini Review

Despite recent technological innovations and the development of minimally invasive surgery, esophagectomy remains an operation burdened with severe postoperative complications. Fluorescence imaging, particularly using indocyanine green (ICG), offers the ability to address a number of issues faced during esophagectomy. The three main indications for the intraoperative use of ICG during esophagectomy are visualization of conduit vascular supply, allow identification of sentinel nodes and visualization of the thoracic duct. The purpose of this mini review is to present an overview of current practice in fluorescence imaging utilizing ICG during esophagectomy, as well as to demonstrate how this technology can guide lymphadenectomy and reduce surgical morbidity such as anastomotic leaking and chylothorax.

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.

Indocyanine Green Fluorescence Using in Conduit Reconstruction for Patients With Esophageal Cancer to Improve Short-Term Clinical Outcome: A Meta-Analysis

Objectives

This meta-analysis evaluated the short-term safety and efficacy of indocyanine green (ICG) fluorescence in gastric reconstruction to determine a suitable anastomotic position during esophagectomy.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyzes 2020 (PRISMA) were followed for this analysis.

Results

A total of 9 publications including 1,162 patients were included. The operation time and intraoperative blood loss were comparable in the ICG and control groups. There was also no significant difference in overall postoperative mortality, reoperation, arrhythmia, vocal cord paralysis, pneumonia, and surgical wound infection. The ICG group had a 2.66-day reduction in postoperative stay. The overall anastomotic leak (AL) was 17.6% (n = 131) in the control group and 4.5% (n = 19) in the ICG group with a relative risk (RR) of 0.29 (95% CI 0.18–0.47). A subgroup analysis showed that the application of ICG in cervical anastomosis significantly reduced the incidence of AL (RR of 0.31, 95% CI 0.18–0.52), but for intrathoracic anastomosis, the RR 0.35 was not significant (95% CI 0.09–1.43). Compared to an RR of 0.35 in publications with a sample size of <50, a sample size of >50 had a lower RR of 0.24 (95% CI 0.12–0.48). Regarding intervention time of ICG, the application of ICG both before and after gastric construction had a better RR of 0.25 (95% CI 0.07–0.89).

Conclusions

The application of ICG fluorescence could effectively reduce the incidence of AL and shorten the postoperative hospital stay for patients undergoing cervical anastomosis but was not effective for patients undergoing intrathoracic anastomosis. The application of ICG fluorescence before and after gastric management can better prevent AL.

Systematic Review Registration

PROSPERO, CRD:42021244819.

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.

Clinical utility of near-infrared perfusion assessment of the gastric tube during Ivor Lewis esophagectomy

BACKGROUND

Anastomotic leakage (AL) after Ivor Lewis esophagectomy with intrathoracic anastomosis carries a significant morbidity. Adequate perfusion of the gastric tube (GT) is an important predictor of anastomotic integrity. Recently, near infrared fluorescent (NIRF) imaging using indocyanine green (ICG) was introduced in clinical practice to evaluate tissue perfusion. We evaluated the feasibility and efficacy of GT indocyanine green angiography (ICGA) after Ivor Lewis esophagectomy.

METHODS

This retrospective analysis used data from a prospectively kept database of consecutive patients who underwent Ivor Lewis (IL) esophagectomy with GT construction for cancer between January 2016 and December 2020. Relevant outcomes were feasibility, ICGA complications and the impact of ICGA on AL.

RESULTS

266 consecutive IL patients were identified who matched the inclusion criteria. The 115 patients operated with perioperative ICGA were compared to a control group in whom surgery was performed according to the standard of care. ICGA perfusion assessment was feasible and safe in all 115 procedures and suggested a poorly perfused tip in 56/115 (48.7%) cases, for which additional resection was performed. The overall AL rate was 16% (43/266), with 12% (33/266) needing an endoscopic our surgical intervention and 6% (17/266) needing ICU support. In univariable and multivariable analyses, ICGA was not correlated with the risk of AL (ICGA:14.8% vs non-ICGA:17.2%, p = 0.62). However, poor ICGA perfusion of the GT predicted a higher AL rate, despite additional resection of the tip (ICGA poorly perfused: 19.6% vs ICG well perfused: 10.2%, p = 0.19).

CONCLUSIONS

ICGA is safe and feasible, but did not result in a reduction of AL. The interpretation and necessary action in case of perioperative presence of ischemia on ICGA have yet to be determined. Prospective randomized trials are warranted to analyze its benefit on AL in esophageal surgery. Trial registration Ethical approval for a prospective esophageal surgery database was granted by the Ethical committee of the Ghent University Hospital. Belgian registration number: B670201111232. Ethical approval for this retrospective data analysis was granted by our institutional EC. Registration number: BC-09216.

Quantitative Fluorescence Imaging of Perfusion—An Algorithm to Predict Anastomotic Leakage

This study tests fluorescence imaging-derived quantitative parameters for perfusion evaluation of the gastric tube during surgery and correlates these parameters with patient outcomes in terms of anastomotic leakage. Poor fundus perfusion is seen as a major factor for the development of anastomotic leakage and strictures. Fluorescence perfusion imaging may reduce the incidence of complications. Parameters for the quantification of the fluorescence signal are still lacking. Quantitative parameters in terms of maximal intensity, mean slope and influx timepoint were tested for significant differences between four perfusion areas of the gastric tube in 22 patients with a repeated ANOVA test. These parameters were compared with patient outcomes. Maximal intensity, mean slope and influx timepoint were significantly different between the base of the gastric tube and the fundus (p < 0.0001). Patients who developed anastomotic leakage showed a mean slope of almost 0 in Location 4. The distance of the demarcation of ICG to the fundus was significantly higher in the three patients who developed anastomotic leakage (p < 0.0001). This study presents quantitative intra-operative perfusion imaging with fluorescence. Quantification of the fluorescence signal allows for early risk stratification of necrosis.

Real-time fluorescence image-guided gastrointestinal oncologic surgery: Towards a new era

Technological improvements are crucial in the evolution of surgery. Real-time fluorescence-guided surgery (FGS) has spread worldwide, mainly because of its usefulness during the intraoperative decision-making processes. The success of any gastrointestinal oncologic resection is based on the anatomical identification of the primary tumor and its regional lymph nodes. FGS allows also to evaluate the blood perfusion at the gastrointestinal stumps after colorectal or esophageal resections. Therefore, a reduction on the anastomotic leak rates has been postulated as one of the foreseeable benefits provided by the use of FGS in these procedures. Although the use of fluorescence in lymph node detection was initially described in breast cancer surgery, the technique is currently applied in gastric or splenic flexure cancers, as they both present complex and variable lymphatic drainages. FGS allows also to perform intraoperative lymphograms or sentinel lymph node biopsies. New applications of FGS are being developed to assist in the detection of peritoneal metastases or in the evaluation of the tumor resection margins. The present review aims to provide a general overview of the current status of real-time FGS in gastrointestinal oncologic surgery. We put a special focus on the different applications of FGS, discussing the main findings and limitations found in the contemporary literature and also the promising near future applications.

Usefulness of blood flow evaluation with indocyanine green fluorescence imaging during laparoscopic surgery for strangulated bowel obstruction: A cohort study

INTRODUCTION

Intestinal blood flow evaluation during strangulated bowel obstruction is often based on the subjective assessment of the operator. Therefore, we aimed to comprehensively determine the presence or absence of intestinal blood flow based on normal light and indocyanine green (ICG) fluorescence imaging. Moreover, we ascertained whether the chosen surgical plan was appropriate, based on the patients' postoperative course and pathological findings.

METHODS

All 14 patients diagnosed with strangulated bowel obstruction at our hospital who underwent laparoscopic surgery between July 2019 and January 2021 were enrolled. Surgical plans were chosen based on normal light imaging combined with near-infrared imaging after intravenous ICG injection. Intestinal resection was performed via a small laparotomy if resection was considered necessary. In the intestinal resection group, the presence of intestinal necrosis was examined based on the pathological findings of the resected specimens. In the intestinal preservation group, postoperative complications, such as delayed intestinal perforation and intestinal stricture, were examined.

RESULTS

Intestinal resection was performed in 4 cases. The pathological findings of the resected specimens showed necrosis of the small intestine in all cases. No intra-abdominal complication occurred any of the cases, and the median postoperative hospital stay was 9.9 days.

CONCLUSIONS

The selection of a surgical plan in conjunction with ICG fluorescence findings was valid in all 14 cases. ICG fluorescence imaging is useful in laparoscopic surgery for strangulated bowel obstruction and may be a novel method for evaluating intestinal blood flow during surgery.

Indocyanine green fluorescence imaging ensures perfusion of the remnant stomach during laparoscopic splenectomy in a patient after distal gastrectomy: A case report

Background

After distal gastrectomy, ischemic necrosis of the remnant stomach is a rare but serious complication. For distal pancreatectomy or splenectomy, ensuring adequate blood supply to the remnant stomach is important for patients with a history of distal gastrectomy. We report a case of successful splenectomy with indocyanine green (ICG) used to evaluate the blood supply to the remnant stomach in a patient after distal gastrectomy.

Case presentation

A 65-year-old woman who underwent distal gastrectomy for gastric cancer a year earlier had a splenic tumor that was increasing in size. We planned laparoscopic splenectomy because there was a possibility of a malignant splenic tumor. Intraoperative ICG fluorescence imaging confirmed perfusion of the remnant stomach. The patient was discharged on postoperative day 8 after an uncomplicated postoperative course.

Conclusion

ICG fluorescence imaging is useful for evaluating blood flow to the remnant stomach during laparoscopic splenectomy in patients after distal gastrectomy.

•

Ischemic necrosis of the remnant stomach is a serious complication for patients with a history of distal gastrectomy.

•

During laparoscopic surgery, the method for evaluating the blood supply to remnant stomach has not been established.

•

ICG fluorescence imaging is only way to visually evaluate the blood supply to organs during surgery.

•

Using ICG fluorescence imaging during laparoscopic splenectomy, ischemic necrosis of the remnant stomach can be prevented.

Salvage Esophagectomy

Salvage esophagectomy is an option for patients with recurrent or persistent esophageal cancer after definitive chemoradiation therapy or those who undergo active surveillance after induction chemoradiation therapy. Salvage resection is associated with higher rates of morbidity compared with planned esophagectomy but offers patients with locally advanced disease a chance at improved long-term survival. Salvage resection should be preferentially performed in a multidisciplinary setting by high-volume and experienced surgeons. Technical considerations, such as prior radiation dosage, radiation field, and choice of conduit, should be taken into account.

Indocyanine green fluorescence imaging for evaluating blood flow in the reconstructed conduit after esophageal cancer surgery

We investigated the effectiveness of indocyanine green (ICG) fluorescence blood flow imaging of the gastric conduit to evaluate anastomotic leakage after esophagectomy. We identified 19 articles using the PRISMA standard for systematic reviews. The more recent studies reported attempts at objective quantification of ICG fluorescence imaging, rather than qualitative assessment. Anastomotic leakage after esophagectomy occurred in 0-33% of the patients who underwent ICG fluorescence imaging. According to the six studies that compared the incidence of anastomotic leakage in the ICG group and the control group, it ranged from 0 to 18.3% in the ICG group and from 0 to 25.2% in the control group, respectively. Overall, the incidence of anastomotic leakage in the ICG group (8.4%) was lower than that in the control group (18.5%). Although the incidence of anastomotic leakage was as high as 43.1% in patients who did not undergo any intraoperative intervention for poor blood flow, it was only 24% in patients who underwent intraoperative intervention. This systematic review revealed that ICG fluorescence imaging may be a crucial adjunctive tool for reducing anastomotic leakage after esophagectomy, suggesting that it should be performed during esophageal reconstruction.

Innovative marking method using novel endoscopic clip equipped with fluorescent resin to locate gastric cancer

An asymptomatic 76-year-old man presented to our department for the treatment of gastric cancer. Esophagogastroduodenoscopy revealed a superficial elevated lesion with an irregular central depression in the lower third of the stomach; this was confirmed to be adenocarcinoma by biopsy, while abdominal contrast-enhanced CT revealed no abnormal lesions. Based on the patient's clinical diagnosis of early gastric cancer, we planned laparoscopic gastrectomy with preoperative placement of four endoscopic marking clips equipped with indocyanine green-conjugated resin to determine the resection margin. During surgery, a dedicated laparoscopic system was used to detect indocyanine green fluorescence emitted by the clips and determine their precise position. The clips helped to identify an accurate resection line for the stomach, enabling accurate laparoscopic distal gastrectomy with regional lymphadenectomy. We successfully demonstrated the usefulness of clips with fluorescent resin for detecting gastric cancer in patients. We report the first case using the clips to accurately locate a site of interest.

Indocyanine Green (ICG) fluorescence angiography of gastric conduit after transhiatal thoracic esophagectomy with proximal gastrectomy for esophagogastric junction adenocarcinoma: A case report and initial experience at a tertiary government hospital in the Philippines

INTRODUCTION AND IMPORTANCE

We documented the initial experience in our institution where we used indocyanine green (ICG) fluorescence angiography as adjunct in the evaluation of the vascular supply of a reconstructed gastric conduit for esophageal replacement for esophagogastric junction (EGJ) cancer surgery.

CASE PRESENTATION

A 62-year-old patient consulted with a two-month history of melena and weight loss and unremarkable chest and abdominal physical examinations.

CLINICAL FINDINGS AND INVESTIGATIONS

Upper endoscopy and contrast-enhanced computed tomography scans of the chest and abdomen demonstrated an EGJ tumor with no nodal and distant metastases, which revealed adenocarcinoma on biopsy.

INTERVENTION AND OUTCOME

The patient underwent combined thoracoscopic-assisted and transhiatal thoracic esophagectomy with proximal gastrectomy. Esophageal reconstruction was done via a retrosternal gastric pull-up. The perfusion and viability of the gastric conduit were confirmed as per usual methods of inspection and palpation. ICG fluorescence angiography further demonstrated and confirmed the vascular perfusion of the gastric conduit and the optimal site of anastomosis. The patient had an unremarkable postoperative course with no reported anastomotic leakage and stricture formation at 12 months follow-up.

RELEVANCE AND IMPACT

ICG fluorescence angiography represents a feasible and promising tool in assessing viability of esophageal replacement and choosing the optimal site for anastomosis with the proximal esophagus. It can aid in choosing the most appropriate site of anastomosis to prevent ischemia-related complications such as leakage or stricture. This particular case can serve as an initial learning experience to guide surgeons in our institution in the use of ICG fluorescence angiography for esophageal replacements after esophagectomy.

Quantitative serosal and mucosal optical imaging perfusion assessment in gastric conduits for esophageal surgery: an experimental study in enhanced reality

Introduction/objective

Gastric conduit (GC) is used for reconstruction after esophagectomy. Anastomotic leakage (AL) incidence remains high, given the extensive disruption of the gastric circulation. Currently, there is no reliable method to intraoperatively quantify gastric perfusion. Hyperspectral imaging (HSI) has shown its potential to quantify serosal StO2. Confocal laser endomicroscopy (CLE) allows for automatic mucosal microcirculation quantification as functional capillary density area (FCD-A). The aim of this study was to quantify serosal and mucosal GC’s microperfusion using HSI and CLE. Local capillary lactate (LCL) served as biomarker.

Methods

GC was formed in 5 pigs and serosal StO2% was quantified at 3 regions of interest (ROI) using HSI: fundus (ROI-F), greater curvature (ROI-C), and pylorus (ROI-P). After intravenous injection of sodium-fluorescein (0.5 g), CLE-based mucosal microperfusion was assessed at the corresponding ROIs, and LCLs were quantified via a lactate analyzer.

Results

StO2 and FCD-A at ROI-F (41 ± 10.6%, 3.3 ± 3.8, respectively) were significantly lower than ROI-C (68.2 ± 6.7%, p value: 0.005; 18.4 ± 7, p value: 0.01, respectively) and ROI-P (72 ± 10.4%, p value: 0.005; 15.7 ± 3.2 p value: 0.001). LCL value at ROI-F (9.6 ± 4.7 mmol/L) was significantly higher than at ROI-C (2.6 ± 1.2 mmol/L, p value: 0.04) and ROI-P (2.6 ± 1.3 mmol/L, p value: 0.04). No statistically significant difference was found in all metrics between ROI-C and ROI-P. StO2 correlated with FCD-A (Pearson’s r = 0.67). The LCL correlated negatively with both FCD-A (Spearman’s r =  − 0.74) and StO2 (Spearman’s r =  −  0.54).

Conclusions

GC formation causes a drop in serosal and mucosal fundic perfusion. HSI and CLE correlate well and might become useful intraoperative tools.

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.

Management of Complications After Esophagectomy

Esophagectomy is a complex operation with many potential complications. Early recognition of postoperative complications allows for the best chance for patient survival. Diagnosis and management of conduit complications, including leak, necrosis, and conduit-airway fistulae, are reviewed. Other common complications, such as chylothorax and recurrent laryngeal nerve injury, also are discussed.

Correlation between indocyanine green visualization time in the gastric tube and postoperative endoscopic assessment of the anastomosis after esophageal surgery

PURPOSE

To evaluate the correlation between blood supply speed in the gastric tube (GT), assessed by the intraoperative indocyanine green (ICG) fluorescence method, and postoperative endoscopic assessment (PEA) of the anastomosis or anastomotic leakage (AL).

METHODS

The subjects of this retrospective analysis were 66 consecutive patients who underwent GT reconstruction using ICG fluorescence during esophageal surgery. We measured the ICG visualization time, from ICG injection to visualization at the top of the GT. We performed PEA on 54 patients and classified ulcer formation as involving less than or more than half of the circumference.

RESULTS

PEA revealed that nine patients (16.7%) had an anastomotic ulcer involving more than half of the circumference and ten (15.4%) had AL. The ICG visualization time in these patients was significantly delayed compared with that in those with less than half of the circumference involved by ulcer formation (37 s vs. 27 s; P = 0.015) and without AL (36 s vs. 28 s; P = 0.045). Multivariate analysis revealed that delay in the ICG visualization time (> 36 s) of the pulled-up GT (odds ratio, 6.098; 95% confidence interval, 1.125-33.024; P = 0.036) was an independent risk factor associated with AL.

CONCLUSION

Delay in the ICG visualization time of pulled-up GT was associated with ulcer formation on the anastomosis and AL after esophageal surgery.

Subtotal gastrectomy for gastric tube cancer using intraoperative indocyanine green fluorescence method

INTRODUCTION

Currently, the frequency of evaluating the flow of a reconstructed gastric tube using indocyanine green (ICG) fluorescence has been increasing. However, it has been difficult to decide on the operation method for patients with gastric tube cancer (GTC). We herein report a case in which ICG was effective in a patient with resection of GTC.

PRESENTATION OF CASE

An 83-year-old man underwent subtotal esophagectomy with gastric tube reconstruction via the retrosternal route for esophageal cancer and right hemicolectomy for ascending colon cancer 16 years earlier. Postoperatively, the proximal part of the gastric tube had poor blood flow. Therefore, the patient underwent proximal-side resection of the gastric tube. Thereafter, free jejunal graft reconstruction was performed. The patient had not developed recurrence at that point. Recently, the patient visited the hospital complaining of nausea and chest discomfort. Upper gastrointestinal endoscopy revealed a type 0-IIa + IIc lesion located around the pylorus. A biopsy showed adenocarcinoma. Based on these findings, the patient was diagnosed with gastric tube cancer (cT1bN0M0StageI). The invasion depth of the cancer was predicted to be widespread submucosal invasion. Therefore, the patient underwent surgery. Intraoperatively, we evaluated the flow of the gastric tube after clamping the right gastroepiploic artery using ICG fluorescence. As a result, the flow of the gastric tube was deemed insufficient. Consequently, subtotal gastrectomy was performed with preservation of the right gastroepiploic artery via Roux-en-Y reconstruction.

DISCUSSION

ICG fluorescence is useful for evaluating the flow of the gastric tube helping to decide the operating method.

CONCLUSION

We herein report a case of subtotal gastrectomy for GTC using intraoperative ICG fluorescence.

Feasibility and usability of real-time intraoperative quantitative fluorescent-guided perfusion assessment during resection of gastroesophageal junction cancer

PURPOSE

Anastomotic leakage after resection of gastroesophageal junction cancer is a dangerous complication, and leakage rates have remained stable for decades. Perfusion is crucial for anastomotic healing, but traditional perfusion assessment is limited in a minimally invasive environment. New methods as indocyanine green fluorescence angiography (ICG-FA) have proven promising, but quantitative analysis has been challenging. This study aimed to demonstrate the feasibility and usability of real-time intraoperative quantitative fluorescence angiography (q-ICG) with a touchscreen tablet.

METHODS

A software for q-ICG was previously developed and validated. Ten patients underwent perfusion assessment in white light (WL), with ICG-FA, and with q-ICG during Ivor-Lewis esophageal resection. The usability of the tablet-based software was tested with the System Usability Scale (SUS®). Furthermore, we investigated the differences in perfusion assessment as the distance from the conduit margin to a surgeon selected point of sufficient perfusion for anastomosis using the different modalities.

RESULTS

Q-ICG was successful in all patients, with an excellent median SUS® of 82.5 (77.5-93.8). Significant differences in distances from the conduit margin to points of sufficient perfusion selected by the surgeons were found: ICG: WL = 14.1 mm (p = 0.048), q-ICG: WL = 32.08 mm (p < 0.001), and q-ICG: ICG = 17.95 mm (p = 0.002). Furthermore, significant differences of perfusion were found between the points, when q-ICG was performed retrospectively in the surgeon selected areas (p = 0.008-0.013).

CONCLUSION

Real-time intraoperative touchscreen-based q-ICG was feasible with excellent usability, and differences in sufficient perfusion points selected by the surgeons between modalities were found. Further studies should focus on clinical relevance and determine cutoff values associated with anastomotic leakage.

Impact of postoperative complications on survival after oesophagectomy for oesophageal cancer

BACKGROUND

Recent evidence suggests that complications after oesophagectomy may decrease short- and long-term survival of patients with oesophageal cancer. This study aimed to analyse the impact of complications on survival in a Western cohort.

METHODS

Complications after oesophagectomy were recorded for all patients operated on between January 2006 and February 2017, with severity defined using the Clavien-Dindo classification. Associations between complications and overall and recurrence-free survival were assessed using univariable and multivariable Cox regression models.

RESULTS

Of 430 patients, 292 (67·9 per cent) developed postoperative complications, with 128 (39·8 per cent) classified as Clavien-Dindo grade III or IV. No significant associations were detected between Clavien-Dindo grade and either tumour (T) (P = 0·071) or nodal (N) status (P = 0·882). There was a significant correlation between Clavien-Dindo grade and ASA fitness grade (P = 0·032). In multivariable analysis, overall survival in patients with Clavien-Dindo grade I complications was similar to that in patients with no complications (hazard ratio (HR) 0·97, P = 0·915). However, patients with grade II and IV complications had significantly shorter overall survival than those with no complications: HR 1·64 (P = 0·007) and 1·74 (P = 0·013) respectively.

CONCLUSION

Increasing severity of complications after oesophagectomy was associated with decreased overall survival. Prevention of complications should improve survival.

International Variation in Surgical Practices in Units Performing Oesophagectomy for Oesophageal Cancer: A Unit Survey from the Oesophago-Gastric Anastomosis Audit (OGAA)

BACKGROUND

Anastomotic leaks are associated with significant risk of morbidity, mortality and treatment costs after oesophagectomy. The aim of this study was to evaluate international variation in unit-level clinical practice and resource availability for the prevention and management of anastomotic leak following oesophagectomy.

METHOD

The Oesophago-Gastric Anastomosis Audit (OGAA) is an international research collaboration focussed on improving the care and outcomes of patients undergoing oesophagectomy. Any unit performing oesophagectomy worldwide can register to participate in OGAA studies. An online unit survey was developed and disseminated to lead surgeons at each unit registered to participate in OGAA. High-income country (HIC) and low/middle-income country (LMIC) were defined according to the World Bank whilst unit volume were defined as < 20 versus 20-59 versus ≥60 cases/year in the unit.

RESULTS

Responses were received from 141 units, a 77% (141/182) response rate. Median annual oesophagectomy caseload was reported to be 26 (inter-quartile range 12-50). Only 48% (68/141) and 22% (31/141) of units had an Enhanced Recovery After Surgery (ERAS) program and ERAS nurse, respectively. HIC units had significantly higher rates of stapled anastomosis compared to LMIC units (66 vs 31%, p = 0.005). Routine post-operative contrast-swallow anastomotic assessment was performed in 52% (73/141) units. Stent placement and interventional radiology drainage for anastomotic leak management were more commonly available in HICs than LMICs (99 vs 59%, p < 0.001 and 99 vs 83%, p < 0.001).

CONCLUSIONS

This international survey highlighted variation in surgical technique and management of anastomotic leak based on case volume and country income level. Further research is needed to understand the impact of this variation on patient outcomes.

Bowel obstruction associated with a feeding jejunostomy and its association to weight loss after thoracoscopic esophagectomy

Background

Our aim was to clarify the incidence of bowel obstruction associated with a feeding jejunostomy (BOFJ) after thoracoscopic esophagectomy and its association to characteristics and postoperative change in body weight.

Methods

We reviewed 100 consecutive patients who underwent thoracoscopic esophagectomy with gastric tube reconstruction and placement of a jejunostomy feeding catheter for esophageal cancer. The incidence of BOFJ was evaluated and the change in body weight after surgery was compared between patients with and without BOFJ.

Results

BOFJ developed in 17 patients. Compared to patients without BOFJ, those with BOFJ had a higher preoperative body mass index (23.3 kg/m² versus 20.9 kg/m², P = 0.022), and greater postoperative body weight loss rate: 3 month, decrease to 84.2% of initial body weight versus 89.3% (P = 0.002). Patients with BOFJ had shorter distance between the jejunostomy and midline (40 mm versus 48 mm, P = 0.011) compared to patients without BOFJ. On multivariate analysis, higher preoperative body mass index (odds ratio (OR) = 9.248; 95% confidence interval (CI) = 1.344–63.609; p = 0.024), higher postoperative weight loss at 3 months (OR = 8.490; 95% CI = 1.765–40.837, p = 0.008), and shorter distance between the jejunostomy and midline (OR = 8.160; 95% CI = 1.675–39.747, p = 0.009) were independently associated with BOFJ.

Conclusion

Patients of BOFJ had greater preoperative body mass, shorter distance between jejunostomy and midline, and greater postoperative weight loss.

Fluorescent imaging using indocyanine green during esophagectomy to prevent surgical morbidity: a systematic review and meta-analysis

Background

Fluorescent imaging using indocyanine green (ICG) is an emerging technique that aids the surgeon with intraoperative decision making during upper gastrointestinal cancer surgery. In this systematic review we aim to provide an overview of current practice of fluorescence imaging using ICG during esophagectomy, and to show how this technology can prevent surgical morbidity, such as anastomotic leakage, graft necrosis and chylothorax.

Methods

The PRISMA standard for systematic reviews was used. The PubMed and Embase database were searched to identify articles matching our systematic literature search. Two authors screened all included articles for eligibility. Risk of bias was assessed for all included articles.

Results

A total of 25 articles were included in this review: 22 articles on perfusion assessment, and three on the detection of chyle fistula. Five out of 22 articles concerning perfusion assessment evaluated fluorescence signals in quantitative values. In 20 articles the pooled incidence of anastomotic leakage and graft necrosis in the ICG group was 11.10% (95% CI: 8.06-15.09%) and in eight studies the pooled change in management rate was 24.55% (95% CI: 19.16-30.88%). After change in management, the pooled incidence of anastomotic leakage and graft necrosis was 14.08% (95% CI: 6.55-27.70%). A meta-analysis showed that less anastomotic leakages and graft necrosis occur in the ICG group (OR 0.30, 95% CI: 0.14-0.63). Three case-reports (N=3) were identified regarding chyle fistula detection, and ICG lymphography detected the thoracic duct in all cases and the chyle fistula in one case.

Conclusions

Fluorescence imaging using ICG is a promising and safe technology to reduce surgical morbidity after esophagectomy with continuity restoration. ICG fluorescence angiography showed a reduction in anastomotic leakage and graft necrosis. Future studies are needed to demonstrate the feasibility of ICG lymphography for chyle fistula detection.

Conduit necrosis following esophagectomy: An up-to-date literature review

Esophageal conduit ischaemia and necrosis is an uncommon but devastating complication of esophagectomy and remains one of the most challenging issues in surgical practice. The incidence, time interval to develop symptoms, and clinical presentation are highly variable with no predictable pattern. Evidence comes from case reports and case series rather than randomized controlled trials. We describe the issues surrounding conduit necrosis affecting the stomach, jejunum and colon as an esophageal replacement and the advantages, disadvantages and challenges of each type of reconstruction. Diagnosis is challenging for the most experienced surgeon. Upper gastrointestinal endoscopy and computed tomography thorax with both oral and intravenous contrast is the gold standard. Management, either conservative or interventional is also a difficult decision. Management options include conservative treatment and more aggressive treatments such as stent insertion, surgical debridement and repair of the esophagus using jejunum, colon or a musculocutaneous flap. In spite of recent advances in surgical techniques, there is no reliable strategy to manage esophageal conduit necrosis. Our review covers the pathophysiology and clinical significance of esophageal necrosis while highlighting current techniques of prevention, diagnosis and treatment of this life-threatening condition.

Near-infrared fluorescence guided esophageal reconstructive surgery: A systematic review

BACKGROUND

After an esophagectomy, the stomach is most commonly used to restore continuity of the upper gastrointestinal tract. These esophago-gastric anastomoses are prone to serious complications such as leakage associated with high morbidity and mortality. Graft perfusion is considered to be an important predictor for anastomotic integrity. Based on the current literature we believe Indocyanine green fluorescence angiography (ICGA) is an easy assessment tool for gastric tube (GT) perfusion, and it might predict anastomotic leakage (AL).

AIM

To evaluate feasibility and effectiveness of ICGA in GT perfusion assessment and as a predictor of AL.

METHODS

This study was designed according to the PRISMA guidelines and registered in the PROSPERO database. PubMed and EMBASE were independently searched by 2 reviewers for studies presenting data on intraoperative ICGA GT perfusion assessment during esophago-gastric reconstruction after esophagectomy. Relevant outcomes such as feasibility, complications, intraoperative surgical changes based on ICGA findings, quantification attempts, anatomical data and the impact of ICGA on postoperative anastomotic complications, were collected by 2 independent researchers. The quality of the included articles was assessed based on the Methodological Index for Non-Randomized Studies. The 19 included studies presented data on 1192 esophagectomy patients, in 758 patients ICGA was used perioperative to guide esophageal reconstruction.

RESULTS

The 19 included studies for qualitative analyses all described ICGA as a safe and easy method to evaluate gastric graft perfusion. AL occurred in 13.8% of the entire cohort, 10% in the ICG guided group and 20.6% in the control group (P < 0.001). When poorly perfused cases are excluded from the analyses, the difference in AL was even larger (AL well-perfused group 6.3% vs control group 20.5%, P < 0.001). The AL rate in the group with an altered surgical plan based on the ICG image was 6.5%, similar to the well perfused group (6.3%) and significantly less than the poorly perfused group (47.8%) (P < 0.001), suggesting that the technique is able to identify and alter a potential bad outcome.

CONCLUSION

ICGA is a safe, feasible and promising method for perfusion assessment. The lower AL rate in the well perfused group suggest that a good fluorescent signal predicts a good outcome.

Impact of the Kocher maneuver on anastomotic leak after esophagogastrostomy in combined thoracoscopic-laparoscopic esophagectomy

OBJECTIVES

Anastomotic leak is a common complication after esophagectomy for esophageal cancer. This study evaluated the impact of the Kocher maneuver on the incidence of anastomotic leak following esophagogastrostomy using a 3-cm-wide gastric conduit.

METHODS

This single-institution, retrospective, cohort study included 43 patients who underwent thoraco-laparoscopic esophagectomy. The Kocher maneuver was not performed in the first half of the study period between April 2014 and May 2015 (first half group, n=14), but was performed in the second half between May 2015 and January 2017 (second half group, n=29). Primary endpoint was the incidence of anastomotic leak. Metrological values of the gastric conduit were postoperatively assessed on computed tomography. Blood perfusion of the gastric conduit was prospectively examined using the indocyanine green fluorescence method.

RESULTS

The incidence of anastomotic leak was 14%; the incidence was significantly lower in the second half group than in the first half group (3.4% vs. 35.7%, p=0.01). The Kocher maneuver was the only significant independent risk factor associated with anastomotic leak (OR 0.064, 95% CI 0.007-0.625, p=0.018). The postoperative length of the entire gastric conduit was significantly shorter in the second half group than in the first half group. A more anal location of the 3-cm-wide gastric conduit was associated with better blood perfusion.

CONCLUSIONS

The Kocher maneuver may enable shortening of the gastric conduit, leading to better blood perfusion of the tip of the gastric conduit, and a significant reduction in the occurrence of anastomotic leak.

Indocyanine green for the prevention of anastomotic leaks following esophagectomy: a meta-analysis

BACKGROUND

Intraoperative evaluation with fluorescence angiography using indocyanine green (ICG) offers a dynamic assessment of gastric conduit perfusion and can guide anastomotic site selection during an esophagectomy. This study aims to evaluate the predictive value of ICG for the prevention of anastomotic leak following esophagectomy.

METHODS

A comprehensive search of electronic databases using the search terms "indocyanine/fluorescence" AND esophagectomy was completed to include all English articles published between January 1946 and 2018. Articles were selected by two independent reviewers. The quality of included studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) instrument.

RESULTS

Seventeen studies were included for meta-analysis after screening and exclusions. The pooled anastomotic leak rate when ICG was used was found to be 10%. When limited to studies without intraoperative modifications, the pooled sensitivity, specificity, and diagnostic odds ratio were 0.78 (95% CI 0.52-0.94; p = 0.089), 0.74 (95% CI 0.61-0.84; p = 0.012), and 8.94 (95% CI 1.24-64.21; p = 0.184), respectively. Six trials compared ICG with an intraoperative intervention to improve perfusion to no ICG. ICG with intervention was found to have a risk reduction of 69% (OR 0.31, 95% CI 0.15-0.63).

CONCLUSIONS

In non-randomized trials, the use of ICG as an intraoperative tool for visualizing microvascular perfusion and conduit site selection to decrease anastomotic leaks is promising. However, poor data quality and heterogeneity in reported variables limits generalizability of findings. Randomized, multi-center trials are needed to account for independent risk factors for leak rates and to better elucidate the impact of ICG in predicting and preventing anastomotic leaks.

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.

Clinical application of photodynamic medicine technology using light-emitting fluorescence imaging based on a specialized luminous source

The natural amino acid 5-aminolevulinic acid (ALA) is a protoporphyrin IX (PpIX) precursor and a new-generation photosensitive substance that accumulates specifically in cancer cells. When indocyanine green (ICG) is irradiated with near-infrared (NIR) light, it shifts to a higher energy state and emits infrared light with a longer wavelength than the irradiated NIR light. Photodynamic diagnosis (PDD) using ALA and ICG-based NIR fluorescence imaging has emerged as a new diagnostic technique. Specifically, in laparoscopic examinations for serosa-invading advanced gastric cancer, peritoneal metastases could be detected by ALA-PDD, but not by conventional visible-light imaging. The HyperEye Medical System (HEMS) can visualize ICG fluorescence as color images simultaneously projected with visible light in real time. This ICG fluorescence method is widely applicable, including for intraoperative identification of sentinel lymph nodes, visualization of blood vessels in organ resection, and blood flow evaluation during surgery. Fluorescence navigation by ALA-PDD and NIR using ICG imaging provides good visualization and detection of the target lesions that is not possible with the naked eye. We propose that this technique should be used in fundamental research on the relationship among cellular dynamics, metabolic enzymes, and tumor tissues, and to evaluate clinical efficacy and safety in multicenter cooperative clinical trials.