Indocyanine green fluorescence angiography: a new ERAS item

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.

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 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.

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.

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 Indocyanine Near-Infrared Fluorescence in Colorectal Surgery

Purposes

The aim of this study was to evaluate the importance of Indocyanine Green in control of anastomosis perfusion and on anastomotic leakage rates during laparoscopic and robotic colorectal procedures.

Methods

A retrospective review of patients who underwent elective minimally invasive surgery for colorectal cancer from 1 January 2018 to 31 December 2020 was performed. All patients underwent Near-Infrared Fluorescence-Indocyanine Green system in two moments: before performing the anastomosis and after completing the anastomotic procedure. Primary outcomes were the rate of intraoperative change in the surgical resection due to an inadequate vascularization and the rate of postoperative anastomotic leakage. Secondary outcomes were the postoperative complications, both medical and surgical (intra-abdominal bleeding, anastomotic leakage).

Results

Our analysis included 93 patients. Visible fluorescence was detected in 100% of the cases. In 7 patients (7.5%), the planned site of resection was changed due to inadequate perfusion. The mean extension of the surgical resection in these 7 patients was 2.2 ± 0.62. Anastomotic leakage occurred in 2 patients (2.1%). Other complications included 8 postoperative bleedings (8.6%) and 1 pulmonary thromboembolism.

Conclusions

The intraoperative use of Near-Infrared Fluorescence-Indocyanine Green in colorectal surgery is safe, feasible, and associated with a substantial reduction in postoperative anastomotic leakage rate.

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.

Indocyanine green fluorescence angiography in colorrectal surgery. First case series in Mexico

INTRODUCTION AND AIM

Anastomosis leak occurs in 1-19% of colorrectal surgeries. Our objective was to present the first Mexican case series on colorrectal surgery using indocyanine green fluorescence angiography to evaluate perfusion prior to carrying out the anastomosis.

MATERIALS AND METHODS

A retrospective, analytic, descriptive study was conducted. We studied the case records of consecutive patients that underwent colorrectal surgery with indocyanine green angiography performed by the same group of colorrectal surgeons.

RESULTS

Twenty-one case records were reviewed. Eleven (52.3%) of the patients were women, mean patient age was 57 years (38-82), and mean body mass index was 25 kg/m² (17-34). Fifteen (71.4%) patients were diagnosed with malignant disease. Indocyanine green angiography changed our therapeutic decision in three (14.2%) patients. Two colorrectal anastomoses (14.2%) were performed at fewer than 5 cm from the anal verge and 13 (61.9%) were performed at more than 5 cm from the anal verge. Three of the anastomoses were ileocolic (14.2%), two were coloanal (9.5%), and one was ileoanal (4.7%). There were six (28.5%) complications, no cases of anastomotic leak, and no complications associated with the use of indocyanine green. The mortality rate was 0%.

CONCLUSION

The present case series is the first on colorrectal surgery conducted in Mexico using indocyanine green fluorescence angiography, with excellent results.

Quantifying tissue perfusion after peripheral endovascular procedures: Novel tissue perfusion endpoints to improve outcomes

Peripheral artery disease (PAD) is a flow-limiting condition caused by narrowing of the peripheral arteries typically due to atherosclerosis. It affects almost 200 million people globally with patients either being asymptomatic or presenting with claudication or critical or acute limb ischemia. PAD-affected patients display increased mortality rates, rendering their management critical. Endovascular interventions have proven crucial in PAD treatment and decreasing mortality and have significantly increased over the past years. However, for the functional assessment of the outcomes of revascularization procedures for the treatment of PAD, the same tests that have been used over the past decades are still being employed. Those only allow an indirect evaluation, while an objective quantification of limb perfusion is not feasible. Standard intraarterial angiography only demonstrates post-intervention vessel patency, hence is unable to accurately estimate actual limb perfusion and is incapable of quantifying treatment outcome. Therefore, there is a significant necessity for real-time objectively measurable procedural outcomes of limb perfusion that will allow vascular experts to intraoperatively quantify and assess outcomes, thus optimizing treatment, obviating misinterpretation, and providing significantly improved clinical results. The purpose of this review is to familiarize readers with the currently available perfusion-assessment methods and to evaluate possible prospects.

Management of post-traumatic ischaemic ileal stricture using intraoperative indocyanine green fluorescence-guided resection

Blunt abdominal trauma can affect mesenteric circulation which may lead to bowel strictures. Indocyanine green (ICG) angiography can be used to assess mesenteric blood flow and bowel perfusion as a guide to resect length intraoperatively. But this concept has not been applied to ischaemic bowel strictures. We present a case of ischaemic ileal stricture induced by blunt abdominal trauma which was managed by resection and anastomosis. Intraoperative near-infrared (NIR) ICG angiography was used as a guide to resect the bowel length. This case emphasises that ischaemic bowel strictures should be suspected in patients presenting with intestinal obstruction following trauma. Resection and anastomosis of the affected segment remains the primary treatment modality with excellent outcomes. NIR ICG angiography is a real-time objective and useful resource for assessing bowel perfusion and could be used to determine the length of the segment to be resected in patients with ischaemic bowel stricture.

NIR-II cell endocytosis-activated fluorescent probes for in vivo high-contrast bioimaging diagnostics

Fluorescence probes have great potential to empower bioimaging, precision clinical diagnostics and surgery. However, current probes are limited to in vivo high-contrast diagnostics, due to the substantial background interference from tissue scattering and nonspecific activation in blood and normal tissues. Here, we developed a kind of cell endocytosis-activated fluorescence (CEAF) probe, which consists of a hydrophilic polymer unit and an acid pH-sensitive small-molecule fluorescent moiety that operates in the "tissue-transparent" second near-infrared (NIR-II) window. The CEAF probe stably presents in the form of quenched nanoaggregates in water and blood, and can be selectively activated and retained in lysosomes through cell endocytosis, driven by a synergetic mechanism of disaggregation and protonation. In vivo imaging of tumor and inflammation with a passive-targeting and affinity-tagged CEAF probe, respectively, yields highly specific signals with target-to-background ratios over 15 and prolonged observation time up to 35 hours, enabling positive implications for surgical, diagnostic and fundamental biomedical studies.

Indocyanine green fluorescence angiography versus standard intraoperative methods for prevention of anastomotic leak in colorectal surgery: meta-analysis

BACKGROUND

Assessment of anastomotic blood perfusion with intraoperative indocyanine green fluorescence angiography (ICG-FA) may be effective in preventing anastomotic leak compared with standard intraoperative methods in colorectal surgery.

METHODS

MEDLINE, PubMed, Cochrane Central Register of Controlled Trials and the Cochrane Library were searched for RCTs and observational studies on intraoperative ICG-FA to May 2020. Odds ratios (ORs), risk differences and mean differences (MDs) were calculated with 95 per cent c.i. based on intention-to-treat analysis. The number needed to treat for an additional beneficial outcome was also estimated.

RESULTS

Twenty-five comparative studies included a total of 7735 patients. The use of intraoperative ICG fluorescence angiography was linked with a significant reduction in all grades anastomotic leak (OR 0.39 (95 per cent c.i. 0.31 to 0.49), P < 0.001; number needed to treat for an additional beneficial outcome (NNTB) 23) and length of hospital stay (MD -0.72 (95 per cent c.i. -1.22 to -0.21) days, P = 0.006). A significantly lower incidence of grade A (OR 0.33 (0.18 to 0.60), P < 0.001), grade B (OR 0.58 (0.35 to 0.97), P = 0.04) and grade C (OR 0.59 (0.38 to 0.92), P = 0.02) anastomotic leak was demonstrated in favour of ICG-FA. For low or ultra-low rectal resection, the odds of developing anastomotic leakage was 0.32 (0.23 to 0.45) (P < 0.001; NNTB 14). There were no differences in duration of surgery, and no adverse events related to ICG fluorescent injection.

CONCLUSION

The use of ICG-FA instead of standard intraoperative methods to assess anastomosis blood perfusion in colorectal surgery leads to a significant reduction in anastomotic leakage and in the need for surgical reintervention for anastomotic leak, especially in patients with low or ultra-low rectal resections.

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.

Indocyanine green fluorescence angiography in colorrectal surgery. First case series in Mexico

INTRODUCTION AND AIM

Anastomotic leak occurs in 1-19% of colorrectal surgeries. Our objective was to present the first Mexican case series on colorrectal surgery using indocyanine green fluorescence angiography to evaluate perfusion prior to carrying out the anastomosis.

MATERIALS AND METHODS

A retrospective, analytic, descriptive study was conducted. We studied the case records of consecutive patients that underwent colorrectal surgery with indocyanine green angiography performed by the same group of colorrectal surgeons.

RESULTS

Twenty-one case records were reviewed. Eleven (52.3%) of the patients were women, mean patient age was 57 years (38-82), and mean body mass index was 25 kg/m2 (17-34). Fifteen (71.4%) patients were diagnosed with malignant disease. Indocyanine green angiography changed our therapeutic decision in three (14.2%) patients. Two colorrectal anastomoses (14.2%) were performed at fewer than 5 cm from the anal verge and 13 (61.9%) were performed at more than 5 cm from the anal verge. Three of the anastomoses were ileocolic (14.2%), two were coloanal (9.5%), and one was ileoanal (4.7%). There were six (28.5%) complications, no cases of anastomotic leak, and no complications associated with the use of indocyanine green. The mortality rate was 0%.

CONCLUSION

The present case series is the first on colorrectal surgery conducted in Mexico using indocyanine green fluorescence angiography, with excellent results.

Intraoperative testing of colorectal anastomosis and the incidence of anastomotic leak: A meta-analysis

BACKGROUND

AL remains one of the most threatening complications in colorectal surgery. Significant efforts are put to understand the pathophysiological mechanisms involved in the development of leakage and to create the strategies to prevent it. We aimed to determine whether intraoperative testing of mechanical integrity and perfusion of colorectal anastomosis could reduce the incidence of AL.

METHODS

A systematic review and meta-analysis of papers published before November 2019 on PubMed, Scopus, Web of Science, and Cochrane Library databases and comparing intraoperative testing of the colorectal anastomosis with standard care were conducted. Odds ratios (ORs) and 95% confidence interval (CIs) were used to assess the association between intraoperative testing and AL.

RESULTS

A total of 23 studies totaling 7115 patients were included. Pooled analysis revealed intraoperative tests, for integrity (OR 0.52, 95% CI 0.34-0.82, P < .001) and perfusion (OR 0.40, 95% CI 0.22-0.752, P < .001) of the lower gastrointestinal tract anastomoses are associated with significantly lower AL rate.

CONCLUSIONS

Intraoperative testing for either integrity or perfusion of anastomoses both reduce the AL rate. Studies looking at the combination of these two testing methods of anastomosis, especially intraoperative endoscopy, and indocyanine green fluorescence angiography may be very promising to further reduction of the AL.