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

Fluorescence and tracers in surgery: the coming future

The revolution that we are seeing in the world of surgery will determine the way we understand surgical approaches in coming years. Since the implementation of minimally invasive surgery, innovations have constantly been developed to allow the laparoscopic approach to go further and be applied to more and more procedures. In recent years, we have been in the middle of another revolutionary era, with robotic surgery, the application of artificial intelligence and image-guided surgery. The latter includes 3D reconstructions for surgical planning, virtual reality, holograms or tracer-guided surgery, where ICG-guided fluorescence has provided a different perspective on surgery. ICG has been used to identify anatomical structures, assess tissue perfusion, and identify tumors or tumor lymphatic drainage. But the most important thing is that this technology has come hand in hand with the potential to develop other types of tracers that will facilitate the identification of tumor cells and ureters, as well as different light beams to identify anatomical structures. These will lead to other types of systems to assess tissue perfusion without the use of tracers, such as hyperspectral imaging. Combined with the upcoming introduction of ICG quantification, these developments represent a real revolution in the surgical world. With the imminent implementation of these technological advances, a review of their clinical application in general surgery is timely, and this review serves that aim.

Navigating complexities and considerations for suspected anastomotic leakage in the upper gastrointestinal tract: A state of the art review

This state-of-the-art review explores the intricacies of anastomotic leaks following oesophagectomy and gastrectomy, crucial surgeries for globally increasing esophageal and gastric cancers. Despite advancements, anastomotic leaks occur in up to 30 % and 10 % of oesophagectomy and gastrectomy cases, respectively, leading to prolonged hospital stays, substantial impact upon short- and long-term health-related quality of life and greater mortality. Recognising factors contributing to leaks, including patient characteristics and surgical techniques, are vital for preoperative risk stratification. Diagnosis is challenging, involving clinical signs, biochemical markers, and various imaging modalities. Management strategies range from non-invasive approaches, including antibiotic therapy and nutritional support, to endoscopic interventions such as stent placement and emerging vacuum-assisted closure devices, and surgical interventions, necessitating timely recognition and tailored interventions. A step-up approach, beginning non-invasively and progressing based on treatment success, is more commonly advocated. This comprehensive review highlights the absence of standardised treatment algorithms, emphasizing the importance of individualised patient-specific management.

Two Cases of Robot-Assisted Totally Minimally Invasive Esophagectomy with Colon Interposition for Gastroesophageal Junction Cancer: Surgical Considerations

This case report presents 2 patients with gastroesophageal junction cancer who both underwent totally minimally invasive esophagectomy with colon interposition. Patients 1 and 2, who were 43-year-old and 78-year-old men, respectively, had distinct clinical presentations and medical histories. Patient 1 underwent minimally invasive robotic esophagectomy with a laparoscopic total gastrectomy, colonic conduit preparation, and intrathoracic esophago-colono-jejunostomy. Patient 2 underwent completely robotic total gastrectomy, colon conduit preparation, and intrathoracic esophago-colono-jejunostomy. The primary challenge in colon interposition is assessing colon vascularity and ensuring an adequate conduit length, which is critical for successful anastomosis. In both cases, we used indocyanine green fluorescence angiography to evaluate vascularity. Determining the appropriate conduit is challenging; therefore, it is crucial to ensure a slightly longer conduit during reconstruction. Because totally minimally invasive colon interposition can reduce postoperative pain and enhance recovery, this surgical technique is feasible and beneficial.

Quantification of fluorescence angiography for visceral perfusion assessment: measuring agreement between two software algorithms

BACKGROUND

Indocyanine green fluorescence angiography (ICG-FA) may reduce perfusion-related complications of gastrointestinal anastomosis. Software implementations for quantifying ICG-FA are emerging to overcome a subjective interpretation of the technology. Comparison between quantification algorithms is needed to judge its external validity. This study aimed to measure the agreement for visceral perfusion assessment between two independently developed quantification software implementations.

METHODS

This retrospective cohort analysis included standardized ICG-FA video recordings of patients who underwent esophagectomy with gastric conduit reconstruction between August 2020 until February 2022. Recordings were analyzed by two quantification software implementations: AMS and CPH. The quantitative parameter used to measure visceral perfusion was the normalized maximum slope derived from fluorescence time curves. The agreement between AMS and CPH was evaluated in a Bland-Altman analysis. The relation between the intraoperative measurement of perfusion and the incidence of anastomotic leakage was determined for both software implementations.

RESULTS

Seventy pre-anastomosis ICG-FA recordings were included in the study. The Bland-Altman analysis indicated a mean relative difference of + 58.2% in the measurement of the normalized maximum slope when comparing the AMS software to CPH. The agreement between AMS and CPH deteriorated as the magnitude of the measured values increased, revealing a proportional (linear) bias (R2 = 0.512, p < 0.001). Neither the AMS nor the CPH measurements of the normalized maximum slope held a significant relationship with the occurrence of anastomotic leakage (median of 0.081 versus 0.074, p = 0.32 and 0.041 vs 0.042, p = 0.51, respectively).

CONCLUSION

This is the first study to demonstrate technical differences in software implementations that can lead to discrepancies in ICG-FA quantification in human clinical cases. The possible variation among software-based quantification methods should be considered when interpreting studies that report quantitative ICG-FA parameters and derived thresholds, as there may be a limited external validity.

A 10-year experience with anastomotic leaks in upper gastrointestinal surgery-Retrospective cohort study

BACKGROUND

Anastomotic leak (AL) in upper gastrointestinal (UGI) surgery continues to be a diagnostic challenge. We seek to identify clinical parameters that predict AL and examine the effectiveness of investigations in evaluating AL following UGI surgeries.

METHODS

592 patients underwent UGI surgeries with an anastomosis between January 2011 and January 2021. Data on patient characteristics, surgery, postoperative investigations and outcomes were prospectively collected and analysed.

RESULTS

The overall occurrence of AL was 6.4 %. Tachycardia >120 BPM (OR 6.959, 95 % CI 1.856-26.100, p = 0.004) and leukocyte count >19 × 109/L (OR 3.327, 95 % CI 1.009-10.967, p = 0.048) were independent predictors of AL. On multivariate analysis, patients whose anastomosis was deemed high risk and had pre-emptive investigation done postoperatively to exclude a leak were less likely to require intervention and were more likely to be managed conservatively (66.7 % vs 14.3 %, p = 0.025). Methylene blue test, oral contrast study and Computed Tomography scan with intravenous and oral contrast had 50.0 %, 20.0 % and 9.1 % false negative results, while esophagogastroduodenoscopy had none. There was no misdiagnosed AL when more than 1 investigation (n = 15, 39.5 %) were performed.

CONCLUSION

Our study demonstrates that the presence of a triad including desaturation, tachycardia and leucocytosis predicts for AL following UGI surgery and for confirmation of a leak, evaluation with 2 or more investigation is needed. A practice of evaluating high risk anastomosis prior to commencement of feeding decreased the need for surgical intervention and improves success of conservative treatment.

Role of indocyanine green fluorescence imaging for evaluating blood supply in the gastric conduit via the substernal route after McKeown minimally invasive esophagectomy

BACKGROUND

Anastomotic leakage (AL) is a determining factor of morbidity and mortality after esophagectomy. Adequate perfusion of the gastric conduit is crucial for AL prevention. This study aimed to determine whether intraoperative angiography using indocyanine green (ICG) fluorescence improves the incidence of AL after McKeown minimally invasive esophagectomy (MIE) with gastric conduit via the substernal route (SR).

METHODS

This retrospective cohort study included 120 patients who underwent MIE with gastric conduit via SR for esophageal cancer between February 2019 and April 2023. Of 120 patients, 88 experienced intraoperative angiography using ICG (ICG group), and 32 patients experienced intraoperative angiography without ICG (no-ICG group). Baseline characteristics and operative outcomes, including AL as the main concern, were compared between the 2 groups. In addition, the outcomes among patients in the ICG group with different levels of fluorescence intensity were compared.

RESULTS

The ICG and no-ICG groups were comparable in baseline characteristics and operative outcomes. There was no significant difference between the 2 groups regarding the rate of AL (31.0% vs 37.5%; P = .505), median dates of AL (9 vs 9 days; P = .810), and severity of AL (88.9%, 11.11%, and 0.0% vs 66.7%, 16.7%, and 16.7% for grades I, II, and III, respectively; P = .074). Patients in the ICG group with lower intensity of ICG had higher rates of leakage (24.6%, 39.3%, and 100% in levels I, II, and III of ICG intensity, respectively; P = .04).

CONCLUSION

The use of ICG did not seem to reduce the rate of AL. However, abnormal intensity of ICG fluorescence was associated with a higher rate of AL, which implies a predictive potential.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Current applications of indocyanine green (ICG) in abdominal, gynecologic and urologic surgery: a meta-review and quality analysis with use of the AMSTAR 2 instrument

BACKGROUND

Indocyanine green (ICG) is an injectable fluorochrome that has recently gained popularity as a means of assisting intraoperative visualization during laparoscopic and robotic surgery. Many systematic reviews and meta-analyses have been published. We conducted a meta-review to synthesize the findings of these studies.

METHODS

PubMed and Embase were searched to identify systematic reviews and meta-analyses coping with the uses of ICG in abdominal operations, including Metabolic Bariatric Surgery, Cholecystectomy, Colorectal, Esophageal, Gastric, Hepato-Pancreato-Biliary, Obstetrics and Gynecology (OG), Pediatric Surgery, Surgical Oncology, Urology, (abdominal) Vascular Surgery, Adrenal and Splenic Surgery, and Interdisciplinary tasks, until September 2023. We submitted the retrieved meta-analyses to qualitative analysis based on the AMSTAR 2 instrument.

RESULTS

We identified 116 studies, 41 systematic reviews (SRs) and 75 meta-analyses (MAs), spanning 2013-2023. The most thoroughly investigated (sub)specialties were Colorectal (6 SRs, 25 MAs), OG (9 SRs, 15 MAs), and HPB (4 SRs, 12 MAs). Interestingly, there was high heterogeneity regarding the administered ICG doses, routes, and timing. The use of ICG offered a clear benefit regarding anastomotic leak prevention, particularly after colorectal and esophageal surgery. There was no clear benefit regarding sentinel node detection after OG. According to the AMSTAR 2 tool, most meta-analyses ranked as "critically low" (34.7%) or "low" (58.7%) quality. There were only five meta-analyses (6.7%) that qualified as "moderate" quality, whereas there were no "high" quality reviews.

CONCLUSIONS

Regardless of the abundance of pertinent literature and reviews, surgeons should be cautious when interpreting their results on ICG use in abdominal surgery. Future reviews should focus on ensuring methodological vigor; establishing clear protocols of ICG dose, route of administration, and timing; and improving reporting quality. Other sources of data (e.g., registries) and novel methods of data analysis (e.g., machine learning) might also contribute to an enhanced role of ICG as a decision-making tool in surgery.

A novel imaging technology to assess tissue oxygen saturation and its correlation with indocyanine green in the gastric conduit during thoracic esophagectomy

BACKGROUND

Anastomotic leakage in esophagectomy is a serious complication, and assessing blood perfusion in the conduit can help minimize this risk. Indocyanine green is the most widely used method to assess tissue blood flow; however, this technique has disadvantages. Evaluating tissue oxygen saturation in the gastric conduit during thoracic esophagectomy compared with indocyanine green blood perfusion assessment addresses these disadvantages and can be performed easily and repeatedly.

METHODS

This was a prospective study of patients with esophageal cancer who underwent thoracic esophagectomy. Intraoperative tissue oxygen saturation and indocyanine green measurements were obtained to determine the anastomotic site and to compare the correlation between the 2 methods. Tissue oxygen saturation and indocyanine green values were obtained at the tip of the gastric conduit, the demarcation line indicating visible perfusion, and the end of the right gastroepiploic artery.

RESULTS

Fifty-seven patients were enrolled in this study; 3 developed anastomotic leakage, and all 3 underwent robotic thoracic surgery. The tissue oxygen saturation value decreased gradually toward the tip of the conduit, as did congestion, and was significantly decreased at the tip compared with the value at the demarcation line (P = .001). Mean tissue oxygen saturation differed significantly between the leakage and no-leakage groups at the anastomosis site (P = .04). We found a negative correlation between tissue oxygen saturation and indocyanine green values at the end of the right gastroepiploic artery (r = -0.361; P = .03).

CONCLUSION

Tissue oxygen saturation imaging was useful in determining the anastomotic site and addressed the disadvantages associated with indocyanine green.

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.

A novel device to assess the oxygen saturation and congestion status of the gastric conduit in thoracic esophagectomy

BACKGROUND

In thoracic esophagectomy, anastomotic leakage is one of the most important surgical complications. Indocyanine green (ICG) is the most widely used method to assess tissue blood flow; however, this technique has been pointed out to have disadvantages such as difficulty in evaluating the degree of congestion, lack of objectivity in evaluating the degree of staining, and bias easily caused by ICG injection, camera distance, and other factors. Evaluating tissue oxygen saturation (StO2) overcomes these disadvantages and can be performed easily and repeatedly. It is also possible to measure objective values including the degree of congestion. We evaluate novel imaging technology to assess tissue oxygen saturation (StO2) in the gastric conduit during thoracic esophagectomy.

METHODS

Fifty patients were enrolled, with seven excluded due to intraoperative findings, leaving 43 for analysis. These patients underwent thoracic esophagectomy for esophageal cancer. The device was used intraoperatively to evaluate tissue oxygen saturation (StO2) and total hemoglobin index (T-HbI), which guided the optimal site for gastric tube anastomosis. The efficacies of StO2 and T-HbI in relation to short-term outcomes were analyzed.

RESULTS

StO2, indicating blood supply to the gastric tube, remained stable beyond the right gastroepiploic artery (RGEA) end but significantly decreased distally to the demarcation line (p <  0.05). T-HbI, indicative of congestion, significantly decreased past the RGEA (p <  0.05). Three patients experienced anastomotic leakage. These patients exhibited significantly lower StO2 (p <  0.01) and higher T-HbI (p <  0.01) at both the RGEA end and the demarcation line. Furthermore, the anastomotic site, usually within 3 cm of the RGEA's anorectal side, also showed significantly lower StO2 (p <  0.01) and higher T-HbI (p <  0.01) in patients with anastomotic leakage.

CONCLUSIONS

The novel device provides real-time, objective evaluations of blood flow and congestion in the gastric tube. It proves useful for safer reconstruction during thoracic esophagectomy, particularly by identifying optimal anastomosis sites and predicting potential anastomotic leakage.

[Indocyanine green in delayed esophageal reconstruction after previous extirpation]

Advanced chemo- and radiotherapy makes it possible to expand the cohort of patients who can undergo surgical treatment for esophageal cancer. Optimization of perioperative approach, diagnosis and modern options for complications reduced early postoperative mortality after esophagectomy. Conduit ischemia with failure of esophageal-gastric or esophageal-intestinal anastomosis is one of the most serious complications. To minimize the risk of anastomotic leakage and graft necrosis in these patients, various methods of intraoperative assessment of graft viability are being investigated. Near-infrared fluorescence imaging with indocyanine green is valuable for real time assessment of graft perfusion. To date, fluorescence imaging is analyzed regarding perfusion of the gastric stalk after esophagectomy. However, there are still few or no data on this method for analysis of colonic conduit perfusion. The absence of plastic material for gastrointestinal reconstruction is the most dangerous moment in case of ischemia and necrosis of colonic graft. We present our first case of delayed retrosternal esophageal repair using intraoperative indocyanine green fluorescence imaging for assessment of conduit perfusion.

Indocyanine green fluorescence in gastrointestinal surgery: Appraisal of current evidence

Applying indocyanine green (ICG) fluorescence in surgery has created a new dimension of navigation surgery to advance in various disciplines. The research in this field is nascent and fragmented, necessitating academic efforts to gain a comprehensive understanding. The present review aims to integrate diverse perspectives and recent advances in its application in gastrointestinal surgery. The relevant articles were selected by using the appropriate keyword search in PubMed. The angiography and cholangiography property of ICG fluorescence is helpful in various hepatobiliary disorders. In gastroesophageal and colorectal surgery, the lymphangiography and angiography property of ICG is applied to evaluate bowel vascularity and guide lymphadenectomy. The lack of objective parameters to assess ICG fluorescence has been the primary limitation when ICG is used to evaluate bowel perfusion. The optimum dose and timing of ICG administration need to be standardized in some new application areas in gastrointestinal surgery. Binding tumor-specific ligands with fluorophores can potentially widen the fluorescence application to detect primary and metastatic gastrointestinal tumors. The narrative review outlines prior contributions, limitations, and research opportunities for future studies across gastrointestinal sub-specialty. The findings of the present review would be helpful for scholars and practitioners to explore and progress in this exciting domain of gastrointestinal surgery.

Impact of perioperative decreased serum albumin level on anastomotic leakage in esophageal squamous cell carcinoma patients treated with neoadjuvant chemotherapy followed by minimally invasive esophagectomy

BACKGROUND

Anastomotic leakage (AL) is a severe complication following esophagectomy with high mortality. Perioperative decreased serum albumin level is considered a predictive of AL, however, its impact on AL incidence in patients treated with neoadjuvant chemotherapy (NCT) followed by minimally invasive esophagectomy (MIE) is not well defined.

METHODS

The data of 318 consecutive esophageal cancer patients who underwent MIE were collected retrospectively from January 2021 to December 2021. The perioperative level of albumin was detected and the baseline of altering levels for albumin was established. The incidence of postoperative complications and survival rate were analyzed between groups.

RESULTS

After exclusion, 137 patients were enrolled and assigned to more decreased albumin (MA) and less decreased albumin (LA) groups. The levels of albumin descended significantly after MIE (p < 0.0001). There was no significant difference in the clinicopathologic characteristics or surgical outcomes between groups. The incidence of postoperative AL was 10.2% in MA group and 1.4% in LA group (p = 0.033). Three patients died due to AL in MA group, while no mortality was observed in LA group (p = 0.120). The rate of other postoperative complications was similar between groups. Progression-free survival (PFS) in LA group was a little higher than that in MA group, but it was no significant difference (p = 0.853). Similarly, no difference was observed in overall survival (OS) between groups (p = 0.277).

CONCLUSIONS

Severely deficient serum albumin after MIE was an indicator of AL in esophageal cancer patients treated with NCT.

TRIAL REGISTRATION

Chinese clinical trial registry: ChiCTR2200066694, registered December14th,2022. https://www.chictr.org.cn/edit.aspx?pid=185067&htm=4 .

Epidemiology of Postoperative Complications After Esophagectomy: Implications for Management

BACKGROUND

Despite advances in operative techniques and postoperative care, esophagectomy remains a morbid operation. Leveraging complication epidemiology and the correlation of these complications may improve rescue and refine early recovery pathways.

METHODS

This study retrospectively reviewed all esophagectomies performed at a tertiary academic center from 2014 to 2021 and quantified the timing of the most common complications. Daily incidence values for index complications were calculated, and a covariance matrix was created to examine the correlation of the complications with each other. Study investigators performed a Cox proportional hazards analysis to clarify the association between early diagnosis of postoperative atrial fibrillation and pneumonia with subsequent anastomotic leak.

RESULTS

The study analyzed 621 esophagectomies, with 580 (93.4%) cervical anastomoses and 474 (76%) patients experiencing complications. A total of 159 (25.6%) patients had postoperative atrial fibrillation, and 155 (25.0%) had an anastomotic leak. The median (interquartile range [IQR]) postoperative day of these complications was day 2 (IQR, days 2-3) and day 8 (IQR, days 7-11), respectively. Our covariance matrix found significant associations in the variance of the most common postoperative complications, including pneumonia, atrial fibrillation, anastomotic leak, and readmissions. Early postoperative atrial fibrillation (hazard ratio, 8.1; 95% CI, 5.65-11.65) and postoperative pneumonia (hazard ratio, 3.8; 95% CI, 1.98-7.38) were associated with anastomotic leak.

CONCLUSIONS

Maintaining a high index of suspicion for early postoperative complications is crucial for rescuing patients after esophagectomy. Early postoperative pneumonia and atrial fibrillation may be sentinel complications for an anastomotic leak, and their occurrence may be used to prompt further clinical investigation. Early recovery protocols should consider the development of early complications into postoperative feeding and imaging algorithms.

Outcomes of Anastomotic Evaluation Using Indocyanine Green Fluorescence during Minimally Invasive Esophagectomy

BACKGROUND

Limited evidence exists assessing whether anastomotic evaluation using indocyanine green fluorescence (IGF) during minimally invasive esophagectomy (MIE) predicts or improves outcomes. We hypothesized that IGF helps surgeons predict anastomotic complications and reduces anastomotic leaks after MIE.

METHODS

In September 2019, our institution began routinely using IGF for intraoperative evaluation of anastomoses during MIE. Data were collected from patients undergoing MIE in the two years before and after this technology began being routinely used. Baseline characteristics and outcomes, including anastomotic leak, in patients who underwent indocyanine green fluorescence evaluation (ICG) and those who did not (nICG) were compared. Outcomes were also compared between ICG patients with normal versus abnormal fluorescence.

RESULTS

Overall, 181 patients were included. Baseline demographic and clinical characteristics did not differ between the ICG and nICG groups. ICG patients experienced higher rates of anastomotic leak (10.2% vs. 1.6%, P = .015) and 90-day mortality (8.5% vs. 1.6%, P = .04) compared to nICG patients. Due to lack of equipment availability, 19 nICG patients underwent MIE after the use of IGF became routine, and none developed leaks. ICG patients with abnormal fluorescence had higher rates of anastomotic leak (71.4% vs 1.9%, P < .001) and 30-day mortality (28.6% vs 0%, P = .012) compared to those with normal fluorescence.

DISCUSSION

Abnormal intraoperative IGF was associated with increased rate of anastomotic leak, suggesting predictive potential of IGF. However, its use was associated with an increased leak rate and higher mortality. Further studies are warranted to assess possible physiologic effects of indocyanine green on the esophageal anastomosis.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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 ≥ 10 s and max perfusion was > 25 s in all the patients in the ICYG that developed anastomotic leaks. All patients were noted to have at least 1 cm 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 0.77 cm.

CONCLUSION

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.

Evaluating Performance of Circular Staplers Using Comparative Test Methods for Evidence-Based Surgery

BACKGROUND

Circular stapler anastomosis is a common surgical procedure. Despite technological advancements, anastomotic leak remains a postoperative concern. Assessment of new technologies is impeded by variations in test methods and analysis, precluding outcome reproducibility and direct comparisons of results across studies. The development of robust and reproducible preclinical test methods is critical to accelerating stapling technology advancements.

METHODOLOGY

Leak pressure, staple line perfusion and security, and device removal force were quantified for triple-row (Tri-staple EEA, TriEEA) and double-row staplers (Echelon Circular Powered, ECP). Leak and perfusion testing were performed in vivo. Device removal force and staple line security testing were performed with synthetic medium using an Instron. Data were analyzed using unpaired student's t-test or Kruskal-Wallis test, with statistical significance defined as P < .05.

RESULTS

Leak pressure was 73% higher in TriEEA vs ECP (P = .016). TriEEA staple line failure force was lower than ECP at 40 and 50 mmHg (P = .001 and P = .023, respectively). Perfusion to the staple line was higher (148%) for TriEEA than for ECP (P = .003) and the force required to remove the device from its stapled anastomosis was 78% lower for TriEEA than for ECP (P < .001).

DISCUSSION/CONCLUSIONS

This report addresses a primary limitation in stapling research by presenting novel methodologies which enhance clinical relevance and provide sufficient detail for reproduction by independent investigators. These methods are applied to a comparison between triple-row and double-row staplers to demonstrate utility of new test methods in assessing key technology design features.

McKeown Versus Ivor-Lewis Esophagectomy for Patients with a History of Total Pharyngolaryngectomy: A Comparison Study

BACKGROUND

Oncologic esophagectomy in patients with a history of total pharyngolaryngectomy (TPL) is challenging. There are two different esophagectomy procedures: total esophagectomy with cervical anastomosis (McKeown) and subtotal esophagectomy with intrathoracic anastomosis (Ivor-Lewis). Differences in outcomes between McKeown and Ivor-Lewis esophagectomies for patients with this history remain unclear.

METHODS

We retrospectively reviewed 36 patients with a history of TPL who underwent oncologic esophagectomy and compared the clinical outcomes between the procedures.

RESULTS

Twelve (33.3%) and 24 (66.7%) patients underwent McKeown and Ivor-Lewis esophagectomies, respectively. McKeown esophagectomy was more frequently performed for the supracarinal tumors (P = 0.002). Other baseline characteristics, including the history of radiation therapy, were comparable between the groups. Postoperatively, the incidences of pneumonia and anastomotic leakage were higher in the McKeown group than in the Ivor-Lewis group (P = 0.029 and P < 0.001, respectively). Neither tracheal necrosis nor remnant esophageal necrosis was observed. The overall and recurrence-free survival rates were comparable between the groups (P = 0.494 and P = 0.813, respectively).

CONCLUSIONS

When performing esophagectomy for patients with a history of TPL, if it is oncologically acceptable and technically available, Ivor-Lewis is preferable over McKeown esophagectomy for avoiding postoperative complications.

Different gastric tubes in esophageal reconstruction during esophagectomy

Esophagectomy is currently the mainstay of treatment for resectable esophageal carcinoma. Gastric grafts are the first substitutes in esophageal reconstruction. According to the different tailoring methods applied to the stomach, gastric grafts can be classified as whole stomach, subtotal stomach and gastric tube. Gastric-tube placement has been proven to be the preferred method, with advantages in terms of postoperative complications and long-term survival. In recent years, several novel methods involving special-shaped gastric tubes have been proposed, which have further decreased the incidence of perioperative complications. This article will review the progress and clinical application status of different types of gastric grafts from the perspectives of preparation methods, studies of anatomy and perioperative outcomes, existing problems and future outlook.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

Gastric ischemic preconditioning results in a statistically significant improvement in conduit perfusion and reduction in post-operative anastomotic leaks.

Gastric conduit reconstruction after esophagectomy with right gastroepiploic artery absence: a case report

Gastric conduit reconstruction is the standard choice after esophagectomy. Conduit's vascular supply is of primary importance mainly based on right gastroepiploic vessels. A 57-year-old male with absent right gastroepiploic artery, due to a duodenal bleeding ulcer treated with gastroduodenal artery ligation 10 years ago, was treated for gastroesophageal cancer and required esophagectomy. Surgical merits of this troublesome scenario are highlighted. Previous surgical history is highly important for patients requiring complex surgery as esophagectomy. The use of the stomach as conduit after esophagectomy is always the primary option; however vascular supply of it should not be compromised. Variations are rare and careful planning may overcome obstacles as in this case.

Fluorescent Imaging in Visceral Surgery: Current Opportunities and Future Perspectives

Background

Fluorescent imaging using indocyanine green (FI-ICG) has become quite popular in the past century, giving the surgeon various pre- and intraoperative approaches in visceral surgery. Nevertheless, several aspects and pitfalls of using the technology need to be addressed.

Summary

This article focused on the applications of FI-ICG in esophageal and colorectal surgery as this is where the clinical relevance is most important. Important benchmark studies were summarized to explain the background. In addition, dosage, the timing of application, and future perspectives - especially quantification methods - were the article's content.

Key Message

There are currently encouraging data on the use of FI-ICG, particularly concerning perfusion assessment to reduce anastomotic leakage, although its use is mainly subjective. The optimal dosage remains unclear; for perfusion evaluation, it should be around 0.1 mg/kg body weight. Moreover, the quantification of FI-ICG opens new possibilities, so that reference values may be available in the future. However, in addition to perfusion measurement, the detection of additional hepatic lesions such as liver metastases or lesions of peritoneal carcinomatosis is also possible. A standardization of FI-ICG and further studies are needed to fully utilize FI-ICG.

Perfusion assessment by fluorescence time curves in esophagectomy with gastric conduit reconstruction: a prospective clinical study

BACKGROUND

Intraoperative perfusion assessment with indocyanine green fluorescence angiography (ICG-FA) may reduce postoperative anastomotic leakage rates after esophagectomy with gastric conduit reconstruction. This study evaluated quantitative parameters derived from fluorescence time curves to determine a threshold for adequate perfusion and predict postoperative anastomotic complications.

METHODS

This prospective cohort study included consecutive patients who underwent FA-guided esophagectomy with gastric conduit reconstruction between August 2020 and February 2022. After intravenous bolus injection of 0.05-mg/kg ICG, fluorescence intensity was registered over time by PINPOINT camera (Stryker, USA). Fluorescent angiograms were quantitatively analyzed at a region of interest of 1 cm diameter at the anastomotic site on the conduit using tailor-made software. Extracted fluorescence parameters were both inflow (T₀, T_max, F_max, slope, Time-to-peak) as outflow parameters (T_90% and T_80%). Anastomotic complications including anastomotic leakage (AL) and strictures were documented. Fluorescence parameters in patients with AL were compared to those without AL.

RESULTS

One hundred and three patients (81 male, 65.7 ± 9.9 years) were included, the majority of whom (88%) underwent an Ivor Lewis procedure. AL occurred in 19% of patients (n = 20/103). Both time to peak as T_max were significantly longer for the AL group in comparison to the non-AL group (39 s vs. 26 s, p = 0.04 and 65 vs. 51 s, p = 0.03, respectively). Slope was 1.0 (IQR 0.3-2.5) and 1.7 (IQR 1.0-3.0) for the AL and non-AL group (p = 0.11). Outflow was longer in the AL group, although not significantly, T_90% 30 versus 15 s, respectively, p = 0.20). Univariate analysis indicated that T_max might be predictive for AL, although not reaching significance (p = 0.10, area under the curve 0.71) and a cut-off value of 97 s was derived, with a specificity of 92%.

CONCLUSION

This study demonstrated quantitative parameters and identified a fluorescent threshold which could be used for intraoperative decision-making and to identify high-risk patients for anastomotic leakage during esophagectomy with gastric conduit reconstruction. A significant predictive value remains to be determined in future studies.

Preservation of remnant esophagus during total pharyngolaryngectomy in a patient with previous subtotal esophagectomy: a case report

Background

With the improved survival rate of patients with esophageal cancer, secondary cancers, including pharyngolaryngeal cancer, have become a problem. Phanryngolaryngeal cancer surgery often requires esophagogastric anastomosis resection in patients with a previous history of subtotal esophagectomy. Owing to adhesions, especially surrounding the esophagogastric anastomosis, caused by the initial surgery, the second surgery might cause postoperative complications.

Case presentation

A 65-year-old man was diagnosed with early stage esophageal squamous cell carcinoma and underwent endoscopic mucosal dissection. However, the histopathological depth of the tumor was pT1b, and additional treatment was required. After administration of the neoadjuvant chemotherapy, he underwent thoracoscopic esophagectomy and retrosternum reconstruction via a gastric tube (pT1N3M0 stage III). Eight months after the first surgery, tumor recurrences were observed at the anastomosis and left cervical lymph node. Definitive chemoradiotherapy was performed for the recurrences, and complete response was achieved. Seven months after chemoradiotherapy, he was diagnosed with hypopharyngeal squamous cell carcinoma in the right piriform fossa (cT2N2bM0 stage IVA), and salvage surgery was chosen as treatment. The surgical findings revealed strong adhesion around the remnant esophagus, which was difficult to dissect from surrounding tissue and was associated with a risk of breaking of the anastomosis. However, indocyanine green fluorescence imaging findings indicated sufficient blood flow to preserve the remnant esophagus, including the anastomosis, even after the interruption of blood flow from the proximal side of the esophagus by total pharyngolaryngectomy. Finally, approximately 4 cm of the remnant esophagus was preserved, and the free jejunum reconstruction with cervical vascular anastomosis was performed. Moreover, the patient was discharged without complications on postoperative day 38. After 10 months of the second surgery, a metastatic lymph node was observed in the right neck. Immune checkpoint inhibitors and chemotherapy were administered, and the patient is alive and under treatment 1.5 years after the second surgery.

Conclusions

Blood supply to the remnant cervical esophagus was thought to be from the gastric conduit over the anastomosis and surrounding capillaries. Thus, the preservation of the remnant esophagus can be considered in total pharyngolaryngectomy even after < 2 years of esophagectomy by blood flow evaluation using indocyanine green fluorescence.

Preservation of remnant esophagus during total pharyngolaryngectomy in a patient with previous subtotal esophagectomy: a case report

BACKGROUND

With the improved survival rate of patients with esophageal cancer, secondary cancers, including pharyngolaryngeal cancer, have become a problem. Phanryngolaryngeal cancer surgery often requires esophagogastric anastomosis resection in patients with a previous history of subtotal esophagectomy. Owing to adhesions, especially surrounding the esophagogastric anastomosis, caused by the initial surgery, the second surgery might cause postoperative complications.

CASE PRESENTATION

A 65-year-old man was diagnosed with early stage esophageal squamous cell carcinoma and underwent endoscopic mucosal dissection. However, the histopathological depth of the tumor was pT1b, and additional treatment was required. After administration of the neoadjuvant chemotherapy, he underwent thoracoscopic esophagectomy and retrosternum reconstruction via a gastric tube (pT1N3M0 stage III). Eight months after the first surgery, tumor recurrences were observed at the anastomosis and left cervical lymph node. Definitive chemoradiotherapy was performed for the recurrences, and complete response was achieved. Seven months after chemoradiotherapy, he was diagnosed with hypopharyngeal squamous cell carcinoma in the right piriform fossa (cT2N2bM0 stage IVA), and salvage surgery was chosen as treatment. The surgical findings revealed strong adhesion around the remnant esophagus, which was difficult to dissect from surrounding tissue and was associated with a risk of breaking of the anastomosis. However, indocyanine green fluorescence imaging findings indicated sufficient blood flow to preserve the remnant esophagus, including the anastomosis, even after the interruption of blood flow from the proximal side of the esophagus by total pharyngolaryngectomy. Finally, approximately 4 cm of the remnant esophagus was preserved, and the free jejunum reconstruction with cervical vascular anastomosis was performed. Moreover, the patient was discharged without complications on postoperative day 38. After 10 months of the second surgery, a metastatic lymph node was observed in the right neck. Immune checkpoint inhibitors and chemotherapy were administered, and the patient is alive and under treatment 1.5 years after the second surgery.

CONCLUSIONS

Blood supply to the remnant cervical esophagus was thought to be from the gastric conduit over the anastomosis and surrounding capillaries. Thus, the preservation of the remnant esophagus can be considered in total pharyngolaryngectomy even after < 2 years of esophagectomy by blood flow evaluation using indocyanine green fluorescence.

Real-time quantification of intestinal perfusion and arterial versus venous occlusion using laser speckle contrast imaging in porcine model

PURPOSE

Real-time intraoperative perfusion assessment may reduce anastomotic leaks. Laser speckle contrast imaging (LSCI) provides dye-free visualization of perfusion by capturing coherent laser light scatter from red blood cells and displays perfusion as a colormap. Herein, we report a novel method to precisely quantify intestinal perfusion using LSCI.

METHODS

ActivSight™ is an FDA-cleared multi-modal visualization system that can detect and display perfusion via both indocyanine green imaging (ICG) and LSCI in minimally invasive surgery. An experimental prototype LSCI perfusion quantification algorithm was evaluated in porcine models. Porcine small bowel was selectively devascularized to create regions of perfused/watershed/ischemic bowel, and progressive aortic inflow/portal vein outflow clamping was performed to study arterial vs. venous ischemia. Continuous arterial pressure was monitored via femoral line.

RESULTS

LSCI perfusion colormaps and quantification distinguished between perfused, watershed, and ischemic bowel in all vascular control settings: no vascular occlusion (p < 0.001), aortic occlusion (p < 0.001), and portal venous occlusion (p < 0.001). LSCI quantification demonstrated similar levels of ischemia induced both by states of arterial inflow and venous outflow occlusion. LSCI-quantified perfusion values correlated positively with higher mean arterial pressure and with increasing distance from ischemic bowel.

CONCLUSION

LSCI relative perfusion quantification may provide more objective real-time assessment of intestinal perfusion compared to conventional naked eye assessment by quantifying currently subjective gradients of bowel ischemia and identifying both arterial/venous etiologies of ischemia.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

Esophagectomy-prevention of complications-tips and tricks for the preoperative, intraoperative and postoperative stage

Esophagectomy still remains the mainstay of treatment for localized esophageal cancer. Many progresses have been made in the technique of esophagectomy in the last decades but the overall morbidity for this operation remains formidable. Postoperative complication and mortality rate after esophagectomy are significant; anastomotic leak has an incidence of 11,4%. The occurrence of a complication is a significant negative prognostic factor for long term survival and is also linked to longer postoperative stay, a lower quality of life, increased hospital costs. Preventing the occurrence of postoperative morbidity and reducing associated postoperative mortality rate is a major goal for surgeons experienced in resective esophageal surgery. Many details of pre, intra and postoperative care for patients undergoing esophagectomy need to be shared among the professionals taking care of these patients (oncologists, dieticians, physiotherapists, surgeons, nurses, anesthesiologists, gastroenterologists) in order to improve the short and long term clinical results.

Indocyanine green fluorescence in robot-assisted minimally invasive esophagectomy with intrathoracic anastomosis: a prospective study

Indocyanine green fluorescence angiography (ICG-FA) allows for real-time intraoperative assessment of the perfusion of the gastric conduit during esophagectomy. The aim of this study was to investigate the effect of the implementation of ICG-FA during robot-assisted minimally invasive esophagectomy (RAMIE) with an intrathoracic anastomosis. In this prospective cohort study, a standardized protocol for ICG-FA was implemented in a high-volume center in December 2018. All consecutive patients who underwent RAMIE with an intrathoracic anastomosis were included. The primary outcome was whether the initial chosen site for the anastomosis on the gastric conduit was changed based on ICG-FA findings. In addition, ICG-FA was quantified based on the procedural videos. Out of the 63 included patients, the planned location of the anastomosis was changed in 9 (14%) patients, based on ICG-FA. The median time to maximum intensity at the base of the gastric conduit was shorter (25 s; range 13-49) compared to tip (34 s; range 12-83). In patients with anastomotic leakage, the median time to reach the FImax at the tip was 56 s (range 30-83) compared to 34 s (range 12-66) in patients without anastomotic leakage (p = 0.320). The use of ICG-FA resulted in an adaptation of the anastomotic site in nine (14%) patients during RAMIE with intrathoracic anastomosis. The quantification of ICG-FA showed that the gastric conduit reaches it maximum intensity in a base-to-tip direction. Perfusion of the entire gastric conduit was worse for patients with anastomotic leakage, although not statistically different.

The impact of nitroglycerine and volume on gastric tube microperfusion assessed by indocyanine green fluorescence imaging

The influence of hypervolemia and intraoperative administration of nitroglycerine on gastric tube microperfusion remains unclear The present study aimed to investigate the impact of different hemodynamic settings on gastric tube microperfusion quantified by fluorescence imaging with Indocyanine green (ICG-FI) as a promising tool for perfusion evaluation. Three groups with seven pigs each were formed using noradrenaline, nitroglycerin, and hypervolemia for hemodynamic management, respectively. ICG-FI, hemodynamic parameters, and transit-time flow measurement (TTFM) in the right gastroepiploic artery were continuously assessed. Fluorescent microspheres (FM) were administered, and the partial pressure of tissue oxygen was quantified. The administration of nitroglycerine and hypervolemia were both associated with significantly impaired microperfusion compared to the noradrenaline group quantified by ICG-FI. Even the most minor differences in microperfusion could be sufficiently predicted which, however, could not be represented by the mean arterial pressure measurement. Histopathological findings supported these results with a higher degree of epithelial damage in areas with impaired perfusion. The values measured by ICG-FI significantly correlated with the FM measurement. Using tissue oxygenation and TTFM for perfusion measurement, changes in microperfusion could not be comprehended. Our results support current clinical practice with restrictive volume and catecholamine administration in major surgery. Hypervolemia and continuous administration of nitroglycerine should be avoided.

Use of fluorescence imaging and indocyanine green during laparoscopic cholecystectomy: Results of an international Delphi survey

BACKGROUND

Published empirical data have increasingly suggested that using near-infrared fluorescence cholangiography during laparoscopic cholecystectomy markedly increases biliary anatomy visualization. The technology is rapidly evolving, and different equipment and doses may be used. We aimed to identify areas of consensus and nonconsensus in the use of incisionless near-infrared fluorescent cholangiography during laparoscopic cholecystectomy.

METHODS

A 2-round Delphi survey was conducted among 28 international experts in minimally invasive surgery and near-infrared fluorescent cholangiography in 2020, during which respondents voted on 62 statements on patient preparation and contraindications (n = 12); on indocyanine green administration (n = 14); on potential advantages and uses of near-infrared fluorescent cholangiography (n = 18); comparing near-infrared fluorescent cholangiography with intraoperative x-ray cholangiography (n = 7); and on potential disadvantages of and required training for near-infrared fluorescent cholangiography (n = 11).

RESULTS

Expert consensus strongly supports near-infrared fluorescent cholangiography superiority over white light for the visualization of biliary structures and reduction of laparoscopic cholecystectomy risks. It also offers other advantages like enhancing anatomic visualization in obese patients and those with moderate to severe inflammation. Regarding indocyanine green administration, consensus was reached that dosing should be on a milligrams/kilogram basis, rather than as an absolute dose, and that doses >0.05 mg/kg are necessary. Although there is no consensus on the optimum preoperative timing of indocyanine green injections, the majority of participants consider it important to administer indocyanine green at least 45 minutes before the procedure to decrease the light intensity of the liver.

CONCLUSION

Near-infrared fluorescent cholangiography experts strongly agree on its effectiveness and safety during laparoscopic cholecystectomy and that it should be used routinely, but further research is necessary to establish optimum timing and doses for indocyanine green.

Evaluation of inter-user variability in indocyanine green fluorescence angiography to assess gastric conduit perfusion in esophageal cancer surgery

Indocyanine Green Fluorescence Angiography (ICGFA) has been deployed to tackle malperfusion-related anastomotic complications. This study assesses variations in operator interpretation of pre-anastomotic ICGFA inflow in the gastric conduit. Utilizing an innovative online interactive multimedia platform (Mindstamp), esophageal surgeons completed a baseline opinion-practice questionnaire and proceeded to interpret, and then digitally assign, a distal transection point on 8 ICGFA videos of esophageal resections (6 Ivor Lewis, 2 McKeown). Annotations regarding gastric conduit transection by ICGFA were compared between expert users versus non-expert participants using ImageJ to delineate longitudinal distances with Shapiro Wilk and t-tests to ascertain significance. Expert versus non-expert correlation was assessed via Intraclass Correlation Coefficients (ICC). Thirty participants (13 consultants, 6 ICGFA experts) completed the study in all aspects. Of these, a high majority (29 participants) stated ICGFA should be used routinely with most (21, including 5/6 experts) stating that 11-50 cases were needed for competency in interpretation. Among users, there were wide variations in dosing (0.05-3 mg/kg) and practice impact. Agreement regarding ICGFA video interpretation concerning transection level among experts was 'moderate' (ICC = 0.717) overall but 'good' (ICC = 0.871) among seven videos with Leave One Out (LOO) exclusion of the video with highest disagreement. Agreement among non-experts was moderate (ICC = 0.641) overall and in every subgroup including among consultants (ICC = 0.626). Experts choose levels that preserved more gastric conduit length versus non-experts in all but one video (P = 0.02). Considerable variability exists with ICGFA interpretation and indeed impact. Even adept users may be challenged in specific cases. Standardized training and/or computerized quantitative fluorescence may help better usage.

Robot-assisted Ivor Lewis Esophagectomy (RAILE): A review of surgical techniques and clinical outcomes

In the past 20 years, robotic system has gradually found a place in esophagectomy which is a demanding procedure in the deep and narrow thoracic cavity containing crucial functional structures. Ivor Lewis esophagectomy (ILE) is a mainstream surgery type for esophagectomy and is widely accepted for its capability in lymphadenectomy and relatively mitigated trauma. As a minimally invasive technique, robot-assisted Ivor Lewis esophagectomy (RAILE) has been frequently compared with the video-assisted procedure and the traditional open procedure. However, high-quality evidence elucidating the advantages and drawbacks of RAILE is still lacking. In this article, we will review the surgical techniques, both short and long-term outcomes, the learning curve, and explicate the current progress and clinical efficacy of RAILE.

The role of fluorescence angiography in colonic interposition after esophagectomy

Colonic interposition is an alternative for gastric conduit reconstruction after esophagectomy. Anastomotic leakage (AL) occurs in 15-25% of patients and may be attributed to reduced blood supply after vascular ligation. Indocyanine green fluorescence angiography (ICG-FA) can visualize tissue perfusion. We aimed to give an overview of the first experiences of ICG-FA and AL rate in colonic interposition. This study included all consecutive patients who underwent a colonic interposition between January 2015 and December 2021 at a tertiary referral center. Surgery was performed for the following indications: inability to use the stomach because of previous surgery or extensive tumour involvement, cancer recurrence in the gastric conduit, or because of complications after initial esophagectomy. Since 2018 ICG-FA was performed before anastomotic reconstruction by administration of ICG injection (0.1 mg/kg/bolus), using the Spy-phi (Stryker, Kalamazoo, MI). Twenty-eight patients (9 female, mean age 62.8), underwent colonic interposition of whom 15 (54%) underwent ICG-FA-guided surgery. Within the ICG-FA group, three (20%) AL occurred, whereas in the non-ICG-FA group, three AL and one graft necrosis (31%) occurred (P=0.67). There was a change of management due to the FA assessment in three patients in the FA group (20%) which led to the choice of a different bowel segment for the anastomosis. Mean operative times in the ICG-FA and non-ICG-FA groups were 372±99 and 399±113 minutes, respectively (P=0.85). ICG-FA is a safe, easy and feasible technique to assess perfusion of colonic interpositions. ICG-FA is of added value leading to a change in management in a considerable percentage of patients. Its role in prevention of AL remains to be elucidated.

Linear- versus circular-stapled esophagogastric anastomosis during esophagectomy: systematic review and meta-analysis

BACKGROUND

Different techniques have been described for esophagogastric anastomosis. Over the past decades, surgeons have been improving anastomotic techniques with a gradual shift from hand-sewn to stapled anastomosis. Nowadays, circular-stapled (CS) and linear-stapled (LS) anastomosis are commonly used during esophagectomy.

METHODS

PubMed, MEDLINE, Scopus, and Web of Science were searched up to June 2022. The included studies evaluated short-term outcomes for LS vs. CS anastomosis in patients undergoing esophagectomy for cancer. Primary outcomes were anastomotic leak (AL) and stricture (AS). Risk ratio (RR) and standardized mean difference (SMD) were used as pooled effect size measures whereas 95% confidence intervals (95%CI) were used to assess relative inference.

RESULTS

Eighteen studies (2861 patients) were included. Overall, 1371 (47.9%) underwent CS while 1490 (52.1%) LS. Compared to CS, LS was associated with a significantly reduced RR for AL (RR = 0.70; 95% CI 0.54-0.91; p < 0.01) and AS (RR = 0.32; 95% CI 0.20-0.51; p < 0.0001). Stratified subgroup analysis according to the level of anastomosis (cervical and thoracic) still shows a tendency toward reduced risk for LS. No differences were found for pneumonia (RR 0.78; p = 0.12), reflux esophagitis (RR 0.74; p = 0.36), operative time (SMD -0.25; p = 0.16), hospital length of stay (SMD 0.13; p = 0.51), and 30-day mortality (RR 1.26; p = 0.42).

CONCLUSIONS

LS anastomosis seems associated with a tendency toward a reduced risk for AL and AS. Although surgeon's own training and experience might direct the choice of esophagogastric anastomosis, our meta-analysis encourages the use of LS anastomosis.

Real-life introduction of powered circular stapler for esophagogastric anastomosis: cohort and propensity matched score study

Anastomotic leakage after esophagectomy is one of the most feared complications, which results in increased morbidity and mortality. Our aim was to evaluate the impact of a powered circular stapler on complications after esophagectomy with intrathoracic anastomosis for esophageal cancer. Between May 2019 and July 2021, all consecutive oesophagectomies for cancer with intrathoracic anastomosis in a high-volume center were included in this retrospective study. Surgeons were free to choose either a manual or a powered circular stapler. Preoperative characteristics and postoperative complications were recorded in a prospective database, according to EsoData. Propensity score matching (age, body mass index, Eastern cooperative oncology group (ECOG) performance and neoadjuvant therapy) was conducted to reduce potential confounding. We included 128 patients. Powered and manual circular staplers were used in 62 and 66 patients, respectively. Fewer anastomotic leakages were observed with the powered stapler group (OR = 7.3 (95%CI: 1.58-33.7); [3.2% (n = 2) vs 19.7% (n = 13), respectively; p = 0.004]). After propensity score matching, this remained statistically significant (OR = 8.5 (95%CI: 1.80-40.1); [4.1% (n = 2) vs 20.4% (n = 10), respectively; p = 0.013]). Additionally, anastomotic diameter was significantly higher with the powered stapler (median: 29 mm (63.3%) vs 25 mm (57.1%), respectively; p < 0.0001). There was no significant difference in comprehensive complication index (p = 0.146). A decreased mean length of stay was observed in the powered stapler group (11.1 vs 18.7 days respectively; p = 0.022). Postoperative anastomotic leakage after esophageal resection was significantly reduced after the introduction of the powered circular stapler, consequently resulting in a reduced length of stay. Further evaluation on long-term strictures and quality of life are warranted to support these results.

[Intraoperative fluorescence-guided perfusion assessment using indocyanine green-Increased safety in gastrointestinal anastomoses?]

Insufficiency of gastrointestinal anastomoses represents a relevant risk of morbidity and mortality for affected patients. The perfusion quality of the ends of the intestine is the decisive parameter for ensuring sufficient healing of an anastomosis. Intraoperative fluorescence-guided perfusion assessment with indocyanine green is increasingly being used in modern visceral surgery to evaluate tissue perfusion prior to the fashioning of gastrointestinal anastomoses. This technique provides the possibility to distinguish between adequately and inadequately perfused tissue in order to place the anastomosis in the region with the best possible perfusion. Thus, surgeons have a measuring instrument that enables an objective assessment of the perfusion quality of the tissue to be undertaken in addition to a purely subjective macroscopic visual assessment, in order to achieve a better functional result for the patients. Currently, however, the value of this technique has not yet been conclusively clarified. The aim of this review article is to characterize the benefits of intraoperative fluorescence-guided perfusion assessment and to classify it with respect to its significance for routine clinical practice.

Utility and usability of laser speckle contrast imaging (LSCI) for displaying real-time tissue perfusion/blood flow in robot-assisted surgery (RAS): comparison to indocyanine green (ICG) and use in laparoscopic surgery

Background

Utility and usability of laser speckle contrast imaging (LSCI) in detecting real-time tissue perfusion in robot-assisted surgery (RAS) and laparoscopic surgery are not known. LSCI displays a color heatmap of real-time tissue blood flow by capturing the interference of coherent laser light on red blood cells. LSCI has advantages in perfusion visualization over indocyanine green imaging (ICG) including repeat use on demand, no need for dye, and no latency between injection and display. Herein, we report the first-in-human clinical comparison of a novel device combining proprietary LSCI processing and ICG for real-time perfusion assessment during RAS and laparoscopic surgeries.

Methods

ActivSight™ imaging module is integrated between a standard laparoscopic camera and scope, capable of detecting tissue blood flow via LSCI and ICG in laparoscopic surgery. From November 2020 to July 2021, we studied its use during elective robotic-assisted and laparoscopic cholecystectomies, colorectal, and bariatric surgeries (NCT# 04633512). For RAS, an ancillary laparoscope with ActivSight imaging module was used for LSCI/ICG visualization. We determined safety, usability, and utility of LSCI in RAS vs. laparoscopic surgery using end-user/surgeon human factor testing (Likert scale 1–5) and compared results with two-tailed t tests.

Results

67 patients were included in the study—40 (60%) RAS vs. 27 (40%) laparoscopic surgeries. Patient demographics were similar in both groups. No adverse events to patients and surgeons were observed in both laparoscopic and RAS groups. Use of an ancillary laparoscopic system for LSCI/ICG visualization had minimal impact on usability in RAS as evidenced by surgeon ratings of device usability (set-up 4.2/5 and form-factor 3.8/5). LSCI ability to detect perfusion (97.5% in RAS vs 100% in laparoscopic cases) was comparable in both RAS and laparoscopic cases.

Conclusions

LSCI demonstrates comparable utility and usability in detecting real-time tissue perfusion/blood flow in RAS and laparoscopic surgery.

Graphical abstract

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.

Qualitative features of esophageal fluorescence angiography and anastomotic outcomes in children

BACKGROUND

Indocyanine green (ICG) is commonly used to assess perfusion, but quality defining features are lacking. We sought to establish qualitative features of esophageal ICG perfusion assessments, and develop an esophageal anastomotic scorecard to risk-stratify anastomotic outcomes.

METHODS

Single institution, retrospective analysis of children with an intraoperative ICG perfusion assessment of an esophageal anastomosis. Qualitative perfusion features were defined and a perfusion score developed. Associations between perfusion and clinical features with poor anastomotic outcomes (PAO, leak or refractory stricture) were evaluated with logistic and time-to-event analyses. Combining significant features, we developed and tested an esophageal anastomotic scorecard to stratify PAO risk.

RESULTS

From 2019 to 2021, 53 children (median age 7.4 months) underwent 55 esophageal anastomoses. Median (IQR) follow-up was 14 (10-19.9) months; mean (SD) perfusion score was 13.2 (3.4). Fifteen (27.3%) anastomoses experienced a PAO and had significantly lower mean perfusion scores (11.3 (3.3) vs 14.0 (3.2), p = 0.007). Unique ICG perfusion features, severe tension, and primary or rescue traction-induced esophageal lengthening [Foker] procedures were significantly associated with PAO on both logistic and Cox regression. The scorecard (range 0-7) included any Foker (+2), severe tension (+1), no arborization on either segment (+1), suture line hypoperfusion >twice expected width (+2), and segmental or global areas of hypoperfusion (+1). A scorecard cut-off >3 yielded a sensitivity of 73% and specificity of 93% (AUC 0.878 [95%CI 0.777 to 0.978]) in identifying a PAO.

CONCLUSIONS

A scoring system comprised of qualitative ICG perfusion features, tissue quality, and anastomotic tension can help risk-stratify esophageal anastomotic outcomes accurately.

LEVELS OF EVIDENCE

Diagnostic - II.

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

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

Intraoperative visualization and quantitative assessment of tissue perfusion by imaging photoplethysmography: comparison with ICG fluorescence angiography

Intraoperative monitoring of tissue perfusion is of great importance for optimizing surgery and reducing postoperative complications. To date, there is no standard procedure for assessing blood circulation in routine clinical practice. Over the past decade, indocyanine green (ICG) fluorescence angiography is most commonly used for intraoperative perfusion evaluation. Imaging photoplethysmography (iPPG) potentially enables contactless assessment of the blood supply to organs. However, no strong evidence of this potential has been provided so far. Here we report results of a comparative assessment of tissue perfusion obtained using custom-made iPPG and commercial ICG-fluorescence systems during eight different gastrointestinal surgeries. Both systems allow mapping the blood-supply distribution over organs. It was demonstrated for the first time that the quantitative assessment of blood perfusion by iPPG is in good agreement with that obtained by ICG-fluorescence imaging in all surgical cases under study. iPPG can become an objective quantitative monitoring system for tissue perfusion in the operating room due to its simplicity, low cost and no need for any agent injections.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Systematic Review Registration

PROSPERO, CRD:42021244819.

Transthoracic Esophagectomy: Hand-sewn Versus Side-to-side Linear-stapled Versus Circular-stapled Anastomosis: A Systematic Review and Meta-analysis

BACKGROUND

Three anastomotic techniques are mostly used to create an esophagogastric anastomosis in a transthoracic esophagectomy: hand-sewn (HS), side-to-side linear-stapled (SSLS), and circular-stapled (CS). The aim of this study was to compare surgical outcomes after HS, SSLS, and CS intrathoracic esophagogastric anastomosis.

MATERIALS AND METHODS

A systematic review using the MEDLINE database was performed to identify original articles analyzing outcomes after HS, SSLS, and CS esophagogastric anastomosis. The main outcome was an anastomotic leakage rate. Secondary outcomes included overall morbidity, major morbidity, and mortality. A meta-analysis of proportions and linear regression models were used to assess the effect of each anastomotic technique on the different outcomes.

RESULTS

A total of 101 studies comprising 12,595 patients were included; 8835 (70.1%) with CS, 2532 (20.1%) with HS, and 1228 (9.8%) with SSLS anastomosis. Anastomotic leak occurred in 10% [95% confidence interval (CI), 6%-15%], 9% (95% CI, 6%-13%), and 6% (95% CI, 5%-7%) of patients after HS, SSLS, and CS anastomosis, respectively. Risk of anastomotic leakage was significantly higher with HS anastomosis (odds ratio=1.73, 95% CI: 1.47-2.03, P<0.0001) and SSLS (odds ratio=1.68, 95% CI: 1.36-2.08, P<0.0001), as compared with CS. Overall morbidity (HS: 52% vs. SLSS: 39% vs. CS: 35%) and major morbidity (HS: 33% vs. CS: 19%) rates were significantly lower with CS anastomosis. Mortality rate was 4% (95% CI, 3%-6%), 2% (95% CI, 2%-3%), and 3% (95% CI, 3%-4%) after HS, SSLS, and CS anastomosis, respectively.

CONCLUSION

HS and SSLS intrathoracic esophagogastric anastomoses are associated with significantly higher rates of an anastomotic leak than CS anastomosis.

Quantification of gastric tube perfusion following esophagectomy using fluorescence imaging with indocyanine green

INTRODUCTION

Anastomotic leakage (AL) remains a prevalent and life-threatening complication after esophagectomy. Gastric tube perfusion assessment using indocyanine green fluorescence imaging (ICG-FI) has been published in several studies and appears to be a promising tool to reduce AL rates by changing the surgical approach, namely by an intraoperative evaluation of the anastomosis localization.

METHODS

In this study, gastric tube perfusion was quantified by using ICG-FI in 20 high-risk patients undergoing esophagectomy. From a time-dependent fluorescence intensity curve, the following three parameters were evaluated: slope of fluorescence intensity (SFI), background subtracted peak fluorescence intensity (BSFI), and time to slope (TTS).

RESULTS

The values between pyloric region and tip showed a similar downward trend and SFI and BSFI significantly correlated with the distance to the pyloric region. SFI and BSFI were significantly decreased at the tip of the gastric tube. The placement of anastomosis in an area with homogenous fluorescence pattern was correlated with no AL in 92.9% of cases. An inhomogeneous fluorescence pattern at anastomotic site was a risk factor for the occurrence of an AL (p < 0.05). Reduction of perfusion up to 32% using SFI and up to 23% using BSFI was not associated with AL.

CONCLUSION

ICG-FI can be used to quantify the gastric tube perfusion by calculating SFI, BSFI, and TTS. The anastomosis should be created in areas with homogeneous fluorescence pattern. A reduction in blood flow of up to 32% can be accepted without causing an increased rate of insufficiency.

Quantitative perfusion assessment of gastric conduit with indocyanine green dye to predict anastomotic leak after esophagectomy

Impaired gastric conduit perfusion is a risk factor for anastomotic leak after esophagectomy. The aim of this study is to evaluate the feasibility of intraoperative quantitative assessment of gastric conduit perfusion with indocyanine green fluorescence angiography as a predictor for cervical esophagogastric anastomotic leak after esophagectomy. Indocyanine green fluorescence angiography using the SPY Elite system was performed in patients undergoing a transhiatal or McKeown esophagectomy from July 2015 through December 2020. Ingress (dye uptake) and Egress (dye exit) at two anatomic landmarks (the tip of a conduit and 5 cm from the tip) were assessed. The collected data in the leak group and no leak group were compared by univariate and multivariable analyses. Of 304 patients who were evaluated, 70 patients developed anastomotic leak (23.0%). There was no significant difference in patients' demographic between the groups. Ingress Index, which represents a proportion of blood inflow, at both the tip and 5 cm of the conduit was significantly lower in the leak group (17.9 vs. 25.4% [P = 0.011] and 35.9 vs. 44.6% [P = 0.019], respectively). Ingress Time, which represents an estimated time of blood inflow, at 5 cm of the conduit was significantly higher in the leak group (69.9 vs. 57.1 seconds, P = 0.006). Multivariable analysis suggested that these three variables can be used to predict future leak. Variables of gastric conduit perfusion correlated with the incidence of cervical esophagogastric anastomotic leak. Intraoperative measurement of gastric conduit perfusion can be predictive for anastomotic leak following esophagectomy.

Characterization of Near-Infrared Imaging and Indocyanine-Green Use Amongst General Surgeons: A Survey of 263 General Surgeons

BACKGROUND

Near-infrared fluorescence imaging (NIRFI) is an increasingly utilized imaging modality, however its use amongst general surgeons and its barriers to adoption have not yet been characterized.

METHODS

This survey was sent to Canadian Association of General Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons members. Survey development occurred through consensus of NIRFI experienced surgeons.

RESULTS

Survey completion rate for those opening the email was 16.0% (n = 263). Most respondents had used NIRFI (n = 161, 61.2%). Training, higher volumes, and bariatric, thoracic, or foregut subspecialty were associated with use (P < .001).Common reasons for NIRFI included anastomotic assessment (n = 117, 72.7%), cholangiography (n = 106, 65.8%), macroscopic angiography (n = 66, 41.0%), and bowel viability assessment (n = 101, 62.7%). Technical knowledge, training and poor evidence were cited as common barriers to NIRFI adoption.

CONCLUSIONS

NIRFI use is common with high case volume, bariatric, foregut, and thoracic surgery practices associated with adoption. Barriers to use appear to be lack of awareness, low confidence in current evidence, and inadequate training. High quality randomized studies evaluating NIRFI are needed to improve confidence in current evidence; if deemed beneficial, training will be imperative for NIRFI adoption.