Fluorescence angiography vs. direct palpation for bowel viability evaluation with strangulated bowel obstruction

Indocyanine green fluorescence-guided surgery in the emergency setting: the WSES international consensus position paper

BACKGROUND

Decision-making in emergency settings is inherently complex, requiring surgeons to rapidly evaluate various clinical, diagnostic, and environmental factors. The primary objective is to assess a patient's risk for adverse outcomes while balancing diagnoses, management strategies, and available resources. Recently, indocyanine green (ICG) fluorescence imaging has emerged as a valuable tool to enhance surgical vision, demonstrating proven benefits in elective surgeries.

AIM

This consensus paper provides evidence-based and expert opinion-based recommendations for the standardized use of ICG fluorescence imaging in emergency settings.

METHODS

Using the PICO framework, the consensus coordinator identified key research areas, topics, and questions regarding the implementation of ICG fluorescence-guided surgery in emergencies. A systematic literature review was conducted, and evidence was evaluated using the GRADE criteria. A panel of expert surgeons reviewed and refined statements and recommendations through a Delphi consensus process, culminating in final approval.

RESULTS

ICG fluorescence imaging, including angiography and cholangiography, improves intraoperative decision-making in emergency surgeries, potentially reducing procedure duration, complications, and hospital stays. Optimal use requires careful consideration of dosage and timing due to limited tissue penetration (5-10 mm) and variable performance in patients with significant inflammation, scarring, or obesity. ICG is contraindicated in patients with known allergies to iodine or iodine-based contrast agents. Successful implementation depends on appropriate training, availability of equipment, and careful patient selection.

CONCLUSIONS

Advanced technologies and intraoperative navigation techniques, such as ICG fluorescence-guided surgery, should be prioritized in emergency surgery to improve outcomes. This technology exemplifies precision surgery by enhancing minimally invasive approaches and providing superior real-time evaluation of bowel viability and biliary structures-areas traditionally reliant on the surgeon's visual assessment. Its adoption in emergency settings requires proper training, equipment availability, and standardized protocols. Further research is needed to evaluate cost-effectiveness and expand its applications in urgent surgical procedures.

Knowledge, attitudes and practices of using Indocyanine Green (ICG) fluorescence in emergency surgery: an international web-based survey in the ARtificial Intelligence in Emergency and trauma Surgery (ARIES)-WSES project

Fluorescence imaging is a real-time intraoperative navigation modality to enhance surgical vision and it can guide emergency surgeons while performing difficult, high-risk surgical procedures. The aim of this study is to assess current knowledge, attitudes, and practices of emergency surgeons in the use of indocyanine green (ICG) in emergency settings. Between March 08, 2023 and April 10, 2023, a questionnaire composed of 27 multiple choice and open-ended questions was sent to 200 emergency surgeons who had previously joined the ARtificial Intelligence in Emergency and trauma Surgery (ARIES) project promoted by the WSES. The questionnaire was developed by an emergency surgeon with an interest in advanced technologies and artificial intelligence. The response rate was 96% (192/200). Responders affirmed that ICG fluorescence can support the performance of difficult surgical procedures in the emergency setting, particularly in the presence of severe inflammation and in evaluating bowel viability. Nevertheless, there were concerns regarding accessibility and availability of fluorescence imaging in emergency settings. Eighty-seven out of 192 (45.3%) respondents have a fluorescence imaging system of vision for both elective and emergency surgical procedures; 32.3% of respondents have this system solely for elective procedures; 21.4% of respondents do not have this system, 15% do not have experience with it, and 38% do not use this imaging in emergency surgery. Less than 1% (2/192) affirmed that ICG fluorescence changed always their intraoperative decision-making. Precision surgery effectively tailors surgical interventions to individual patient characteristics using advanced technology, data analysis and artificial intelligence. ICG fluorescence can serve as a valid and safe tool to guide emergency surgery in different scenarios, such as intestinal ischemia and severe acute cholecystitis. Due to the lack of high-level evidence within this field, a consensus of expert emergency surgeons is needed to encourage stakeholders to increase the availability of fluorescence imaging systems and to support emergency surgeons in implementing ICG fluorescence in their daily practice.

Near-infrared indocyanine green angiography in recognizing bowel ischemia in emergency surgery: game changer or overrated?

Assessing bowel perfusion in emergency intestinal surgery can prove challenging even for experienced surgeons. The necessity of a technological tool assisting clinicians is undisputed. Near-infrared indocyanine green (NIR-ICG) angiography has been increasingly used in elective colorectal surgery to evaluate intestinal perfusion with promising results. This review aims to answer whether a similar outcome can be observed in acute cases of bowel ischemia. We conducted online research of the literature using keywords such as "indocyanine green", "bowel", "emergency" and "ischemia", to identify articles concerning the use of ICG-angiography in evaluating bowel perfusion during emergency operations. PubMed was the primary database. 11 articles were included in this systematic review with a total of 358 patients. Most papers showed a positive effect after using NIR-ICG-angiography, whereas one study indicated the limitations of the method by exhibiting increased reoperation and mortality rates. Moreover, a significant variation in indocyanine green (ICG) dose and fluorescence identification systems was observed. NIR-ICG-angiography has the potential to become a fundamental tool in emergency intestinal operations. Nevertheless, additional research, especially high-quality, randomized studies, as well as quantification techniques are still needed to support these preliminary observations.

Usefulness of fluorescence imaging with indocyanine green for evaluation of bowel perfusion in the urgency setting: a systematic review and meta-analysis

INTRODUCTION

Fluorescence imaging with indocyanine green (ICG) has been extensively utilized to assess bowel perfusion in oncologic surgery. In the emergency setting, there are many situations in which bowel perfusion assessment is required. Large prospective studies or RCTs evaluating feasibility, safety and utility of ICG in the emergency setting are lacking. The primary aim is to assess the usefulness of ICG for evaluation of bowel perfusion in the emergency setting.

MATERIALS AND METHODS

The manuscript was drafted following the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA). A systematic literature search was carried out through Pubmed, Scopus, and the ISI Web of Science. Assessment of included study using the methodological index for nonrandomized studies (MINORS) was calculated. The meta-analysis was carried out in line with recommendations from the Cochrane Collaboration and Meta-analysis of Observational Studies in Epidemiology guidelines, and the Mantel-Haenszel random effects model was used to calculate effect sizes.

RESULTS

10 093 papers were identified. Eighty-four were reviewed in full-text, and 78 were excluded: 64 were case reports; 10 were reviews without original data; 2 were letters to the editor; and 2 contained unextractable data. Finally, six studies 22-27 were available for quality assessment and quantitative synthesis. The probability of reoperation using ICG fluorescence angiography resulted similar to the traditional assessment of bowel perfusion with a RD was -0.04 (95% CI: -0.147 to 0.060). The results were statistically significant P =0.029, although the heterogeneity was not negligible with a 59.9% of the I2 index. No small study effect or publication bias were found.

CONCLUSIONS

This first metanalysis on the use of IGC fluorescence for ischemic bowel disease showed that this methodology is a safe and feasible tool in the assessment of bowel perfusion in the emergency setting. This topic should be further investigated in high-quality studies.

Acute Small-bowel Obstruction: An Appraisal of Common Etiology and Management at the Federal Medical Centre, Keffi, North-central Nigeria

BACKGROUND

Acute small intestinal obstruction is a common surgical emergency in the sub-Saharan region. Over the decades, complicated inguinal hernias have been identified as a leading cause. However, we observed from our clinical practice that complicated inguinal hernias were not the most common etiology.

AIMS AND OBJECTIVES

This study aimed to evaluate the common etiology of acute small bowel obstruction in the study center and compare our findings with that from other centers and existing literature.

MATERIALS AND METHODS

This was a retrospective, cross sectional study carried out over a period of five years (January 2017 to December 2021). This study looked at the patients presenting with acute, mechanical, small bowel obstruction that did not respond to conservative treatment in our hospital facility. Relevant information were extracted from patients' clinical details and entered into the proforma prepared for this study.

RESULTS

A total of 147 patients were recruited into this study out of which 85(57.8%) were males and 62 (42.2%) were females (M:F=1.44:1). Majority (80.3%) of the patients that presented with post-operative bowel adhesion had previous appendectomy. Simple bowel obstruction was seen in 93 (63.3%) patients while strangulated obstruction and gangrenous bowel were seen in 26 (17.7%) patients and 22 (15.0%) patients respectively. Majority (47.6%) of the patients had adhesiolysis done while others had bowel resection.

CONCLUSION

The common cause of acute small bowel obstruction as observed in this study is post-operative adhesions arising from previous appendectomy and laparotomies.

Utility of indocyanine green fluorescent dye in emergency general surgery: a review of the contemporary literature

For decades, indocyanine green (ICG) has been available for medical and surgical use. The indications for ICG use in surgery have expanded where guided surgery directed by fluorescence and near-infrared fluorescent imaging offers numerous advantages. Recently, surgeons have reported using ICG operative navigation in the emergency setting, with fluorescent cholangiography being the most common procedure. The utility of ICG also involves real-time perfusion assessment, such as ischemic organs and limbs. The rising use of ICG in surgery can be explained by the ICG's rapid technological evolution, accuracy, ease of use, and great potential to guide precision surgical diagnosis and management. The review aims to summarize the current literature on the uses of ICG in emergency general surgery. It provides a comprehensive and practical summary of the use of ICG, including indication, route of administration, and dosages. To simplify the application of ICG, we subdivided its use into anatomical mapping and perfusion assessment. Anatomical mapping includes the biliary tree, ureters, and bowel. Perfusion assessment includes bowel, pancreas, skin and soft tissue, and gonads. This review provides a reference to emergency general surgeons to aid in implementing ICG in the emergency setting for more enhanced and safer patient care.

ICG-augmented hyperspectral imaging for visualization of intestinal perfusion compared to conventional ICG fluorescence imaging: an experimental study

BACKGROUND

Small bowel malperfusion (SBM) can cause high morbidity and severe surgical consequences. However, there is no standardized objective measuring tool for the quantification of SBM. Indocyanine green (ICG) imaging can be used for visualization, but lacks standardization and objectivity. Hyperspectral imaging (HSI) as a newly emerging technology in medicine might present advantages over conventional ICG fluorescence or in combination with it.

METHODS

HSI baseline data from physiological small bowel, avascular small bowel and small bowel after intravenous application of ICG was recorded in a total number of 54 in-vivo pig models. Visualizations of avascular small bowel after mesotomy were compared between HSI only (1), ICG-augmented HSI (IA-HSI) (2), clinical evaluation through the eyes of the surgeon (3) and conventional ICG imaging (4). The primary research focus was the localization of resection borders as suggested by each of the four methods. Distances between these borders were measured and histological samples were obtained from the regions in between in order to quantify necrotic changes 6 h after mesotomy for every region.

RESULTS

StO2 images (1) were capable of visualizing areas of physiological perfusion and areas of clearly impaired perfusion. However, exact borders where physiological perfusion started to decrease could not be clearly identified. Instead, IA-HSI (2) suggested a sharp-resection line where StO2 values started to decrease. Clinical evaluation (3) suggested a resection line 23 mm (±7 mm) and conventional ICG imaging (4) even suggested a resection line 53 mm (±13 mm) closer towards the malperfused region. Histopathological evaluation of the region that was sufficiently perfused only according to conventional ICG (R3) already revealed a significant increase in pre-necrotic changes in 27% (±9%) of surface area. Therefore, conventional ICG seems less sensitive than IA-HSI with regards to detection of insufficient tissue perfusion.

CONCLUSIONS

In this experimental animal study, IA-HSI (2) was superior for the visualization of segmental SBM compared to conventional HSI imaging (1), clinical evaluation (3) or conventional ICG imaging (4) regarding histopathological safety. ICG application caused visual artifacts in the StO2 values of the HSI camera as values significantly increase. This is caused by optical properties of systemic ICG and does not resemble a true increase in oxygenation levels. However, this empirical finding can be used to visualize segmental SBM utilizing ICG as contrast agent in an approach for IA-HSI. Clinical applicability and relevance will have to be explored in clinical trials.

LEVEL OF EVIDENCE

Not applicable. Translational animal science. Original article.

Application of fluorescence-guided surgery in the acute care setting: a systematic literature review

PURPOSE

Fluorescence-based imaging has found application in several fields of elective surgery, but there is still a lack of evidence in the literature about its use in emergency setting. The present review critically summarizes currently available applications and limitations of indocyanine green (ICG) fluorescence in abdominal emergencies including acute cholecystitis, mesenteric ischemia, and trauma surgery.

METHODS

A systematic review was performed according to the PRISMA statement identifying articles about the use of ICG fluorescence in the management of the most common general surgery emergency. Only studies focusing on the use of ICG fluorescence for the management of acute surgical conditions in adults were included.

RESULTS

Thirty-six articles were considered for qualitative analysis. The most frequent disease was occlusive or non-occlusive mesenteric ischemia followed by acute cholecystitis. Benefits from using ICG for acute cholecystitis were reported in 48% of cases (clear identification of biliary structures and a safer surgical procedure). In one hundred and twenty cases that concerned the use of ICG for occlusive or non-occlusive mesenteric ischemia, ICG injection led to a modification of the surgical decision in 44 patients (36.6%). Three studies evaluated the use of ICG in trauma patients to assess the viability of bowel or parenchymatous organs in abdominal trauma, to evaluate the perfusion-related tissue impairment in extremity or craniofacial trauma, and to reassess the efficacy of surgical procedures performed in terms of vascularization. ICG injection led to a modification of the surgical decision in 50 patients (23.9%).

CONCLUSION

ICG fluorescence is a safe and feasible tool also in an emergency setting. There is increasing evidence that the use of ICG fluorescence during abdominal surgery could facilitate intra-operative decision-making and improve patient outcomes, even in the field of emergency surgery.

A Hypothetical New Challenging Use for Indocyanine Green Fluorescence during Laparoscopic Appendectomy: A Mini-Series of Our Experience and Literary Review

Laparoscopic appendectomy (LA) is a well-standardized surgical procedure, but there are still controversies about the different devices to be used for the appendiceal stump closure and the related postoperative complications. Indocyanine green (ICG) fluorescence angiography (FA) has already been shown to be helpful in elective and emergency surgery, providing intraoperative information on tissue and organ perfusion, thus guiding the surgical decisions and the technical strategies. According to these two aspects, we report a mini-series of the first five patients affected by gangrenous and flegmonous acute appendicitis intraoperatively evaluated with ICG-FA during LA. The patients were admitted to the Emergency Department with an usual range of symptoms for acute appendicitis. The patients were successfully managed by fully LA with the help of a new hypothetical challenging use of ICG-FA.

Extensive Organ Necrosis After Thoracic Endovascular Aortic Repair for Thoracic Aortic Aneurysm: A Report of the Usefulness of Laparoscopic Indocyanine Green Intraoperative Blood Flow Assessment

An 85-year-old man underwent thoracic endovascular aortic repair (TEVAR) for a thoracic aortic aneurysm (TAA). The day after TEVAR, the patient complained of abdominal pain. Blood tests showed lactic acidosis. Contrast-enhanced CT of the abdomen showed emphysema and poor contrast areas in the lower esophagus, total stomach, and duodenum. The left lobe of the liver also showed a poorly contrasted area. Indocyanine green (ICG) intraoperative blood flow evaluation was performed by laparoscopy to evaluate how organ ischemia is and whether resection of necrotic organs is possible. It was judged that resection of the poor perfusion area would not improve prognosis because of the extensive area of poor perfusion in the ICG intraoperative perfusion evaluation. In TEVAR for TAA, embolization of the celiac artery (CA) can be performed if collateral blood flow is demonstrated. However, in this case, extensive organ necrosis happened. We discuss the cause of this case and the usefulness of ICG intraoperative blood flow assessment when ischemia is suspected.