Utility of indocyanine-green fluorescent imaging during robot-assisted sphincter-saving surgery on rectal cancer patients

Role of Indocyanine Green Angiography to Assess Intra-operative Bowel Vascularity and its Association with Post-operative Outcome in Robot-assisted Rectal Resection: a Prospective Indian Cohort Study

Adequate intestinal perfusion is one of the critical factors influencing anastomotic leak (AL) in colorectal surgery. The use of indocyanine green fluoroscence angiography (ICG-FA) intra-operatively to ensure optimal perfusion is being increasingly used. This prospective study aimed to assess the role of ICG-FA in robot-assisted surgery for rectal cancer. This was a prospective cohort study carried out between July 2019 and July 2023, comprising patients undergoing elective robot-assisted rectal resection. The primary objective was to determine the role of ICG-FA in assessing bowel vascularity and in deciding the transection point of the bowel. The secondary objective was to assess the effect of ICG-FA on the post-operative outcomes, and also the effect of the various variables on the ICG staining grade. A total of 50 patients were included. Sixty percent of the patients received pre-operative radiotherapy, including short-course radiotherapy (SCRT) and long-course concurrent chemoradiation (LCRT). A change in transection line based on a less than normal ICG-FA grade was done in 11 patients (22%). Post-operatively, AL was present in 8 patients, out of whom 5 underwent re-operation. Administration of pre-operative RT was the only factor significantly associated with post-operative AL (p < 0.05). The present study showed that a change in the transection point based on the intra-operative ICG-FA was made in 22% of the patients. ICG-FA could hence be used as a potential adjunct to the operative surgeon in assessing the bowel vascularity in a minimally invasive approach like robotic or laparoscopic surgery.

Fluorescence angiography with indocyanine green for low anterior resection in patients with rectal cancer: a prospective before and after study

BACKGROUND

Inadequate bowel perfusion is among risk factors for colorectal anastomotic leaks. Perfusion can be assessed with indocyanine green fluorescence angiography (ICG) during colon resections. Possible benefits from its systematic use in high-risk patients with rectal cancer remain inconsistent. This study aimed to evaluate the surgical modifications induced by ICG assessment during rectal cancer surgery and associated anastomotic leaks.

METHODS

This prospective before and after cohort study was conducted in a single Canadian high-volume colorectal surgery center. Eligible patients were undergoing a low anterior resection for rectal cancer below 15 cm from the anal margin. Stapled and handsewn coloanal anastomoses were included. The experimental group was recruited prospectively, undergoing surgery using fluorescence angiography with ICG. The control group was built retrospectively from consecutive patients who had been operated on without ICG, prior to its implementation.

RESULTS

Each cohort included 113 patients. The use of ICG led to modifications from initial surgical plan in 10.6% of patients, with no occurrence of anastomotic leaks in this specific group. When comparing leak rates, using ICG seemed to be protective, but this could not be statistically proven, overall (13.3% vs. 6.2%, p = 0.07), nor for handsewn coloanal anastomoses (11.8% vs. 5.9%, p = 0.67). A lack of power could explain such non-significant results, especially with low overall anastomotic leak rates recorded.

CONCLUSION

ICG influenced ultimate proximal resection margin in a clinically relevant proportion of cases. It might be associated with reduced leak rates although not formally proven with this data. This technology is safe and easy to apply in high-volume colorectal centers.

Indocyanine green near-infrared fluorescence bowel perfusion assessment to prevent anastomotic leakage in minimally invasive colorectal surgery (AVOID): a multicentre, randomised, controlled, phase 3 trial

BACKGROUND

Anastomotic leakage is a severe postoperative complication in colorectal surgery and compromised bowel perfusion is considered a major contributing factor. Conventional methods to assess bowel perfusion have a low predictive value for anastomotic leakage. We therefore aimed to evaluate the efficacy of real-time assessment with near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) in the prevention of anastomotic leakage.

METHODS

This multicentre, randomised, controlled, phase 3 trial was done in eight hospitals in the Netherlands. We included adults (aged >18 years) who were scheduled for laparoscopic or robotic colorectal surgery (with planned primary anastomosis) for benign and malignant diseases. Preoperatively, patients were randomly assigned (1:1) to fluorescence-guided bowel anastomosis (FGBA) or conventional bowel anastomosis (CBA) by variable block randomisation (block sizes 4, 6, and 8) and stratified by site. The operating surgeon and investigators analysing the data were not masked to group assignment. Patients were unmasked after the surgical procedure or after study end. In the FGBA group, surgeons marked anastomosis levels per conventional perfusion assessment and then administered 5 mg of ICG by 2 mL intravenous bolus. They assessed bowel perfusion using NIR fluorescence imaging and adjusted (or kept) transection lines accordingly. Only conventional methods for bowel perfusion assessment were used in the CBA group. The primary outcome was the difference in the rate of clinically relevant anastomotic leakage (ie, requiring active therapeutic intervention but manageable without reoperation [grade B] or requiring reoperation [grade C], per the International Study Group of Rectal Cancer) between the FGBA group and the CBA group within 90 days post-surgery. The primary outcome and safety were assessed in the intention-to-treat population. This study was registered with ToetsingOnline.nl (NL7502) and ClinicalTrials.gov (NCT04712032) and is complete.

FINDINGS

Between July 2, 2020, and Feb 21, 2023, 982 patients were enrolled, of whom 490 were assigned to FGBA and 492 were assigned to CBA. After excluding 51 patients, the intention-to-treat population comprised 931 (463 assigned FGBA and 468 assigned CBA). Patients had a median age of 68·0 years (IQR 59·0-75·0) and 485 (52%) were male and 446 (48%) were female. Ethnicity data were not available. The overall 90-day rate of clinically relevant anastomotic leakage was not significantly different between the FGBA group (32 [7%] of 463 patients) and the CBA group (42 [9%] of 468 patients; relative risk 0·77 [95% CI 0·50-1·20]; p=0·24). No adverse events related to ICG use were observed. 313 serious adverse events in 229 (25%) patients were at 90-day follow-up (159 serious adverse events in 113 [24%] patients in the FGBA group and 154 serious adverse events in 116 [25%] patients in the CBA group). 18 (2%) people died by 90 days (ten in the FGBA group and eight in the CBA group).

INTERPRETATION

ICG NIR fluorescence imaging did not reduce 90-day anastomotic leakage rates in this trial across all types of colorectal surgeries. Further research should be done in subgroups, such as rectosigmoid resections, for which evidence suggests ICG NIR might be beneficial.

FUNDING

Olympus Medical, Diagnostic Green, and Intuitive Foundation.

Fluorescence and tracers in surgery: the coming future

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

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.

Indocyanine green angiography for lower incidence of anastomotic leakage after transanal total mesorectal excision: a propensity score-matched cohort study

Background

Anastomotic leakage (AL) is the most serious complication that can arise during colorectal surgery. Indocyanine green (ICG) angiography offers an intraoperative assessment of colonic vascular perfusion in real time. We aimed to assess ICG's effects on the AL rate in patients who have undergone transanal total mesorectal excision (TaTME) for rectal cancer.

Methods

This retrospective cohort study was conducted at our center from October 2018 to March 2022 to analyze the clinical data of patients with rectal cancer who have undergone TaTME after propensity score matching (PSM). The primary outcome was the proximal colonic transection line modification and clinical AL rate.

Results

A total of 143 patients in the non-ICG group and 143 patients in the ICG group were included after PSM. The proximal colonic transection line of seven patients in the non-ICG group was modified, while 18 were in the ICG group (4.9% vs. 12.5%, p = 0.023). Twenty-three patients (16.1%) in the non-ICG group and five patients (3.5%) in the ICG group were diagnosed with AL (p < 0.001). The ICG group had a less hospital readmission rate than the non-ICG group (0.7% vs. 7.7%, p = 0.003). The between-group differences in basic line and other outcomes were not significant.

Conclusions

ICG angiography is a safe and feasible method to help surgeons identify potentially poor colonic vascular perfusion and modify the proximal colonic transection line, resulting in a significant reduction in AL and hospital readmission rates.

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.

Intraluminal Anastomotic Assessment Using Indocyanine Green Near-Infrared Imaging for Left-Sided Colonic and Rectal Resections: a Systematic Review

BACKGROUND

Indocyanine green fluorescence angiography (ICG-FA) has been used in colorectal surgery to assess anastomotic perfusion and reduce the risks of anastomotic leaks. The main objective of this paper is to review the data on the transanal application of ICG-FA for the intraluminal assessment of colorectal anastomosis.

METHODS

A literature search was conducted for articles published between 2011 and 2021 using PubMed and Cochrane databases, related to the application of ICG for the intraluminal assessment of colorectal anastomosis. Original scientific manuscripts, review articles, meta-analyses, and case reports were considered eligible.

RESULTS

A total of 305 studies have been identified. After abstract screening for duplicates, 285 articles remained. Of those, 271 were not related to the topic of interest, 4 were written in a language other than English, and 4 had incomplete data. Six articles remained for the final analysis. The intraluminal assessment of colorectal anastomosis with ICG-FA is feasible, safe, and may reduce the incidence of leaks.

CONCLUSION

The intraluminal assessment of anastomotic perfusion via ICG-FA may be a promising novel application of ICG technology. More data is needed to support this application further to reduce leak rates after colorectal surgery, and future randomized clinical trials are awaited.

Indocyanine green (ICG) fluorescence guide for the use and indications in general surgery: recommendations based on the descriptive review of the literature and the analysis of experience

Indocyanine Green is a fluorescent substance visible in near-infrared light. It is useful for the identification of anatomical structures (biliary tract, ureters, parathyroid, thoracic duct), the tissues vascularization (anastomosis in colorectal, esophageal, gastric, bariatric surgery, for plasties and flaps in abdominal wall surgery, liver resection, in strangulated hernias and in intestinal ischemia), for tumor identification (liver, pancreas, adrenal glands, implants of peritoneal carcinomatosis, retroperitoneal tumors and lymphomas) and sentinel node identification and lymphatic mapping in malignant tumors (stomach, breast, colon, rectum, esophagus and skin cancer). The evidence is very encouraging, although standardization of its use and randomized studies with higher number of patients are required to obtain definitive conclusions on its use in general surgery. The aim of this literature review is to provide a guide for the use of ICG fluorescence in general surgery procedures.

Contamination and ecological risk assessment of toxic metals in Awetu watershed stream waters and sediments, Ethiopia

The study analyzed the contamination level and ecological risk assessment of toxic metals Awetu watershed streams. A total of 20 water and 20 sediment samples were collected and analyzed for the toxic metals of Arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), and zinc (Zn). Sediment samples showed severe contamination levels based on ranges in sediment quality guidelines (SQGs). Water samples showed high grades of contamination factor and potential ecological risk factor by toxic metals. The synergistic effects of toxic metals in the sampling sites were evaluated by Nemerow pollution index, potential ecological risk index and modified degree of contamination and were found to have similar results. Dololo stream (D1, D2, D3, and D4) and Kito (K1, K2, and K3) were found at 'toxic' contamination and 'severe' ecological risk. Cd, Mn, Ni, Pb, and Sn contributed to the highest ecological risk. Toxic metal contamination in Dololo stream is attributed to institutions carrying out various anthropogenic activities along the stream bank, including traditional metal plating, garages, laboratory effluents, extensive agriculture, carwash, irresponsible waste disposal, and urban population growth. The result shows Awetu watershed streams are seriously contaminated by toxic metals. Therefore, future pollution control and management plans should accentuate the strict regulation of discharge of wastes from these anthropogenic activities.

The Role of Indocyanine Green Fluorescence in Rectal Cancer Robotic Surgery: A Narrative Review

Background: In rectal cancer surgery, anastomotic leakage (AL) remains the most feared complication, with a frequency of up to 30% in non-high-volume centers. The preservation of proper vascularization is a key factor for successful anastomosis. The use of fluorescence with indocyanine green (ICG) as an intraoperative method to verify optimal perfusion is becoming an interesting tool in rectal surgery. Today, robotic surgery, together with the use of the intraoperative evaluation of the perfusion with ICG, could be a real strategy to deal with AL, allowing for a more delicate and less traumatic surgical technique. This strategy may allow for an extremely accurate surgery, and for optimal control of the proper vascularization of the rectum. Methods: The purpose of this descriptive review is to analyze the impact of fluorescence and robotic surgery on short-term surgical outcomes for rectal cancer. Results: We performed a systematic literature search using the PubMed, Embase and Cochrane library databases. The primary endpoints were to evaluate the application of ICG fluorescence in robotic rectal surgery and the rate of anastomotic leakage when using these technological implementations. The secondary endpoints were to evaluate the dosage of ICG and the timing of application by different surgeons. Conclusions: ICG fluorescence is an inexpensive and quick method to assess bowel perfusion, providing immediate feedback to the surgeon, even if its role has not been proven. A quantitative system must be systematically introduced to minimize the subjectiveness of the visualized image.

AVOID; a phase III, randomised controlled trial using indocyanine green for the prevention of anastomotic leakage in colorectal surgery

INTRODUCTION

Anastomotic leakage (AL) is one of the major complications after colorectal surgery. Compromised tissue perfusion at the anastomosis site increases the risk of AL. Several cohort studies have shown that indocyanine green (ICG) combined with fluorescent near-infrared imaging is a feasible and reproducible technique for real-time intraoperative imaging of tissue perfusion, leading to reduced leakage rates after colorectal resection. Unfortunately, these studies were not randomised. Therefore, we propose a randomised controlled trial to assess the value of ICG-guided surgery in reducing AL after colorectal surgery.

METHODS AND ANALYSIS

A multicentre, randomised controlled clinical trial will be conducted to assess the benefit of ICG-guided surgery in preventing AL. A total of 978 patients scheduled for colorectal surgery will be included. Patients will be randomised between the Fluorescence Guided Bowel Anastomosis group and the Conventional Bowel Anastomosis group. The primary endpoint is clinically relevant AL (defined as requiring active therapeutic intervention or reoperation) within 90 days after surgery. Among the secondary endpoints are 30-day clinically relevant AL, all-cause postoperative complications, all-cause and AL-related mortality, surgical and non-surgical reinterventions, total surgical time, length of hospital stay and all-cause and AL-related readmittance.

ETHICS AND DISSEMINATION

This protocol has been approved by the Medical Ethical Committee Leiden-Den Haag-Delft (METC-LDD) and is registered at ClinicalTrials.gov and trialregister.nl. The results of this study will be reported through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04712032; NL7502.

Evaluating the Effect of Intraoperative Near-Infrared Observation on Anastomotic Leakage After Stapled Side-to-Side Anastomosis in Colon Cancer Surgery Using Propensity Score Matching

BACKGROUND

Recent studies have clarified that near-infrared observation using indocyanine green has the advantage of evaluating perfusion of the anastomotic site, especially in rectal cancer surgery, resulting in a reduction in anastomotic leak.

OBJECTIVE

The aim of this study was to evaluate the efficacy of near-infrared observation for reducing the anastomotic leak after stapled side-to-side anastomosis in colon cancer surgery.

DESIGN

This was a retrospective propensity score case-matched study.

SETTINGS

The study was conducted at 3 institutions in the Yokohama Clinical Oncology Group.

PATIENTS

From January 2011 to December 2019, patients who underwent colon cancer surgery with stapled side-to-side anastomosis were included.

MAIN OUTCOME MEASURES

The main outcome was the percentage of anastomotic leak within 30 days after surgery.

RESULTS

A total of 1034 patients were collected. There were 532 patients who underwent near-infrared observation and 502 who did not. A total of 370 patients were matched to the near-infrared and non-near-infrared groups. In the near-infrared group, 12 patients (3.2%) were judged to have poor perfusion (4 patients) and no perfusion (8 patients), so the planned transection point was changed. There were no cases of anastomotic leak among these 12 patients. The anastomotic leak rates were 3.5% (13/370) in the non-near-infrared group and 0.8% (3/370) in the near-infrared group. The anastomotic leak and reoperation rates were significantly lower in the near-infrared group than in the non-near-infrared group (OR, 0.224; 95% CI, 0.063-0.794, p = 0.001; OR, 0.348; 95% CI, 0.124-0.977, p = 0.036).

LIMITATIONS

Although we reduced selection bias by performing propensity score matching, this was a retrospective study and was not randomized.

CONCLUSION

This large-scale case-matched study showed that assessing perfusion by near-infrared observation significantly reduced the anastomotic leak and reoperation rates after stapled side-to-side anastomosis in colon cancer surgery and may be better suited to colo-colonic anastomosis. Video Abstract at http://links.lww.com/DCR/B513.Japanese Clinical Trials Registry: UMIN-CTR000039977.

EVALUACIN DEL EFECTO DE LA OBSERVACIN INTRAOPERATORIA CON INFRARROJO CERCANO SOBRE LA FUGA ANASTOMTICA DESPUS DE UNA ANASTOMOSIS LATEROLATERAL CON ENGRAPADORA EN LA CIRUGA DE CNCER DE COLON MEDIANTE EL EMPAREJAMIENTO POR PUNTAJES DE PROPENSIN

ANTECEDENTES:Estudios recientes han aclarado que la observación con infrarrojo cercano con verde de indocianina tiene la ventaja de evaluar la perfusión del sitio anastomótico, especialmente en la cirugía de cáncer de recto, lo que resulta en una reducción de la fuga anastomótica.OBJETIVO:El objetivo de este estudio fue evaluar la eficacia de la observación con infrarrojo cercano para reducir la fuga anastomótica después de una anastomosis latero-lateral con engrapadora en la cirugía de cáncer de colon.DISEÑO:Este fue un estudio retrospectivo emparejado con puntaje de propensión.AJUSTE:El estudio se llevó a cabo en tres instituciones del Grupo de Oncología Clínica de Yokohama.PACIENTES:Desde enero de 2011 hasta diciembre de 2019, se incluyeron pacientes que se sometieron a cirugía de cáncer de colon con anastomosis latero-lateral con engrapadora.PRINCIPALES MEDIDAS DE RESULTADO:El resultado principal fue el porcentaje de fuga anastomótica dentro de los 30 días posteriores a la cirugía.RESULTADOS:Se recogió un total de 1034 pacientes. Hubo 532 pacientes que se sometieron a observación con infrarrojo cercano y 502 que no. Un total de 370 pacientes fueron emparejados con los grupos de infrarrojo cercano y no infrarrojo cercano. En el grupo de infrarrojo cercano, se consideró que 12 casos (3,2%) tenían mala perfusión (4 casos) y ninguna perfusión (8 casos), por lo que se cambió el punto de transección planificado. No hubo casos de fuga anastomótica entre estos 12 casos. Las tasas de fuga anastomótica fueron del 3,5% (13/370) en el grupo sin infrarrojo cercano y del 0,8% (3/370) en el grupo con infrarrojo cercano. Las tasas de fuga anastomótica y de reintervención fueron significativamente menores en el grupo con infrarrojo cercano que en el grupo sin infrarrojo cercano (razón de posibilidades 0,224, intervalo de confianza del 95% 0,063-0,794, p = 0,001; razón de posibilidades 0,348, intervalo de confianza del 95% 0,124 -0,977, p = 0,036, respectivamente).LIMITACIONES:Aunque se redujo el sesgo de selección al realizar el emparejamiento por puntaje de propensión, este fue un estudio retrospectivo y no fue aleatorio.CONCLUSIÓN:Este estudio de casos emparejados a gran escala demostró que la evaluación de la perfusión mediante la observación con infrarrojo cercano redujo significativamente la fuga anastomótica y las tasas de reintervención después de la anastomosis latero-lateral con engrapadora en la cirugía de cáncer de colon y puede ser más adecuada para la anastomosis colo-colónica. Consulte Video Resumen en http://links.lww.com/DCR/B513.Registro japonés de ensayos clínicos: UMIN-CTR000039977.

A narrative review of fluorescence imaging in robotic-assisted surgery

Objective

In this review, we provide examples of applications of fluorescence imaging in urologic, gynecologic, general, and endocrine surgeries.

Background

While robotic-assisted surgery has helped increase the availability of minimally invasive procedures across surgical specialties, there remains an opportunity to reduce adverse events associated with open, laparoscopic, and robotic-assisted methods. In 2011, fluorescence imaging was introduced as an option to the da Vinci Surgical System, and has been standard equipment since 2014. Without interfering with surgical workflow, this fluorescence technology named Firefly^® allows for acquisition and display of near-infrared fluorescent signals that are co-registered with white light endoscopic images. As a result, robotic surgeons of all specialties have been able to explore the clinical utility of fluorescence guided surgery.

Methods

Literature searches were performed using the PubMed and MEDLINE databases using the keywords "robotic-assisted fluorescence surgery", "ICG robotic surgery", and "fluorescence guided surgery" covering the years 2011-2020.

Conclusions

Real-time intraoperative fluorescence guidance has shown great potential in helping guide surgeons in both simple and complex surgical interventions. Indocyanine green is one of the most widely-used imaging agents in fluorescence guided surgery, and other targeted, near-infrared imaging agents are in various stages of development. Fluorescence is becoming a reliable tool that can help surgeons in their decision-making process in some specialties, while explorations continue in others.

Clinical effect and standardization of indocyanine green angiography in the laparoscopic colorectal surgery

Anastomotic complications occur after 5% to 20% of operations for rectosigmoid colon cancer. The intestinal perfusion status at the anastomotic site is an important modifiable risk factor, and surgeons should carefully evaluate and optimize the perfusion at the intended site of anastomosis. Indocyanine green (ICG) angiography is a simple noninvasive perfusion assessment modality. The use of ICG angiography is rapidly spreading in the field of colorectal surgery. However, there is debate on its contribution to reducing anastomotic complications. In this review, we discuss the clinical utility and the standardization of ICG angiography. ICG angiography can unequivocally reveal unfavorable perfusion zones and provide quantitative parameters to predict the risk of hypoperfusion-related anastomotic complications. Many studies have demonstrated the clinical utility of ICG angiography for reducing anastomotic complications. Recently, two multicenter randomized clinical trials reported that ICG angiography did not significantly reduce the incidence of anastomotic leakage. Most previous studies have been small-scale single-center studies, and there is no standardized ICG angiography protocol to date. Additionally, ICG angiography evaluations have mostly relied on surgeons’ subjective judgment. For these reasons, it is necessary to establish a standardized ICG angiography protocol and develop a quantitative analysis protocol for the objective assessment. In conclusion, ICG angiography could be useful for detecting poorly perfused colorectal segments to prevent anastomotic leakage after colorectal surgery. An optimized and standardized ICG angiography protocol should be established to improve the reliability of perfusion assessments. In the future, artificial intelligence-based quantitative analyses could be used to easily assess colonic perfusion status.

Role of near-infrared fluorescence in colorectal surgery

Near-infrared fluorescence (NIRF) is a technique of augmented reality that, when applied in the operating theatre, allows the colorectal surgeon to visualize and assess bowel vascularization, to identify lymph nodes draining a cancer site and to identify ureters. Herein, we review the literature regarding NIRF in colorectal surgery.

Computer-assisted quantification and visualization of bowel perfusion using fluorescence-based enhanced reality in left-sided colonic resections

BACKGROUND

Fluorescence-based enhanced reality (FLER) is a computer-based quantification method of fluorescence angiographies to evaluate bowel perfusion. The aim of this prospective trial was to assess the clinical feasibility and to correlate FLER with metabolic markers of perfusion, during colorectal resections.

METHODS

FLER analysis and visualization was performed in 22 patients (diverticulitis n = 17; colorectal cancer n = 5) intra- and extra-abdominally during distal and proximal resection, respectively. The fluorescence signal of indocyanine green (0.2 mg/kg) was captured using a near-infrared camera and computed to create a virtual color-coded cartography. This was overlaid onto the bowel (enhanced reality). It helped to identify regions of interest (ROIs) where samples were subsequently obtained. Resections were performed strictly guided according to clinical decision. On the surgical specimen, samplings were made at different ROIs to measure intestinal lactates (mmol/L) and mitochondria efficiency as acceptor control ratio (ACR).

RESULTS

The native (unquantified) fluorescent signal diffused to obvious ischemic areas during the distal appreciation. Proximally, a lower diffusion of ICG was observed. Five anastomotic complications occurred. The expected values of local capillary lactates were correlated with the measured values both proximally (3.62 ± 2.48 expected vs. 3.17 ± 2.8 actual; rho 0.89; p = 0.0006) and distally (4.5 ± 3 expected vs. 4 ± 2.5 actual; rho 0.73; p = 0.0021). FLER values correlated with ACR at the proximal site (rho 0.76; p = 0.04) and at the ischemic zone (rho 0.71; p = 0.01). In complicated cases, lactates at the proximal resection site were higher (5.8 ± 4.5) as opposed to uncomplicated cases (2.45 ± 1.5; p = 0.008). ACR was reduced proximally in complicated (1.3 ± 0.18) vs. uncomplicated cases (1.68 ± 0.3; p = 0.023).

CONCLUSIONS

FLER allows to image the quantified fluorescence signal in augmented reality and provides a reproducible estimation of bowel perfusion (NCT02626091).

Fluorescence-guided cancer surgery-A new paradigm

Fluorescence-guided surgery is an emerging and promising operative adjunct to assist the surgeon in various aspects of oncosurgery, ranging from assessing perfusion, identification, and characterization of tumors and peritoneal metastases, mapping of lymph nodes/leaks, and assistance for fluorescence-guided surgery (FGS). This study aims to provide an overview of principles, currently available dyes, platforms, and surgical applications and summarizes the available literature on the utility of FGS with a focus on abdomino-thoracic malignancies.

Intra-operative assessment of left-sided colorectal anastomotic integrity: a systematic review of available techniques

AIM

Anastomotic leak (AL) after colorectal resection is associated with increased rates of morbidity and mortality: potential permanent stoma formation, increased local recurrence, reduced cancer-related survival, poor functional outcomes and associated quality of life. Techniques to reduce leak rates are therefore highly sought.

METHOD

A literature search was performed for published full text articles using PubMed, Cochrane and Scopus databases with a focus on colorectal surgery 1990-2020. Additional papers were detected by scanning references of relevant papers.

RESULTS

A total of 53 papers were included after a thorough literature search. Techniques assessed included leak tests, endoscopy, perfusion assessment and fluorescence studies. Air-leak testing remains the most commonly used method across Europe, due to ease of reproducibility and low cost. There is no evidence that this reduces the leak rate; however, identification of a leak intra-operatively provides the opportunity for either suture reinforcement or formal takedown with or without re-do of the anastomosis and consideration of diversion. Suture repair alone of a positive air-leak test is associated with an increased AL rate. The use of fluorescence studies to guide the site of anastomosis has demonstrated reduced leak rates in distal anastomoses, is safe, feasible and has a promising future.

CONCLUSION

Although over reliance on any assessment tool should be avoided, intra-operative techniques with the aim of reducing AL rates are increasingly being employed. Standardization of these methods is imperative for routine use. However, in the interim it is recommended that all anastomoses should be assessed intra-operatively for mechanical failure, particularly distal anastomoses.

Indocyanine green fluorescence angiography prevents anastomotic leakage in rectal cancer surgery: a systematic review and meta-analysis

BACKGROUND

The role of intraoperative use of indocyanine green (ICG) fluorescence angiography (ICGFA) to prevent anastomotic leakage (AL) in rectal cancer surgery remains controversial.

METHODS

The systematic review for studies evaluating ICGFA in patients undergoing rectal cancer surgery in PubMed, Embase, Web of Science, and the Cochrane Library was performed up to April 30, 2020. The primary outcome was the incidence of AL. The analysis was performed using RevMan v5.3 and Stata v12.0 software.

RESULTS

Eighteen studies comprising 4038 patients were included. In the present meta-analysis, intraoperative use of ICGFA markedly reduced AL rate (OR = 0.33; 95% CI: 0.24-0.45; P < 0.0001; I2 = 0%) in rectal cancer surgery, which was still significant in surgeries limited to symptomatic AL (OR = 0.44; 95% CI: 0.31-0.64; P < 0.0001; I2 = 22%). This intervention was also associated with shorter postoperative stays (MD = - 1.27; 95% CI: - 2.42 to - 0.13; P = 0.04; I2 = 60%). However, reoperation rate (OR = 0.61; 95% CI: 0.34-1.10; P = 0.10; I2 = 6%), ileus rate (OR = 1.30; 95% CI: 0.60-2.82; P = 0.51; I2 = 56%), and surgical site infection rate (OR = 1.40; 95% CI: 0.62-3.20; P = 0.42; I2 = 0%) were not significantly different between the two groups.

CONCLUSION

The use of ICGFA was associated with a lower AL rate after rectal cancer resection. However, more multi-center RCTs with large sample size are required to further verify the value of ICGFA in rectal cancer surgery.

CT/NIRF dual-modal imaging tracking and therapeutic efficacy of transplanted mesenchymal stem cells labeled with Au nanoparticles in silica-induced pulmonary fibrosis

Mesenchymal stem cells (MSCs) have shown promising therapeutic effects in cell-based therapies and regenerative medicine. Efficient tracking of MSCs is an urgent clinical need that will help us to understand their behavior after transplantation and allow adjustment of therapeutic strategies. However, no clinically approved tracers are currently available, which limits the clinical translation of stem cell therapy. In this study, a nanoparticle (NP) for computed tomography (CT)/fluorescence dual-modal imaging, Au@Albumin@ICG@PLL (AA@ICG@PLL), was developed to track bone marrow-derived mesenchymal stem cells (BMSCs) that were administered intratracheally into mice with silica-induced pulmonary fibrosis, which facilitated understanding of the therapeutic effect and the possible molecular mechanism of stem cell therapy. The AuNPs were first formed in bovine serum albumin (BSA) solution and modified with indocyanine green (ICG), and subsequently coated with a poly-l-lysine (PLL) layer to enhance intracellular uptake and biocompatibility. BMSCs were labeled with AA@ICG@PLL NPs with high efficiency without an effect on biological function or therapeutic capacity. The injected AA@ICG@PLL-labeled BMSCs could be tracked via CT and near-infrared fluorescence (NIRF) imaging for up to 21 days after transplantation. Using these NPs, the molecular anti-inflammatory mechanism of transplanted BMSCs was revealed, which included the downregulation of proinflammatory cytokines, suppression of macrophage activation, and delay of the fibrosis process. This study suggests a promising role for imaging-guided MSC-based therapy for pulmonary fibrosis, such as idiopathic pulmonary fibrosis (IPF) and pneumoconiosis.

[Evidence of indocyanine green fluorescence in robotically assisted colorectal surgery : What is the status?]

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is increasingly being used in various areas of abdominal surgery. The constant improvement in the technology enables easy intraoperative use and progressively influences operative decision-making, also in robotically assisted colorectal surgery.

OBJECTIVE

Summation of current evidence on the use of ICG fluorescence imaging in robotically assisted colorectal surgery.

MATERIAL AND METHODS

The assessment of evidence is based on a comprehensive literature search (PubMed).

RESULTS

First individual studies (feasibility, case matched, prospective cohort, multicenter phase II, single center randomized controlled study/trial) showed a significant reduction in the incidence of anastomotic leakage (AL) after colorectal anastomosis through the use of ICG fluorescence angiography (FA, 9.1% vs. 16.3%; p = 0.04). First feasibility studies demonstrated lymph node detection or navigation as well as ureter visualization.

CONCLUSION

The ICG-FA reliably detects tissue perfusion, quickly and effectively with few side effects. It can influence intraoperative decision-making and reduce AL rates. In addition, patients may be offered more precise tumor therapy via ICG sentinel lymph node (SLN) detection and lateral pelvic lymph node (LPN) mapping and navigation. Iatrogenic lesions, such as ureteral injuries can be sufficiently prevented by appropriate visualization; however, valid data in order to be able to derive standardized operative consequences require further convincing multicenter, randomized controlled trials (mRCT).

The efficacy of intraoperative ICG fluorescence angiography on anastomotic leak after resection for colorectal cancer: a meta-analysis

OBJECTIVE

The purpose of this study was to investigate whether intraoperative indocyanine green fluorescence angiography can reduce the incidence of anastomotic leak.

METHODS

Present authors conducted a systematic search of PubMed, EMBASE, and Cochrane databases for randomized controlled trials (RCTs), prospective nonrandomized trials, and retrospective trials up to March 2020. Eleven papers fulfilling the screening criteria were included.

INTERVENTION

Indocyanine green was injected intravenously after the division of the mesentery and colon but before anastomosis. The primary outcome measure was AL rate with at least 3 months of follow-up. Secondary outcome measure was operation time, postoperative complications, surgical site infection, reoperation, and ileus rate. The results were analyzed using STATA 12.0 software (Stata Corp, College Station, TX, USA).

RESULT

A total of 3137 patients were collected in 11 studies. Meta-analysis showed that compared with conventional surgery, the ICG fluorescence angiography resulted in a fewer AL rate (OR = 0.31; 95% CI 0.21 to 0.44; P < 0.0001), postoperative complications (OR = 0.70; 95% CI 0.51 to 0.96; P < 0.025), and reoperation rate (OR = 0.334; 95% CI 0.16 to 0.68; P = 0.003). Operation time (weighted mean difference - 25.162 min; 95% CI - 58.7 to 8.375; P = 0.141), surgical site infection rate (OR = 1.11; 95% CI 0.59 to 2.09; P = 0.742) did not differ between the two groups.

CONCLUSION

The result revealed that indocyanine green was associated with a lower anastomotic leakage rate after colorectal cancer resection. However, larger, multicentered, high-quality randomized controlled trials are needed to confirm the benefit of indocyanine green fluorescence angiography.

Does intraoperative indocyanine green fluorescence angiography decrease the incidence of anastomotic leakage in colorectal surgery? A systematic review and meta-analysis

BACKGROUND

Colorectal anastomoses in patients with colorectal cancer carry a high risk of leakage. Indocyanine green fluorescence angiography (ICG-FA) is a new technique that allows surgeons to assess the blood perfusion of the anastomosis during operation. This meta-analysis aimed to evaluate whether ICG-FA could prevent anastomotic leakage (AL) in colorectal surgery.

METHODS

Four databases (PubMed, Embase, Web of Science, and Cochrane Library) were searched to identify suitable literatures until March 2020 that compared AL rates between intraoperative use and non-use of ICG-FA in colorectal surgery for cancer. The Review Manager 5.3 software was used to perform the statistical analysis. Evaluation of articles quality and analysis for publication bias were also conducted.

RESULTS

Thirteen studies of 4037 patients were included in the meta-analysis. The study included 1806 patients in the ICG group and 2231 patients in the control group. The pooled incidence of AL in ICG group was 3.8% compared with 7.8% in control group. There was a significant difference in AL rate with or without use of ICG-FA (OR 0.44; 95% CI 0.33-0.59; P < 0.00001). Reoperation rates were 2.6% and 6.9% in ICG and control groups, respectively. Application of intraoperative ICG-FA was associated with a lower risk of reoperation (OR 0.39; 95% CI 0.16-0.94; P = 0.04). Overall complication rate was 15.6% in the ICG group compared with 21.2% in the control group. Overall complications were significantly reduced when using ICG-FA (OR 0.62; 95% CI 0.47-0.82; P = 0.0008). Mortality rate was not statistically different with or without the use of ICG-FA (OR 1.22; 95% CI 0.20-7.30; P = 0.83).

CONCLUSION

The results revealed that ICG-FA reduced risks of AL, reoperation, and overall complications for colorectal cancer patients undergoing colorectal surgery. Well-designed RCTs are needed to confirm the usefulness of intraoperative ICG-FA for preventing surgical complications like AL and reoperation.

Clinical role of fluorescence imaging in colorectal surgery - an updated review

INTRODUCTION

Colorectal surgery has markedly advanced due to the introduction of laparoscopic and robotic surgery. During the past 20 years, these two modalities have been further enhanced by fluorescence imaging.

AREAS COVERED

This article will review the common and novel uses for fluorophores in colorectal surgery, including tissue perfusion for anastomotic creation, ureter identification, lymphatic mapping, and tumor localization.

EXPERT OPINION

The versatility of this technology permeates through many aspects of colorectal procedures. The white light spectrum has historically been the only available modality to visualize tissue perfusion, tumor implants, and structures including the ureters and lymph nodes. The ability of the near-infrared spectrum to penetrate biologic tissues allows the identification of these structures with injection of fluorophores. The two most common intravenously utilized fluorophores are methylene blue and indocyanine green. Additionally, novel tumor marker-specific fluorophores are being investigated for purposes of cancer detection.

Clinical utility of transanal indocyanine green near-infrared fluorescence imaging for evaluation of colorectal anastomotic perfusion

BACKGROUND

Although indocyanine green (ICG) fluorescence imaging has been reported to be useful for assessing colorectal perfusion, unstable quantification remains an issue. We performed ICG fluorescence observation from the luminal side and examined the usefulness of the transanal approach.

METHODS

A total of 69 patients who underwent left-side colon surgery were enrolled in this cohort study. After the anastomosis had been constructed, ICG 0.2 mg/kg was injected intravenously. The anastomotic site was then observed by a scope inserted transanally. The following items were examined in the areas of the anastomotic site with the highest- and lowest-fluorescence intensity: maximum fluorescence (Fmax), time from ICG injection to Fmax (Tmax), time from start of dyeing to Fmax (ΔT), and the contrast pattern of the mucosa.

RESULTS

Anastomotic leakage (AL) occurred in nine cases. Tmax and ΔT values of the lowest-fluorescence area in the distal intestine showed significant differences in the cases with AL (P = 0.015 and P = 0.040, respectively). Regarding the contrast pattern of the mucosa of the lowest-fluorescence area in the proximal and distal intestine, the patients in whom the vessels were not depicted in the area had a significantly higher incidence of AL than those in whom vessels were depicted in the area (P = 0.031 and P = 0.030, respectively). Some of the areas in which vessels were not depicted by ICG fluorescence observation from the luminal side corresponded to the points of leakage. There were heterogeneous changes that might not be grasped by observation from the serosal side.

CONCLUSION

Transanal ICG fluorescence imaging can evaluate perfusion over the entire circumference of the anastomosis in detail and aid in assessing the risk of AL. Therefore, the examination of the detailed low-perfusion area enables us to take measures for AL and to search for safer operative managements.

Anastomosis Leak: Is There Still a Place for Indocyanine Green Fluorescence Imaging in Colon-Rectal Surgery? A Retrospective, Propensity Score-Matched Cohort Study

Anastomotic leakage (AL) represents one of the most relevant complications of colorectal cancer surgery. The aim of this study was to evaluate the utility of intraoperative indocyanine green (ICG) fluorescence imaging in the prevention of AL during laparoscopic colorectal surgery. Methods. We retrospectively analyzed 272 patients who underwent rectal and left colon surgery, consecutively enrolled between 2015 and 2019. Due to the heterogeneity of our groups, a propensity score matching (PSM) was performed with a 1:1 PSM cohort. Results. AL occurred in 36 (13.2%) patients. One hundred seventy-seven (65%) of them underwent an intraoperatory ICG test (ICG-group), whereas 95 patients (35%) did not receive the intraoperatory ICG test (no-ICG group). AL occurred in 10.8% of ICG group patients and in 17.8% of no-ICG group patients (P = 0.07). The ICG group registered significantly less type B and type C fistulas than the no-ICG group (57.9 vs 88.2%; P = .043). After PSM, the overall AL rate was less in the ICG group than the no-ICG group (9.3% vs 16%; P = 0.058), while type B and type C fistulas occurred in 5.48% in the ICG group vs 13.70% in the no-ICG group (P = 0.09). Univariate analysis demonstrated a protective effect of intraoperative ICG imaging against AL occurrence (odds ratio (OR: 0.66)). Conclusions. Hypoperfusion is a well-recognized cause of AL. The ICG assessment of colic vascularization is a simple, inexpensive, and side effects free method, which can sensibly reduce both overall AL and type B and type C fistulas when routinely used.

Intra-operative fluorescence angiography is reproducible and reduces the rate of anastomotic leak after colorectal resection for cancer: a prospective case-matched study

AIM

Intra-operative fluorescence angiography (IOFA) with indocyanine green provides information on tissue perfusion that may help prevent an anastomotic leak (AL). The aim of this study was to assess the impact of IOFA on outcomes after left-sided colonic or low anterior resection with anastomosis for colorectal cancer.

METHODS

All patients with left-sided colonic or rectal cancer, operated between June 2017 and December 2018, were prospectively included. IOFA has been routinely implemented since May 2018. Reproducibility of IOFA, after a 1:1 matching for relevant clinical risk factors of AL, was studied in patients with IOFA (IOFA+) and without IOFA (IOFA-). Outcomes were compared in terms of postoperative events such as clinically relevant AL as the primary end-point.

RESULTS

In the IOFA+ group, changing of the initially planned colon transection due to inadequate perfusion occurred in five out of 46 patients (10.9%). Agreement between intra-operative assessment and postoperative blind review of IOFA was deemed strong (Cohen's kappa index 0.893, 95% CI 0.788-0.998, P < 0.001). Among 111 patients, 42 matched patients were included in each group. There was significantly more clinically relevant AL in the IOFA- group compared to the IOFA+ group (16.7% vs 2.4%, P = 0.026) involving significantly more anastomotic dehiscence which required re-intervention (19% vs 2.4%, P = 0.014). Additionally, more descending colon ischaemia/necrosis was observed in the IOFA- group compared with the IOFA+ group (9.5% vs 0%, P = 0.040).

CONCLUSION

In this prospective case-matched study, IOFA decreased the occurrence of clinically relevant AL due to necrosis of the descending colon or anastomosis. Upon blind review, perfusion assessment using IOFA was reproducible.

Intraoperative use of fluorescence with indocyanine green reduces anastomotic leak rates in rectal cancer surgery: an individual participant data analysis

BACKGROUND

Fluorescence imaging by means of Indocyanine green (ICG) has been applied to intraoperatively determine the perfusion of the anastomosis. The purpose of this Individual Participant Database meta-analysis was to assess the effectiveness in decreasing the incidence of anastomotic leak (AL) after rectal cancer surgery.

METHODS

We searched PubMed, Embase, Cochrane Library and ClinicalTrial.gov, EU Clinical Trials and ISRCTN registries on September 1st, 2019. We considered eligible those studies comparing the assessment of anastomotic perfusion during rectal cancer surgery by intraoperative use of ICG fluorescence compared with standard practice. We defined as primary outcome the incidence of AL at 30 days after surgery. The studies were assessed for quality by means of the ROBINS-I and the Cochrane risk tools. We calculated odds ratios (ORs) using the Individual patient data analysis, restricted to rectal lesions, according to original treatment allocation.

RESULTS

The review of the literature and international registries produced 15 published studies and 5 ongoing trials, for 9 of which the authors accepted to share individual participant data. 314 patients from two randomized trials, 452 from three prospective series and 564 from 4 non-randomized studies were included. Fluorescence imaging significantly reduced the incidence of AL (OR 0.341; 95% CI 0.220-0.530; p < 0.001), independent of age, gender, BMI, tumour and anastomotic distance from the anal verge and neoadjuvant therapy. Also, overall morbidity and reintervention rate were positively influenced by the use of ICG.

CONCLUSIONS

The incidence of AL may be reduced when ICG fluorescence imaging is used to assess the perfusion of a colorectal anastomosis. Limitations relate to the consistent number of non-randomized studies included and their heterogeneity in defining and assessing AL. Ongoing large randomized studies will help to determine the exact role of routine ICG fluorescence imaging may decrease the incidence of AL in surgery for rectal cancer.

Indocyanine Green-Enhanced Colorectal Surgery-between Being Superfluous and Being a Game-Changer

Nowadays, surgical innovations incorporate new technological conquests and must be validated by evidence-based medicine. The use of augmented reality-assisted indocyanine green (ICG) fluorescence has generated a myriad of intraoperative applications such as demonstration of key anatomical landmarks, sentinel lymph nodes, and real-time assessment of local blood flow. This paper presents a systematic review of the clinical evidence regarding the applications of ICG near-infrared (NIR) fluorescence in colorectal surgery. After we removed duplicate publications and screened for eligibility, a total of 36 articles were evaluated: 23 on perfusion assessment, 10 on lymph node mapping, and 3 on intraoperative identification of ureters. Lack of homogenous studies, low statistical power, and confounding evidence were found to be common amongst publications supporting the use of ICG in colorectal surgery, raising concerns over this seductive technique's cost efficiency and redundancy. The compiled data showed that ICG NIR fluorescence may be a game-changer in particular situations, as proven for low colorectal anastomosis or lateral pelvic lymph node dissection, but it remains controversial for routine use and sentinel lymph node assessment. Further randomized studies are needed to confirm these conclusions. Future research directions include tumor-targeted fluorescence imaging and digital software for quantitative evaluation of fluorescence.

Colonic perfusion assessment with indocyanine-green fluorescence imaging in anterior resections: a propensity score-matched analysis

BACKGROUND

Colonic perfusion is crucial for anastomotic healing and this could be evaluated intraoperatively using indocyanine-green fluorescence imaging (ICG FI). The aim of this study was to ascertain whether the use of ICG FI resulted in the reduction of anastomotic complications, i.e. AL and anastomotic stricture.

METHODS

Consecutive patients who underwent anterior resections or low anterior resections at our institution in the period from January 1st 2013 to December 31st 2018 were retrospectively reviewed. Surgery performed during the period from January 1st 2013 to December 31st 2015 did not involve the use of ICG FI (ICG-) while surgery during the period from January 1st 2016 to December 31st 2018 was performed with the use of ICG FI (ICG+). The anastomotic leakage rates of the two groups were compared after propensity score matching, taking into account the height of the anastomosis and any history of pelvic irradiation.

RESULTS

There was a total of 258 and 317 patients who had surgery with and without ICG FI, respectively. There were 253 patients in each group after propensity score matching. The overall anastomotic leakage rate was 3.6% and 7.9% for ICG+ and ICG-, respectively, (p = 0.035). Subgroup analysis showed that the use of ICG FI was significantly associated with a lower anastomotic leakage rate in total mesorectal excision (TME), 4.7% versus 11.6%, p = 0.043, but not in non-TME resections, 3.5% versus 2.4%, (p = 0.612). ICG FI, together with sex and anastomotic height, were independent predictors of anastomotic leakage.

CONCLUSIONS

The routine use of ICG FI was associated with a lower anastomotic leakage rate in anterior resections. The reduction in anastomotic leakage rate was mainly seen in TME.

Could fluorescence-guided surgery be an efficient and sustainable option? A SICE (Italian Society of Endoscopic Surgery) health technology assessment summary

BACKGROUND

Indocyanine green fluorescence vision is an upcoming technology in surgery. It can be used in three ways: angiographic and biliary tree visualization and lymphatic spreading studies. The present paper shows the most outstanding results from an health technology assessment study design, conducted on fluorescence-guided compared with standard vision surgery.

METHODS

A health technology assessment approach was implemented to investigate the economic, social, ethical, and organizational implications related to the adoption of the innovative fluorescence-guided view, with a focus on minimally invasive approach. With the support of a multidisciplinary team, qualitative and quantitative data were collected, by means of literature evidence, validated questionnaires and self-reported interviews, considering the dimensions resulting from the EUnetHTA Core Model.

RESULTS

From a systematic search of literature, we retrieved the following studies: 6 on hepatic, 1 on pancreatic, 4 on biliary, 2 on bariatric, 4 on endocrine, 2 on thoracic, 11 on colorectal, 7 on urology, 11 on gynecology, 2 on gastric surgery. Fluorescence guide has shown advantages on the length of hospitalization particularly in colorectal surgery, with a reduction of the rate of leakages and re-do anastomoses, in spite of a slight increase in operating time, and is confirmed to be a safe, efficacious, and sustainable vision technology. Clinical applications are still presenting a low evidence in the literature.

CONCLUSION

The present paper, under the patronage of Italian Society of Endoscopic Surgery, based on an HTA approach, sustains the use of fluorescence-guided vision in minimally invasive surgery, in the fields of general, gynecologic, urologic, and thoracic surgery, as an efficient and economically sustainable technology.

Clinical efficacy of bowel perfusion assessment during laparoscopic colorectal resection using laser speckle contrast imaging: A matched case-control study

INTRODUCTION

Disadvantages of bowel perfusion assessment with indocyanine green fluorescence angiography include the need for a fluorophore and the subjective nature of the assessment. This study was performed to evaluate the clinical efficacy of bowel perfusion assessment using laser speckle contrast imaging (LSCI) during laparoscopic colorectal surgery.

METHODS

The study population comprised the first 27 consecutive patients who underwent laparoscopic left-sided colorectal resection with intraoperative perfusion assessment using LSCI. The operative outcomes of these patients were compared with those of a matched group of patients without perfusion assessment. We analyzed the flux data expressed in laser speckle perfusion units.

RESULTS

After propensity score matching, we found no significant between-group differences in the patients' characteristics with the exception of the cancer stage. No patients undergoing LSCI perfusion assessment developed anastomotic leakage, but five (18.5%) patients in the control group did, at a significantly higher rate in male patients (P = .042). There were no significant differences in other operative outcomes. The laser speckle perfusion unit values after ligating marginal vessels were significantly lower than before ligation (P < .01).

CONCLUSIONS

With respect to anastomotic leakage, LSCI may improve patient outcomes after colorectal surgery. This technique appears to be a superior tool with the advantages of measurement repeatability and quantitativity and no need for a fluorophore.

The Use of Enhanced Technologies in Robotic Surgery and Its Impact on Outcomes in Rectal Cancer: A Systematic Review

The main advantage of the robotic approach is the surgical precision that the technology offers. It is particularly useful in rectal cancer as this is a technically challenging procedure. The technological advantage of the robot leads to better postoperative outcomes. Apart from the 3D vision and endowrist instrumentation in comparison to laparoscopy, the options of using fluorescence imaging, endowrist stapler, and table motion have revolutionised the way of performing an anterior resection. Thus, the true benefit of these advances will be the quality of the surgery, which leads to better postoperative outcomes. This article focuses on the current status of applications of new modalities and technology development in robotic rectal surgery. A systematic literature search was performed using PubMed, MEDLINE, and cochrane database. The studies included were considered based on the following (1) articles written in English, (2) full text is available, (3) whether the topic is related to the use of novel technologies during robotic rectal surgery, and (4) sample: adult patients and malignant rectal disease. The primary end point was to analyse the current use of technological advances in robotic rectal surgery. Only a few studies are currently available on the use of these different technologies in robotic colorectal surgery. Many of these reports describe promising results, although with short-term outcomes. The use of technologies in robotic colorectal surgery is safe and feasible and can be used together to improve short-term outcomes. Intraoperative fluorescence angiography has demonstrated to reduce the rate of anastomotic leak, whereas the robotic stapler and the table motion simplify anatomic resection.

Indocyanine green fluorescence angiography to evaluate anastomotic perfusion in colorectal surgery

BACKGROUND

The aim of this study was to evaluate the efficacy of indocyanine green (ICG) fluorescence angiography with respect to the anastomotic leakage rate for patients undergoing colorectal operations.

METHODS

This prospective cohort involved patients who underwent colorectal surgery between August 2018 and September 2019. ICG was injected after colonic transection. Vascular perfusion was observed by ICG fluorescence system before completing anastomosis. Data was compared with those by subjective visual evaluation. The primary outcome was anastomotic leakage rate within 30 days from surgery.

RESULTS

A total of 131 patients were enrolled, of which ICG was injected in 63 of them. Demographic data were similar between the two groups. There were two (3.23%) and three (4.35%) anastomotic leaks in the ICG and non-ICG group respectively (p = 1.000). Change of resection plane occurred in one patient in the ICG group. There was no ICG related toxicity or adverse events.

CONCLUSION

ICG fluorescent imaging is a feasible and safe tool to assess colonic vascularisation for patients undergoing colorectal surgery. However, it did not significantly lower the anastomotic leakage rate. ICG should not be routinely used in colorectal surgery before an available large scale randomised controlled trial to prove any clinical benefits.

A standardized use of intraoperative anastomotic testing in colorectal surgery in the new millennium: is technology taking over? A systematic review and network meta-analysis

BACKGROUND

Anastomotic leakage (AL) remains the most challenging complication following colorectal resection. There are several tests that can be used to test anastomotic integrity intraoperatively including air leak testing (ALT) and intraoperative colonoscopy (IOC). Indocyanine green (ICG) can be used to visualise blood supply to the bowel used in the anastomosis. However, there is no consensus internationally regarding routine use and which technique is superior. The aim of this study was to determine which intraoperative anastomotoic leak test (IALT) was most effective in reducing AL.

METHODS

A systematic review and network meta-analysis were performed. An electronic systematic search was performed using Pubmed, CENTRAL, and Web of Science, of studies comparing ALT, IOC, and ICG. The inclusion criteria were as follows: (a) patients must have had colorectal surgery with formation of an anastomosis; (b) studies must have compared one or more IALTs; (c) and studies must have clear research methodology.

RESULTS

Eleven articles totalling 3844 patients met the inclusion criteria and were included in this meta-analysis. Point estimation showed that the AL rate in the control group (no IALT) was significantly higher when compared to the ICG group (RR 0.44; Crl 0.14-0.87) and higher, but without reaching statistical significance, when compared to ALT (RR 0.53; Crl 0.21-1.30) and IOC (RR 0.49; Crl 0.10-1.80). Indirect comparison showed that the AL rate in the ICG group was lower, when compared to both ALT (RR 0.44; Crl 0.14-0.87) and IOC (RR 0.44; Crl 0.14-0.87).

CONCLUSIONS

This study suggests that intraoperative testing for a good blood supply using ICG may reduce the AL rate following colorectal surgery.

Indocyanine green fluorescence imaging to reduce the risk of anastomotic leakage in laparoscopic low anterior resection for rectal cancer: a propensity score-matched cohort study

BACKGROUND

Recent studies have shown the potential benefit of indocyanine green fluorescence imaging (ICG-FI) in lowering the anastomotic leakage (AL) rates by changing the surgical plan. The aim of this study was to evaluate the effect of ICG-FI on the AL rates in laparoscopic low anterior resection (LAR) for rectal cancer.

METHODS

From September 2014 to December 2017, data from patients who underwent laparoscopic LAR for rectal cancer were collected and analyzed. The primary endpoint was the AL rate within 30 days after surgery. The incidence of AL in patients who underwent ICG (ICG-FI group) was compared with that in patients who did not undergo ICG (non-ICG-FI group) using propensity score matching.

RESULTS

Data from 550 patients were collected from 3 institutions. A total of 211 patients were matched in both groups by the propensity score. ICG-FI shifted the point of the proximal colon transection line toward the oral side in 12 patients (5.7%). The AL rates of Clavien-Dindo (CD) grade ≥ II and ≥ III were 10.4% (22/211) and 9.5% (20/211) in the non-ICG-FI group and 4.7% (10/211) and 2.8% (6/211) in the ICG-FI group, respectively. ICG-FI significantly reduced the AL rate of CD grade ≥ II and ≥ III (odds ratio (OR) 0.427; 95% confidence interval (CI) 0.197-0.926; p = 0.042 and OR 0.280; CI 0.110-0.711; p = 0.007, respectively). The rate of reoperation was significantly lower (OR 0.192; CI 0.042-0.889; p = 0.036) and the postoperative hospital stay significantly shorter (mean difference 2.62 days; CI 0.96-4.28; p = 0.002) in the ICG-FI group than in the non-ICG-FI group.

CONCLUSIONS

ICG-FI was associated with significantly lower odds of AL in laparoscopic LAR for rectal cancer.

CLINICAL TRIAL

The study was registered with the Japanese Clinical Trials Registry as UMIN000032654.

Laser Speckle Contrast Imaging for Intraoperative Quantitative Assessment of Intestinal Blood Perfusion During Colorectal Surgery: A Prospective Pilot Study

BACKGROUND

The main limitation of perfusion assessment with indocyanine green fluorescence angiography during colorectal surgery is that the surgeon assesses the quality of perfusion subjectively. The ideal intestinal viability test must be minimally invasive, objective, and reproducible. We evaluated the quantitativity and reproducibility of laser speckle contrast imaging for perfusion assessment during colorectal surgery.

METHODS

This was a prospective, nonrandomized, pilot study of 8 consecutive patients who underwent elective left-sided colorectal resection. Laser speckle perfusion images at the site of proximal transection of the bowel were obtained intraoperatively. We tested the hypothesis that laser speckle contrast imaging was able to quantitatively identify areas of diminished intestinal perfusion after devascularization and assessed the reproducibility of this method.

RESULTS

All surgical procedures were uneventful and blood flow measurements were successfully made in all patients. None of the patients developed postoperative complications related to the anastomosis and stoma. Data analyses were successfully optimized to perform quantitative regional perfusion assessments in all cases. The bowel tissue blood flows of the anal side region adjacent to the transection line were significantly lower than those of the oral side region adjacent to the transection line after ligation of marginal vessels ( P = .012). Interrater reliability was high (intraclass correlation coefficients = 0.989), and a Bland-Altman plot showed few differences of mean flux data between 2 investigators.

CONCLUSION

Laser speckle contrast imaging is feasible for real-time assessment of bowel perfusion with quantitativity and excellent reproducibility during colorectal surgery without administration of any contrast agents.

Transanal total mesorectal excision for rectal cancer with indocyanine green fluorescence angiography

BACKGROUND

The aim of this study was to evaluate the impact of fluorescence angiography (FA) on any change in proximal resection margin and/or anastomotic leak (AL) following transanal total mesorectal excision (TaTME) for rectal cancer (RC).

METHODS

This retrospective cohort study was conducted at two centers by three senior surgeons. Both institutions' prospectively maintained Institutional Review Board-approved databases were retrospectively queried for all consecutive patients between July 2015 and May 2017 who had laparoscopic hybrid trans-abdominal total mesorectal excision (TME) and TaTME for RC with colorectal or coloanal anastomosis < 10 cm from the anal verge. All patients had intraoperative FA to assess colonic perfusion of the planned proximal resection margin before bowel transection and after construction of the anastomosis. Primary outcomes measured any changes in proximal resection margins and AL rates.

RESULTS

Fifty-four patients (31 males; mean age 63 ± 12 years) were included; 30 (55%) of whom received neoadjuvant chemoradiation. The average anastomotic height was 3.6 cm from the anal verge and 8 (14.5%) patients required intersphincteric dissection. Forty-six patients (85%) had loop ileostomy. FA led to a change in the proximal resection margin in 10 patients (18.5%), one of whom had AL on postoperative day 3 requiring diagnostic laparoscopy and loop ileostomy. A second patient, without a change in the proximal resection margin, also had an AL. The overall AL rate was 3.7%.

CONCLUSIONS

FA changed the planned proximal resection margin in 18.5% of patients, possibly accounting for the relatively low AL rate. FA is imperfect, and subjective but does have the potential to improve outcomes.

Indocyanine Green Fluorescence Angiography and the Incidence of Anastomotic Leak After Colorectal Resection for Colorectal Cancer: A Meta-analysis

BACKGROUND

Anastomotic leak is a life-threatening complication of colorectal surgery. Recent studies showed that indocyanine green fluorescence angiography might be a method to prevent anastomotic leak.

OBJECTIVE

The purpose of this study was to investigate whether intraoperative indocyanine green fluorescence angiography can reduce the incidence of anastomotic leak.

DATA SOURCES

Potential relevant studies were identified from the following databases: PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure.

STUDY SELECTION

This meta-analysis included comparative studies investigating the association between indocyanine green fluorescence angiography and anastomotic leak in patients undergoing surgery for colorectal cancer where the diagnosis of anastomotic leak was confirmed by CT and the outcomes of the indocyanine green group were compared with a control group.

INTERVENTION

Indocyanine green was injected intravenously after the division of the mesentery and colon but before anastomosis.

MAIN OUTCOME MEASURES

The Newcastle-Ottawa Scale was used to assess methodologic quality of the studies. ORs and 95% CIs were used to assess the association between indocyanine green and anastomotic leak.

RESULTS

In 4 studies with a total sample size of 1177, comparing the number of anastomotic leaks in the indocyanine green and control groups, the ORs were 0.45 (95% CI, 0.18-1.12), 0.30 (95% CI, 0.03-2.98), 0.17 (95% CI, 0.01-3.69), and 0.12 (95% CI, 0.03-0.52). The combined OR was 0.27 (95% CI, 0.13-0.53). The difference was statistically significant (p < 0.001), and there was no significant heterogeneity (p = 0.48; I = 0).

LIMITATIONS

Data could not be pooled because of the small number of studies; some differences between studies may influence the results. Also, the pooled data were not randomized.

CONCLUSIONS

The result revealed that indocyanine green was associated with a lower anastomotic leakage rate after colorectal resection. However, larger, multicentered, high-quality randomized controlled trials are needed to confirm the benefit of indocyanine green fluorescence angiography.

Quantitative analysis of colon perfusion pattern using indocyanine green (ICG) angiography in laparoscopic colorectal surgery

Purpose

This study aimed to quantitatively evaluate colon perfusion patterns using indocyanine green (ICG) angiography to find the most reliable predictive factor of anastomotic complications after laparoscopic colorectal surgery.

Methods

Laparoscopic fluorescence imaging was applied to colorectal cancer patients (n = 86) from July 2015 to December 2017. ICG (0.25 mg/kg) was slowly injected into peripheral blood vessels, and the fluorescence intensity of colonic flow was measured sequentially, producing perfusion graphs using a video analysis and modeling tool. Colon perfusion patterns were categorized as either fast, moderate, or slow based on their fluorescence slope, T_1/2MAX and time ratio (TR = T_1/2MAX/T_MAX). Clinical factors and quantitative perfusion factors were analyzed to identify predictors for anastomotic complications.

Results

The mean age of patients was 65.4 years, and the male-to-female ratio was 63:23. Their operations were laparoscopic low anterior resection (55 cases) and anterior resection (31 cases). The incidence of anastomotic complication was 7%, including colonic necrosis (n = 1), anastomotic leak (n = 3), delayed pelvic abscess (n = 1), and delayed anastomotic dehiscence (n = 1). Based on quantitative analysis, the fluorescence slope, T_1/2MAX, and TR were related with anastomotic complications. The cut-off value of TR to categorize the perfusion pattern was determined to be 0.6, as shown by ROC curve analysis (AUC 0.929, P < 0.001). Slow perfusion (TR > 0.6) was independent factor for anastomotic complications in a logistic regression model (OR 130.84; 95% CI 6.45–2654.75; P = 0.002). Anastomotic complications were significantly correlated with the novel factor TR (> 0.6) as the most reliable predictor of perfusion and anastomotic complications.

Conclusions

Quantitative analysis of ICG perfusion patterns using T_1/2MAX and TR can be applied to detect segments with poor perfusion, thereby reducing anastomotic complications during laparoscopic colorectal surgery.

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

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

Tracking of transplanted human umbilical cord-derived mesenchymal stem cells labeled with fluorescent probe in a mouse model of acute lung injury

The aim of the present study was topreliminarily visualize the distribution of humanumbilical cord-derived-mesenchymal stem cells (hUC-MSCs) in treating acute lung injury (ALI) using a targeted fluorescent technique. Anovel fluorescent molecule probe was first synthesized via the specific binding of antigen and antibody in vitro to label the hUC-MSCs. Two groups of mice, comprising a normal saline (NS)+MSC group and lipopolysaccharide (LPS)+MSC group, were subjected to optical imaging. At 4 h following ALI mouse model construction, the labeled hUC-MSCs were transplanted into the mice in the NS+MSC group and LPS+MSC group by tail vein injection. The mice were sacrificed 30 min, 1 day, 3 days and 7 days following injection of the labeled hUC-MSCs, and the lungs, heart, spleen, kidneys and liver were removed. The excised lungs, heart, spleen, kidneys and liver were then detected on asmall animal fluorescent imager. The fluorescent results showed that the signal intensity in the lungs of the LPS+MSC group was significantly higher, compared with that of the NS+MSC group at 30 min (3.53±0.06×10⁻⁴, vs. 1.95±0.05×10⁻⁴ scaled counts/sec), 1 day (36.20±0.77×10⁻⁴, vs. 23.45±0.43×10⁻⁴ scaled counts/sec), 3 days (11.83±0.26×10⁻⁴, vs. 5.39±0.10×10⁻⁴ scaled counts/sec), and 7 days (3.14±0.04×10⁻⁴, vs. 0.00±0.00×10⁻⁴ scaled counts/sec; all P<0.05). The fluorescence intensity in the liver of the LPS+MSC group, vs. NS+MSC group was measured at 30 min (0.00±0.00×10⁻⁴, vs. 0.00±0.00×10⁻⁴ scaled counts/sec); 1 day (5.53±0.08×10⁻⁴, vs. 5.44±0.16×10⁻⁴ scaled counts/sec); 3 days (0.00±0.00×10⁻⁴, vs. 8.67±0.05×10⁻⁴ scaled counts/sec); 7 days (0.00±0.00×10⁻⁴, vs. 0.00±0.00×10⁻⁴ scaled counts/sec). The signal intensity of the heart, spleen and kidneys was minimal. In conclusion, the novel targeted fluorescence molecular probe was suitable for tracking the distribution processes of hUC-MSCs in treating ALI.

Intraoperative use of ICG fluorescence imaging to reduce the risk of anastomotic leakage in colorectal surgery: a systematic review and meta-analysis

BACKGROUND

Indocyanine green (ICG) fluorescence imaging has been proven to be an effective tool to assess anastomotic perfusion. The aim of this systematic review and meta-analysis was to evaluate its efficacy in reducing the anastomotic leakage (AL) rate after colorectal surgery.

METHODS

PubMed, Scopus, WOS, Google Scholar and Cochrane Library were searched up to January 2017 for studies comparing fluorescence imaging with standard care. ClinicalTrials.gov register was searched for ongoing trials. The primary outcome measure was AL rate with at least 1 month of follow-up. ROBINS-I tool was used for quality assessment. A meta-analysis with random-effects model was performed to calculate odds ratios (ORs) from the original data.

RESULTS

One thousand three hundred and two patients from 5 non-randomized studies were included. Fluorescence imaging significantly reduced the AL rate in patients undergoing surgery for colorectal cancer (OR 0.34; CI 0.16-0.74; p = 0.006). Low AL rates were shown in rectal cancer surgery (ICG 1.1% vs non-ICG 6.1%; p = 0.02). There was no significant decrease in the AL rate when colorectal procedures for benign and malignant disease were combined. To date, there are no published randomized control trials (RCTs) on this subject, though 3 ongoing RCTs were identified.

CONCLUSIONS

ICG fluorescence imaging seems to reduce AL rates following colorectal surgery for cancer. However, the inherent bias of the non-randomized studies included, and their differences in AL definition and diagnosis could have influenced results. Large well-designed RCTs are needed to provide evidence for its routine use in colorectal surgery.

Long-term survival after multidisciplinary therapy for brain metastases from asymptomatic esophageal adenocarcinoma

Asymptomatic T1 (invaded submucosa) esophageal carcinoma rarely metastasizes to the brain. A 53-year-old Japanese man complaining of right hemiparesis and convulsion was admitted to our hospital. Brain imaging demonstrated a ring-like, enhanced brain tumor in the left parietal lobe. The pathological findings of the resected tumor were consistent with a metastatic adenocarcinoma from the gastrointestinal tract. Additional examinations revealed an elevated-type tumor in the lower third of the thoracic esophagus. The patient underwent thoracoscopic esophagectomy with lymph node dissection followed by reconstruction with gastric tube substitution. The immunohistochemical findings of the resected specimen were similar to those of the metastatic brain tumor. Although the patient received adjuvant chemotherapy (5-fluorouracil, docetaxel plus cisplatin), a solitary small brain metastasis was detected 4 months after esophagectomy. Excision of the sequential metastases with whole-brain radiation therapy and gamma-knife therapy were performed. The patient survived for 50 months after beginning the initial treatment. This report describes a rare case of brain metastases from T1 esophageal adenocarcinoma in a patient without gastrointestinal symptoms.