Intraoperative near-infrared fluorescence imaging as an adjunct to robotic-assisted minimally invasive esophagectomy. Innovations (Phila). 2014;9:391-393. [PMID: 25238427 DOI: 10.1097/imi.0000000000000091]

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.

Intraoperative fluorescence imaging in esophagectomy and its application to the robotic platform: a narrative review

Background and Objective

Robotic-assisted esophagectomy is an approach to minimally invasive esophagectomy (MIE) that has demonstrated equivalent or improved outcomes relative to open and other minimally invasive techniques. The robotic approach also allows unique opportunities to improve complications following esophagectomy through use of enhanced visualization tools, including intraoperative fluorescence imaging. In this review, we summarize the specific uses of intraoperative fluorescence imaging as an adjunct tool during esophagectomy and discuss its application to the robotic platform.

Methods

A literature search was conducted via PubMed in February 2022 with the following keywords: esophagectomy, esophageal cancer, infrared, near-infrared (NIR) and fluorescence. Peer-reviewed academic journal articles published in English between 2000 and 2021 were included.

Key Content and Findings

There is a growing body of literature evaluating the use of intraoperative fluorescence imaging in robotic-assisted esophagectomy. This includes assessment of gastric conduit perfusion, including feasibility, creation of the gastroesophageal anastomosis, and qualification of perfusion, along with lymphatic mapping and identification of critical anatomy. These tools are uniquely leveraged using the robotic platform to standardize and quantify key technical aspects of the operation.

Conclusions

Intraoperative fluorescence imaging provides the opportunity to assess perfusion and identify anatomy for more precise and patient-specific dissection and reconstruction. Among all the operative techniques for esophagectomy, robotic-assisted esophagectomy is uniquely suited to utilize these imaging modalities to optimize outcomes and minimize risk associated with esophagectomy.

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.

Indocyanine green (ICG) fluorescence imaging for prevention of anastomotic leak in totally minimally invasive Ivor Lewis esophagectomy: a systematic review and meta-analysis

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is an emerging technology that might help decreasing anastomotic leakage (AL) rates. The aim of this study was to determine the usefulness of ICG fluorescence imaging for the prevention of AL after minimally invasive esophagectomy with intrathoracic anastomosis.

METHODS

A systematic literature review of the MEDLINE and Cochrane databases was performed to identify all articles on totally minimally invasive Ivor Lewis esophagectomy. Studies were then divided into two groups based on the use or not of ICG for perfusion assessment. Primary outcome was anastomotic leak. Secondary outcomes included operative time, ICG-related adverse reactions, and mortality rate. A meta-analysis was conducted to estimate the overall weighted proportion and its 95% confidence interval (CI) for main outcomes.

RESULTS

A total of 3,171 patients were included for analysis: 381 (12%) with intraoperative ICG fluorescence imaging and 2,790 (88%) without ICG. Mean patients' age and proportion of males were similar between groups. Mean operative time was also similar between both groups (ICG: 354.8 vs. No-ICG: 354.1 minutes, P = 0.52). Mean ICG dose was 12 mg (5-21 mg). No ICG-related adverse reactions were reported. AL rate was 9% (95% CI, 5-17%) and 9% (95% CI, 7-12%) in the ICG and No-ICG groups, respectively. The risk of AL was similar between groups (odds ratio 0.85, 95% CI 0.53-1.28, P = 0.45). Mortality was 3% (95% CI, 1-9%) in patients with ICG and 2% (95% CI, 2-3%) in those without ICG. Median length of hospital stay was also similar between groups (ICG: 13.6 vs. No-ICG: 11.2 days, P = 0.29).

CONCLUSION

The use of ICG fluorescence imaging for perfusion assessment does not seem to reduce AL rates in patients undergoing minimally invasive esophagectomy with intrathoracic anastomosis.

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.

Technique of robotic esophagectomy

Robotic surgery continues to grow in thoracic surgery, and currently plays an evolving role in esophagectomy. Robotic assisted minimally invasive esophagectomy (RAMIE) has continued to expand, with many institutions adapting the technique. As the overall experience continues to grow, new data is emerging in its support. We present our approach to this operation.

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.

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.

Specific complications and limitations of robotic esophagectomy

Regardless of the approach to esophagectomy, it is an operation that may be associated with significant risk to the patient. Robotic-assisted minimally invasive esophagectomy (RAMIE) has the same potential for short- and long-term complications as does open and minimally invasive esophagectomy. These complications include among others, the risk for anastomotic leak, gastric tip necrosis, vocal cord palsy, and chylothorax. Moreover, there are additional risks that are unique to the robotic platform such as hardware or software malfunction. These risks are heavily influenced by numerous factors including the patient's comorbidities, whether neoadjuvant therapy was administered, and the extent of the surgical team's experience. The limitations of RAMIE are therefore based on the careful assessment of the patient for operability, the tumor for resectability and the team for surgical ability. This article will tackle the topic of complications and limitations of RAMIE by examining each of these issues. It will also describe the recommended terminology for reporting post-esophagectomy complications.

Robotic resection for esophageal cancer

Background

In the surgical treatment of esophageal cancer, complete tumor resection is the most important factor and determines long-term survival. With an increase in robotic expertise in other fields of surgery, robotic-assisted minimally invasive esophagectomy (RAMIE) was born. Currently, there is a lack of convincing data on the extent of expected benefits (perioperative and oncologic outcomes and/or quality of life). Some evidence exists that patients’ overall quality of life and physical function improves, with less fatigue and pain 3 months after surgery. We aimed to review the available literature regarding robotic esophagectomy, compare perioperative, oncologic, and quality of life outcomes with open and minimally invasive approaches, and give a brief overview of our standardized four-arm RAMIE technique and explore future directions.

Methods

A Medline (PubMed) search was conducted including the following key words: esophagectomy, minimally invasive esophagectomy, robotic esophagectomy, Ivor Lewis and McKeown. We present the history, different techniques used, outcomes, and the standardization of robotic esophagectomy.

Results

Robotic esophagectomy offers a steeper learning curve with fewer complications but comparable oncological results compared to conventional minimally invasive esophagectomy.

Conclusions

Available studies suggest that RAMIE is associated with benefits regarding length of stay, clinical outcomes, and quality of life—if patients are treated in an experienced center with a standardized technique for robotic esophagectomy—making it a potentially beneficial tool in the treatment of esophageal cancer. However, center-wide standardization and prospective data collection will be a necessity to prove superiority of robotic esophagectomy.

Vascular calcification does not predict anastomotic leak or conduit necrosis following oesophagectomy

BACKGROUND

Anastomotic leaks (AL) and gastric conduit necrosis (CN) are serious complications following oesophagectomy. Some studies have suggested that vascular calcification may be associated with an increased AL rate, but this has not been validated in a United Kingdom population.

AIM

To investigate whether vascular calcification identified on the pre-operative computed tomography (CT) scan is predictive of AL or CN.

METHODS

Routine pre-operative CT scans of 414 patients who underwent oesophagectomy for malignancy with oesophagogastric anastomosis at the Queen Elizabeth Hospital Birmingham between 2006 and 2018 were retrospectively analysed. Calcification of the proximal aorta, distal aorta, coeliac trunk and branches of the coeliac trunk was scored by two reviewers. The relationship between these calcification scores and occurrence of AL and CN was then analysed. The Esophagectomy Complications Consensus Group definition of AL and CN was used.

RESULTS

Complication data were available in n = 411 patients, of whom 16.7% developed either AL (15.8%) or CN (3.4%). Rates of AL were significantly higher in female patients, at 23.0%, compared to 13.9% in males (P = 0.047). CN was significantly more common in females, (8.0% vs 2.2%, P = 0.014), patients with diabetes (10.6% vs 2.5%, P = 0.014), a history of smoking (10.3% vs 2.3%, P = 0.008), and a higher American Society of Anaesthesiologists grade (P = 0.024). Out of the 14 conduit necroses, only 4 occurred without a concomitant AL. No statistically significant association was found between calcification of any of the vessels studied and either of these outcomes. Multivariable analyses were then performed to identify whether a combination of the calcification scores could be identified that would be significantly predictive of any of the outcomes. However, the stepwise approach did not select any factors for inclusion in the final models. The analysis was repeated for composite outcomes of those patients with either AL or CN (n = 69, 16.7%) and for those with both AL and CN (n = 10, 2.4%) and again, no significant associations were detected. In the subset of patients that developed these outcomes, no significant associations were detected between calcification and the severity of the complication.

CONCLUSION

Calcification scoring was not significantly associated with Anastomotic Leak or CN in our study, therefore should not be used to identify patients who are high risk for these complications.

The Difficult Esophageal Conduit

A variety of esophageal diseases are treated with esophagectomy, from benign to esophageal cancer. Careful attention must be given to management of the difficult conduit, including patients who have had prior gastric surgery and other procedures, patients with conditions such as diabetic gastroparesis, which can affect the stomach as a future usable conduit, and patients who have an absent or unusable stomach. In these situations, consideration should be raised for the use of alternative conduits, including jejunal and colonic interposition conduits. The esophageal surgeon should also be adept at management of intraoperative difficulties with the conduit.

Minimally Invasive and Robotic Esophagectomy: A Review

Great advances have been made in the surgical management of esophageal disease since the first description of esophageal resection in 1913. We are in the era of minimally invasive esophagectomy. The current three main approaches to an esophagectomy are the Ivor Lewis technique, McKeown technique, and the transhiatal approach to esophagectomy. These operations were associated with a high morbidity and mortality. The recent advances in minimally invasive surgical techniques have greatly improved the outcomes of these surgical procedures. This article reviews the literature and describes the various techniques available for performing minimally invasive esophagectomy and robot-assisted esophagectomies, the history behind the development of these techniques, the variations, and the contemporary outcomes after such procedures.

Intraoperative near infrared fluorescence imaging for the assessment of the gastric conduit

Esophagectomy remains a mainstay of multi-modality therapy in the treatment of malignant disease, as well as selected benign conditions. Anastomotic and conduit complications remain the Achilles' heel of these operations, contributing to major morbidity and mortality. Adequate vascular perfusion of the gastric conduit is vital to avoid these complications, with surgeon observational assessment the mainstay of determining the vascular health of the gastric conduit. Rates of morbidity remain significant, and technologies aimed at better assessing relative tissue perfusion and ischemia are increasingly under investigation and utilized. One such technique is the use of intraoperative near-infrared fluorescence imaging to directly assess these parameters. The application of this technique has shown promise in perfusion assessment during esophagectomy, and potential reduction in anastomotic complications.

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.

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.

The Role of Intraoperative Fluorescence Imaging During Esophagectomy

Intraoperative fluorescence imaging (FI) with indocyanine green has several potential uses during esophagectomy. Intravascular injection for enhancing the visualization of conduit vascularity and assessing macro and microperfusion has the most literature support and may help reduce anastomotic leaks. Peritumoral injection has been reported for use in identifying sentinel nodes during lymphadenectomy and intralymphatic injection may be used to help preserve or ligate the thoracic duct. The authors' own technique of FI for conduit assessment is described. They routinely use this strategy to guide anastomosis placement and reduce leaks.

Fluorescent image-based evaluation of gastric conduit perfusion in a preclinical ischemia model

Background

This study evaluated near-infrared (NIR) fluorescent images to assess gastric conduit perfusion after an esophagectomy in a porcine model of gastric conduit ischemia. The time necessary to acquire a sufficient fluorescent signal to confirm ischemia in the gastric conduit after peripheral or central venous injection of indocyanine green (ICG) was also investigated.

Methods

A reversible gastric conduit ischemic pig model was established through ligation and release of the right gastroepiploic artery (RGEA, n=10). The esophageal reconstruction was performed to create an esophagogastric anastomosis. After ligation of the RGEA, ICG was injected into an ear vein (n=6) or the inferior vena cava (n=4). Under fluorescent imaging system guidance, the fluorescent signal-to-background ratio (SBR) in the gastric conduit or esophagus was measured during the entire procedure. We estimated the time necessary to acquire fluorescent signals in the gastric conduit using two different injection routes.

Results

When the RGEA was ligated, the SBR in the esophagus was significantly higher than that in the gastric conduit (P=0.02), and the SBR in the gastric conduit recovered within 180 s after release of the ligation. The time to acquire a fluorescent signal was faster with a central route than with a peripheral route (P=0.04).

Conclusions

We successfully created an ischemic animal model of the gastric conduit. Using this animal model, we evaluated the sensitivity and applicability of the fluorescent imaging system for observation and identification of ischemic areas during an esophagectomy.

Modified exposure method for gastric mobilization in robot-assisted esophagectomy

Background

We describe a modified method to facilitate gastric mobilization in robotic esophagectomy. Furthermore, we performed a prospective comparative analysis of surgical outcomes between the conventional method and described technique.

Methods

From April 1st, 2016 to December 31st, 2016, 59 consecutive patients were included who underwent robot-assisted McKeown esophagectomy for esophageal squamous cell carcinoma in our institution. They were subdivided into two groups based on the method of gastric exposure: a grasper retraction (GR) group (n=27) and a thread retraction (TR) group (n=32). For the GR patients, robotic instruments were directly used to expose the surgical field for gastric mobilization. However, for TR patients, the right gastroepiploic arcade and the short gastric vessels were fully exposed via a polyester tape combined with a thread loop.

Results

There was no incidence of postoperative 30-day mortality. The median gastric mobilization time was 53 min (range, 38-77 min). It took significantly less time in the TR group compared to the GR group (P=0.005). The median amount of blood loss was 8 mL (range, 5-14 mL), and no significant difference was found between the two groups (P=0.573). The median number of dissected lymph nodes was 10 (range, 7-16), and there was no significant difference between groups (P=0.386). Similarly, the postoperative morbidity rates did not statistically differ between the two groups (P=0.942).

Conclusions

The robot-assisted McKeown procedure presented is a safe and easy to perform technique for stomach retraction during gastric mobilization. Compared with the conventional GR method of gastric mobilization, TR requires less operating time and allows for an excellent operative field. The technique could, therefore, help surgeons to overcome some of the defects of robotic esophagectomy during gastric mobilization.

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.

Attaining Proficiency in Robotic-Assisted Minimally Invasive Esophagectomy While Maximizing Safety During Procedure Development

OBJECTIVE

Robotic-assisted minimally invasive esophagectomy (RAMIE) is an emerging complex operation with limited reports detailing morbidity, mortality, and requirements for attaining proficiency. Our objective was to develop a standardized RAMIE technique, evaluate procedure safety, and assess outcomes using a dedicated operative team and 2-surgeon approach.

METHODS

We conducted a study of sequential patients undergoing RAMIE from January 25, 2011, to May 5, 2014. Intermedian demographics and perioperative data were compared between sequential halves of the experience using the Wilcoxon rank sum test and the Fischer exact test. Median operative time was tracked over successive 15-patient cohorts.

RESULTS

One hundred of 313 esophageal resections performed at our institution underwent RAMIE during the study period. A dedicated team including 2 attending surgeons and uniform anesthesia and OR staff was established. There were no significant differences in age, sex, histology, stage, induction therapy, or risk class between the 2 halves of the study. Estimated blood loss, conversions, operative times, and overall complications significantly decreased. The median resected lymph nodes increased but was not statistically significant. Median operative time decreased to approximately 370 minutes between the 30th and the 45th cases. There were no emergent intraoperative complications, and the anastomotic leak rate was 6% (6/100). The 30-day mortality was 0% (0/100), and the 90-day mortality was 1% (1/100).

CONCLUSIONS

Excellent perioperative and short-term patient outcomes with minimal mortality can be achieved using a standardized RAMIE procedure and a dedicated team approach. The structured process described may serve as a model to maximize patients' safety during development and assessment of complex novel procedures.

Future directions in esophageal cancer therapy

Resection techniques for esophageal carcinoma continue to evolve, from endoscopic mucosal resection or endoscopic submucosal dissection for early stage disease to standard and robot-assisted minimally invasive esophagectomy as part of multimodal therapy for locally advanced disease. Though currently limited to assessing conduit perfusion and sentinel lymph nodes, embedded technology in the robotic surgical platform will likely play an expanded role during esophagectomy in the future. The use of targeted therapies, checkpoint inhibitors, engineered immune cell therapy, and cancer vaccines show promise in the treatment of systemic disease. Radiation therapy techniques are becoming increasingly sophisticated and they may play a more active role in stage IV disease in the future.

Emerging Trends in the Etiology, Prevention, and Treatment of Gastrointestinal Anastomotic Leakage

Anastomotic leaks represent one of the most alarming complications following any gastrointestinal anastomosis due to the substantial effects on post-operative morbidity and mortality of the patient with long-lasting effects on the functional and oncologic outcomes. There is a lack of consensus related to the definition of an anastomotic leak, with a variety of options for prevention and management. A number of patient-related and technical risk factors have been found to be associated with the development of an anastomotic leak and have inspired the development of various preventative measures and technologies. The International Multispecialty Anastomotic Leak Global Improvement Exchange group was convened to establish a consensus on the definition of an anastomotic leak as well as to discuss the various diagnostic, preventative, and management measures currently available.

Robotic surgery for upper gastrointestinal cancer: Current status and future perspectives

Robotic surgery with the da Vinci Surgical System has been increasingly applied in a wide range of surgical specialties, especially in urology and gynecology. However, in the field of upper gastrointestinal (GI) tract, the da Vinci Surgical System has yet to be standard as a result of a lack of clear benefits in comparison with conventional minimally invasive surgery. We have been carrying out robotic gastrectomy and esophagectomy for operable patients with resectable upper GI malignancies since 2009, and have demonstrated the potential advantages of the use of the robot in possibly reducing postoperative local complications including pancreatic fistula following gastrectomy and recurrent laryngeal nerve palsy after esophagectomy, even though there have been a couple of problems to be solved including longer duration of operation and higher cost. The present review provides updates on robotic surgery for gastric and esophageal cancer based on our experience and review of the literature.

Advances in fluorescent-image guided surgery

Fluorescence imaging is increasingly gaining intraoperative applications. Here, we highlight a few recent advances in the surgical use of fluorescent probes.

Initial report of near-infrared fluorescence imaging as an intraoperative adjunct for lymph node harvesting during robot-assisted laparoscopic gastrectomy

INTRODUCTION

Adequate lymphadenectomy is a fundamental aspect of oncologically sound gastrectomies. Robot-assisted laparoscopic gastrectomy is a minimally invasive alternative that allows functional imaging to be easily integrated to the surgical field and may aid in intraoperative identification of lymphovascular bundles.

METHODS

Indocyanine green application and near-infrared fluorescence imaging were used during robot-assisted laparoscopic gastrectomy as an adjunct for the identification of relevant lymph node basins in real time.

RESULTS

A total of 31 patients were included. Twenty-nine gastrectomies were performed for adenocarcinoma and two wedge resections for neuroendocrine tumors. The mean lymph node retrieval was twenty-nine (range 17-61) for adenocarcinoma and five for neuroendocrine tumors. In all cases, at least five lymph nodes were seen along the main nodal basins, which provided real time intraoperative feedback regarding lymph node identification. Average time for indocyanine green application and functional imaging was less than 10 min.

CONCLUSIONS

Near-infrared fluorescent imaging may provide an improved method to help visualize lymph nodes intraoperatively during robot-assisted laparoscopic gastrectomy, thus adding a potentially valuable adjunct for lymphadenectomy and overall lymph node retrieval. J. Surg. Oncol. 2016;113:768-770. © 2016 Wiley Periodicals, Inc.

Ischemic and injured bowel evaluation by Fluorescence imaging

AIM

Although fluorescence has been proposed for estimation of bowel perfusion decades ago it is still not widely used. In emergency situations like mesenteric ischemia, fluorescence might give objective criteria to evaluate the perfusion and guide the decisions of surgeons.

METHOD

The use of near-inrafrared angiography by PinPoint (Novadaq) in a serial of four emergency situations of acute mesenteric ischemia has been evaluated in a university hospital setting.

RESULTS

The use of the near-infrared tool is in emergency situations easy to handle and little time-consuming. The angiography showed clearly the perfusion in regions that were not estimated as recoverable by the surgeons. In one of the cases a significant amount of bowel could be spared by use of the system.

CONCLUSION

Although the assessment of the perfusion with the applied system is comprehensible, it would be desirable to evaluate a threshold level in order to further objectify it. While the surgeons who used the tool were subjectively assured by the expressiveness it would need a randomized and maybe experimental setting to evaluate objectively the amount of spared bowel length.

Fluorescence in robotic surgery

Currently, there are several clinical applications for intraoperative ICG, such as identification of vascular and biliary anatomy, assessment of organ and tissue perfusion, lymph node mapping, and real-time identification of lesions. In this paper we present a review of the available literature related to the use of ICG fluorescence in robotic surgery in order to provide a better understanding of the current applications, show the rapid growth of this technique, and demonstrate the potential future applications.