Indocyanine green angiography for evaluation of gastric conduit perfusion during esophagectomy--first experience

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.

Accurate intraoperative real-time blood flow assessment of the remnant stomach during robot-assisted distal pancreatectomy with celiac axis resection using indocyanine green fluorescence imaging and da Vinci Firefly technology

INTRODUCTION

Ischemic gastropathy is one of the unique postoperative complications associated with distal pancreatectomy with celiac axis resection for locally advanced pancreatic cancer. Therefore, it is essential to evaluate blood flow to the stomach following a resection; however, no intraoperative procedures have been established to assess this issue. Herein we describe two cases in which intraoperative evaluation of real-time blood flow in the residual stomach was performed using indocyanine green fluorescence and da Vinci Firefly technology during a robot-assisted distal pancreatectomy with celiac axis resection.

METHODS

Robot-assisted distal pancreatectomy with celiac axis resection was performed using a da Vinci Xi surgical system on two patients with locally advanced pancreatic cancer and suspected invasion of the celiac artery. Indocyanine green (ICG) (0.5 mg/kg) was injected intravenously after resection to evaluate real-time blood flow of the stomach using the da Vinci Firefly system. Blood flow of the stomach was evaluated 60 seconds after the intravenous injection of ICG.

RESULTS

All cases were confirmed that there was sufficient blood flow in the residual stomach. Therefore, reconstruction of the left gastric artery was not performed, and the surgery was completed with preservation of the stomach. Good postoperative outcomes were achieved and there was no evidence of ischemic gastropathy or delayed gastric emptying in both cases.

CONCLUSION

This method is very useful in determining whether or not to perform reconstruction of the left gastric artery and/or additional resection of the remnant stomach during a robot-assisted distal pancreatectomy with celiac axis resection.

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.

Laparoscopic real-time vessel navigation using indocyanine green fluorescence during laparoscopy-assisted gastric tube reconstruction: First experience

A considerable percentage of morbidity and mortality after oesophagectomy is due to leakage of oesophagogastrostomy, which is mainly caused by ischaemia of the gastric tube. Therefore, we performed laparoscopic real-time vessel navigation (LRTVN) using indocyanine green fluorescence (ICG) during laparoscopy-assisted gastric tube reconstruction (LAGR) to evaluate gastric tube blood flow and avoid vascular injury. This study included five oesophageal cancer patients who underwent video-assisted thoracoscopic oesophagectomy and LAGR. We confirmed the presence of the left gastroepiploic artery (LGEA) in all cases, and no findings such as post-operative gastric tube ischaemia were observed. In all cases, no vascular injury was observed, and the vascularization of LGEA was confirmed. This report is the first to consider the usefulness of LRTVN using ICG during LAGR. LRTVN using ICG during LAGR was considered to be useful for evaluating gastric tube blood flow and avoiding vascular injury around the splenic hiatus.

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.

Association between indocyanine green fluorescence blood flow speed in the gastric conduit wall and superior mesenteric artery calcification: predictive significance for anastomotic leakage after esophagectomy

BACKGROUND

Near-infrared fluorescence using indocyanine green (ICG) has been applied as a real-time navigation tool to observe blood flow in gastric conduit wall after esophagectomy. Atherosclerosis might impair the blood flow of the systemic organs. The aim of the study was to investigate the significances of ICG blood flow speed in the gastric conduit wall and atherosclerotic calcification for the prediction of anastomotic leakage after esophagectomy.

METHODS

The 109 esophageal cancer patients were prospectively enrolled. ICG fluorescence blood flow speed in the gastric conduit wall and abdominal aortic calcification index (ACI), celiac artery (CA) calcification, and superior mesenteric artery (SMA) calcification were determined. Then, the correlation between ICG fluorescence blood flow speed and anastomotic leakage as well as ACI, CA, and SMA calcification were evaluated.

RESULTS

Anastomotic leakage occurred in 15 patients. ACI ranged from 0 to 65. CA calcification and SMA calcification were present in 25 and 12 patients. Multivariate analysis demonstrated that ICG fluorescence blood flow speed in the gastric conduit wall of 2.07 cm/s or less (P < 0.001) and SMA calcification (P = 0.026) were the significant independent predictors of anastomotic leakage. Only SMA calcification was significantly associated with ICG fluorescence blood flow speed in the gastric conduit wall (P = 0.026).

CONCLUSIONS

This study demonstrated that ICG fluorescence blood flow speed in the gastric conduit wall can predict anastomotic leakage after esophagectomy and microvascular perfusion of capillary vessels of the gastric conduit might be impaired by systemic atherosclerosis.

Indocyanine green fluorescence imaging for subtotal esophagectomy due to esophageal stenosis after acute esophageal necrosis: a report of two cases

Although esophageal stricture after acute esophageal necrosis (AEN) is often refractory to dilation therapy, there have been few reports of surgical intervention. We report two rare cases of successful subtotal esophagectomy and esophagogastrostomy for esophageal strictures after AEN using indocyanine green (ICG) fluorescence imaging. In case 1, emergent esophagogastroduodenoscopy (EGD) in a 56-year-old man with coffee-ground emesis revealed black esophageal mucosa in the middle to lower esophagus, indicating AEN. Despite conservative therapy, an esophageal stricture developed after 2 weeks. Repeated endoscopic balloon dilation (EBD) did not resolve the stenosis; esophagectomy was thus performed approximately 6 months after AEN onset. We evaluated the blood flow to the esophagus using ICG fluorescence imaging to determine the proximal surgical resection line. The postoperative course was uneventful. In case 2, an 81-year-old woman with upper gastrointestinal bleeding with hematemesis and chest pain was diagnosed with AEN by EGD and was treated with conservative therapy. An esophageal stricture developed after 3 weeks, and repeated EBD was ineffective. Approximately 2 months after AEN onset, she underwent esophagectomy using ICG fluorescence imaging. The postoperative course was uneventful. Considering that AEN is a blood flow disorder, ICG fluorescence imaging is a useful technology to prevent surgical morbidity.

Validation of quantitative assessment of indocyanine green fluorescent imaging in a one-vessel model

Objectives

Evaluation of intestinal perfusion remains subjective and depends on the surgeon´s individual experience. Intraoperative quality assessment of tissue perfusion with indocyanine green (ICG) fluorescence using a near-infrared camera system has been described in different ways and for different indications. The aim of the present study was to evaluate fluorescent imaging (FI) in the quantitative assessment of intestinal perfusion in a gastric tube model in pigs and to compare the results to results obtained with florescent microspheres (FM), the gold standard for tissue perfusion.

Methods

Seven pigs (56.0±3.0 kg), both males and females, underwent gastric tube formation after transection and ligation of the gastric arteries, except the right gastroepiploic artery, to avoid collateral blood flow.

After baseline assessment (T0), hypotension (T1) was induced by propofol (Karampinis et al 2017) (< 60 mmHg). Then, propofol was paused to obtain normotension (T2, Mean arterial pressure (MAP) 60–90 mmHg). Finally, hypertension (T3, MAP>90 mmHg) was induced by norepinephrine.

Measurements were performed in three regions of interest (ROIs) under standardized conditions: the fundus (D1), corpus (D2), and prepyloric area (D3). Hemodynamic parameters and transit-time flow measurement (TTFM) in the right gastroepiploic artery were continuously assessed. FI, FM and the partial pressure of tissue oxygen (TpO₂) were quantified in each ROI.

Results

The study protocol could successfully be performed during stable hemodynamics. Flow in the gastroepiploic artery measured by transit time flow measurement (TTFM) was related to hemodynamic changes between the measurements, indicating improved blood flow with increasing MAP. The distal part of the gastric tube (D1) showed significantly (p<0.05) impaired perfusion compared to the proximal parts D3 and D2 using FM. ICG-FI also showed the highest values in D3 and the lowest values in D1 at all hemodynamic levels (T1-T3; p<0,05).

Conclusion

Visual and quantitative assessment of gastric tube perfusion is feasible in an experimental setting using ICG-FI. This might be a promising tool for intraoperative assessment during visceral surgery in the future.

Fluorescence Image-Based Evaluation of Gastric Tube Perfusion during Esophagogastrostomy

During esophagectomy and esophagogastrostomy, the prediction of anastomotic leakage relies on the operating surgeon's tactile or visual diagnosis. Therefore, anastomotic leaks are relatively unpredictable, and new intraoperative evaluation methods or tools are essential. A fluorescence imaging system enables visualization over a wide region of interest, and provides intuitive information on perfusion intraoperatively. Surgeons can choose the best anastomotic site of the gastric tube based on fluorescence images in real time during surgery. This technology provides better surgical outcomes when used with an optimal injection dose and timing of indocyanine green.

The role of indocyanine green fluorescence in bronchopleural fistula prevention

A 57-year-old woman with non-small-cell lung cancer qualified for pneumonectomy. At the start of the surgery, a pedicled intercostal muscle flap was harvested. Indocyanine green fluorescence revealed ischemia in the distal part of the flap. After pneumonectomy, the ischemic portion of the muscle was removed and the well-perfused proximal part was sutured to the bronchial stump. Reassessment with indocyanine green showed good perfusion of the flap. The postoperative period was uneventful, but follow-up bronchoscopy revealed bronchial suture line dehiscence with the muscle flap separating the bronchial lumen from the postpneumonectomy space. The bronchial stump healed spontaneously by secondary intention.

Impact of indocyanine green-fluorescence imaging on distal pancreatectomy with celiac axis resection combined with reconstruction of the left gastric artery

BACKGROUND

We previously reported the usefulness of distal pancreatectomy with celiac axis resection (DP-CAR) with left gastric artery (LGA) reconstruction to prevent ischemic gastropathy. To evaluate the reconstruction quality, we performed intraoperative angiography with indocyanine green (ICG)-fluorescence imaging.

METHODS

21 consecutive patients planned for DP-CAR with LGA reconstruction were enrolled in this prospective, exploratory single-arm study from 2014 to 2017. After LGA reconstruction, intraoperative angiography revealed continuous arterial flow passing through the anastomotic sites and gradually increasing tissue perfusion in the stomach.

RESULTS

Three patients were excluded. Among the remaining 18 patients, we obtained good flow in 11 patients and poor flow in 7 patients after initial LGA reconstruction. Among the seven patients with poor flow, five underwent LGA re-anastomosis, three recovered good flow. The incidence of grade B/C DGE was 14% (2/14) in the finally good flow group and 75% (3/4) in the poor flow group (p = 0.019). Ischemic gastropathy occurred in two patients (50%) in the poor flow group (p = 0.039), including one with a gastric perforation.

DISCUSSION

Our data show that intraoperative angiography with ICG-fluorescence imaging can evaluate the reconstruction quality, thus contributing to improvements in the short-term outcome of DP-CAR with LGA reconstruction.

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.

Utilization of indocynanine green fluorescent imaging (ICG-FI) for the assessment of microperfusion in vascular medicine

Intraoperative valuation of organ and tissue microperfusion is always a current topic in different surgical situations. Although indocyanine green fluorescent imaging (ICG-FI) has turned to be a more and more common technique to evaluate organ perfusion, only few studies tried to quantitatively validate the technique for microperfusion assessment. The aim of the following manuscript is to present the results of our interdisciplinary research confirming additional quantitative assessment tools in different surgical conditions. Thus, we are implementing the background-subtracted peak fluorescent intensity (BSFI), the slope of fluorescence intensity (SFI), and the time to slope (TTS) using ICG-FI in several regions of interest (ROI).

A practical guide for the use of indocyanine green and methylene blue in fluorescence-guided abdominal surgery

Near-infrared (NIR) fluorescence imaging is gaining clinical acceptance over the last years and has been used for detection of lymph nodes, several tumor types, vital structures and tissue perfusion. This review focuses on NIR fluorescence imaging with indocyanine green and methylene blue for different clinical applications in abdominal surgery with an emphasis on oncology, based on a systematic literature search. Furthermore, practical information on doses, injection times, and intraoperative use are provided.

Standardizing procedures improves and homogenizes short-term outcomes after minimally invasive esophagectomy

PURPOSE

Esophageal cancer is one of the deadliest cancers worldwide. Esophagectomy with lymphadenectomy is regarded as the only curative option for resectable esophageal cancer, but it is associated with high morbidity and mortality. Multidisciplinary team (MDT) management was recently associated with improved outcomes after surgery for esophageal cancer. The aim of this study was to investigate the effect of standardizing procedures for minimally invasive esophagectomy (MIE) in the MDT setting.

METHODS

This was a case-matched control study of 154 patients with esophageal cancer who underwent thoracoscopic esophagectomy in the prone position (TEP) between 2012 and 2016. Surgery was performed by two attending surgeons (surgeons A and B) who began working together in the same MDT in 2015. At that time, the following surgical procedures were standardized between surgeons A and B: mediastinal lymphadenectomy, abdominal procedures, and estimation of the blood supply of the gastric conduit. Short-term outcomes were compared between the following paired groups using propensity scores: surgeon A's pre- and post-standardization groups, surgeon B's pre- and post-standardization groups, and surgeon A's post-standardization group and surgeon B's post-standardization group.

RESULTS

Concerning surgeon A, the estimated total blood loss in the post-standardization group (142 ± 87 mL) was significantly lower than that in the pre-standardization group (376 ± 215 mL, P = 0.006). The rate of left recurrent laryngeal nerve palsy in the post-standardization group (13%) was significantly lower than that in the pre-standardization group (47%, P = 0.046). Concerning surgeon B, the rate of anastomotic leakage in the post-standardization group (0%) was significantly lower than that in the pre-standardization group (11%, P = 0.039). Comparing the post-standardization groups of surgeons A and B, there were no significant differences in operative outcomes or morbidity.

CONCLUSIONS

Standardizing procedures for MIE improved and homogenized surgical short-term outcomes.

Visualized Evaluation of Blood Flow to the Gastric Conduit and Complications in Esophageal Reconstruction

BACKGROUND

Evaluation of the blood supply to gastric conduits is critically important to avoid complications after esophagectomy. We began visual evaluation of blood flow using indocyanine green (ICG) fluorescent imaging in July 2015, to reduce reconstructive complications. In this study, we aimed to statistically verify the efficacy of blood flow evaluation using our simplified ICG method.

STUDY DESIGN

A total of 285 consecutive patients who underwent esophagectomy and gastric conduit reconstruction were reviewed and divided into 2 groups: before and after introduction of ICG evaluation. The entire cohort and 68 patient pairs after propensity score matching (PS-M) were evaluated for clinical outcomes and the effect of visualized evaluation on reducing the risk of complication.

RESULTS

The leakage rate in the ICG group was significantly lower than in the non-ICG group for each severity grade, both in the entire cohort (285 subjects) and after PS-M; the rates of other major complications, including recurrent laryngeal nerve palsy and pneumonia, were not different. The duration of postoperative ICU stay was approximately 1 day shorter in the ICG group than in the non-ICG group in the entire cohort, and approximately 2 days shorter after PS-M. Visualized evaluation of blood flow with ICG methods significantly reduced the rate of anastomotic complications of all Clavien-Dindo (CD) grades. Odds ratios for ICG evaluation decreased with CD grade (0.3419 for CD ≥ 1; 0.241 for CD ≥ 2; and 0.2153 for CD ≥ 3).

CONCLUSIONS

Objective evaluation of blood supply to the reconstructed conduit using ICG fluorescent imaging reduces the risk and degree of anastomotic complication.

Indocyanine green tissue angiography affects anastomotic leakage after esophagectomy. A retrospective, case-control study

PURPOSE

Optimal perfusion of the gastric conduit during esophagectomy is elementary for the anastomotic healing since poor perfusion has been associated with increased morbidity due to anastomotic leaks. Until recently surgical experience was the main tool to assess the perfusion of the anastomosis. We hypothesized that anastomoses located in the zone of optimal ICG perfusion of the gastric conduit ("optizone") have a reduced anastomotic leakage rate after esophagectomy.

METHODS

Indocyanine green (ICG) fluorescence tissue angiography was used to evaluate the anastomotic perfusion in 35 patients undergoing esophagectomy with gastric conduit reconstruction. The transition point of the "optizone" to the malperfused area of the conduit was defined macroscopically and with the use of ICG angiography during the operation. The anastomosis was performed in the optizone whenever possible. The results of the ICG patients were retrospectively reviewed and compared with 55 patients previously operated without ICG angiography.

RESULTS

The visual assessment of the conduit perfusion concurred with the ICG angiography in 27 cases. In 8 cases (22.8%) the ICG angiography deviated from the visual aspect. One case of anastomotic leakage was observed in the group of patients in which the anastomosis could be performed in the optizone (1/33; 3%) compared with 10 cases in the control group (18%; p = 0.04). In two cases we had to perform the anastomosis in an area of compromised ICG perfusion. Both patients developed an anastomotic leakage.

CONCLUSIONS

ICG tissue angiography represents a feasible and reliable technical support in the evaluation of the anastomotic perfusion after esophagectomy. In this retrospective analysis we observed a significant decrease in anastomotic leakage rate when the anastomosis could be placed in the zone of good perfusion defined by ICG fluorescence. A prospective trial is needed in order to provide higher level evidence for the use of ICG fluorescence in reducing leakage rates after esophagectomy.

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

Purpose

Identification of the infrapyloric artery (IPA) type is a key component of pylorus-preserving gastrectomy. As the indocyanine green (ICG) fluorescence technique is known to help visualize blood vessels and flow during reconstruction, we speculated that this emerging technique would be helpful in identifying the IPA type.

Materials and Methods

From August 2015 to February 2016, 20 patients who underwent robotic or laparoscopic gastrectomy were prospectively enrolled. After intravenous injection of approximately 3 mL of ICG (2.5 mg/mL), a near-infrared fluorescence apparatus was applied. The identified shape of the IPA was confirmed by examining the actual anatomy following infrapyloric dissection.

Results

The mean interval time between ICG injection and visualization of the artery was 22.2 seconds (range, 14–30 seconds), and the mean duration of the arterial phase was 16.1 seconds (range, 9–30 seconds). The overall positive predictive value (PPV) of ICG fluorescence in identifying the IPA type was 80% (16/20). The IPA type was incorrectly predicted in four patients, all of whom were obese with a body mass index (BMI) of more than 25 kg/m².

Conclusions

Our preliminary results indicate that intraoperative vascular imaging using the ICG fluorescence technique may be helpful for robotic or laparoscopic pylorus-preserving gastrectomy.

Blood flow speed of the gastric conduit assessed by indocyanine green fluorescence: New predictive evaluation of anastomotic leakage after esophagectomy

Anastomotic leakage is considered as an independent risk factor for postoperative mortality after esophagectomy, and an insufficient blood flow in the reconstructed conduit may be a risk factor of anastomotic leakage. We investigated the clinical significance of blood flow visualization by indocyanine green (ICG) fluorescence in the gastric conduit as a means of predicting the leakage of esophagogastric anastomosis after esophagectomy.Forty patients who underwent an esophagectomy with gastric conduit reconstruction were prospectively investigated. ICG fluorescence imaging of the gastric conduit was detected by a near-infrared camera system during esophagectomy and correlated with clinical parameters or surgical outcomes.In 25 patients, the flow speed of ICG fluorescence in the gastric conduit wall was simultaneous with that of the greater curvature vessels (simultaneous group), whereas in 15 patients this was slower than that of the greater curvature vessels (delayed group). The reduced speed of ICG fluorescence stream in the gastric conduit wall was associated with intraoperative blood loss (P = 0.008). Although anastomotic leakage was not found in the simultaneous group, it occurred in 7 patients of the delayed group (P < 0.001). A flow speed of ICG fluorescence in the gastric conduit wall of 1.76 cm/s or less was determined by a receiver operating characteristic (ROC) curve, identified as a significant independent predictor of anastomotic leakage after esophagectomy (P = 0.004).This preliminary study demonstrates that intraoperative evaluation of blood flow speed by ICG fluorescence in the gastric conduit wall is a useful means to predict the risk of anastomotic leakage after esophagectomy.

Indocyanine green fluorescence angiography for intraoperative assessment of gastrointestinal anastomotic perfusion: a systematic review of clinical trials

PURPOSE

Anastomotic leakage following gastrointestinal surgery remains a frequent and serious complication associated with a high morbidity and mortality. Indocyanine green fluorescence angiography (ICG-FA) is a newly developed technique to measure perfusion intraoperatively. The aim of this paper was to systematically review the literature concerning ICG-FA to assess perfusion during the construction of a primary gastrointestinal anastomosis in order to predict anastomotic leakage.

METHODS

The following four databases PubMed, Scopus, Embase, and Cochrane were independently searched by two authors. Studies were included in the review if they assessed anastomotic perfusion intraoperatively with ICG-FA in order to predict anastomotic leakage in humans.

RESULTS

Of 790 screened papers 14 studies were included in this review. Ten studies (n = 916) involved patients with colorectal anastomoses and four studies (n = 214) patients with esophageal anastomoses. All the included studies were cohort studies. Intraoperative ICG-FA assessment of colorectal anastomoses was associated with a reduced risk of anastomotic leakage (n = 23/693; 3.3 % (95 % CI 1.97-4.63 %) compared with no ICG-FA assessment (n = 19/223; 8.5 %; 95 % CI 4.8-12.2 %). The anastomotic leakage rate in patients with esophageal anastomoses and intraoperative ICG-FA assessment was 14 % (n = 30/214). None of the studies involving esophageal anastomoses had a control group without ICG-FA assessment.

CONCLUSION

No randomized controlled trials have been published. ICG-FA seems like a promising method to assess perfusion at the site intended for anastomosis. However, we do not have the sufficient evidence to determine that the method can reduce the leak rate.

Management of Conduit Necrosis Following Esophagectomy

The management of conduit necrosis during or after esophagectomy requires the assembly of a multidisciplinary team to manage nutrition, sepsis, intravenous access, reconstruction, and recovery. Reconstruction is most often performed as a staged procedure. The initial surgery is likely to involve esophageal diversion onto the chest where possible, making an effort to preserve esophageal length. Optimization of patients before reconstruction enhances outcomes following reconstruction with either jejunum or colon after gastric conduit failure. Maintaining enteral access for feeding at all times is imperative. Management of patients should be performed at high-volume esophageal centers performing regular reconstructions.

Intraoperative near-infrared fluorescence imaging as an adjunct to robotic-assisted minimally invasive esophagectomy

During esophagectomy, identification and preservation of the right gastroepiploic vascular arcade are critical and may be challenging with minimally invasive approaches. We assessed the use of near-infrared fluorescence imaging fluorescence angiography (NIFI-FA) during robotic-assisted minimally invasive esophagectomy (RAMIE) as an aid to visualize the gastric vasculature with mobilization. After intravenous administration of 10 mg of indocyanine green, a robotic platform with near-infrared optical fluorescence capability was used to examine the gastric vasculature in patients undergoing RAMIE. Thirty (71%) of 42 patients undergoing RAMIE were assessed using NIFI-FA during mobilization of the greater gastric curve and fundus; 11 were excluded because the system was not available, and 1 was excluded because of documented allergy to iodinated contrast. The median time from indocyanine green administration to detectable fluorescence was 37.5 seconds (range, 20-105 seconds). Near-infrared fluorescence imaging FA identified or confirmed termination of the vascular arcade in all 30 cases. Subjectively, NIFI-FA often identified otherwise unvisualized small transverse vessels between the termination of the vascular arcade and the first short gastric artery, as well as between the short gastric arteries. Identification and/or confirmation of the vascular arcade position during mobilization of the greater curve/omentum were also aided by NIFI-FA. Although there are limitations to the current technology, NIFI-FA may be a useful adjunct to confirm and identify the position of gastroepiploic vessels, allow for safer and more confident dissections during gastric mobilization, as well as potentially decrease serious intraoperative vascular misadventures.

Visualization of blood supply route to the reconstructed stomach by indocyanine green fluorescence imaging during esophagectomy

Background

Ensuring an adequate blood supply is essential to the safe performance of an anastomosis during esophagectomy and the prevention of anastomotic leakage. Recently, indocyanine green (ICG) fluorescence imaging has been used to visualize the blood supply when anastomosis is performed in vascular surgery. We used ICG fluorescence imaging to visualize the blood supply for reconstruction during esophagectomy.

Methods

Since January 2009, we have performed ICG fluorescence imaging in 33 patients with thoracic esophageal cancer who underwent thoracic esophagectomy. After pulling up the reconstructed stomach, 2.5 mg of ICG was injected as a bolus. ICG fluorescence imaging was performed with a near-infrared camera, and the images were recorded.

Results

ICG fluorescence was easily detected in all patients 1 min after injection. Vascular networks were well visualized in the gastric wall and omentum. The blood supply route was located in the greater omentum beside the splenic hilum in 22 (66.7%) of the 33 patients.

Conclusions

ICG fluorescence can be used to evaluate the blood supply to the reconstructed stomach in patients undergoing esophagectomy for esophageal cancer. On ICG fluorescence imaging, the splenic hiatal vessels were the major blood supply for the anastomosis in most patients.

An outcome analysis of intraoperative angiography for postmastectomy breast reconstruction

BACKGROUND

Intraoperative angiography is a useful tool for predicting both tissue perfusion during postmastectomy breast reconstruction and mastectomy flap and free flap survival.

OBJECTIVES

The authors determine whether the routine use of laser-assisted indocyanine green (ICG) fluorescence angiography (SPY Imaging; LifeCell Corp, Branchburg, New Jersey) in breast reconstruction decreases the incidence of complications and whether this new technology is cost-effective.

METHODS

A retrospective review was conducted for 184 consecutive patients who underwent breast reconstruction using intraoperative ICG angiography from April 2009 to December 2011 at Emory University (Atlanta, Georgia). The incidence of complications (including mastectomy skin necrosis, flap necrosis, fat necrosis, unexpected reoperations, infections, and dehiscence) among these patients was compared with data for 184 consecutive patients who underwent breast reconstruction at Emory University from October 2007 to April 2009, prior to the introduction of ICG angiography. Patient data recorded included age, body mass index, smoking status, and history of preoperative radiation as well as the timing and type of reconstruction, along with complications. The cost of unexpected reoperations for perfusion-related complications and associated hospital stays was calculated.

RESULTS

The 184 patients who underwent procedures using ICG angiography imaging had a lower incidence of mastectomy skin necrosis (13% vs 23.4%; P = .010) and unexpected reoperations for perfusion-related complications (5.9% vs 14.1%, P = .009). The 184 patients who underwent procedures without ICG angiography had a higher mean degree of severity of mastectomy skin necrosis (2.22 vs 1.83 on a scale of 1-3; P = .065). There were no significant differences in the degree of flap necrosis, nipple necrosis, fat necrosis, dehiscence, infection, implant exposure, flap loss, seroma, hematoma, or the number of overall complications between the 2 groups. The use of ICG angiography saved patients an average of $610.

CONCLUSIONS

The use of ICG angiography during postmastectomy breast reconstruction decreased the incidence and severity of mastectomy skin necrosis as well as the incidence of unexpected reoperations for perfusion-related complications. The technology was found to be cost-effective.