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

Evaluation of the benefit of indocyanine green as an educational and practical tool for ureteral identification in laparoscopic pelvic surgery: a cross-sectional study

BACKGROUND

Indocyanine green (ICG) is a visible near-infrared fluorescent dye. Several studies have reported its benefit in identifying important anatomical structures, tissue vascularization, and sentinel lymph nodes in the case of tumors. Studies have shown that ICG is critical and safe in gynecologic surgeries. However, research on how ICG dye can help surgeons in laparoscopic surgeries correctly identify the course of the ureter has yet to be further investigated.

METHOD

This cross-sectional study enrolled 62 gynecology attending and resident surgeons who were asked to identify the course of the ureter on images of laparoscopic surgeries. The results were then compared with images in which ICG dye highlighted the course of the ureter. The purpose of this study was to detect the ability of surgical assistants and residents to adequately identify the course of the ureter in laparoscopic pelvic surgeries.

RESULTS

No statistically significant differences were found in terms of year of residency, years of experience, number of laparoscopic procedures attended, and correct identification of ureter course. ICG proved useful in identifying the correct ureteral trajectory.

CONCLUSIONS

ICG can be a valuable tool to improve the correct identification of ureters and improve surgical outcomes.

Indocyanine green fluorescence in the evaluation of post-resection pancreatic remnant perfusion after a pancreaticoduodenectomy: a clinical study protocol

BACKGROUND

Pancreaticoduodenectomy is associated with an incidence of postoperative complications of approximately 41%. One of the most severe complications is a postoperative pancreatic fistula. The exact cause of postoperative fistula development is still unknown, but it appears to be multifactorial. Proper perfusion of pancreatic remnant is essential for the healing of pancreaticojejunostomy. To date, there is no method to reliably evaluate the vascular supply of the remnant. One of the methods for the assessment of organ perfusion is the indocyanine green fluorescence. This study aims to determine if indocyanine green fluorescence is a reliable method to measure the perfusion of the post-resection pancreatic remnant. The secondary outcome is to determine if intraoperative evaluation of the vascular supply of the post-resection remnant may predict the increased risk of postoperative pancreatic fistula development.

METHODS

This study is designed as a prospective, observational study. All consecutive patients undergoing open or robotic pancreaticoduodenectomies at our department during the 1st May 2024-31st December 2026 period will be enrolled. The exclusion criteria are an allergy to indocyanine green and refusal by the patient. The adequacy of the vascular supply of the post-resection pancreatic remnant will be intraoperatively evaluated using a fluorescence detector. Patients will be divided into two groups: Those with high risk of pancreatic fistula development and those with low risk. The incidence of pancreatic fistulas in both groups is to be compared. Postoperative data including morbidity, mortality, hospital stay, intensive care unit stay and postoperative fistula development will be collected.

DISCUSSION

If an intraoperative assessment of the perfusion of post-resection pancreatic remnant using indocyanine green is proven to be a suitable method to estimate the increased risk of the pancreatic fistula, the list of the existing known risk factors could be expanded. In the most high-risk patients the modification of the surgical procedure could be considered.

TRIAL REGISTRATION

Number: NCT06198400 ClinicalTrials.Gov. Date 08.01.2024.

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

Objective

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.

Patients and methods

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.

Results

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).

Conclusion

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.

Diagnostic laparoscopy with indocyanine green fluorescence test for the evaluation of intestinal perfusion in abdominal blunt injury: a case report

BACKGROUND

The indocyanine green (ICG) fluorescence test has become a standard test in surgical procedures, facilitating the assessment of blood perfusion in real-time. While its utility in emergency surgeries for evaluating anastomotic blood supply is well-established, its application in trauma cases, especially those involving mesenteric hematoma, remains underexplored. Herein, we present a case to illustrate the efficacy of the ICG fluorescence test in such scenarios.

CASE PRESENTATION

A 51-year-old man with uncontrolled hypertension suffered blunt abdominal trauma following a motor vehicle accident. We used the intra-operative ICG fluorescence test to chart the surgical plan for the patient. A combination of diagnostic laparoscopy with ICG fluorescence testing effectively excluded bowel ischemia, leading to the avoidance of intestinal resection and the need for a temporary ostomy. The patient resumed enteral nutrition.

CONCLUSIONS

Our case underscores the efficacy of ICG fluorescence testing in assessing bowel viability and guiding surgical strategies in trauma patients with mesenteric hematoma. By facilitating real-time visualization of blood perfusion, ICG testing enables the adoption of conservative treatments in patients who would traditionally require more invasive surgical interventions, with minimal effect on operation time and cost.

Hyperspectral Imaging Detects Clitoral Vascular Issues in Gender-Affirming Surgery

The aim of this study was to assess the efficacy of hyperspectral imaging (HSI) as an intraoperative perfusion imaging modality during gender affirmation surgery (GAS). The hypothesis posited that HSI could quantify perfusion to the clitoral complex, thereby enabling the prediction of either uneventful wound healing or the occurrence of necrosis. In this non-randomised prospective clinical study, we enrolled 30 patients who underwent GAS in the form of vaginoplasty with the preparation of a clitoral complex from 2020 to 2024 and compared patients' characteristics as well as HSI data regarding clitoris necrosis. Individuals demonstrating uneventful wound healing pertaining to the clitoral complex were designated as Group A. Patients with complete necrosis of the neo-clitoris were assigned to Group B. Patient characteristics were collected and subsequently a comparative analysis carried out. No significant difference in patient characteristics was observed between the two groups. Necrosis occurred when both StO2 and NIR PI parameters fell below 40%. For the simultaneous occurrence of StO2 and NIR PI of 40% or less, a sensitivity of 92% and specificity of 72% was calculated. Intraoperatively, the onset of necrosis in the clitoral complex can be reliably predicted with the assistance of HSI.

Role of artificial intelligence in colorectal cancer

The sphere of artificial intelligence (AI) is ever expanding. Applications for clinical practice have been emerging over recent years. Although its uptake has been most prominent in endoscopy, this represents only one aspect of holistic patient care. There are a multitude of other potential avenues in which gastrointestinal care may be involved. We aim to review the role of AI in colorectal cancer as a whole. We performed broad scoping and focused searches of the applications of AI in the field of colorectal cancer. All trials including qualitative research were included from the year 2000 onwards. Studies were grouped into pre-operative, intra-operative and post-operative aspects. Pre-operatively, the major use is with endoscopic recognition. Colonoscopy has embraced the use for human derived classifications such as Narrow-band Imaging International Colorectal Endoscopic, Japan Narrow-band Imaging Expert Team, Paris and Kudo. However, novel detection and diagnostic methods have arisen from advances in AI classification. Intra-operatively, adjuncts such as image enhanced identification of structures and assessment of perfusion have led to improvements in clinical outcomes. Post-operatively, monitoring and surveillance have taken strides with potential socioeconomic and environmental savings. The uses of AI within the umbrella of colorectal surgery are multiple. We have identified existing technologies which are already augmenting cancer care. The future applications are exciting and could at least match, if not surpass human standards.

Utilization of Indocyanine Green (ICG) Fluorescence in Patients with Pediatric Colorectal Diseases: The Current Applications and Reported Outcomes

In pediatric colorectal surgery, achieving and visualizing adequate perfusion during complex reconstructive procedures are paramount to ensure postoperative success. However, intraoperative identification of proper perfusion remains a challeng. This review synthesizes findings from the literature spanning from January 2010 to March 2024, sourced from Medline/PubMed, EMBASE, and other databases, to evaluate the role of indocyanine green (ICG) fluorescence imaging in enhancing surgical outcomes. Specifically, it explores the use of ICG in surgeries related to Hirschsprung disease, anorectal malformations, cloacal reconstructions, vaginal agenesis, bladder augmentation, and the construction of antegrade continence channels. Preliminary evidence suggests that ICG fluorescence significantly aids in intraoperative decision-making by improving the visualization of vascular networks and assessing tissue perfusion. Despite the limited number of studies, initial findings indicate that ICG may offer advantages over traditional clinical assessments for intestinal perfusion. Its application has demonstrated a promising safety profile in pediatric patients, underscoring the need for larger, prospective studies to validate these observations, quantify benefits, and further assess its impact on clinical outcomes. The potential of ICG to enhance pediatric colorectal surgery by providing real-time, accurate perfusion data could significantly improve surgical precision and patient recovery.

History and evidence for state of the art of lymphadenectomy in esophageal cancer surgery

The current curative multimodal treatment of advanced esophageal cancers consists of neoadjuvant or perioperative chemo(radio)therapy followed by a radical surgical resection of the primary tumor and a 2- or 3-field lymphadenectomy. One of the most important predictors of long-term survival of esophageal cancer patients is lymph node involvement. The distribution pattern of lymph node metastases in esophageal cancer is unpredictable and depends on the primary tumor location, histology, T-stage and application of neoadjuvant or perioperative treatment. The optimal extent of the lymphadenectomy remains controversial; there is no global consensus on this topic yet. Some surgeons advocate an aggressive and extended lymph node dissection to remove occult metastatic disease, to optimize oncological outcomes. Others promote a more restricted lymphadenectomy, since the benefit of an extended lymphadenectomy, especially after neoadjuvant chemoradiotherapy, has not been clearly demonstrated, and morbidity may be reduced. In this review, we describe the development of lymphadenectomy, followed by a summary of current evidence for lymphadenectomy in esophageal cancer treatment.

Indocyanine green: The guide to safer and more effective surgery

In this editorial we comment on the article by Kalayarasan and co-workers published in the recent issue of the World Journal of Gastrointestinal Surgery. The authors present an interesting review on the use of indocyanine green fluorescence in different aspects of abdominal surgery. They also highlight future perspectives of the use of indocyanine green in mini-invasive surgery. Indocyanine green, used for fluorescence imaging, has been approved by the Food and Drug Administration and is safe for use in humans. It can be administered intravenously or intra-arterially. Since its advent, there have been several advancements in the applications of indocyanine green, especially in the surgical field, such as intraoperative mapping and biopsy of sentinel lymph node, measurement of hepatic function prior to resection, in neurosurgical cases to detect vascular anomalies, in cardiovascular cases for patency and assessment of vascular abnormalities, in predicting healing following amputations, in helping visualization of hepatobiliary anatomy and blood vessels, in reconstructive surgery, to assess flap viability and for the evaluation of tissue perfusion following major trauma and burns. For these reasons, the intraoperative use of indocyanine green has become common in a variety of surgical specialties and transplant surgery. Colorectal surgery has just lately begun to adopt this technique, particularly for perfusion visualization to prevent anastomotic leakage. The regular use of indocyanine green coupled with fluorescence angiography has recently been proposed as a feasible tool to help improve patient outcomes. Using the best available data, it has been shown that routine use of indocyanine green in colorectal surgery reduces the rates of anastomotic leak. The use of indocyanine green is proven to be safe, feasible, and effective in both elective and emergency scenarios. However, additional robust evidence from larger-scale, high-quality studies is essential before incorporating indocyanine green guided surgery into standard practice.

Indocyanine green (ICG) fluorescence-enhanced applications in pediatric surgery

The breadth of pediatric surgical practice and variety of anatomic anomalies that characterize surgical disease in children and neonates require a unique level of operative mastery and versatility. Intraoperative navigation of small, complex, and often abnormal anatomy presents a particular challenge for pediatric surgeons. Clinical experience with fluorescent tissue dye, specifically indocyanine green (ICG), is quickly gaining widespread incorporation into adult surgical practice as a safe, non-toxic means of accurately visualizing tissue perfusion, lymphatic flow, and biliary anatomy to enhance operative speed, safety, and patient outcomes. Experience in pediatric surgery, however, remains limited. ICG-fluorescence guided surgery is poised to address the challenges of pediatric and neonatal operations for a growing breadth of surgical pathology. Fluorescent angiography has permitted intraoperative visualization of colorectal flap perfusion for complex pelvic reconstruction and anastomotic perfusion after esophageal atresia repair, while its hepatic absorption and biliary excretion has made it an excellent agent for delineating the dissection plane in the Kasai portoenterostomy and identifying both primary and metastatic hepatoblastoma lesions. Subcutaneous and intra-lymphatic ICG injection can identify iatrogenic chylous leaks and improved yields in sentinel lymph node biopsies. ICG-guided surgery holds promise for more widespread use in pediatric surgical conditions, and continued evaluation of efficacy will be necessary to better inform clinical practice and identify where to focus and develop this technical resource.

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.

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.

Enhancing visualization and guidance in general surgery: a comprehensive and narrative review of the current cutting-edge technologies and future perspectives

BACKGROUND

In the last decade, there has been a great effort in developing new technologies to enhance surgical visualization and guidance. This comprehensive and narrative review aimed to provide a wide and extensive overview of the current state of the art on this topic and their near-future perspectives linked to the development of artificial intelligence (AI), by focusing on the most recent and relevant literature.

METHODS

A comprehensive and narrative review of the literature was performed by searching specific terms on PubMed/MEDLINE, Scopus, and Embase databases, assessing the current state of the art on this topic.

RESULTS

Fluorescence-guided surgery, contrast-enhanced ultrasound (CEUS), ultra-high frequency ultrasound (UHFUS), photoacoustic imaging (PAI), and augmented reality (AR) are boosting the field of image-guided techniques as the rapid development of AI in surgery is promising a more automated decision-making and surgical movements in the operating room.

CONCLUSION

Fluorescence-guided surgery, CEUS, UHFUS, PAI, and AR are becoming crucial to give surgeons a new level of information during the intervention, with the right timing and sequence, and represent the future of surgery. As many more controlled studies are needed to validate the employment of these technologies, the next generation of surgeons must become more familiar with the basics of AI to better incorporate new tools into the daily surgical practice of the future.

Inferior Mesenteric Artery Ligation Level in Rectal Cancer Surgery beyond Conventions: A Review

Within the intricate field of rectal cancer surgery, the contentious debate over the optimal level of ligation of the inferior mesenteric artery (IMA) persists as an ongoing discussion, influencing surgical approaches and patient outcomes. This narrative review incorporates historical perspectives, technical considerations, and functional as well as oncological outcomes, addressing key questions related to anastomotic leakage risks, genitourinary function, and oncological concerns, providing a more critical understanding of the well-known inconclusive evidence. Beyond the dichotomy of high versus low tie, it navigates the complexities of colorectal cancer surgery with a fresh perspective, posing a transformative question: "Is low tie ligation truly reproducible?" Considering a multidimensional approach that enhances patient outcomes by integrating the surgeon, patient, technique, and technology, instead of a rigid and categorical statement, we argued that a balanced response to this challenging question may require compromise.

[Status Quo of Surgical Navigation]

Surgical navigation, also referred to as computer-assisted or image-guided surgery, is a technique that employs a variety of methods - such as 3D imaging, tracking systems, specialised software, and robotics to support surgeons during surgical interventions. These emerging technologies aim not only to enhance the accuracy and precision of surgical procedures, but also to enable less invasive approaches, with the objective of reducing complications and improving operative outcomes for patients. By harnessing the integration of emerging digital technologies, surgical navigation holds the promise of assisting complex procedures across various medical disciplines. In recent years, the field of surgical navigation has witnessed significant advances. Abdominal surgical navigation, particularly endoscopy, laparoscopic, and robot-assisted surgery, is currently undergoing a phase of rapid evolution. Emphases include image-guided navigation, instrument tracking, and the potential integration of augmented and mixed reality (AR, MR). This article will comprehensively delve into the latest developments in surgical navigation, spanning state-of-the-art intraoperative technologies like hyperspectral and fluorescent imaging, to the integration of preoperative radiological imaging within the intraoperative setting.

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.

Quantification of indocyanine green near-infrared fluorescence bowel perfusion assessment in colorectal surgery

BACKGROUND

Indocyanine green near-infrared fluorescence bowel perfusion assessment has shown its potential benefit in preventing anastomotic leakage. However, the surgeon's subjective visual interpretation of the fluorescence signal limits the validity and reproducibility of the technique. Therefore, this study aimed to identify objective quantified bowel perfusion patterns in patients undergoing colorectal surgery using a standardized imaging protocol.

METHOD

A standardized fluorescence video was recorded. Postoperatively, the fluorescence videos were quantified by drawing contiguous region of interests (ROIs) on the bowel. For each ROI, a time-intensity curve was plotted from which perfusion parameters (n = 10) were derived and analyzed. Furthermore, the inter-observer agreement of the surgeon's subjective interpretation of the fluorescence signal was assessed.

RESULTS

Twenty patients who underwent colorectal surgery were included in the study. Based on the quantified time-intensity curves, three different perfusion patterns were identified. Similar for both the ileum and colon, perfusion pattern 1 had a steep inflow that reached its peak fluorescence intensity rapidly, followed by a steep outflow. Perfusion pattern 2 had a relatively flat outflow slope immediately followed by its plateau phase. Perfusion pattern 3 only reached its peak fluorescence intensity after 3 min with a slow inflow gradient preceding it. The inter-observer agreement was poor-moderate (Intraclass Correlation Coefficient (ICC): 0.378, 95% CI 0.210-0.579).

CONCLUSION

This study showed that quantification of bowel perfusion is a feasible method to differentiate between different perfusion patterns. In addition, the poor-moderate inter-observer agreement of the subjective interpretation of the fluorescence signal between surgeons emphasizes the need for objective quantification.

Real-time quantification of bowel perfusion using Laparoscopic Laser Speckle Contrast Imaging (LSCI) in a porcine model

BACKGROUND/PURPOSE

Real-time quantification of tissue perfusion can improve intraoperative surgical decision making. Here we demonstrate the utility of Laser Speckle Contrast Imaging as an intra-operative tool that quantifies real-time regional differences in intestinal perfusion and distinguishes ischemic changes resulting from arterial/venous obstruction.

METHODS

Porcine models (n = 3) consisted of selectively devascularized small bowel loops that were used to measure the perfusion responses under conditions of control/no vascular occlusion, arterial inflow occlusion, and venous outflow occlusion using laser speckle imaging and indocyanine green fluoroscopy. Laser Speckle was also used to assess perfusion differences between small bowel antimesenteric-antimesenteric and mesenteric-mesenteric anastomoses. Perfusion quantification was measured in relative perfusion units calculated from the laser speckle perfusion heatmap.

RESULTS

Laser Speckle distinguished between visually identified perfused, watershed, and ischemic intestinal segments with both color heatmap and quantification (p < .00001). It detected a continuous gradient of relative intestinal perfusion as a function of distance from the stapled ischemic bowel edge. Strong positive linear correlation between relative perfusion units and changes in mean arterial pressure resulting from both arterial (R2 = .96/.79) and venous pressure changes (R2 = .86/.96) was observed. Furthermore, Laser Speckle showed that the antimesenteric anastomosis had a higher perfusion than mesenteric anastomosis (p < 0.01).

CONCLUSIONS

Laser Speckle Contrast Imaging provides objective, quantifiable tissue perfusion information in both color heatmap and relative numerical units. Laser Speckle can detect spatial/temporal differences in perfusion between antimesenteric and mesenteric borders of a bowel segment and precisely detect perfusion changes induced by progressive arterial/venous occlusions in real-time.

Intraoperative bowel perfusion assessment methods and their effects on anastomotic leak rates: meta-analysis

BACKGROUND

Anastomotic leak is one of the most feared complications of colorectal surgery, and probably linked to poor blood supply to the anastomotic site. Several technologies have been described for intraoperative assessment of bowel perfusion. This systematic review and meta-analysis aimed to evaluate the most frequently used bowel perfusion assessment modalities in elective colorectal procedures, and to assess their associated risk of anastomotic leak. Technologies included indocyanine green fluorescence angiography, diffuse reflectance spectroscopy, laser speckle contrast imaging, and hyperspectral imaging.

METHODS

The review was preregistered with PROSPERO (CRD42021297299). A comprehensive literature search was performed using Embase, MEDLINE, Cochrane Library, Scopus, and Web of Science. The final search was undertaken on 29 July 2022. Data were extracted by two reviewers and the MINORS criteria were applied to assess the risk of bias.

RESULTS

Some 66 eligible studies involving 11 560 participants were included. Indocyanine green fluorescence angiography was most used with 10 789 participants, followed by diffuse reflectance spectroscopy with 321, hyperspectral imaging with 265, and laser speckle contrast imaging with 185. In the meta-analysis, the total pooled effect of an intervention on anastomotic leak was 0.05 (95 per cent c.i. 0.04 to 0.07) in comparison with 0.10 (0.08 to 0.12) without. Use of indocyanine green fluorescence angiography, hyperspectral imaging, or laser speckle contrast imaging was associated with a significant reduction in anastomotic leak.

CONCLUSION

Bowel perfusion assessment reduced the incidence of anastomotic leak, with intraoperative indocyanine green fluorescence angiography, hyperspectral imaging, and laser speckle contrast imaging all demonstrating comparable results.

Reconstruction, oversewing, or taking the anastomosis down - which surgical intervention is most potent in the treatment of anastomotic leaks following colorectal resections?

PURPOSE

Anastomotic leak (AL) following colorectal resections can be treated interventionally. However, most cases require surgical intervention. Thus, several surgical techniques are available, which intend to affect the further course positively. The aim of this retrospective analysis is to determine which surgical technique proves to have the biggest potential in reducing the morbidity and mortality as well as to minimize the need of re-interventions after AL.

METHODS

All patients with a history of AL following colorectal resection between 2008 and 2020 were analyzed. Patient's outcomes following surgical treatment of AL, including morbidity and mortality, clinical and para-clinical (laboratory examinations, ultrasound, and CT-scan) detection of AL recurrence, re-intervention rate, and the length of hospital stay were documented and correlated with the surgical technique used (e.g. simply over-sewing the AL, over-sewing the AL with the construction of a protective ileostomy, resection and reconstruction of the anastomosis, peritoneal lavage and transanal drainage, or taking the anastomosis down and constructing an end stoma).

RESULTS

A total of 2,724 colorectal resections were documented. Grade C AL occurred in 92 (4.4% AL occurrence-rate) and 31 (7.2% AL occurrence-rate) cases following colon and rectal resections, respectively. The anastomosis was not preservable in 52 and 17 cases following colon and rectal resections, respectively. Therefore, the anastomosis had been taken down and an end-stoma had been constructed. Over-sewing the AL with the construction of a protective ileostomy had the highest anastomosis preservation rate (14 of 18 cases) and lowest re-intervention rate (mean value of 1.5 re-interventions) following colon and rectal resections (7 of 9 cases; mean value, 1.5 re-interventions).

CONCLUSION

In cases where an AL is preservable, over-sewing the anastomosis and constructing a protective ileostomy has the greatest potential for positive short-term outcomes following colorectal resections.

Application of indocyanine green in surgery: A review of current evidence and implementation in trauma patients

Background: Modern surgical medicine strives to manage trauma while improving outcomes using functional imaging. Identification of viable tissues is crucial for the surgical management of polytrauma and burn patients presenting with soft tissue and hollow viscus injuries. Bowel anastomosis after trauma-related resection is associated with a high rate of leakage. The ability of the surgeon’s bare eye to determine bowel viability remains limited, and the need for a more standardized objective assessment has not yet been fulfilled. Hence, there is a need for more precise diagnostic tools to enhance surgical evaluation and visualization to aid early diagnosis and timely management to minimize trauma-associated complications. Indocyanine green (ICG) coupled with fluorescence angiography is a potential solution for this problem. ICG is a fluorescent dye that responds to near-infrared irradiation. Methods: We conducted a narrative review to address the utility of ICG in the surgical management of patients with trauma as well as elective surgery. Discussion: ICG has many applications in different medical fields and has recently become an important clinical indicator for surgical guidance. However, there is a paucity of information regarding the use of this technology to treat traumas. Recently, angiography with ICG has been introduced in clinical practice to visualize and quantify organ perfusion under several conditions, leading to fewer cases of anastomotic insufficiency. This has great potential to bridge this gap and enhance the clinical outcomes of surgery and patient safety. However, there is no consensus on the ideal dose, time, and manner of administration nor the indications that ICG provides a genuine advantage through greater safety in trauma surgical settings. Conclusions: There is a scarcity of publications describing the use of ICG in trauma patients as a potentially useful strategy to facilitate intraoperative decisions and to limit the extent of surgical resection. This review will improve our understanding of the utility of intraoperative ICG fluorescence in guiding and assisting trauma surgeons to deal with the intraoperative challenges and thus improve the patients’ operative care and safety in the field of trauma surgery.

Real-time semi-quantitative assessment of anastomotic blood perfusion in mini‑invasive rectal resections by Sidestream Dark Field (SDF) imaging technology: a prospective in vivo pilot study

PURPOSE

Anastomotic leakage (AL) is one of the severe complications after rectal surgery, and anastomotic ischemia is one of the main factors. This prospective in vivo pilot study aimed to evaluate the effectiveness of Sidestream Dark Field (SDF) imaging in quantitative assessment of anastomotic microcirculation and to analyze its correlation with AL.

METHODS

Thirty-three patients with rectal cancer who underwent laparoscopic low anterior resection from 2019 to 2020 were enrolled. Microcirculation was measured by SDF imaging at the descending colon, the mesocolon transection line (MTL), and 1 cm and 2 cm distal to the MTL. Anastomotic microcirculation was measured at the stapler anvil edge before anastomosis. Quantitative perfusion-related parameters were as follows: microcirculation flow index (MFI), perfused vessel density (PVD), proportion of perfused vessels (PPV), and total vessel density (TVD).

RESULTS

All patients obtained stable microcirculation images. Functional microcirculation parameters (MFI, PPV, PVD) decreased successively from the descending colon, the colon at MTL, and 1 cm and 2 cm distal to the MTL (all P < 0.01). Extremely poor microcirculation was found at the intestinal segment 2 cm distal to the MTL. Micro-perfusion was significantly lower at the colonic limb of the anastomosis compared with the descending colon (all P < 0.001). Anastomotic leakage occurred in 3 patients (9.1%) whose anastomotic microcirculation was significantly lower than those without AL (all P < 0.01). Blood perfusion at the colonic limb of the anastomosis was significantly higher in patients with left colic artery preservation than in controls.

CONCLUSION

SDF imaging is a promising technique for evaluating anastomotic microcirculation and has potential clinical significance for risk stratification of AL.

Interobserver Variability in the Assessment of Fluorescence Angiography in the Colon

BACKGROUND

Fluorescence angiography in colorectal surgery is a technique that may lead to lower anastomotic leak rates. However, the interpretation of the fluorescent signal is not standardised and there is a paucity of data regarding interobserver agreement. The aim of this study is to assess interobserver variability in selection of the transection point during fluorescence angiography before anastomosis.

METHODS

An online survey with still images of fluorescence angiography was distributed through colorectal surgery channels containing images from 13 patients where several areas for transection were displayed to be chosen by raters. Agreement was assessed overall and between pre-planned rater cohorts (experts vs non-experts; trainees vs consultants; colorectal specialists vs non colorectal specialists), using Fleiss' kappa statistic.

RESULTS

101 raters had complete image ratings. No significant difference was found between raters when choosing a point of optimal bowel transection based on fluorescence angiography still images. There was no difference between pre-planned cohorts analysed (experts vs non-experts; trainees vs consultants; colorectal specialists vs non colorectal specialists). Agreement between these cohorts was poor (<.26).

CONCLUSION

Whilst there is no learning curve for the technical adoption of FA, understanding the fluorescent signal characteristics is key to successful use. We found significant variation exists in interpretation of static fluorescence angiography data. Further efforts should be employed to standardise fluorescence angiography assessment.

Quantitative perfusion assessment using indocyanine green during surgery - current applications and recommendations for future use

PURPOSE

Incorrect assessment of tissue perfusion carries a significant risk of complications in surgery. The use of near-infrared (NIR) fluorescence imaging with Indocyanine Green (ICG) presents a possible solution. However, only through quantification of the fluorescence signal can an objective and reproducible evaluation of tissue perfusion be obtained. This narrative review aims to provide an overview of the available quantification methods for perfusion assessment using ICG NIR fluorescence imaging and to present an overview of current clinically utilized software implementations.

METHODS

PubMed was searched for clinical studies on the quantification of ICG NIR fluorescence imaging to assess tissue perfusion. Data on the utilized camera systems and performed methods of quantification were collected.

RESULTS

Eleven software programs for quantifying tissue perfusion using ICG NIR fluorescence imaging were identified. Five of the 11 programs have been described in three or more clinical studies, including Flow® 800, ROIs Software, IC Calc, SPY-Q™, and the Quest Research Framework®. In addition, applying normalization to fluorescence intensity analysis was described for two software programs.

CONCLUSION

Several systems or software solutions provide a quantification of ICG fluorescence; however, intraoperative applications are scarce and quantification methods vary abundantly. In the widespread search for reliable quantification of perfusion with ICG NIR fluorescence imaging, standardization of quantification methods and data acquisition is essential.

Anastomotic perfusion assessment with indocyanine green in robot-assisted low-anterior resection, a multicenter study of interobserver variation

BACKGROUND

Securing sufficient blood perfusion to the anastomotic area after low-anterior resection is a crucial factor in preventing anastomotic leakage (AL). Intra-operative indocyanine green fluorescent imaging (ICG-FI) has been suggested as a tool to assess perfusion. However, knowledge of inter-observer variation among surgeons in the interpretation of ICG-FI is sparse. Our primary objective was to evaluate inter-observer variation among surgeons in the interpretation of bowel blood-perfusion assessed visually by ICG-FI. Our secondary objective was to compare the results both from the visual assessment of ICG and from computer-based quantitative analyses of ICG-FI between patients with and without the development of AL.

METHOD

A multicenter study, including patients undergoing robot-assisted low anterior resection with stapled anastomosis. ICG-FI was evaluated visually by the surgeon intra-operatively. Postoperatively, recorded videos were anonymized and exchanged between centers for inter-observer evaluation. Time to visibility (TTV), time to maximum visibility (TMV), and time to wash-out (TWO) were visually assessed. In addition, the ICG-FI video-recordings were analyzed using validated pixel analysis software to quantify blood perfusion.

RESULTS

Fifty-five patients were included, and five developed clinical AL. Bland-Altman plots (BA plots) demonstrated wide inter-observer variation for visually assessed fluorescence on all parameters (TTV, TMV, and TWO). Comparing leak-group with no-leak group, we found no significant differences for TTV: Hazard Ratio; HR = 0.82 (CI 0.32; 2.08), TMV: HR = 0.62 (CI 0.24; 1.59), or TWO: HR = 1.11 (CI 0.40; 3.11). In the quantitative pixel analysis, a lower slope of the fluorescence time-curve was found in patients with a subsequent leak: median 0.08 (0.07;0.10) compared with non-leak patients: median 0.13 (0.10;0.17) (p = 0.04).

CONCLUSION

The surgeon's visual assessment of the ICG-FI demonstrated wide inter-observer variation, there were no differences between patients with and without AL. However, quantitative pixel analysis showed a significant difference between groups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04766060.

Cost analysis of indocyanine green fluorescence angiography for prevention of anastomotic leakage in colorectal surgery

BACKGROUND

Indocyanine green, near infrared, fluorescence angiography (ICG-FA) is increasingly adopted in colorectal surgery for intraoperative tissue perfusion assessment to reduce anastomotic leakage rates. However, the economic impact of this intervention has not been investigated. This study is a cost analysis of the routine use of ICG-FA in colorectal surgery from the hospital payer perspective.

METHODS

A decision analysis model was developed for colorectal resections considering two scenarios: resection without using ICG-FA and resection with intraoperative ICG-FA for anastomotic perfusion assessment. Incorporated into the model were the costs of ICG agent, fluorescence angiography equipment, surgery, anastomotic leak, and the leak rates with and without ICG-FA. All input data were derived from recent publications.

RESULTS

The routine use of ICG-FA for colorectal anastomosis is cost saving when cost analysis is performed using the following base case assumptions: 8.6% leak rate without ICG-FA, odds ratio of 0.46 for reduction of leakage with ICG-FA (4.8% leak rate relative to 8.6% base case), cost of ICG-FA of $250, and incremental cost of leak, not requiring reoperation, of $9,934.50. In one-way sensitivity analyses, routine use of ICG-FA was cost saving if the cost of an anastomotic leak is more than $5616.29, the cost of ICG-FA is less than $634.44, the leak rate (without ICG-FA) is higher than 4.9%, or the odds ratio for reduction of leak with ICG-FA is less than 0.69. There is a per-case saving of $192.22 with the use of ICG-FA.

CONCLUSION

Using the best available evidence and most conservative base case values, routine use of ICG-FA in colorectal surgery was found to be cost saving. Since the evidence suggests there is a reduction in leak rate, the routine use of ICG-FA is a dominating strategy. However, the overall quality of evidence is low and there is a clear need for prospective, randomized controlled trials.

The effect of intracorporeal versus extracorporeal anastomosis in robotic right colectomy on perianastomotic perfusion: a substudy to a multicenter RCT

PURPOSE

Previous studies have shown that intracorporeal anastomosis (ICA) in minimally invasive right colectomy may improve postoperative recovery compared with extracorporeal anastomosis (ECA). It has been hypothesized that creating the anastomosis extracorporeally may cause mesenteric traction and compromised intestinal perfusion. The purpose of this study was to investigate the effect of either ICA or ECA on intestinal perfusion.

METHOD

This was a substudy to a multicenter, triple-blind randomized clinical trial comparing ICA with ECA in patients undergoing robotic right colectomy for colonic cancer. Videos from intraoperative Indocyanine Green (ICG) fluorescence imaging were analyzed with quantitative ICG perfusion assessment (q-ICG). q-ICG was performed by extracting perfusion metrics from a time-intensity curve generated from an image analysis software: F_MAX: maximal fluorescence intensity, T_MAX: time until maximal fluorescent signal, T_1/2MAX: time until half-maximal fluorescent signal, time ratio (T_1/2MAX/T_MAX) and slope.

RESULTS

A total of 68 patients (33 ICA and 35 ECA) were available for analysis. Demographics were similar between the groups, except for mean arterial blood pressure at the time of ICG infusion, which was significantly lower in the ICA group. We found a significantly steeper slope in the ICA group compared to the ECA group (6.3 vs. 4.7 AU/sec, P = .048). There were no significant differences in F_MAX, T_MAX, T_1/2MAX, and time ratio.

CONCLUSION

We found evidence of an improved intestinal perfusion following ICA compared with ECA. This finding may be related to patient outcomes and should be explored further in the future.

TRIAL REGISTRATION

CLINICALTRIALS

gov NCT03130166.

Can indocyanine green during laparoscopic sleeve gastrectomy be considered a new intraoperative modality for leak testing?

BACKGROUND

Indocyanine green (ICG) when injected intravenously into the bloodstream allows us to show stomach vascularity in real time. The aim of our study was to observe the preliminary results of the application of indocyanine green fluorescence (IGF) during laparoscopic sleeve gastrectomy (LSG) in our center and how the perfusion of the staple line of the stomach affects the onset of fistula.

MATERIALS AND METHODS

82 patients underwent LSG with ICG fluorescence angiography at our center from January 2020 to December 2021. 5 ml of ICG was injected intravenously to identify the blood supply of the stomach, carefully assessing the angle of His.

RESULTS

In the ICG-tested LSG, we recorded adequate perfusion in all patients but one: the leakage rate was 1.2%. This data is inferior to the non-tested patients' group.

CONCLUSION

Intraoperative ICG testing may be helpful in determining which patients are at an increased risk for leakage but there are multiple factors contribute to the pathophysiology and the incidence of gastric fistula not only the perfusion. Trial registration Retrospectively registrated.

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

A Comparison of Different Types of Esophageal Reconstructions: A Systematic Review and Network Meta-Analysis

Background: A total esophagectomy with gastric tube reconstruction is the mainstream procedure for esophageal cancer. Colon interposition and free jejunal flap for esophageal reconstruction are the alternative choices when the gastric tube is not available. However, to date, a solution for the high anastomosis leakage rates among these three types of conduits has not been reported. The aim of this network meta-analysis was to investigate the rate of anastomotic leakage (AL) among the three procedures to determine the best esophageal substitute or the future direction for improving the conventional gastric pull-up (GPU). Methods: We searched PubMed, Cochrane, and Embase databases. We included esophageal cancer patients receiving esophagectomy and excluded patients with other cancer. The random effect model was used in this network meta-analysis. The Newcastle–Ottawa Scale (NOS) was used for the quality assessment of studies in the network meta-analysis, and funnel plots were used to evaluate publication bias. The primary outcome is anastomosis leakage; the secondary outcomes are stricture formation, length of hospital stays, and mortality rate. Results: Nine studies involving 1613 patients were included in this network meta-analysis. The trend results indicated the following. Regarding anastomosis leakage, free jejunal flap was the better procedure; regarding stricture formation, colon interposition was the better procedure; regarding mortality rate, free jejunal flap was the better procedure; regarding length of hospital stay, gastric pull-up was the better treatment. Discussion: Overall, if technically accessible, free jejunal flap is a better choice than colon interposition when gastric conduit cannot be used, but further study should be conducted to compare groups with equal supercharged patients. In addition, jejunal flap (JF) cannot replace traditional gastric pull-up (GPU) due to technical complexities, more anastomotic sites, and longer operation times. However, the GPU method with the supercharged procedure would be a possible solution to lower postoperative AL. The limitation of this meta-analysis is that the number of articles included was low; we aim to update the result when new data are available. Funding: None. Registration: N/A.

Modified -shaped esophagojejunostomy in totally laparoscopic total gastrectomy: a report of 40 consecutive cases from a single center

Objective

Intracorporeal esophagojejunostomy remains a challenging technique in totally laparoscopic total gastrectomy (TLTG) because of the lack of an established standard anastomosis method. However, π-shaped esophagojejunostomy in TLTG is reportedly safe and feasible. Therefore, we evaluated the short-term surgical outcomes of our modified π-shaped esophagojejunostomy in TLTG.

Methods

This study involved patients without neoadjuvant therapy diagnosed with gastric cancer who underwent TLTG by the same surgeon with modified π-shaped esophagojejunostomy from April 2018 to October 2019. Clinicopathologic data were collected and retrospectively analyzed.

Results

Forty patients diagnosed with gastric cancer were included. The mean operative time and estimated blood loss were 264.6 ± 56.9 minutes and 68.5 ± 53.3 mL, respectively. Postoperative flatus occurred at 4.6 ± 1.7 days. The mean time to resumption of diet was 7.4 ± 1.7 days postoperatively. One patient was diagnosed with anastomotic leakage and managed with conservative therapy. Pleural effusion was the most common complication, occurring in four (10%) patients. One patient developed intra-abdominal bleeding that required reoperation. Other complications were atrial fibrillation and wound infection. No mortality occurred during the 6-month follow-up.

Conclusions

Modified π-shaped esophagojejunostomy is safe and feasible for intracorporeal anastomosis in TLTG and showed favorable surgical outcomes in this study.

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.

Leak after sleeve gastrectomy with positive intraoperative indocyanine green test: Avoidable scenario?

BACKGROUND

The staple line gastric leak (GL) is estimated to be the most serious complication of the sleeve gastrectomy. The use of indocyanine green (ICG) has been introduced in minimally invasive surgery to show the vascularization of the stomach in real time and its application to the gastroesophageal junction (GE) during Laparoscopic Sleeve Gastrectomy (LSG) seems very promising.

CASE PRESENTATION

We present the case of a 40-year-old female underwent laparoscopic sleeve gastrectomy. Intraoperative indocyanine green test showed a small dark area in the proximal third of the staple line reinforced with fibrin glue. Two weeks later the patient presented to the emergency room (ED) with abdominal pain, fever, vomiting, intolerance to oral intake and the evidence of a leak on the abdomen Computer Tomography (CT). The UIN for ClinicalTrial.gov Protocol Registration and Results System is: NCT05337644 for the Organization UFoggia.

CONCLUSIONS

This case report shows that intraoperative ICG test can be helpful in determining which patients are at greater risk of the leak and, more importantly, the cause of the leak but further tests are needed to determine if the ICG predicts leak due to ischemia.

Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations

Background

Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery.

Purpose, and Research design

Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery.

Study sample and data collection

Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed.

Conclusions

It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future.

Totally Laparoscopic Left Colectomy With Preoperative Simulation Using 3D CT Angiography and Intraoperative Navigation Using the Indocyanine Green (ICG) Fluorescence Method

Introduction

Laparoscopic reconstruction after left colectomy is mostly performed with functional end-to-end anastomosis through about 5–7 cm sized incision. However, this procedure poses some problems, including increased intestinal mobilization range and parietal destruction, insufficient blood flow to the intestinal tract due to arterial arch malformation, and dominant artery dissection. In this paper, we present a case of descending colon cancer for which totally laparoscopic surgery and intracorporeal anastomosis could be performed safely with preoperative simulation and intraoperative navigation.

Case presentation

A 34-year-old male was complaint fecal occult blood positive and a colonoscopy was performed. The patient was diagnosed with descending colon cancer cT2N0N0 Stage I. Preoperative CT angiography findings showed that the inferior mesenteric artery (IMA) branched into the left colic artery (LCA) and the sigmoid arteries (S1, S2) in order and showed LCA and S1 as the dominant arteries, and a totally laparoscopic descending colectomy (D2 dissection and S2 artery preserving) was scheduled. At his operation, for investigate blood flow of anastomotic region, ICG was used. After an intravenous injection of ICG, blood flow was evaluated and intestinal dissection was performed at the scheduled dissection line. Intracorporeal anastomosis was then performed using the overlap method and a linear stapler.

Conclusion

Although the intracorporeal anastomosis procedure has a high degree of difficulty, the use of preoperative simulation and intraoperative navigation may reduce the surgeon's intraoperative stress and enable safe and accurate intestinal dissection and anastomosis in the totally laparoscopic surgery.

Anastomotic leakage in colorectal cancer surgery

The safety of colorectal surgery for oncological disease is steadily improving, but anastomotic leakage is still the most feared and devastating complication from both a surgical and oncological point of view. Anastomotic leakage affects the outcome of the surgery, increases the times and costs of hospitalization, and worsens the prognosis in terms of short- and long-term outcomes. Anastomotic leakage has a wide range of clinical features ranging from radiological only finding to peritonitis and sepsis with multi-organ failure. C-reactive protein and procalcitonin have been identified as early predictors of anastomotic leakage starting from postoperative day 2-3, but abdominal-pelvic computed tomography scan is still the gold standard for the diagnosis. Several treatments can be adopted for anastomotic leakage. However, there is not a universally accepted flowchart for the management, which should be individualized based on patient's general condition, anastomotic defect size and location, indication for primary resection and presence of the proximal stoma. Non-operative management is usually preferred in patients who underwent proximal faecal diversion at the initial operation. Laparoscopy can be attempted after minimal invasive surgery and can reduce surgical stress in patients allowing a definitive treatment. Reoperation for sepsis control is rarely necessary in those patients who already have a diverting stoma at the time of the leak, especially in extraperitoneal anastomoses. In patients without a stoma who do not require abdominal reoperation for a contained pelvic leak, there are several treatment options, including laparoscopic diverting ileostomy combined with trans-anal anastomotic tube drainage, percutaneous drainage or recently developed endoscopic procedures, such as stent or clip placement or endoluminal vacuum-assisted therapy. We describe the current approaches to treat this complication, as well as the clinical tests necessary to diagnose and provide an effective therapy.

Intraoperative Guidance Using Hyperspectral Imaging: A Review for Surgeons

Hyperspectral imaging (HSI) is a novel optical imaging modality, which has recently found diverse applications in the medical field. HSI is a hybrid imaging modality, combining a digital photographic camera with a spectrographic unit, and it allows for a contactless and non-destructive biochemical analysis of living tissue. HSI provides quantitative and qualitative information of the tissue composition at molecular level in a contrast-free manner, hence making it possible to objectively discriminate between different tissue types and between healthy and pathological tissue. Over the last two decades, HSI has been increasingly used in the medical field, and only recently it has found an application in the operating room. In the last few years, several research groups have used this imaging modality as an intraoperative guidance tool within different surgical disciplines. Despite its great potential, HSI still remains far from being routinely used in the daily surgical practice, since it is still largely unknown to most of the surgical community. The aim of this study is to provide clinical surgeons with an overview of the capabilities, current limitations, and future directions of HSI for intraoperative guidance.

The Role of Indocyanine Green Fluorescence Angiography in Complex Abdominal Wall Reconstruction: A Scoping Review of the Literature

BACKGROUND

Indocyanine green fluorescence angiography (ICGFA) is a technique for assessing vascularity and perfusion which has multiple proven applications across a variety of surgical procedures. Studies have been performed assessing its potential role in evaluating skin flap viability in complex abdominal wall reconstruction (CAWR) in order to avoid postoperative surgical site occurrences (SSO).

OBJECTIVES

This scoping review was intended to summarise the literature concerning ICGFA in CAWR in order to facilitate future evidence-based guidelines for its use.

ELIGIBILITY CRITERIA

Inclusion - cohort studies, randomised controlled trials, case series, case reports and ventral midline hernias only. Exclusion - patients aged under 18 years and non-human test subjects.

SOURCES OF EVIDENCE

PubMed, MEDLINE®, Cochrane, Embase and OpenGrey RESULTS: A total of 3416 unique titles were yielded from our search of which 9 met our inclusion criteria: 3 case reports, 1 retrospective case series, 1 prospective case series, 3 non-blinded, non-randomised retrospective case-controlled studies and 1 prospective, double-blinded randomised controlled study. The included studies varied considerably in size and method however the consensus appeared to support ICGFA as being a safe and feasible means of assessing tissue flap vascularity in CAWR. The studies returned contrasting results regarding the impact of ICGFA in predicting and avoiding SSOs however there were insufficient numbers of studies for a meta-analysis.

CONCLUSIONS

We identify three case reports and four lower quality studies suggesting a possible application for ICGFA in CAWR and two higher quality studies showing no overall benefit. Evidence-based guidelines on the role of ICGFA in CAWR will require the assessment of further studies.

Comprehensive Review of Fluorescence Applications in Gynecology

Since the introduction of indocyanine green (ICG) as a fluorophore in near-infrared imaging, fluorescence visualization has become an essential tool in many fields of surgery. In the field of gynecology, recent new applications have been proposed and found their place in clinical practice. Different applications in gynecology were investigated, subcategorized, and overviewed concerning surgical applications and available dyes. Specific applications in which fluorescence-guided surgery was implemented in gynecology are described in this manuscript—namely, sentinel node biopsy, mesometrium visualization, angiography of different organs, safety issues in pregnant women, ureters visualization, detection of peritoneal metastases, targeted fluorophores for cancer detection, fluorescent contamination hysterectomy, lymphography for lower limb lymphedema prevention, tumor margin detection, endometriosis, and metastases mapping. With evolving technology, further innovative research on the new applications of fluorescence visualization in cancer surgery may help to establish these techniques as standards of high-quality surgery in gynecology. However, more investigations are necessary in order to assess if these innovative tools can also be effective to improve patient outcomes and quality of life in different gynecologic malignancies.

Quantitative evaluation of colon perfusion after high versus low ligation in rectal surgery by indocyanine green: a pilot study

BACKGROUND

In the field of rectal cancer surgery, there remains ongoing debate on the merits of high ligation (HL) and low ligation (LL) of the inferior mesenteric artery (IMA) in terms of perfusion and anastomosis leakage. Recently, infrared fluorescence of indocyanine green (ICG) imaging has been used to evaluate perfusion status during colorectal surgery.

OBJECTIVE

The purpose of this study is to compare the changes in perfusion status between HL and LL through quantitative evaluation of ICG.

METHODS

Patients with rectosigmoid or rectal cancer were randomized into a high or LL group. ICG was injected before and after IMA ligation, and region of interest (ROI) values were measured by an image analysis program (HSL video©).

RESULTS

From February to July 2020, 22 patients were enrolled, and 11 patients were assigned to each group. Basic demographics were similar between the two groups, except for albumin level and cardiac ejection fraction. There were no significant differences in F_max between the two groups, but T_max was significantly higher and Slope_max was significantly lower in the HL group than in the LL group. Anastomosis leakage was significantly associated with neoadjuvant chemoradiation and F_max.

CONCLUSION

After IMA ligation, T_max increased and Slope_max decreased significantly in the HL group. However, the intensity of perfusion status (F_max) did not change according to the level of IMA ligation.

Multimodal imaging of laser speckle contrast imaging combined with mosaic filter-based hyperspectral imaging for precise surgical guidance

OBJECTIVE

To enable a real-time surgical guidance system that simultaneously monitors blood vessel perfusion, oxygen saturation, thrombosis, and tissue recovery by combining multiple optical imaging techniques into a single system: visible imaging, mosaic filter-based snapshot hyperspectral imaging (HSI), and laser speckle contrast imaging (LSCI).

METHODS

The multimodal optical imaging system was demonstrated by clamping blood vessels in the small intestines of rats to create areas of restricted blood flow. Subsequent tissue damage and regeneration were monitored during procedures. Using LSCI, vessel perfusion was measured, revealing the biological activity and survival of organ tissues. Blood oxygen saturation was monitored using HSI in the near-infrared region. Principal component analysis was used over the spectral dimension to identify an HSI wavelength combination optimized for hemodynamic biomarker visualization. HSI and LSCI were complimentary, identifying thrombus generation and tissue recovery, which was not possible in either modality alone.

RESULTS AND CONCLUSION

By analyzing multimodal tissue information from visible imaging, LSCI perfusion imaging, and HSI, a recovery prognosis could be determined based on the blood supply to the organ. The unique combination of the complementary imaging techniques into a single surgical microscope holds promise for improving the real-time determination of blood supply and tissue prognosis during surgery.

SIGNIFICANCE

Precise real-time monitoring for vascular anomalies promises to reduce the risk of organ damage in precise surgical operations such as tissue resection and transplantation. In addition, the convergence of label-free imaging technologies removes delays associated with the injection and diffusion of vascular monitoring dyes.

The use of Indocyanine green fluorescent in patients with abdominal trauma for better intraoperative decision-making and less bowel anastomosis leak: case series

Despite technological advances in the management of blunt abdominal trauma, the rate of bowel anastomotic leakage (AL) remains high. The etiology of AL is multifactorial, but insufficient blood perfusion is considered to play a substantial role in the pathogenesis. In recent years, angiography with Indocyanine green (ICG), a fluorescent dye, has been introduced in the clinical practice to assess organ perfusion in several conditions. Given the scarcity of publications describing the use of ICG in trauma patients as a potentially useful strategy that may facilitate intraoperative decisions and limit the extent of bowel resection, we presented the utility of intraoperative ICG fluorescent in abdominal trauma patients in a level 1 trauma center. The use of ICG fluoroscopy in patients with abdominal trauma is feasible and useful; however, large prospective studies in trauma patients are warranted.

Influence of intraoperative vasopressor use on indocyanine green fluorescence angiography: first evaluation in an experimental model

Intraoperative indocyanine green (ICG) fluorescence angiography has gained popularity and acceptance in many surgical fields for the real-time assessment of tissue perfusion. Although vasopressors have the potential to preclude an accurate assessment of tissue perfusion, there is a lack of literature with regards to its effect on ICG fluorescence angiography. An experimental porcine model was used to expose the small bowel for quantitative tissue perfusion assessment. Three increasing doses of norepinephrine infusion (0.1, 0.5, and 1.0 µg/kg/min) were administered intravenously over a 25-min interval. Time-to-peak fluorescence intensity (TTP) was the primary outcome. Secondary outcomes included absolute fluorescence intensity and local capillary lactate (LCL) levels. Five large pigs (mean weight: 40.3 ± 4.24 kg) were included. There was no significant difference in mean TTP (in seconds) at baseline (4.23) as compared to the second (3.90), third (4.41), fourth (4.60), and fifth ICG assessment (5.99). As a result of ICG accumulation, the mean and the maximum absolute fluorescence intensity were significantly different as compared to the baseline assessment. There was no significant difference in LCL levels (in mmol/L) at baseline (0.74) as compared to the second (0.82), third (0.64), fourth (0.60), and fifth assessment (0.62). Increasing doses of norepinephrine infusion have no significant influence on bowel perfusion using ICG fluorescence angiography.

Quantitative fluorescence angiography aids novice and experienced surgeons in performing intestinal resection in well-perfused tissue

Background

Anastomotic leakage (AL) after gastrointestinal resection is a devastating complication with huge consequences for the patient. As AL is associated with poor blood supply, tools for objective assessment of perfusion are in high demand. Indocyanine green angiography (ICG-FA) and quantitative analysis of ICG-FA (q-ICG) seem promising. This study aimed to investigate whether ICG-FA and q-ICG could improve perfusion assessment performed by surgeons of different experience levels.

Methods

Thirteen small bowel segments with a varying degree of devascularization, including two healthy sham segments, were constructed in a porcine model. We recruited students, residents, and surgeons to perform perfusion assessment of the segments in white light (WL), with ICG-FA, and after q-ICG, all blinded to the degree of devascularization.

Results

Forty-five participants fulfilled the study (18 novices, 12 intermediates, and 15 experienced). ICG and q-ICG helped the novices correctly detect the healthy bowel segments to experienced surgeons’ level. ICG and q-ICG also helped novice surgeons to perform safer resections in healthy tissue compared with normal WL. The relative risk (RR) of leaving ischemic tissue in WL and ICG compared with q-ICG, even for experienced surgeons was substantial, intermediates (RR = 8.9, CI95% [4.0;20] and RR = 6.2, CI95% [2.7;14.1]), and experienced (RR = 4.7, CI95% [2.6;8.7] and RR = 4.0, CI95% [2.1;7.5]).

Conclusion

Q-ICG seems to guide surgeons, regardless of experience level, to safely perform resection in healthy tissue, compared with standard WL. Future research should focus on this novel tool’s clinical impact.