Gastric Conduit Perfusion Research Articles

Oxygen Saturation Endoscopic Imaging as a Novel Alternative to Assess Tissue Perfusion During Esophagectomy.

Assessment of gastric conduit perfusion during esophagectomy is crucial to determine its viability and identify the optimal site for anastomosis. Indocyanine green (ICG) fluorescence imaging is commonly used for this purpose, but it is contraindicated in patients with hypersensitivity to ICG, iodine, or shellfish. Oxygen saturation endoscopic imaging (OXEI) is a newer, non-pharmacologic technique for assessing perfusion. We report our experience with OXEI in 3 esophagectomy patients who had contraindications to ICG. All 3 patients underwent robot-assisted esophagectomies. None of the conduits had ischemic areas identified by white light. Using a 5mm laparoscopic specialized camera (ELUXEO Vision, FUJIFILM Healthcare Americas Corp., USA), OXEI was deployed for intracorporeal assessment of gastric conduit perfusion after pull-up into the chest. Postoperative outcomes including anastomotic leaks and complications were recorded. In two patients, OXEI revealed ischemic zones, which were resected to ensure optimal conduit viability. In the remaining patient, OXEI indicated robust vascularity throughout the conduit. All three patients experienced uneventful postoperative courses and were discharged within 10 days. There were no instances of anastomotic leaks or other major complications. In our experience, OXEI is a viable method for intraoperative assessment of gastric conduit perfusion in patients with contraindications to ICG. Prospective studies are needed to validate its efficacy in preventing anastomotic complications and to compare it with other methods of perfusion assessment including gross visual and ICG dye in a larger patient population.

Modification of the lesser curvature incision line enhanced gastric conduit perfusion as determined by indocyanine green fluorescence imaging and decreased the incidence of anastomotic leakage following esophagectomy

Abstract Aim This study aimed to investigate the effectiveness of a modified incision line on the lesser curvature for gastric conduit formation during esophagectomy in enhancing the perfusion of gastric conduit as determined by indocyanine green fluorescence imaging and reducing the incidence of anastomotic leakage. Methods A total of 272 patients who underwent esophagectomy at our institute between 2014 and 2022 were enrolled in this study. These patients were divided based on two different types of cutlines on the lesser curvature: conventional group (n = 141) following the traditional cutline and modified group (n = 131) adopting a modified cutline. Gastric conduit perfusion was assessed by ICG fluorescence imaging, and clinical outcomes after esophagectomy were evaluated. Results The distance from the pylorus to the cutline was significantly longer in the modified group compared with the conventional group (median: 9.0 cm vs. 5.0 cm, p < 0.001). The blood flow speed in the gastric conduit wall was significantly higher in the modified group than that in the conventional group (median: 2.81 cm/s vs. 2.54 cm/s, p = 0.001). Furthermore, anastomotic leakage was significantly lower (p = 0.024) and hospital stay was significantly shorter (p < 0.001) in the modified group compared with the conventional group. Multivariate analysis identified blood flow speed in the gastric conduit wall as the only variable significantly associated with anastomotic leakage. Conclusions ICG fluorescence imaging is a feasible, reliable method for the assessment of gastric conduit perfusion. Modified lesser curvature cutline could enhance gastric conduit perfusion, promote blood circulation around the anastomotic site, and reduce the risk of anastomotic leakage after esophagectomy.

400. MODIFICATION OF THE LESSER CURVATURE INCISION ENHANCES GASTRIC CONDUIT BLOOD FLOW AND DECREASE ANASTOMOTIC LEAKAGE RISK AFTER ESOPHAGECTOMY

Abstract Background We conducted this study to investigate the effectiveness of a modified incision line on the lesser curvature for gastric conduit formation during esophagectomy in enhancing the perfusion of the gastric conduit, as determined by indocyanine green (ICG) fluorescence imaging, and reducing the incidence of anastomotic leakage. Methods A total of 272 patients who underwent esophagectomy at our institution between June 2014 and August 2022 were enrolled in the study. The patients were divided into two groups in accordance with the type of cutline on the lesser curvature: the Conventional group, consisting of patients operated on until 2018 (Conventional group; n = 141), in which the traditional cutline (5.0 cm from the pylorus in routine) was adopted, and the Current group, consisting of patients operated on from 2019 until date (Current group; n = 131), in which a modified cutline on the lesser curvature was adopted, that allowed preservation of the entire right gastric artery was adopted (hereinafter, modified cutline) was adopted. Gastric conduit perfusion during the surgery was assessed by intraoperative ICG fluorescence imaging, and the clinical outcomes after esophagectomy were also evaluated. Results All patients underwent esophagectomy with regional lymph node dissection and gastric conduit reconstruction via the retrosternal route. The distance from the pylorus to the cutline was significantly longer in the Current group as compared with the Conv group (median: 9.0 cm vs. 5.0 cm, p < 0.001). The blood flow speed in the gastric conduit wall assessed by ICG fluorescence imaging was significantly higher in the Current group than that in the Conventional group (median: 2.81 cm/sec vs. 2.54 cm/sec, p = 0.001). Furthermore, the incidence of anastomotic leakage was significantly lower (p = 0.024) and the hospital stay significantly shorter (p < 0.001) in the Current group as compared with the Conventional group. Logistic regression analysis using the data of the entire cohort identified the blood flow velocity in the gastric conduit wall as the only variable that was significantly (negatively) associated with anastomotic leakage. Conclusions ICG fluorescence imaging is a feasible, reliable method for intraoperative assessment of gastric conduit perfusion. Use of the modified lesser curvature cutline could enhance gastric conduit perfusion, promote blood circulation around the anastomosis and ultimately reduce the risk of anastomotic leakage after esophagectomy.

Indocyanine Green (ICG) fluorescence angiography of gastric conduit for reconstruction after esophagectomy: a single center prospective study

Introduction: Esophageal cancer ranks among the most aggressive neoplasms worldwide and is a significant contributor to cancer-related mortality. Surgical intervention through esophagectomy with radical lymph node dissection remains a cornerstone in the curative treatment of mid and lower esophageal and gastroesophageal junction tumors, often preceded by neoadjuvant therapy tailored to histological type. Anastomotic leak (AL) following gastroesophageal anastomosis is a major complication associated with substantial morbidity and mortality. Methods: A prospective study was conducted on 30 patients undergoing esophagectomy with gastric conduit reconstruction from May 2023 to April 2024. Gastroesophageal anastomosis was placed at neck. Intraoperatively, indocyanine green (ICG) fluorescence angiography was employed to assess gastric conduit perfusion. The anastomosis site was selected based on ICG fluorescence dynamics, aiming for anastomosis within 45 seconds of ICG enhancement. Results: The study cohort comprised predominantly male patients (60%) with a mean age of 60.67 years. Most patients presented with squamous cell carcinoma (66.67%), primarily located in the lower esophagus and minimally invasive surgery was predominantly performed. Mean ICG fluorescence angiography time was 32.1 seconds. Anastomotic leak occurred in 23.3% of patients, correlating with significantly longer hospital stays (p=0.005). Although ICG fluorescence angiography was used to guide anastomosis based on perfusion assessment, there was no statistically significant reduction in AL rates observed in this study (p=0.471). Conclusion: In conclusion, while ICG fluorescence angiography represents an innovative approach to evaluating gastric conduit perfusion during esophagectomy, its direct impact on reducing AL in our study was not statistically significant.

Effects of endoluminal vacuum sponge therapy on the perfusion of gastric conduit in a porcine model for esophagectomy.

After esophagectomy, the postoperative rate of anastomotic leakage is up to 30% and is the main driver of postoperative morbidity. Contemporary management includes endoluminal vacuum sponge therapy (EndoVAC) with good success rates. Vacuum therapy improves tissue perfusion in superficial wounds, but this has not been shown for gastric conduits. This study aimed to assess gastric conduit perfusion with EndoVAC in a porcine model for esophagectomy. A porcine model (n = 18) was used with gastric conduit formation and induction of ischemia at the cranial end of the gastric conduit with measurement of tissue perfusion over time. In three experimental groups EndoVAC therapy was then used in the gastric conduit (- 40, - 125, and - 200 mmHg). Changes in tissue perfusion and tissue edema were assessed using hyperspectral imaging. The study was approved by local authorities (Project License G-333/19, G-67/22). Induction of ischemia led to significant reduction of tissue oxygenation from 65.1 ± 2.5% to 44.7 ± 5.5% (p < 0.01). After EndoVAC therapy with - 125 mmHg a significant increase in tissue oxygenation to 61.9 ± 5.5% was seen after 60 min and stayed stable after 120 min (62.9 ± 9.4%, p < 0.01 vs tissue ischemia). A similar improvement was seen with EndoVAC therapy at - 200 mmHg. A nonsignificant increase in oxygenation levels was also seen after therapy with - 40 mmHg, from 46.3 ± 3.4% to 52.5 ± 4.3% and 53.9 ± 8.1% after 60 and 120 min respectively (p > 0.05). An increase in tissue edema was observed after 60 and 120 min of EndoVAC therapy with - 200 mmHg but not with - 40 and - 125 mmHg. EndoVAC therapy with a pressure of - 125 mmHg significantly increased tissue perfusion of ischemic gastric conduit. With better understanding of underlying physiology the optimal use of EndoVAC therapy can be determined including a possible preemptive use for gastric conduits with impaired arterial perfusion or venous congestion.

Evaluation of the gastric conduit perfusion using indocyanine green in thoracoscopic esophagectomy for esophageal cancer.

Indocyanine green has been used in the assessment of the gastric conduit perfusion in thoracoscopic esophagectomy to prevent malperfusion-associated anastomotic leak. This study aims to evaluate the initial results of investigating the gastric conduit perfusion with indocyanine green in the surgical treatment of esophageal cancer. This cross-sectional descriptive study was carried out on 54 esophageal cancer patients undergoing thoracoscopic esophagectomy and gastric conduit reconstruction. The blood flow in the gastric conduit was observed using an infrared camera and indocyanine green after completion of the conduit and after tunneling the conduit through the mediastinum to the neck. The gastric conduit width and length were 5.2 ± 0.3 cm, and 31.5 ± 1.6 cm, respectively. The length of the gastric conduit from the junction between the right and left gastroepiploic to the point where the distal end of the gastric conduit still has a vascular pulse was 11.9 ± 4.3 cm. Seventeen patients (31.5%) had poor blood supply at the distal end of the gastric conduit, with indocyanine green appearance time ⩾ 60 s, in whom anastomotic leaks occurred in five patients (9.3%). The lack of connection between the right and left gastroepiploic vessels was associated with poor blood supply of the distal gastric conduit (p = 0.04). Multivariable logistic regression analysis showed association between the time of indocyanine green appearance at the distal gastric conduit and the risk of anastomotic leak (OR = 1.99, 95% CI = 1.10-3.60, p = 0.02). Investigation of gastric conduit perfusion using indocyanine green in gastric conduit reconstruction detected 31.5% of patients with poor blood supply at the distal end of the conduit, in whom 9.3% had anastomotic leak. The longer indocyanine green appearance time in the distal gastric conduit (segment BC), was associated with the higher rate of the anastomotic leak.

Novel Uses of Indocyanine Green in Thoracic Surgery: A Review and Case Series.

Indocyanine green (ICG) is a water-soluble molecule that emits fluorescence in the near-infrared light spectrum. Due to its fluorescence properties, safety profile, and cost-effectiveness, ICG is used in minimally invasive surgery, enabling real-time visualization of structures during the operation. Until recently, its use was mainly limited to robotic surgery, which required specific technological setups to visualize the fluorescence. With recent technological advancements, however, similar capabilities can now be integrated into smaller laparoscopic instruments, broadening the accessibility and usefulness of ICG. In this article, we present various innovative applications of ICG in thoracic surgery, drawing from recent developments in the field and our own experiences. Specifically, we focus on the novel role of ICG in the evaluation of gastric conduit perfusion, lung nodule localization, and thoracic duct ligation.

The Use of Indocyanine Green to Visualize the Thoracic Duct and Evaluate Gastric Conduit Perfusion in Esophagectomy

Background: In this study, we investigate indocyanine green (ICG) dye visualization of the thoracic duct (TD) and conduit perfusion during esophagectomy to reduce anastomotic leak (AL) and chylothorax adverse events (AEs). Methods: Retrospective data of adult patients who underwent esophagectomy for esophageal carcinoma between July 2019 and 2022 were included (n = 105). ICG was delivered intravenously (2 mL, 2.5 mg/mL) to assess conduit perfusion into the small bowel mesentery, inguinal lymph nodes, or foot web spaces for TD visualization using fluorescence imaging. Incidence of TD injury, chylothorax, AL, and AEs were collected. Results: A total of 23 patients received ICG (ICG for TD and perfusion (n = 12) and perfusion only (n = 11)), while 82 patients were controls. TD was visualized in 6 of 12 patients who received ICG for TD. No intraoperative TD injuries or postoperative chylothoraces occurred in these patients. Non-ICG patients had 1 (1.22%) intraoperative TD injury and 10 (12.2%) postoperative chylothoraces (grade I–IIIb). While 10 non-ICG patients (12.2%) developed AL (grade I–IVb), only 2 (8.7%) ICG patients developed AL (grade IIIa). Conclusions: This study demonstrates the utility of ICG fluorescence in intraoperative TD and conduit perfusion assessment for limiting AEs. Standard incorporation of ICG in esophagectomy may help surgeons improve the quality of care in this patient population.

374. RADIOGRAPHICALLY-DETERMINED FRAILTY IS ASSOCIATED WITH IMPAIRED GASTRIC CONDUIT PERFUSION DURING ESOPHAGECTOMY

Abstract Background Frailty is considered a preoperative risk factor for complications after esophagectomy while impaired gastric conduit perfusion is associated with anastomotic leaks. Patients with impaired conduit perfusion may be candidates for gastric ischemic preconditioning, a surgical procedure performed prior to definitive esophagectomy to improve gastric conduit perfusion. The aim of this study was to investigate the association between radiographic determinants of frailty (morphomics) and gastric conduit perfusion assessed during esophagectomy. Methods Patients undergoing an esophagectomy with a cervical esophagogastric anastomosis (2015–2021) were included. Preoperative CT scans were processed using semiautomated algorithms (MATLAB; MathWorks, MA) to assess skeletal muscle (cross-sectional area, Martin’s criteria), subcutaneous fat (cross-sectional area, decreased when below the cut-off) and bone mineral density (decreased when below the cut-off). Indocyanine green perfusion was assessed intraoperatively (SPY Elite; Stryker, MI) and Ingress Index was calculated (standardized perfusion at the evaluated point). The morphomic index (MI), as an indicator of frailty, was determined using the number of decreased morphomic factors present (0–3). Multiple linear regression was used to analyze the data. Results One hundred and thirty-six patients were evaluated, with 25 patients developing anastomotic leaks (18.4%). Morphomic indices (MIs) of 2 or 3 were independently associated with reduced Ingress Index (p = 0.019 and 0.004, Table). In a sub-analysis for MI, MIs of 2 or 3 were associated with higher age (p = 0.029), lower BMI (p = 0.003), and cardiovascular disease (myocardial infarction, chronic heart failure, and vascular disease, p = 0.017). Other patient demographic factors including age, sex, and comorbidities did not affect Ingress Index. Conclusion Higher Morphomic Index (indicating lower than normal radiographic measures) were associated with impaired gastric conduit perfusion. More patients will be needed to investigate whether increased MI also is associated with development of anastomotic leaks. These findings may be useful in risk stratification and preoperative decision making in patients undergoing esophagectomy. Patients with MI of 2 or higher should be considered for gastric ischemic preconditioning.

The use of indocyanine green (ICYG) angiography intraoperatively to evaluate gastric conduit perfusion during esophagectomy: does it impact surgical decision-making?

Ischemia is known to be a major contributor for anastomotic leaks and indocyanine green (ICYG) fluorescence angiography has been utilized to assess perfusion. Experienced esophageal surgeons have clinically assessed the gastric conduit with acceptable outcomes for years. We sought to examine the impact of ICYG in a surgeon's decision-making during esophagectomy. We queried a prospectively maintained database to identify patients who underwent robotic esophagectomy. Time to initial perfusion, time to maximum perfusion, and residual ischemia were measured and used as a guide to resection of residual stomach. During esophagectomy the surgeon identified the anticipated line of ischemic demarcation (LOD) prior to ICYG injection. The distance between the surgeon's LOD and ICYG LOD was measured. We identified 312 patients who underwent robotic esophagectomy, 251 without ICYG and 61 with ICGY. There were no differences in age, sex, race, body mass index, histology, stage, or neoadjuvant therapy use between groups. The incidence of anastomotic leak did not differ between groups (non-ICYG, 5.2% vs. ICYG, 6.6%), p = 0.67. The initial perfusion time was ≥ 10s and max perfusion was > 25s in all the patients in the ICYG that developed anastomotic leaks. All patients were noted to have at least 1cm of residual gastric ischemia. Fifteen patients underwent independent surgeon evaluation of the ischemic LOD prior to ICYG. Differential distances were noted in 12 (80%) patients with a mean distance between surgical line of demarcation and ICYG LOD of 0.77cm. While the implementation of ICYG during esophagectomy demonstrates no significant improvements in anastomotic leak rates compared to historical controls, surgeon's decision-making is impacted in 80% of cases resulting in additional resection of the gastric conduit. Elevated times to initial perfusion and maximum perfusion were associated with increased gastric ischemia and anastomotic leaks.

Quantitative assessment of gastric ischemic preconditioning on conduit perfusion in esophagectomy: propensity score weighting study.

Gastric ischemic preconditioning prior to esophagectomy has been studied as a method to improve gastric conduit perfusion and reduce anastomotic complications, without conclusive results. The aim of this study is to evaluate the feasibility and safety of gastric ischemic preconditioning in terms of post-operative outcomes and quantitative gastric conduit perfusion. Patients who underwent an esophagectomy with gastric conduit reconstruction between January 2015 and October 2022 at a single high-volume academic center were reviewed. Patient characteristics, surgical approach, post-operative outcomes, and indocyanine green fluorescence angiography data (ingress index for arterial inflow and ingress time for venous outflow, and the distance from the last gastroepiploic branch to the perfusion assessment point) were analyzed. Two propensity score weighting methods were used to investigate whether gastric ischemic preconditioning reduces anastomotic leaks. Multiple linear regression analysis was used to evaluate the conduit perfusion quantitatively. There were 594 esophagectomies with gastric conduit performed, with 41 having a gastric ischemic preconditioning. Among 544 with cervical anastomoses, leaks were seen in 2/30 (6.7%) in the ischemic preconditioning group and 114/514 (22.2%) in the control group (p = 0.041). Gastric ischemic preconditioning significantly reduced anastomotic leaks on both weighting methods (p = 0.037 and 0.047, respectively). Ingress index and time of the gastric conduit with ischemic preconditioning were significantly better than those without preconditioning (p = 0.013 and 0.025, respectively) after removing the effect of the distance from the last gastroepiploic branch to the perfusion assessment point. Gastric ischemic preconditioning results in a statistically significant improvement in conduit perfusion and reduction in post-operative anastomotic leaks.

Optimization of anastomotic technique and gastric conduit perfusion with hyperspectral imaging and machine learning in an experimental model for minimally invasive esophagectomy

IntroductionEsophagectomy is the mainstay of esophageal cancer treatment, but anastomotic insufficiency related morbidity and mortality remain challenging for patient outcome. Therefore, the objective of this work was to optimize anastomotic technique and gastric conduit perfusion with hyperspectral imaging (HSI) for total minimally invasive esophagectomy (MIE) with linear stapled anastomosis. Material and methodsA live porcine model (n = 58) for MIE was used with gastric conduit formation and simulation of linear stapled side-to-side esophagogastrostomy. Four main experimental groups differed in stapling length (3 vs. 6 cm) and simulation of anastomotic position on the conduit (cranial vs. caudal). Tissue oxygenation around the anastomotic simulation site was evaluated using HSI and was validated with histopathology. ResultsThe tissue oxygenation (ΔStO2) after the anastomotic simulation remained constant only for the short stapler in caudal position (−0.4 ± 4.4%, n.s.) while it was impaired markedly in the other groups (short-cranial: −15.6 ± 11.5%, p = 0.0002; long-cranial: −20.4 ± 7.6%, p = 0.0126; long-caudal: −16.1 ± 9.4%, p < 0.0001). Tissue samples from avascular stomach as measured by HSI showed correspondent eosinophilic pre-necrotic changes in 35.7 ± 9.7% of the surface area. ConclusionTissue oxygenation at the site of anastomotic simulation of the gastric conduit during MIE is influenced by stapling technique. Optimal oxygenation was achieved with a short stapler (3 cm) and sufficient distance of the simulated anastomosis to the cranial end of the gastric conduit. HSI tissue deoxygenation corresponded to histopathologic necrotic tissue changes. The experimental model with HSI and ML allow for systematic optimization of gastric conduit perfusion and anastomotic technique while clinical translation will have to be proven.

The first experience of fluorescent angiography with indocyanine green in primary esophagoplasty with gastric conduit in patients with malignant tumors of the esophagus

To evaluate the possibilities of intraoperative indocyanine green fluorescein angiography (ICG technology) in primary esophagoplasty by gastric conduit in patients with malignant tumors of the esophagus. The study included 74 patients. Depending on the localization of the tumor in the esophagus, a Lewis-type or McKeown-type operation was performed. The retrospective group (surgery without the use of ICG technology) included 53 patients who underwent surgery from 2015 to 2020 years.The prospective group (surgery with the use ICG technology) included 21 patients operated on from 2021 to 2023 years. ICG technology was used to assess microcirculation in the gastric conduit during esophagoplasty, as well as to identify the right gastroepiploic artery. The ICG fluorescein angiography technique for assessing microcirculation in the gastric conduit was a simple and easily reproducible procedure. Perfusion of the gastric conduit was regarded as satisfactory in 16 (76%) cases, unsatisfactory in 5 (24%) cases, which required resection of the distal part of the conduit. All cases of poor perfusion were in patients with narrow gastric conduit and neck anastomosis location (McKeown-type operation). Anastomotic leakages occurred in 8 (15%) patients in the retrospective group, 4 (19%) patients in the prospective group (p>0.05). In 4 out of 5 cases of poor gastric conduit perfusion, anastomotic leaks occurred. Immediate postoperative results in the compared groups were also comparable. The use of ICG technology in 5 (45%) cases out of 11, when laparoscopic mobilization of the stomach was performed, helped to visualize the right gastroepiploic artery, which is the main source of blood supply to the formed gastric conduit. The use of ICG technology in 3 patients with a compromised gastrostomy stomach demonstrated the absence of significant microcirculation disorders in the stomach wall. The first experience of using fluorescein angiography with ICG in primary esophagoplasty by gastric conduit in patients with malignant tumors of the esophagus demonstrated the safety, simplicity and availability of this technique. An objective assessment of the effectiveness of the application of ICG technology requires the accumulation of experience.

Wider Gastric Conduit Morphology Is Associated with Improved Blood Flow During Esophagectomy

BackgroundIt remains unclear what is the ideal conduit shape. The aim of this study was to evaluate association between specific gastric conduit morphology, considering width and length, with its perfusion and the incidence of anastomotic leaks after esophagectomy. MethodsPatients who underwent an esophagectomy with cervical esophagogastric anastomosis between 2015 and 2021 were evaluated. Indocyanine green angiography was performed to evaluate gastric conduit perfusion, and ingress index (arterial inflow) and ingress time (venous outflow) were measured. The conduit width at the middle of the conduit and the short gastric length as the length from the last gastroepiploic branch to the perfusion assessment point were measured. Propensity score matching was performed to compare wide conduits with narrow conduits. Narrow and wide conduits were defined as < 4 and ≥ 5 cm, respectively. ResultsThree hundred fifty-eight patients were reviewed. After applying matching, the wide conduits had higher ingress index (48.2 vs 33.3%, p < 0.001) and shorter ingress time (51.2 vs 66.3 s, p = 0.004) compared to the narrow conduits. Including the short gastric length in analysis, creating a wide conduit is a significant factor for better ingress index (p = 0.001), especially when the perfusion assessment point is 5 cm or farther from the last gastroepiploic branch. Anastomotic leaks did not differ between the groups. ConclusionsConduit width is a significant factor of gastric conduit perfusion, especially when the estimated anastomotic site was > 5 cm from the last gastroepiploic branch. Wide conduits seem to have better perfusion and creating a wider conduit might reduce anastomotic leaks.

Additional Microvascular Anastomosis to Gastric Conduit During Esophagectomy Reduces Anastomotic Leaks: Propensity Score Weighting Study.

Impaired gastric conduit perfusion during esophagectomy and reconstruction is considered a key risk factor of anastomotic leaks. The aim of this study is to evaluate the indication and feasibility of additional microvascular anastomosis (AMA) to the gastric conduit in esophageal cancer surgery. Patients who received an esophagectomy with gastric conduit reconstruction between July 2008 and July 2021 at a single center were reviewed. Patient characteristics, anastomotic viability index (AVI) of the gastric conduit measured with thermal imaging, and operative outcomes were analyzed using Fisher's exact test and Mann-Whitney U test. Two propensity score weighting methods (inverse probability of treatment weighting and overlap weighting) were applied to investigate whether AMA reduces anastomotic leaks. Of the 293 patients who underwent an esophagectomy over the study period, 26 received AMA. AVI in the AMA group was significantly lower than that in the control group (0.64 vs. 0.74, p = 0.026). Overall anastomotic leak rates were 3.8% in the AMA group and 12.4% in the control group. Using two different propensity score weighting methods, the same conclusion was obtained that AMA significantly reduced anastomotic leaks after esophagectomy (both p < 0.001). The logistic regression model for estimating probability of anastomotic leaks provided AVI criteria for AMA application and revealed that AMA significantly reduced the estimated leak rates by a maximum of 49%. Additional microvascular anastomosis significantly reduced anastomotic leaks after esophagectomy. The proposed AVI criteria for AMA application can help guide surgeons as to when AMA is needed.

497. INDOCYANINE GREEN FLUORESCENCE ANGIOGRAPHY VERSUS VISUAL ASSESSMENT FOR GASTRIC CONDUIT PERFUSION ASSESSMENT IN PATIENTS UNDERGOING ESOPHAGECTOMY: A RANDOMIZED CONTROLLED STUDY

Abstract Esophago-gastric anastomosis leakage is one of most feared complication after esophagectomy accountable for major postoperative morbidity and mortality. The high rate of anastomotic complications is due the tenuous perfusion of gastric conduit. This prospective randomized control trial compares the efficacy of intraoperative indocyanine green fluorescence angiography (ICG-FA) against visual assessment (VA) in evaluating the perfusion of gastric conduit and proximal esophageal stump in patients undergoing esophagectomy for cancer. Fifty eight consecutive patients who underwent esophagectomy for carcinoma middle, lower third esophagus or gastro-esophageal junction from January 2020 till September 2021 were enrolled. Amongst them 30 patients were randomized to non ICG arm where the perfusion of gastric conduit and esophageal stump was evaluated by visual assessment (VA) based on inspection of the color, the palpation of warmth, pulse, and bleeding from the edges and 28 patients to ICG arm underwent initial appraisal of gastric conduit and esophageal stump perfusion was done by visual assessment followed by ICG-FA. Correlation coefficient was evaluated by Pearson’s R coefficient. Both the groups were similar in demographic parameters. The anastomotic leak was significantly lower in ICG arm [4 % vs 8/28 (27 %) p 0.0261]. Most of the leaks were minor type 1. When visual assessment was compared with ICG assessment, 80% of the vascularized conduits on VA showed good perfusion on ICG-FA. 39% of gastric conduit which seemed to be dusky on VA had good vascularity on ICG-FA. Kappa value was 0.256 p 0.097 i.e., a fair agreement between ICG and visual assessment in evaluating vascularity of gastric conduit was fair. VA of the gastric conduit perfusion can underrate perfusion and hence can jeopardize removal of the devitalized part. ICG fluorescence imaging is an accurate and promising means to ascertain the vascularity of gastric conduit during an esophagectomy. But its utility needs to be validated in larger randomized trials.

260. EFFECT OF ENDOLUMINAL VACUUM THERAPY ON THE PERFUSION OF GASTRIC CONDUIT IN A PORCINE MODEL FOR ESOPHAGECTOMY

Abstract After esophagectomy, the postoperative rate of anastomotic leakage is between 5 and 30% and is the main driver of morbidity and mortality. Complication management is often based on endoluminal vacuum therapy (EndoVAC) with good success rates. Vacuum therapy has been shown to improve tissue perfusion in superficial wounds but this has not been shown for gastric conduits. The present study aimed to assess changes in gastric conduit perfusion in a porcine model for esophagectomy. Porcine model (n = 18) underwent gastric conduit formation and induction of partial conduit ischemia. In three experimental groups EndoVAC therapy was used in the gastric conduit (−40 mmHg, −125 mmHg and − 200 mmHg) with continuous suction. The changes in tissue perfusion and edema were assessed using hyperspectral imaging (HSI). During EndoVAC treatment with −125 mmHg a significant and stable increase in the oxygenation index from 44.9 ± 7.6% to 61.9 ± 5.5% and 62.9 ± 9.4%. (p = 0.02) was seen after 60 minutes and 120 minutes respectively. A similar trend was seen during EndoVAC treatment with −200 mmHg. There was a non-significant increase in tissue oxygenation during treatment with −40 mmHg. A significant increase of tissue water content from 40.8 ± 7.4 to 59.5 ± 10.3 (p = 0.004) was observed after 60 minutes of EndoVAC therapy with −200 mmHg. There were no significant differences in tissue water content during EndoVAC therapy with −40 mmHg and − 125 mmHg. EndoVAC treatment with a pressure of at least −125 mmHg significantly increases perfusion of partial ischemic gastric conduit. With better understanding of underlying physiology, the optimal use of EndoVac treatment can be guided and determined including a possible preemptive use for gastric conduits with impaired arterial perfusion or venous congestion. This can potentially be translated into clinical practice.

290. ANALYTIC MORPHOMIC INDEX AND QUANTITATIVE GASTRIC PERFUSION ASSESSMENT FOR RISK STRATIFICATION OF ANASTOMOTIC LEAKS FOLLOWING ESOPHAGECTOMY

Abstract Sarcopenia, a reduction in muscle mass, has been considered a preoperative risk factor for complications after esophagectomy while impaired perfusion of the gastric conduit has been associated with anastomotic leaks. The aim of this study was to stratify patients by their risk of anastomotic leak following esophagectomy using morphomic factors and quantitative assessment of gastric conduit perfusion. Patients who underwent an esophagectomy with a cervical anastomosis and gastric conduit from 2015–2021 were included. Preoperative CT scans were processed using semiautomated algorithms (MATLAB; MathWorks, MA). Indocyanine green perfusion was assessed intraoperatively (SPY elite; Stryker, MI). Sarcopenia was defined using skeletal muscle area (Martin’s criteria). Decreased subcutaneous fat, decreased bone mineral density, and impaired conduit perfusion were defined as below the cutoff value from the ROC curve. The morphomic index was determined using the number of decreased morphomic factors present (0–3). The Fisher exact test, the Mann–Whitney U test, and multivariable logistic regression were used to make statistical comparisons. 140 patients with both perfusion and morphomic data were evaluated (Leak n = 27; No leak n = 113). Decreased subcutaneous fat, decreased bone mineral density, and impaired gastric conduit perfusion were associated with an anastomotic leak (p = 0.041, 0.017, and 0.010). Neoadjuvant chemoradiation was significantly more common in the leak group (p = 0.048). On multivariable analysis, a higher morphomic Index and impaired gastric perfusion were risk factors for anastomotic leak. The incidence of anastomotic leaks with a high morphomic index (2 or 3) and impaired gastric perfusion was 40.6% compared to 9.4% with a low morphomic index and without impaired gastric perfusion (p = 0.006). Impaired gastric conduit perfusion and decreased preoperative subcutaneous fat area, bone mineral density, and skeletal muscle area, likely surrogates for increased frailty and poor nutritional status, were associated with an increased risk of anastomotic leaks especially when multiple morphomic factors were simultaneously decreased. These findings may be useful in risk stratification and intraoperative decision making in patients undergoing esophagectomy.

591. THE ROLE OF INTRAOPERATIVE HYPERSPECTRAL IMAGING (HSI) IN THE CASE OF USING COLON INTERPOSITION AFTER OESOPHAGECTOMY

Abstract Colon conduit is an alternative option for the reconstruction after oesophagectomy. The impact of using Hypersepctral Imaging (HSI) has been already proved in evaluating the perfusion of gastric conduit, but not in the case of using colon conduit. This is the first study described a new tool evaluating the perfusion of colon conduit and allowing us as esophageal surgeons to choose the appropriate side (left or right) of colon conduit and anastomosis site intraoperatively In 10 patients, who underwent reconstruction with a long segment colon conduit after oesephagectomy from 01.01.2018 till 01.04.2022. HSI was recorded in 8 of these patients at the root and tip of colon conduit after clamping the colic middle vessels allowing us to evaluate the perfusion and the appropriate side of colon conduit (Figure 1) Anastomosis Leakage (AL) grad I° was detected only in one patient (12.5%) of all included patients (n=8). There was no conduit necrosis in all of these patients. Re-anastomosis was necessary only in one patient. There were no need to conduit resection and esophageal diversion or to stent placement in all of included patients. Furthermore, there were no change of the selected side of colon conduit intraoperatively HSI is a promising novel intraoperative imaging tool to evaluate the perfusion of colon conduit objectively, which helping us to make the right decision regarding the side of the colon conduit as well as the site of the anastomosis intraoperatively.

481. QUANTITATIVE ESTIMATION OF GASTRIC CONDUIT PERFUSION TO SELECT ESOPHAGECTOMY PATIENTS AT HIGH RISK OF IMPAIRED PERFUSION

Abstract Impaired gastric conduit perfusion is considered the most important factor of anastomotic leaks following esophagectomy. Gastric ischemic preconditioning (GIP) can improve conduit perfusion and may reduce anastomotic leaks; however, it remains unclear which patients could benefit from preconditioning. The aim of this study is to create a paradigm to select patients at high risk of impaired perfusion who may benefit from GIP. Patients undergoing an esophagectomy with gastric conduit reconstruction and indocyanine green fluorescence angiography from July 2015 to December 2021 (Cohort 1), as well as all patients receiving an esophagectomy from 2003 to 2021 (Cohort 2) were reviewed. Analyzed variables for Cohort 1 included patient pre-operative demographics and ingress index (quantitative assessment of blood perfusion). Multiple linear regression model for conduit perfusion was used to select significant preoperative factors and to build a formula to estimate conduit perfusion. The formula was applied to Cohort 2 to estimate the percentage of patients who could receive GIP prior to esophagectomy. 349 patients were in Cohort 1, and 1965 in Cohort 2. There was a significant correlation with older age and low body mass index (BMI) and impaired conduit perfusion. Other factors, such as heart disease, diabetes, and prior chemoradiation did not correlate (Table). Using only two variables “age” and “BMI”, we determined how many could have poor conduit perfusion, defined as a low ingress index of &amp;lt;40 (the median value from the Cohort 1). When applying the formula to Cohort 2, we estimated that 26.7% (525) of patients would be at risk for low perfusion and for anastomotic leaks. Using BMI and age, we are able to risk stratify patients who are likely to have low perfusion in their gastric conduits (Figure, higher risk in red). We feel that this group will be the most likely to benefit from pre-esophagectomy gastric ischemic conditioning.