Multicentre phase II trial of near-infrared imaging in elective colorectal surgery

The use of indocyanine green for colorectal anastomoses: a systematic review and meta-analysis

INTRODUCTION

Anastomotic leak is a relatively common and debilitating complication. Colorectal leak rates vary widely in the literature, ranging from 1% to 20%. In modern surgical practice, there is much emphasis on the use of indocyanine green (ICG). This is a fluorescent dye administered intravenously to locate and predict an adequate line of anastomosis. We sought to analyse the current literature and supporting evidence behind the use of ICG in the context of elective colorectal surgery.

METHODS

A literature search was conducted for papers published between January 1991 and December 2022 concerning the use of ICG in colorectal surgery. Data on anastomotic leak, overall complication rate, operative time and involvement of artificial intelligence (AI) were compared.

RESULTS

A total of 24 studies were selected, including 3 randomised controlled trials. There was an anastomotic leak rate of 4.3% in cases with ICG administration compared with 9.5% in the control group (p<0.00001). Seven studies mentioned overall complication rates. These were lower in the ICG cohort than in the control group (15.5% vs 24.5%). There was no significant correlation between ICG use and operative time (p=0.78). Five studies looked at AI, with results suggesting that use of AI leads to much better accuracy in ICG metric analysis. However, the current literature is still inconclusive.

CONCLUSIONS

While there is strong evidence behind ICG use in the existing literature, more randomised controlled trials are required for better recommendations. AI in ICG metric interpretation has proved to be difficult owing to interpatient variability. Nevertheless, new data suggest better understanding and standardisation.

Current status and future trends of real-time imaging in gastric cancer surgery: A literature review

Technological advances are crucial for the optimization of gastric cancer surgery, and the success of any gastric cancer surgery is based on the correct and precise anatomical determination of the primary tumour and tissue structures. Real-time imaging-guided surgery is showing increasing potential and utility, mainly because it helps to aid intraoperative decision-making. However, intraoperative imaging faces many challenges in the field of gastric cancer. This article summarizes and discusses the following clinical applications of real-time optical imaging and fluorescence-guided surgery for gastric cancer: (1) the potential of quantitative fluorescence imaging in assessing tissue perfusion, (2) vascular navigation and determination of tumour margins, (3) the advantages and limitations of lymph node drainage assessment, and (4) identification of peritoneal metastases. In addition, preclinical study of tumour-targeted fluorescence imaging are discussed.

A Green Lantern for the Surgeon: A Review on the Use of Indocyanine Green (ICG) in Minimally Invasive Surgery

Indocyanine green (ICG) fluorescence imaging has revolutionized surgical practice across various medical and surgical specialties. This article reviews the clinical applications of ICG in abdominal, urological, thoracic, and gynecological surgery. ICG fluorescence imaging has been widely adopted in general surgery for various applications, including perfusion assessment, intraoperative visualization of the ureter, and tumor localization. It is particularly valuable in evaluating anastomotic leaks and aiding in precise tumor resection during minimally invasive surgeries. Studies have shown mixed results on its effectiveness in reducing anastomotic leak rates, highlighting the need for further research. In thoracic surgery, ICG facilitates the identification and resection of pulmonary bullae, as well as the precise localization of pulmonary nodules during video-assisted surgery. In urology, ICG aids in localizing renal tumors and guiding selective arterial occlusion during partial nephrectomy. Its role in identifying the lymphatic pathway in prostate cancer and sentinel lymph node biopsy in gynecological cancer is also discussed. Despite its benefits, the use of ICG fluorescence faces challenges such as limited tissue penetration, the potential for false results, a lack of standardized protocols, and high equipment costs. Nonetheless, it remains a powerful tool that could improve surgical outcomes.

Clinical validation of 3D virtual modelling for laparoscopic complete mesocolic excision with central vascular ligation for proximal colon cancer

INTRODUCTION

Laparoscopic Complete Mesocolic Excision (CME) with Central Vascular Ligation (CVL) in colon cancer surgery has not been broadly adopted in part because of safety concerns. Pre-operative 3-D virtual modelling (3DVM) may help but needs validation.

METHODS

3DVM were routinely constructed from CT mesenteric angiograms (CTMA) using a commercial service (Visible Patient, Strasbourg, France) for consecutive patients during our CMECVL learning curve over three years. 3DVMs were independently checked versus CTMA and operative findings. CMECVL outcomes were compared versus other patients undergoing standard mesocolic excision (SME) surgery laparoscopically in the same hospital as control. Stakeholders were studied regarding 3DVM use and usefulness (including detail retention) versus CTMA and a physical 3D-printed model.

RESULTS

26 patients underwent 3DVM with intraoperative display during laparoscopic CMECVL within existing workflows. 3DVM accuracy was 96 % re arteriovenous variations at patient level versus CTMA/intraoperative findings including accessory middle colic artery identification in three patients. Twenty-two laparoscopic CMECVL with 3DVM cases were compared with 49 SME controls (age 69 ± 10 vs 70.9 ± 11 years, 55 % vs 53 % males). There were no intraoperative complications with CMECVL and similar 30-day postoperative morbidity (30 % vs 29 %), hospital stay (9 ± 3 vs 12 ± 13 days), 30-day readmission (6 % vs 4 %) and reoperation (0 % vs 4 %) rates. Intraoperative times were longer (215.7 ± 43.9 vs 156.9 ± 52.9 min, p=<0.01) but decreased significantly over time. 3DVM surveys (n = 98, 20 surgeons, 48 medical students, 30 patients/patient relatives) and comparative study revealed majority endorsement (90 %) and favour (87 %).

CONCLUSION

3DVM use was positively validated for laparoscopic CMECVL and valued by clinicians, students, and patients alike.

Developments in the Use of Indocyanine Green (ICG) Fluorescence in Colorectal Surgery

Indocyanine Green (ICG) has significantly advanced minimally invasive surgery. It is widely recognized for its ability to visualize blood vessel patency in real-time across various surgical specialties. While its primary use in colorectal surgery is to evaluate anastomoses for leaks, numerous other applications have been documented in the literature. In this review, we aim to explore both established and emerging applications of ICG fluorescence in colorectal surgery, with the goal of improving patient outcomes. This includes preoperative tumor marking and the detection of metastatic disease. Some applications, such as lymphatic mapping, require further research to determine their impact on clinical practices. Conversely, others, like the intraoperative localizations of ureters, necessitate additional procedures and are not yet widely accepted by the surgical community. However, the development of alternative compounds could offer better solutions. Future research should focus on areas like quantitative ICG and protocol standardization in prospective multicenter studies.

Perfusion outcomes with near-infrared indocyanine green imaging system in laparoscopic total mesorectal excision for mid-rectal or low-rectal cancer (POSTER): a study protocol

INTRODUCTION

Anastomotic leakage (AL) is defined as the failure of complete healing or disruption of the anastomosis subsequent to rectal cancer surgery, resulting in the extravasation of intestinal contents into the intra-abdominal or pelvic cavity. It is a serious complication of rectal cancer surgery, accounting for a considerable increase in morbidity and mortality. The use of fluorescence imaging technology in surgery allows surgeons to better evaluate blood perfusion. However, the conclusions of some existing studies are not consistent, so a consensus on whether the near-infrared indocyanine green (NIR-ICG) imaging system can reduce the incidence of AL is needed.

METHODS

This POSTER trial is designed as a multicentre, prospective, randomised controlled clinical study adhering to the "population, interventions, comparisons, outcomes (PICO)" principles. It is scheduled to take place from August 2019 to December 2024 across eight esteemed hospitals in China. The target population consists of patients diagnosed with rectal cancer through pathological confirmation, with tumours located≤10 cm from the anal verge, eligible for laparoscopic surgery. Enrolled patients will be randomly assigned to either the intervention group or the control group. The intervention group will receive intravenous injections of ICG twice, with intraoperative assessment of anastomotic blood flow using the near-infrared NIR-ICG system during total mesorectal excision (TME) surgery. Conversely, the control group will undergo conventional TME surgery without the use of the NIR-ICG system. A 30-day follow-up period postoperation will be conducted to monitor and evaluate occurrences of AL. The primary endpoint of this study is the incidence of AL within 30 days postsurgery in both groups. The primary outcome investigators will be blinded to the application of ICG angiography. Based on prior literature, we hypothesise an AL rate of 10.3% in the control group and 3% in the experimental group for this study. With a planned ratio of 2:1 between the number of cases in the experimental and control groups, and an expected 20% lost-to-follow-up rate, the initial estimated sample size for this study is 712, comprising 474 in the experimental group and 238 in the control group.

ETHICS AND DISSEMINATION

This study has been approved by Ethics committee of Beijing Friendship Hospital, Capital Medical University (approval number: 2019-P2-055-02). The results will be disseminated in major international conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04012645.

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

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

Blood Perfusion Assessment by Indocyanine Green Fluorescence Imaging for Minimally Invasive Rectal Cancer Surgery (EssentiAL trial): A Randomized Clinical Trial

OBJECTIVE

The aim of the present randomized controlled trial was to evaluate the superiority of indocyanine green fluorescence imaging (ICG-FI) in reducing the rate of anastomotic leakage in minimally invasive rectal cancer surgery.

BACKGROUND

The role of ICG-FI in anastomotic leakage in minimally invasive rectal cancer surgery is controversial according to the published literature.

METHODS

This randomized, open-label, phase 3, trial was performed at 41 hospitals in Japan. Patients with clinically stage 0-III rectal carcinoma less than 12 cm from the anal verge, scheduled for minimally invasive sphincter-preserving surgery were preoperatively randomly assigned to receive a blood flow evaluation by ICG-FI (ICG+ group) or no blood flow evaluation by ICG-FI (ICG- group). The primary endpoint was the anastomotic leakage rate (grade A+B+C, expected reduction rate of 6%) analyzed in the modified intention-to-treat population.

RESULTS

Between December 2018 and February 2021, a total of 850 patients were enrolled and randomized. After the exclusion of 11 patients, 839 were subject to the modified intention-to-treat population (422 in the ICG+ group and 417 in the ICG- group). The rate of anastomotic leakage (grade A+B+C) was significantly lower in the ICG+ group (7.6%) than in the ICG- group (11.8%) (relative risk, 0.645; 95% confidence interval 0.422-0.987; P =0.041). The rate of anastomotic leakage (grade B+C) was 4.7% in the ICG+ group and 8.2% in the ICG- group ( P =0.044), and the respective reoperation rates were 0.5% and 2.4% ( P =0.021).

CONCLUSIONS

Although the actual reduction rate of anastomotic leakage in the ICG+ group was lower than the expected reduction rate and ICG-FI was not superior to white light, ICG-FI significantly reduced the anastomotic leakage rate by 4.2%.

Time required for indocyanine green fluorescence emission for evaluating bowel perfusion in left-sided colon and rectal cancer surgery

BACKGROUND

Indocyanine green fluorescence imaging (ICG-FI) has been reported to be useful in reducing the incidence of anastomotic leakage (AL) in colectomy. This study aimed to investigate the correlation between the required time for ICG fluorescence emission and AL in left-sided colon and rectal cancer surgery using the double-stapling technique (DST) anastomosis.

METHODS

This retrospective study included 217 patients with colorectal cancer who underwent left-sided colon and rectal surgery using ICG-FI-based perfusion assessment at our department between November 2018 and July 2022. We recorded the time required to achieve maximum fluorescence emission after ICG systemic injection and assessed its correlation with the occurrence of AL.

RESULTS

Among 217 patients, AL occurred in 21 patients (9.7%). The median time from ICG administration to maximum fluorescence emission was 32 s (range 25-58 s) in the AL group and 28 s (range 10-45 s) in the non-AL group (p < 0.001). The cut-off value for the presence of AL obtained from the ROC curve was 31 s. In 58 patients with a required time for ICG fluorescence of 31 s or longer, the following risk factors for AL were identified: low preoperative albumin [3.4 mg/dl (range 2.6-4.4) vs. 3.9 mg/dl (range 2.6-4.9), p = 0.016], absence of preoperative mechanical bowel preparation (53.8% vs. 91.1%, p = 0.005), obstructive tumor (61.5% vs. 17.8%, p = 0.004), and larger tumor diameter [65 mm (range 40-90) vs. 35 mm (range 4.0-100), p < 0.001].

CONCLUSION

The time required for ICG fluorescence emission was associated with AL.

Simultaneous fluorescence imaging of bowel perfusion and ureter delineation using methylene blue: a demonstration in a porcine model

BACKGROUND

Intraoperative near-infrared fluorescence imaging (NIRF) with preoperative optical dye administration is a promising technique for quick and easy intraoperative visualization of the ureter and for an improved, real-time assessment of intestinal perfusion. During colorectal surgery, there is a need for simultaneous non-invasive ureteral imaging and bowel perfusion assessment, using one single camera system. The purpose of this study is to investigate the feasibility of simultaneous intestinal perfusion and ureteral imaging using a single commercially available NIRF imaging system.

METHODS

Six Landrace pigs underwent laparotomy under general anesthesia in this experiment. An intravenous (IV) dose of 0.2 mg/kg indocyanine green (ICG) was given to assess bowel perfusion. Two pairs received a methylene blue (MB) iv injection of 0.75, 0.50 or 0.25 mg/kg respectively to investigate ureteral visualization. Quest Spectrum Fluorescence Camera (Quest Medical Imaging, Middenmeer, The Netherlands) was used for NIRF imaging.

RESULTS

Ureter visualization and bowel perfusion under NIRF imaging was achieved in all animals. All ureters were visible after five to ten minutes and remained clearly visible until the end of every experiment (120-420 min). A mixed model analysis did not show any significant differences neither between the three groups nor over time. Importantly, we demonstrated that bowel perfusion could be visualized with methylene blue (MB) as well. We observed no interference between ICG and MB and a faster washout of MB.

CONCLUSION

We successfully demonstrated simultaneous fluorescence angiography with ICG and ureteral imaging with MB in the same surgical procedure, with the same commercially available NIRF imaging equipment. More importantly, we showed that the use MB is adequate for bowel perfusion assessment and ureter visualization with this NIRF imaging system. Besides, MB showed an earlier washout time, which can be clinical beneficial as a repeated dye injection may be necessary during a surgical procedure.

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.

Fluorescent Imaging in Visceral Surgery: Current Opportunities and Future Perspectives

Background

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

Summary

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

Key Message

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

Indocyanine green fluorescence angiography decreases the risk of anastomotic leakage after rectal cancer surgery: a systematic review and meta-analysis

Background

Anastomotic leakage is a serious complication after rectal cancer resection. Intraoperative use of indocyanine green fluorescence angiography (ICGFA) can help prevent anastomotic leakage, but its use is controversial. We conducted a systematic review and meta-analysis to determine the efficacy of ICGFA in reducing anastomotic leakage.

Methods

Relevant data and research published until September 30, 2022, was retrieved from the PubMed, Embase, and Cochrane Library databases, and the difference in the incidence of anastomotic leakage after rectal cancer resection between ICGFA and standard treatment was compared.

Results

This meta-analysis included 22 studies with a total of 4,738 patients. The results showed that ICGFA use during surgery decreased the incidence of anastomotic leakage after rectal cancer surgery [risk ratio (RR) = 0.46; 95% confidence interval (95% CI), 0.39-0.56; p < 0.001]. Simultaneously, in subgroup analyses for different regions, ICGFA was found to be used to reduce the incidence of anastomotic leakage after rectal cancer surgery in Asia (RR = 0.33; 95% CI, 0.23-0.48; p < 0.00001) and Europe (RR = 0.38; 95% CI, 0.27-0.53; p < 0.00001) but not in North America (RR = 0.72; 95% CI, 0.40-1.29; p = 0.27). Regarding different levels of anastomotic leakage, ICGFA reduced the incidence of postoperative type A anastomotic leakage (RR = 0.25; 95% CI, 0.14-0.44; p < 0.00001) but did not reduce the incidence of type B (RR = 0.70; 95% CI, 0.38-1.31; p = 0.27) and type C (RR = 0.97; 95% CI, 0.51-1.97; p = 0.93) anastomotic leakages.

Conclusion

ICGFA has been linked to a reduction in anastomotic leakage after rectal cancer resection. However, multicenter randomized controlled trials with larger sample sizes are required for further validation.

Fluorescence-guided surgery: comprehensive review

BACKGROUND

Despite significant improvements in preoperative workup and surgical planning, surgeons often rely on their eyes and hands during surgery. Although this can be sufficient in some patients, intraoperative guidance is highly desirable. Near-infrared fluorescence has been advocated as a potential technique to guide surgeons during surgery.

METHODS

A literature search was conducted to identify relevant articles for fluorescence-guided surgery. The literature search was performed using Medical Subject Headings on PubMed for articles in English until November 2022 and a narrative review undertaken.

RESULTS

The use of invisible light, enabling real-time imaging, superior penetration depth, and the possibility to use targeted imaging agents, makes this optical imaging technique increasingly popular. Four main indications are described in this review: tissue perfusion, lymph node assessment, anatomy of vital structures, and tumour tissue imaging. Furthermore, this review provides an overview of future opportunities in the field of fluorescence-guided surgery.

CONCLUSION

Fluorescence-guided surgery has proven to be a widely innovative technique applicable in many fields of surgery. The potential indications for its use are diverse and can be combined. The big challenge for the future will be in bringing experimental fluorophores and conjugates through trials and into clinical practice, as well as validation of computer visualization with large data sets. This will require collaborative surgical groups focusing on utility, efficacy, and outcomes for these techniques.

Tissue Oximetry as a Potential Alternative to Indocyanine Green (ICG) Perfusion Assessment in Colorectal Anastomotic Cases

INTRODUCTION

Anastomotic margin tissue perfusion is recognized as critical to successful colorectal anastomosis creation. Near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) is the most common modality used by surgeons as an adjunct to clinical assessment in confirming the adequacy of tissue perfusion. Tissue oxygenation as a surrogate for tissue perfusion has been described in a variety of surgical specialties but its use in colorectal surgery has been limited. Here, we report our experience using a handheld tissue-oxygen meter, IntraOx, for the evaluation of colorectal tissue bed oxygen saturation (StO 2 ) and compared its utility with NIR-ICG in identifying the viability of colonic tissue before anastomosis in a range of colorectal procedures.

MATERIALS AND METHODS

This was an institutional review board-approved multicenter trial consisting of 100 patients undergoing elective colon resections. After specimen mobilization, a clinical margin was chosen based on the oncologic, anatomic, and clinical assessment as per the clinicians' standard technique. The IntraOx device was then used to take a baseline reading of colonic tissue oxygenation on a normal segment of perfused colon. Following this, measurements were taken circumferentially at 5 cm intervals along the bowel proximally and distally to the clinical margin. A StO 2 margin was then determined based on the point at which the StO 2 dropped off by ≥10 percentage points. This was then compared with the NIR-ICG margin using the Spy-Phi system.

RESULTS

StO 2 was found to have a sensitivity and specificity of 94.8% and 93.1%, respectively, and a positive predictive value and negative predictive value of 93.5% and 94.5%, respectively when compared with NIR-ICG. At the 4-week follow-up, no significant complications or leaks were reported.

CONCLUSIONS

The IntraOx handheld device was found to be similar to NIR-ICG in identifying a well-perfused margin of colonic tissue while having the added benefits of high portability and reduced costs. Further studies looking at the effect of the IntraOx on preventing colonic anastomotic complications such as leak and stricture are warranted.

Understanding fluorescence time curves during ileal pouch-anal anastomosis with or without vascular ligation

BACKGROUND

Intraoperative indocyanine green fluorescence angiography (ICG-FA) may be of added value during pouch surgery, in particular after vascular ligations as lengthening maneuver. The aim was to determine quantitative perfusion parameters within the efferent/afferent loop and explore the impact of vascular ligation. Perfusion parameters were also compared in patients with and without anastomotic leakage (AL).

METHODS

All consenting patients that underwent FA-guided ileal pouch-anal anastomosis (IPAA) between July 2020 and December 2021 were included. After intravenous bolus injection of 0.1 mg/kg ICG, the near-infrared camera (Stryker Aim 1688) registered the fluorescence intensity over time. Quantitative analysis of ICG-FA from standardized regions of interests on the pouch was performed using software. Fluorescence parameters were extracted for inflow (T₀, T_max, F_max, slope, Time-to-peak) and outflow (T_90% and T_80%). Change of management related to FA findings and AL rates were recorded.

RESULTS

Twenty-one patients were included, three patients (14%) required vascular ligation to obtain additional length, by ligating terminal ileal branches in two and the ileocolic artery (ICA) in one patient. In nine patients the ICA was already ligated during subtotal colectomy. ICG-FA triggered a change of management in 19% of patients (n = 4/21), all of them had impaired vascular supply (ligated ileocolic/ terminal ileal branches). Overall, patients with intact vascular supply had similar perfusion patterns for the afferent and efferent loop. Pouches with ICA ligation had longer T_max in both afferent as efferent loop than pouches with intact ICA (afferent 51 and efferent 53 versus 41 and 43 s respectively). Mean slope of the efferent loop diminished in ICA ligated patients 1.5(IQR 0.8-4.4) versus 2.2 (1.3-3.6) in ICA intact patients.

CONCLUSION

Quantitative analysis of ICG-FA perfusion during IPAA is feasible and reflects the ligation of the supplying vessels.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Quantification of bowel ischaemia using real-time multispectral Single Snapshot Imaging of Optical Properties (SSOP)

BACKGROUND

Single snapshot imaging of optical properties (SSOP) is a relatively new non-invasive, real-time, contrast-free optical imaging technology, which allows for the real-time quantitative assessment of physiological properties, including tissue oxygenation (StO2). This study evaluates the accuracy of multispectral SSOP in quantifying bowel ischaemia in a preclinical experimental model.

METHODS

In six pigs, an ischaemic bowel segment was created by dividing the arcade branches. Five regions of interest (ROIs) were identified on the bowel loop, as follows: ROI 1: central ischaemic; ROI 2: left marginal; ROI 3: left vascularised; ROI 4: right marginal; and ROI 5: right vascularised. The Trident imaging system, specifically developed for real-time tissue oxygenation imaging using SSOP, was used to image before (T0) and after ischaemia induction. Capillary and systemic lactates were measured at each time point (T0, T15, T30, T45, T60), as well as StO2 values acquired by means of SSOP (SSOP-StO2).

RESULTS

The mean value of SSOP-StO2 in ROI 1 was 30.08 ± 6.963 and was significantly lower when compared to marginal ROIs (ROI 2 + ROI 4: 45.67 ± 10.02 p =  < 0.0001), and to vascularised ROIs (ROI 3 + ROI 5: 48.08 ± 7.083 p =  < 0.0001). SSOP-StO2 was significantly correlated with normalised lactates r = - 0.5892 p < 0.0001 and with histology r =- 0.6251 p = 0.0002.

CONCLUSION

Multispectral SSOP allows for a contrast-free accurate assessment of small bowel perfusion identifying physiological tissue oxygenation as confirmed with perfusion biomarkers.

Interobserver Variability in the Assessment of Fluorescence Angiography in the Colon

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Application of indocyanine green (ICG)-guided surgery in clinical practice: lesson to learn from other organs-an overview on clinical applications and future perspectives

Indocyanine green (ICG) fluorescence-guided surgery is a modality of intra-operative navigation that might support the surgeon with enhanced visualization of anatomical structures in real time. Over the last years, it has emerged as one of the most promising and rapidly developing technical innovations in surgery. The most popular current clinical applications include fluorescence cholangiography, bowel anastomotic perfusion assessment, fluorescence-guided lymphography for sentinel lymph-node identification and guided lymphadenectomy and the possible use in oncological surgery for the identification and localization of tumors and the diagnosis and treatment of peritoneal carcinosis. This paper provides an overview of the multiple fields of applications of ICG fluorescence-guided surgery in visceral and oncological surgery, discussing indications summarizing most recent and significative available literature and giving technical notes of use.

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 fluorescence imaging during laparoscopic rectal cancer surgery could reduce the incidence of anastomotic leakage: a single institutional retrospective cohort study

BACKGROUND

There is insufficient evidence on whether indocyanine green (ICG) fluorescence angiography can reduce the incidence of anastomotic leakage (AL). This retrospective cohort study aimed to evaluate the effect of ICG fluorescence angiography on AL rates in laparoscopic rectal cancer surgery at a single institution.

METHODS

Patients who underwent laparoscopic low anterior resection or intersphincteric resection with ICG fluorescence angiography (ICG group; n = 73) and patients who underwent a similar surgical procedure for rectal cancer without ICG fluorescence (non-ICG group; n = 114) were enrolled consecutively in this study. ICG fluorescence angiography was performed prior to transection of the proximal colon, and anastomosis was performed with sufficient perfusion using ICG fluorescence imaging. AL incidence was compared between both groups, and the risk factors for AL were analyzed.

RESULTS

AL occurred in 3 (4.1%) and 14 (12.3%) patients in the ICG and non-ICG groups, respectively. In the ICG group, the median perfusion time from ICG injection was 34 s, and 5 patients (6.8%) required revision of the proximal transection line. None of the patients requiring revision of the proximal transection line developed AL. In univariate analysis, longer operating time (odds ratio: 2.758; 95% confidence interval: 1.023-7.624) and no implementation of ICG fluorescence angiography (odds ratio: 3.266; 95% confidence interval: 1.038-11.793) were significant factors associated with AL incidence, although the creation of a diverting stoma or insertion of a transanal tube was insignificant.

CONCLUSION

ICG fluorescence angiography was associated with a significant reduction in AL during laparoscopic rectal cancer surgery. Changes in the surgical plan due to ICG fluorescence visibility may help improve the short-term outcomes of patients with rectal cancer.

Near-infrared fluorescent imaging techniques for the detection and preservation of parathyroid glands during endocrine surgery

Objectives

In over 30% of all thyroid surgeries, complications arise from transient and definitive hypoparathyroidism, underscoring the need for real-time identification and preservation of parathyroid glands (PGs). Here, we evaluate the promising intraoperative optical technologies available for the identification, preservation, and functional assessment of PGs to enhance endocrine surgery.

Methods

We performed a review of the literature to identify published studies on fluorescence imaging in thyroid and parathyroid surgery.

Results

Fluorescence imaging is a well-demonstrated approach for both in vivo and in vitro localization of specific cells or tissues, and is gaining popularity as a technique to detect PGs during endocrine surgery. Autofluorescence (AF) imaging and indocyanine green (ICG) angiography are two emerging optical techniques to improve outcomes in thyroid and parathyroid surgeries. Near-infrared-guided technology has significantly contributed to the localization of PGs, through the detection of glandular AF. Perfusion through the PGs can be visualized with ICG, which can also reveal the blood supply after dissection.

Conclusions

Near infrared AF and ICG angiography, providing a valuable spatial and anatomical information, can decrease the incidence of complications in thyroid surgery.

A Narrative Review of the Usefulness of Indocyanine Green Fluorescence Angiography for Perfusion Assessment in Colorectal Surgery

Anastomotic leakage is one of the most dreaded complications of colorectal surgery and is strongly associated with tissue perfusion. Indocyanine green fluorescence angiography (ICG-FA) using indocyanine green and near-infrared systems is an innovative technique that allows the visualization of anastomotic perfusion. Based on this information on tissue perfusion status, surgeons will be able to clearly identify colorectal segments with good blood flow for safer colorectal anastomosis. The results of several clinical trials indicate that ICG-FA may reduce the risk of AL in colorectal resection; however, the level of evidence is not high, as several other studies have failed to demonstrate a reduction in the risk of AL. Several large-scale RCTs are currently underway, and their results will determine whether ICG-FA is, indeed, useful. The major limitation of the current ICG-FA evaluation method, however, is that it is subjective and based on visual assessment by the surgeon. To complement this, the utility of objective evaluation methods for fluorescence using quantitative parameters is being investigated. Promising results have been reported from several clinical trials, but all trials are preliminary owing to their small sample size and lack of standardized protocols for quantitative evaluation. Therefore, appropriately standardized, high-quality, large-scale studies are warranted.

The role of fluorescence angiography in colonic interposition after esophagectomy

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

Safety and feasibility of indocyanine green fluorescence angiography in pediatric gastrointestinal surgery: A systematic review

BACKGROUND

Although ICG-FA may be valuable in assessing anastomotic perfusion, reliable data on its use in pediatric gastrointestinal surgery is lacking. This systematic review analyzes whether ICG is useful for intestinal perfusion assessment in pediatric gastrointestinal surgery and safe to use in neonates.

METHODS

Systematic searches of PubMed, EMBASE & MEDLINE and CENTRAL were performed (last conducted December 6, 2021). The main inclusion criteria were (1) use of ICG for intestinal perfusion assessment and (2) use of ICG in young infants. Exclusion criteria were lack of an English or Dutch full-text and MINORS quality score <60%. Data was presented in overview tables. The usefulness in pediatric gastrointestinal surgery was assessed by surgical outcome. Safety of ICG in neonates was assessed by complication or adverse event occurrence.

RESULTS

Regarding intestinal perfusion assessment, four studies were included, reporting 45 patients (median age 1.5 years). ICG was considered useful for anastomotic blood flow evaluation and intraoperative determination of resection length. Regarding ICG safety in neonates, eight studies were included, reporting 46 infants (median age 24.9 days), of which 18 neonates. All but one studies reported the absence of complications or adverse events. Two studies reported subcutaneous dye retention, which fully disappeared within two weeks.

CONCLUSION

Although the number of available studies is small, ICG might be useful for intraoperative intestinal perfusion assessment, perhaps even more than conventional clinical assessment. Furthermore, its safety profile looks promising in neonates. Larger prospective studies are necessary to confirm these assumptions and seem warranted given the safety profile.

LEVELS OF EVIDENCE

Since this is a systematic review, a Level of Evidence for clinical studies cannot be determined for this manuscript.

All-cause 30- and 90-day inpatient readmission costs associated with 4 minimally invasive colon surgery approaches: A propensity-matched analysis using Medicare and commercial claims data

Background

The purpose of this study is to assess which minimally invasive colon surgery approach may be associated with the least 30- and 90-day inpatient readmission costs from a payer perspective.

Methods

This retrospective claims analysis included adult Medicare and commercially insured beneficiaries who underwent minimally invasive sigmoid, left, or right colon surgery between January 2016 and December 2019. Two cohorts were created based on the use of near-infrared fluorescence (NIF) and were propensity-score matched 1 NIF:5 NoNIF. Four subgroups were then created based on the presence of robotics (R): NIF-NoR, NIF-R, NoNIF-R, and NoNIF-NoR.

Results

A total of 50,148 patients were identified, of which 165 (0.3%) indicated the use of NIF and 49,983 (99.7%) did not. After propensity score matching, 990 patients were included (NIF cohort: 165; NoNIF cohort: 825). Of the 165 NIF patients, 87 were robotic-assisted and 78 were conventional laparoscopy. Of the 825 NoNIF patients, 136 were robotic-assisted and 689 were conventional laparoscopy. Postindex inpatient readmission costs were significantly different between the NIF and NoNIF cohorts with the NIF cohort having the lowest 30- and 90-day postindex readmission costs. Postindex readmission costs were also significantly different across the 4 subgroups at 30 and 90 days, with the NIF-NoR group having the lowest postindex readmission costs (all P < .05).

Conclusion

Using NIF without the robot during minimally invasive colon surgery is associated with the least 30- and 90-day inpatient readmission costs compared to the other 3 approaches. Hospitals may want to consider these potential cost savings when evaluating technologies for laparoscopic colon surgery.

Key Message

Near-infrared fluorescence (NIF) imaging without the robot during minimally invasive colon surgery may significantly save hospitals 30- and 90-day inpatient readmission costs compared to NIF with the robot, NoNIF with the robot, and NoNIF without the robot. This is important as hospitals may want to consider these cost findings in addition to capital equipment and disposable costs when evaluating technologies for laparoscopic colon surgery.

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

CLINICALTRIALS

gov NCT03130166.

Intraoperative uses of near-infrared fluorescence spectroscopy in pediatric surgery: A systematic review

BACKGROUND

The application of near infrared spectroscopy (NIRS) imaging in surgery is growing. This study aimed to systematically review the literature to summarize the intraoperative uses of NIRS in pediatric surgery.

METHODS

A PRISMA-compliant literature search was conducted in PubMed, Embase, Scopus, and Web of Science from inception to February 2020. Title/abstract and then full-text screening were performed. The Oxford centre for Evidence Based Medicine tool (OCEBM) was used to evaluate the level of evidence of included studies.

RESULTS

Reviewers identified 53 articles. Of which, 34 studies (64.2%) were case-series and 11 (20.8%) were case reports. Most of the studies (n = 45, 84.9%) were level 4 on the OCEBM tool. The most common uses of NIRS were to visualize the biliary tree and to identify primary and metastatic malignant tissues. Other applications include assessment of perfusion of tissues including bowel anastomoses, and lymphatic surgery. Several advantages of the introduction of NIRS in pediatric surgery exist including having the potential to reduce operative time and intra/post-operative complications. Moreover, NIRS helps in detecting malignant tissues that can be missed by conventional imaging. However, NIRS has important limitations such as difficulty in identification of the biliary tree in obese patients or inflamed gallbladder, detection of small deeply localized malignant tissues, as well as the high cost.

CONCLUSIONS

NIRS is a promising modality that can be used intraoperatively to augment different pediatric surgical procedures. NIRS has important advantages and limitations compared to conventional surgery, however, more studies are required to evaluate its outcomes and cost-effectiveness.

LEVEL OF EVIDENCE

IV.

Fluorescence angiography likely protects against anastomotic leak in colorectal surgery: a systematic review and meta-analysis of randomised controlled trials

Objective

Observational studies have shown that fluorescence angiography (FA) decreases the incidence of anastomotic leak (AL) in colorectal surgery, but high-quality pooled evidence was lacking. Therefore, we aimed at confirming this preliminary finding using a systematic review and meta-analysis of randomised controlled trials (RCTs) in the field.

Methods

MEDLINE, Embase and CENTRAL were searched for RCTs assessing the effect of intra-operative FA versus standard assessment of bowel perfusion on the incidence of AL of colorectal anastomosis. The systematic review complied with the PRISMA 2020 and AMSTAR2 recommendations and was registered in PROSPERO. Pooled relative risk (RR) and pooled risk difference (RD) were obtained using models with random effects. Heterogeneity was assessed using the Q-test and quantified using the I² value. Certainty of evidence was assessed using the GRADE Pro tool.

Results

One hundred and eleven articles were screened, 108 were excluded and three were kept for inclusion. The three included RCTs compared assessment of the perfusion of the bowel during creation of a colorectal anastomosis using FA versus standard practice. In meta-analysis, FA was significantly protective against AL (3 RCTs, 964 patients, RR: 0.67, 95% CI: 0.46 to 0.99, I²: 0%, p = 0.04). The RD of AL was non-significantly decreased by 4 percentage points (95%CI: − 0.08 to 0, I²: 8%, p = 0.06) when using FA. Certainty of evidence was considered as moderate.

Conclusion

The effect of FA on prevention of AL in colorectal surgery exists but is potentially of small magnitude. Considering the potential magnitude of effect of FA, we advise that future RCTs have an adequate sample size, include a cost-benefit analysis of the technique and better define the subpopulation who could benefit from FA.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09255-1.

Combined indocyanine green and quantitative perfusion assessment with hyperspectral imaging during colorectal resections

Anastomotic insufficiencies still represent one of the most severe complications in colorectal surgery. Since tissue perfusion highly affects anastomotic healing, its objective assessment is an unmet clinical need. Indocyanine green-based fluorescence angiography (ICG-FA) and hyperspectral imaging (HSI) have received great interest in recent years but surgeons have to decide between both techniques. For the first time, two data processing pipelines capable of reconstructing an ICG-FA correlating signal from hyperspectral data were developed. Results were technically evaluated and compared to ground truth data obtained during colorectal resections. In 87% of 46 data sets, the reconstructed images resembled the ground truth data. The combined applicability of ICG-FA and HSI within one imaging system might provide supportive and complementary information about tissue vascularization, shorten surgery time, and reduce perioperative mortality.

Perfusion Visualization during Ileal J-Pouch Formation—A Proposal for the Standardization of Intraoperative Imaging with Indocyanine Green Near-Infrared Fluorescence and a Postoperative Follow-Up in IBD Surgery

Background: An anastomotic leak (AL) after a restorative proctocolectomy and an ileal J-pouch increases morbidity and the risk of pouch failure. Thus, a perfusion assessment during J-pouch formation is crucial. While indocyanine green near-infrared fluorescence (ICG-NIRF) has shown potential to reduce ALs, its suitability in a restorative proctocolectomy remains unclear. We aimed to develop a standardized approach for investigating ICG-NIRF and ALs in pouch surgery. Methods: Patients undergoing a restorative proctocolectomy with an ileal J-pouch for ulcerative colitis at an IBD-referral-center were included in a prospective study in which an AL within 30 postoperative days was the primary outcome. Intraoperatively, standardized perfusion visualization with ICG-NIRF was performed and video recorded for postoperative analysis at three time points. Quantitative clinical and technical variables (secondary outcome) were correlated with the primary outcome by descriptive analysis and logistic regression. A novel definition and grading of AL of the J-pouch was applied. A postoperative pouchoscopy was routinely performed to screen for AL. Results: Intraoperative ICG-NIRF-visualization and its postoperative visual analysis in 25 patients did not indicate an AL. The anastomotic site after pouch formation appeared completely fluorescent with a strong fluorescence signal (category 2) in all cases of ALs (4 of 25). Anastomotic site was not changed. ICG-NIRF visualization was reproducible and standardized. Logistic regression identified a two-stage approach vs. a three-stage approach (Odds ratio (OR) = 20.00, 95% confidence interval [CI] = 1.37–580.18, p = 0.029) as a risk factor for ALs. Conclusion: We present a standardized, comparable approach of ICG-NIRF visualization in pouch surgery. Our data indicate that the visual interpretation of ICG-NIRF alone may not detect ALs of the pouch in all cases—quantifiable, objective methods of interpretation may be required in the future.

Indocyanine Green Near-Infrared Fluoroangiography Is a Useful Tool in Reducing the Risk of Anastomotic Leakage Following Left Colectomy

Purpose

To evaluate whether visualization of the colon perfusion with indocyanine green near-infrared fluoroangiography (ICG-NIFA) reduces the rate of anastomotic leakage (AL) after colorectal anastomosis.

Methods

Patients who underwent elective left colectomy, including all procedures involving the sigmoid colon and the rectum with a colorectal or coloanal anastomosis, were retrospectively analyzed for their demographics, operative details, and the rate of AL. Univariate and multivariate analyses were used to compare patients with and without ICG-NIFA-based evaluation.

Results

Overall, our study included 132 colorectal resections [70 sigmoid resections and 62 total mesorectal excisions (TMEs)], of which 70 (53%) were performed with and 62 (47%) without ICG-NIFA. Patients' characteristics were similar between both the groups. The majority of the procedures [91 (69%)] were performed by certified colorectal surgeons, while 41 (31%) operations were supervised teaching procedures. In the ICG-NIFA group, bowel perfusion could be visualized by fluorescence (dye) in all 70 cases, and no adverse effects related to the fluorescent dye were observed. Following ICG-NIFA, the transection line was changed in 9 (12.9%) cases. Overall, 10 (7.6%) patients developed AL, 1 (1.4%) in the ICG-NIFA group and 9 (14.5%) in the no-ICG-NIFA group (p = 0.006). The multivariate analysis revealed ICG-NIFA as an independent factor to reduce AL.

Conclusion

These results suggest that ICG-NIFA might be a valuable tool to reduce the rate of AL in sigmoid and rectal resections in an educational setting.

The iGreenGO Study: The Clinical Role of Indocyanine Green Imaging Fluorescence in Modifying the Surgeon’s Conduct During the Surgical Treatment of Advanced Gastric Cancer—Study Protocol for an International Multicenter Prospective Study

Background

The near-infrared/indocyanine green imaging fluorescence (NIR/ICG) technology is showing promising results in several fields of surgical oncology. The clinical value of NIR/ICG technology in the surgical treatment of advanced gastric cancer (AGC) is not clearly established.

Methods

This is the protocol of the “iGreenGO” (indocyanine Green Gastric Observation) Study, a national prospective multicenter study. Western patients who undergo curative-intent gastrectomy with D2 lymphadenectomy for AGC constitute the study cohort. All the patients undergo preoperative upper gastrointestinal endoscopy for submucosal peritumoral ICG injection at the most 20 h before surgery. Intraoperative endoscopic injection before starting surgical dissection is also allowed. The primary endpoint is the “change in the surgical conduct” (CSC), i.e., the need to perform further dissection after intraoperative NIR/ICG technology activation at the end of D2 lymphadenectomy. Secondary endpoints include the pattern of abdominal fluorescence distribution according to tumor and patient characteristics, the preoperative clinical variables potentially associated with CSC, and the incidence of stage migration due to NIR/ICG application.

Discussion

The iGreenGO Study is the first study to investigate the clinical role of NIR/ICG technology for the surgical treatment of AGC in a large cohort of Western patients. Results from the present study can further clarify the role of NIR/ICG technology in surgical lymphadenectomy for AGC.

Fluorescence Imaging in Colorectal Surgery: An Updated Review and Future Trends

Fluorescence imaging in colorectal surgery is considered a novel predominantly intraoperative method of ensuring a greater surgical success. The use of fluorescence is linked to advanced tumor visualization and projection of its lymphatics, both vessels and nodes, which results in a higher chance of achieving a total excision. Additionally, iatrogenic complications prove to be reduced using fluorescence during the surgical excision. The combination of fluorescence and artificial intelligence to better facilitate oncological surgery will soon become an established approach in operating rooms worldwide.

Border Line Definition Using Hyperspectral Imaging in Colorectal Resections

Simple Summary

Good oxygenation of both bowel ends is an important prerequisite to promote anastomotic healing after colorectal resections. Bowel oxygenation is usually assessed clinically. Hyperspectral imaging is a contactless and contrast-free tool that allows quantifying tissue oxygen intraoperatively. In this study, the results of 105 colorectal resections with hyperspectral imaging are reported.

Abstract

Background: A perfusion deficit is a well-defined and intraoperatively influenceable cause of anastomotic leak (AL). Current intraoperative perfusion assessment methods do not provide objective and quantitative results. In this study, the ability of hyperspectral imaging (HSI) to quantify tissue oxygenation intraoperatively was assessed. Methods: 115 patients undergoing colorectal resections were included in the final analysis. Before anastomotic formation, the bowel was extracted and the resection line was outlined and imaged using a compact HSI camera, in order to provide instantaneously quantitative perfusion assessment. Results: In 105 patients, a clear demarcation line was visible with HSI one minute after marginal artery transection, reaching a plateau after 3 min. In 58 (55.2%) patients, the clinically determined transection line matched with HSI. In 23 (21.9%) patients, the clinically established resection margin was entirely within the less perfused area. In 24 patients (22.8%), the HSI transection line had an irregular course and crossed the clinically established resection line. In four cases, HSI disclosed a clinically undetected lesion of the marginal artery. Conclusions: Intraoperative HSI is safe, well reproducible, and does not disrupt the surgical workflow. It also quantifies bowel surface perfusion. HSI might become an intraoperative guidance tool, potentially preventing postoperative complications.

Safety and Efficacy of Indocyanine Green in Colorectal Cancer Surgery: A Systematic Review and Meta-Analysis of 11,047 Patients

Despite the technological advances and improved surgical skills, the incidence of anastomotic leakage following colorectal cancer surgery still ranges from 4% to 19%. Therefore, we performed a systematic review and meta-analysis to evaluate the efficacy and safety of indocyanine green (ICG) use in colorectal cancer surgery. An online search of the Embase, MEDLINE, and Cochrane Central Register of Controlled Trials (CENTRAL) databases (from inception to 10 November 2021) was performed, in addition to manual screening. Thirty-two studies involving 11,047 patients were considered eligible for the meta-analysis. The anastomotic leak rate in the ICG and non-ICG groups varied and amounted to 3.7% vs. 7.6%, respectively (RR = 0.46; 95% CI: 0.39-0.56; p < 0.001). The rate in randomized controlled trials (RCTs) was 8.1% in the ICG group compared with 12.1% in the non-ICG group (RR = 0.67; 95% CI: 0.46-0.98; p = 0.04). In non-RCTs, it equaled 3.1% vs. 7.3%, respectively (RR = 0.43; 95% CI: 0.35-0.52; p < 0.001). Although the publications encompassed in our meta-analysis present different patients, with different factors influencing the results, a pooled analysis revealed a lower incidence of anastomotic leak in cases with ICG use. There are several other convincing advantages: safety, simplicity, and short time of the method adjustment. The presented meta-analysis indicates ICG perfusion assessment as a tool worth considering to decrease the rate of complications following colorectal surgery-valuable in the context of other, well-known risk factors.

Impact of change in the surgical plan based on indocyanine green fluorescence angiography on the rates of colorectal anastomotic leak: a systematic review and meta-analysis

BACKGROUND

In the present study, patients with colorectal anastomoses that were assessed with indocyanine green (ICG) fluorescence angiography (FA) were compared to patients who had only white light visual inspection of their anastomosis. The impact of change in surgical plan guided by ICG-FA on anastomotic leak (AL) rates was assessed.

METHODS

PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were queried for eligible studies. Studies included were comparative cohort studies and randomized trials that compared perfusion assessment of colorectal anastomosis with ICG-FA and inspection under white light. Main outcome measures were change in surgical plan guided by ICG-FA and rates of AL. Risk of bias was assessed using RoB-2 and ROBINS-1 tools. Differences between the two groups in categorical and continuous variables were expressed as odds ratio (OR) with 95% confidence interval (CI) and weighted mean difference.

RESULTS

This systematic review included 27 studies comprising 8786 patients (48.5% males). Using ICG-FA was associated with significantly lower odds of AL (OR 0.452; 95% CI 0.366-0.558) and complications (OR 0.747; 95% CI 0.592-0.943) than the control group. The weighted mean rate of change in surgical plan based on ICG-FA was 9.6% (95% CI 7.3-11.8) and varied from 0.64% to 28.75%. A change in surgical plan was associated with significantly higher odds of AL (OR 2.73; 95% CI 1.54-4.82).

LIMITATIONS

Technical heterogeneity due to using different dosage of ICG and statistical heterogeneity in operative time and complication rates.

CONCLUSION

Assessment of colorectal anastomoses with ICG-FA is likely to be associated with lower odds of anastomotic leak than is traditional white light assessment. Change in plan based on ICG-FA may be associated with higher odds of AL. PROSPERO registration number: CRD42021235644.

Effect of hemodialysis on short-term outcomes after colon cancer surgery

BACKGROUND

Hemodialysis patients who undergo surgery have a high risk of postoperative complications. The aim of this study was to determine whether colon cancer surgery can be safely performed in hemodialysis patients.

METHODS

This multicenter retrospective study included 1372 patients who underwent elective curative resection surgery for colon cancer between April 2016 and March 2020.

RESULTS

Of the total patients, 19 (1.4%) underwent hemodialysis, of whom 19 (100%) had poor performance status and 18 had comorbidities (94.7%). Minimally invasive surgery was performed in 78.9% of hemodialysis patients. The postoperative complication rate was significantly higher in hemodialysis than non-hemodialysis patients (36.8% vs. 15.5%, p = 0.009). All postoperative complications in the hemodialysis patients were infectious type. Multivariate analysis revealed a significant association of hemodialysis with complications (odds ratio, 2.9362; 95%CI, 1.1384-7.5730; p = 0.026).

CONCLUSION

Despite recent advances in perioperative management and minimally invasive surgery, it is necessary to be aware that short-term complications can still occur, especially infectious complications in hemodialysis patients.

Laparoscopic restorative proctocolectomy with ileal-J-pouch anal canal anastomosis without diverting ileostomy for total colonic and extensive aganglionosis is safe and feasible with combined Lugol's iodine staining technique and indocyanine green fluorescence angiography

BACKGROUND

We present the surgical technique and outcomes of reduced-port laparoscopic restorative proctocolectomy with ileal-J-pouch anal canal anastomosis (IPACA) without diverting ileostomy for total colonic and extensive aganglionosis (TCA+).

METHODS

We retrospectively reviewed TCA+ cases between 2014 and 2022. Preoperative ileostomy was performed when transanal bowel irrigation was ineffective. Radical surgery for TCA+ was performed at approximately 6 kg. The surgery was performed using laparoscopy through a multi-channel trocar with or without an additional 3-mm trocar and IPACA reconstruction with indocyanine green fluorescence angiography (ICG) to assess anastomotic perfusion and Lugol's iodine staining to visualize the surgical anal canal.

RESULTS

Ten patients with TCA+ were included. Ileostomy was performed in seven cases. The median operation time and blood loss were 274.5 min and 20 ml, respectively. No significant postoperative complications were found. All patients experienced frequent liquid stools and perianal excoriation in the early postoperative period, requiring anti-flatulence or codeine. The median follow-up period was 3.5 years. Three patients required irrigation management 1 year postoperatively, and the others defecated a median of 3.5 times per day. The median Kelly's clinical score was 5 in 5 patients aged >4 years.

CONCLUSION

Reduced-port surgery, combined with Lugol's iodine staining and ICG, was safe, feasible, and had cosmetically and clinically acceptable mid-term outcomes.

Use of near-infrared imaging using indocyanine green associates with the lower incidence of postoperative complications for intestinal and mesenteric injury

Anastomotic leakage after intestinal resection is one of the most serious complications of surgical intervention for hollow viscus injury. Adequate vascular perfusion of the anastomotic site is essential to prevent anastomotic leakage. Near-infrared imaging using indocyanine green (NIR-ICG) is useful for the objective assessment of vascular perfusion. The aim of this study was to evaluate the association of NIR-ICG with intestinal and mesenteric injuries. This was a retrospective, single-center study of patients undergoing surgery for intestinal and mesenteric injuries. NIR-ICG was used to evaluate vascular perfusion. Postoperative complications were assessed between NIR-ICG and non-NIR-ICG groups.The use of NIR-ICG was associated with a lower incidence of Clavien-Dindo grade ≥ III complications with a statistical tendency (p = 0.076). When limited to patients that underwent intestinal resection, the use of NIR-ICG was significantly associated with a lower risk of perioperative complications (p = 0.009). The use of NIR-ICG tended to associate with the lower incidence of postoperative complications after intestinal and mesenteric trauma surgery. NIR-ICG was associated with a significantly lower risk of complications in patients undergoing intestinal resection. The NIR-ICG procedure is simple and quick and is expected to be useful for intestinal and mesenteric trauma.

Use of indocyanine green fluorescence guidance in redo ileocolic resection for Crohn's disease

AIM

Redo ileocolic resection in patients with Crohn's disease (CD) is associated with significant technical challenges that may be associated with high complication rates. The aim of this study was to evaluate the feasibility of near-infrared fluorescence angiography with indocyanine green (ICG), often used to evaluate blood supply to the anastomosis in CD patients undergoing repeat ileocolic resection.

METHOD

This study was a retrospective analysis of patients who underwent redo ileocolic resection using ICG bowel perfusion assessment between 2015 and 2021. Patients were matched and compared on a 1:2 basis with a control group undergoing the same procedure without perfusion assessment.

RESULTS

Twelve patients underwent redo ileocolic resection with ICG perfusion assessment (ICG group). These were compared with 24 patients who underwent the procedure without ICG (control group). Both groups were similar in demographics and operative characteristics including median operating time (255 vs. 255.5 min, p = 0.39) and conversion rate (22% vs. 36.8%, p = 0.68). Median estimated blood loss was significantly higher in the ICG group [150 (50-400) vs. 100 ml (20-125)]. Successful ICG perfusion assessment was seen in all patients in the ICG group and did not change management in any case. Overall postoperative complication rates were comparable between the groups (58.3% vs. 54.1%, p = 0.72). No anastomotic leaks occurred in the ICG group compared with one (1/24, 4.2%) in the control group (p = 0.99).

CONCLUSION

Fluorescence ICG perfusion assessment is feasible and safe in redo ileocolic resection in patients with CD. Larger studies are needed to evaluate whether this technique should be routinely used in these complex surgical interventions.

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.

The Impact of Indocyanine Green Fluorescence Angiography on Intraoperative Decision Making in Right Hemicolectomy: A Case-Control Study

INTRODUCTION

Anastomotic leak (AL) after right hemicolectomy remains a significant clinical challenge with an incidence of 4.2% to 8.2% in European series. Near infrared imaging with indocyanine green (NIR-ICG) allows real-time assessment of bowel perfusion. However, there is a lack of published data assessing the clinical utility of this new technology in right sided colonic resection.

MATERIALS AND METHODS

Data from electronic records were retrospectively analyzed for consecutive patients undergoing right hemicolectomy in a single center between March 1, 2016 and October 31, 2019. Primary outcomes were the incidence of AL and the frequency with which ICG-NIR imaging altered the intraoperative course.

RESULTS

Our study included 127 patients, with 65 in the NIR-ICG group and 62 in the control group. Median length of follow-up was 24 months. There was no significant difference in demographic or pathologic characteristics between the 2 cohorts. There was no significant difference in operation length between the NIR-ICG and control groups (164.7 vs. 162.9 min, P=0.88). The use of NIR-ICG altered the intraoperative course in 4/65 (6.2%) patients. The rate of AL was lower in the NIR-ICG group (1.5% vs. 4.8%), although this did not reach statistical significance.

CONCLUSION

The use of NIR-ICG altered the intraoperative course for notable subset of patients undergoing right hemicolectomy without prolonging operative time. Larger prospective studies are required to evaluate the potential for the routine use of this technology to reduce AL rate in right hemicolectomy.

Assessing the development status of intraoperative fluorescence imaging for perfusion assessments, using the IDEAL framework

Objectives

Intraoperative fluorescence imaging is currently used in a variety of surgical fields for four main purposes: assessing tissue perfusion; identifying/localizing cancer; mapping lymphatic systems; and visualizing anatomy. To establish evidence-based guidance for research and practice, understanding the state of research on fluorescence imaging in different surgical fields is needed. We evaluated the evidence on fluorescence imaging for perfusion assessments using the Idea, Development, Exploration, Assessment, Long Term Study (IDEAL) framework, which was designed for describing the stages of innovation in surgery and other interventional procedures.

Design

Narrative literature review with analysis of IDEAL stage of each field of study.

Setting

All publications on intraoperative fluorescence imaging for perfusion assessments reported in PubMed through 2019 were identified for six surgical procedures: coronary artery bypass grafting (CABG), upper gastrointestinal (GI) surgery, colorectal surgery, solid organ transplantation, reconstructive surgery, and cerebral aneurysm surgery.

Main outcome measures

The IDEAL stage of research evidence was determined for each specialty field using a previously described approach.

Results

196 articles (15 003 cases) were selected for analysis. Current status of research evidence was determined to be IDEAL Stage 2a for upper GI and transplantation surgery, IDEAL 2b for CABG, colorectal and cerebral aneurysm surgery, and IDEAL Stage 3 for reconstructive surgery. Using the technique resulted in a high (up to 50%) rate of revisions among surgical procedures, but its efficacy improving postoperative outcomes has not yet been demonstrated by randomized controlled trials in any discipline. Only one possible adverse reaction to intravenous indocyanine green was reported.

Conclusions

Using fluorescence imaging intraoperatively to assess perfusion is feasible and appears useful for surgical decision making across a range of disciplines. Identifying the IDEAL stage of current research knowledge aids in planning further studies to establish the potential for patient benefit.

A pilot study of near-infrared fluorescence guided surgery for primary tumor localization and lymph node mapping in colorectal cancer

Background

This pilot study aimed to evaluate the feasibility of near-infrared fluorescence imaging for primary tumor localization, lymph node mapping, and metastatic lymph node detection in colorectal cancer (CRC) using indocyanine green (ICG).

Methods

A total of 11 patients with CRC were prospectively enrolled. ICG (25 mg dissolved in 30 mL sterile water) was intravenously injected preoperatively, and the fluorescence intensity of the primary tumor, lymph nodes, and normal tissues, as well as the signal-to-background ratio (SBR) and contrast-to-noise ratio (CNR) were measured at 0.5, 1, 2, 4, and 24 h after ICG injection.

Results

The primary tumor could be located intraoperatively, and the tumor boundary was clear at 2–4 h. There was good contrast in the fluorescence intensity between tumor and normal tissues (SBR =2.11±0.36, CNR =8.74±0.35). The lymph node detection rate was 95% (38/40), and the SBR threshold of lymph nodes was 1.13.

Conclusions

This pilot study showed that primary tumor localization and lymph node mapping in CRC is feasible using near-infrared fluorescence imaging technology, though metastatic lymph nodes cannot be discriminated from benign ones. In addition, cancer nodules missed by both white light mode and palpation by the surgeon were unexpectedly found, resulting in a change in the surgical prognosis in 9.1% (1/11) of patients.