Indocyanine green fluorescence angiography decreases the risk of colorectal anastomotic leakage: Systematic review and meta-analysis

Real-time ancillary diagnostics for intraoperative assessment of intestinal viability in horses-looking for answers across species

Clinical intestinal viability assessment is associated with significant limitations, and there is an undisputable need for ancillary diagnostics during colic surgery. Human and companion animal surgeons struggle with similar intraoperative issues, yet there is little exchange between specialists. Therefore, this narrative review aimed to create an overview of real-time ancillary diagnostics with the potential for intraoperative intestinal viability assessment in horses. Most real-time ancillary diagnostics can be classified as either tissue perfusion or oxygenation assessments. Intestinal perfusion may be quantified using dark field microscopy, laser Doppler flowmetry, or fluorescence angiography (FA). In particular, indocyanine green FA has gained popularity in human medicine and is increasingly employed to predict intestinal injury. Intestinal oxygen saturation can be measured by pulse oximetry or mixed tissue oximetry. The latter can be conducted using visible light or near-infrared spectrophotometry, and these measurements correlate with clinical outcomes in various species. Other real-time diagnostics include thermography and techniques currently under development, such as laser speckle flowgraphy or photoacoustic imaging. The modalities discussed are minimally invasive and may be used for intraoperative assessments of the intestine. However, limitations include the occurrence of artifacts and the subjective nature of some modalities. Techniques such as indocyanine green FA and tissue oximetry are already available in veterinary practice and have the potential for use during colic surgery. However, blinded clinical trials are lacking in all species, and more research is needed to determine the accuracy and cutoff values in equine-specific intestinal lesions.

Advancement of indocyanine green fluorescence imaging technology in laparoscopic surgery for rectal cancer

Indocyanine green fluorescence imaging technology has been increasingly utilized in rectal surgery in recent years. As a safe tracer, indocyanine green can facilitate lymph node tracing, assess the blood supply at anastomotic sites, and localize tumour lesions during laparoscopic surgery, thereby resulting in favourable outcomes. This technology helps surgeons to achieve more precise diagnoses and treatments in laparoscopic procedures, thus ultimately benefiting patients. However, the current application of indocyanine green fluorescence imaging technology still lacks standardized regulations, and certain effects remain contentious. This study provides a comprehensive review of the application of indocyanine green in laparoscopic surgery for rectal cancer based on the pertinent literature.

Impact of indocyanine green fluorescence angiography on surgeon action and anastomotic leak in colorectal resections. A systematic review and meta-analysis

BACKGROUND

Indocyanine green fluorescence angiography (ICGFA) during colorectal surgery either reassures surgeons regarding intestinal perfusion sufficiency or prompts changed surgical strategy by indicating unsuspected insufficiency. This study describes existing evidence supporting ICGFA use in colorectal surgery, particularly regarding impact on intraoperative decisions.

METHODS

Searches were performed on PubMed, ScienceDirect, Scopus, Web of Science, Cochrane Collaboration databases on 5th December 2023, updated to 19th August 2024. Full English language publications of clinical studies in human patients undergoing colorectal resection with primary anastomosis with the use of ICGFA to assess bowel perfusion intraoperatively, with a control group, were included. Pooling of anastomotic leak (AL) rates was performed for primary outcome analysis with odds ratio (OR) and number-needed-to-treat (NNT) calculated regarding leak reduction.

RESULTS

45 studies comprising 14,333 patients were included, with 7 randomised controlled trials (2911 patients). Overall, AL rate was 6.8%, 4.5% with ICGFA and 8.5% without (OR:0.47, p < 0.001, NNT 23), increasing to 9.5%, 7.5% and 11.6%, respectively, in randomised controlled trials (OR:0.62, p < 0.01, NNT 25). In rectal resections, AL rate was 4.7% with ICGFA vs 11.5% without (OR: 0.38, p < 0.0001). 26 studies performed ICGFA before and after anastomosis formation and 19 used ICGFA only prior to bowel transection, with no significant difference of AL rate reduction on subgroup testing. ICGFA prompted a change in surgical plan in 8.4% of thirty-four studies reporting this. Interestingly, in these studies, leak rates overall were 3.7% when ICGFA matched surgeon judgement versus 5.7% when it prompted change (OR 0.51, p < 0.0025), versus 7.7% without (OR 0.45, p < 0.0001). In rectal resections, these figures were 5%, 8.8% (OR 0.42, p = 0.01) and 12.0% (OR0.39, p < 0.0001), respectively.

CONCLUSIONS

ICGFA colorectal perfusion assessment is associated with lower anastomotic leak rates, especially when confirming surgeons' judgement, and may so stratify patients post-operatively regarding subsequent anastomotic leak rate.

Does indocyanine green fluorescence angiography reduce the risk of anastomotic leaks in colorectal resections? A systematic review and meta-analysis of randomized controlled trials

Anastomotic leaks are a significant complication in colorectal surgery. Indocyanine green fluorescence angiography (ICG-FA) has been suggested as a method to reduce the risk. This meta-analysis aims to evaluate the effect of ICG-FA on reducing anastomotic leaks in colorectal surgery. This study follows PRISMA guidelines and is registered on PROSPERO (CRD42022370748). We conducted a comprehensive search of multiple databases and registers for randomized controlled trials (RCTs) comparing ICG-FA with standard methods in colorectal surgery. Data extraction and quality assessment were performed by two independent reviewers, with a third resolving disputes. Odds ratios (OR) and mean differences (MD) were calculated using comprehensive meta-analysis software, version 3. Heterogeneity and publication bias were assessed, and a sensitivity analysis was performed. The analysis included five RCTs with a total of 1369 patients from four countries. The ICG-FA was associated with a 45% reduction in the risk of overall anastomotic leaks (OR: 0.550, p = 0.012). Subgroup analysis showed a 47% reduction in leaks for low anastomoses (OR: 0.53, p = 0.143) and a 69% reduction in grade A leaks (OR: 0.31, p = 0.008). No significant effects were observed for grade B and C leaks, blood loss, surgery duration, hospital stay, mortality, postoperative ileus, reoperation, or surgical site infections. ICG-FA significantly reduces the overall risk of anastomotic leaks, especially grade A leaks, and shows a trend towards fewer leaks in low anastomosis. No significant impact was found on secondary outcomes. Further RCTs are needed to confirm these findings.

Local Myoelectric Sensing During Human Colonic Tissue Perfusion

Objectives: Anastomotic leakage (AL) is one of the most devastating complications after colorectal surgery. The verification of the adequate perfusion of the anastomosis is essential to ensuring anastomosis integrity following colonic resections. This study aimed to evaluate the efficacy of measuring the electrical activity of the colonic muscularis externa at an anastomosis site for perfusion analysis following colorectal surgery. Methods: Strips of human isolated colon were maintained in a horizontal tissue bath to record spontaneous contractions and myoelectric activity and spike potentials (using a bipolar electrode array for the wireless transmission of myoelectric data-the xBar system) from the circular muscle. Intraoperative myoelectric signal assessment was performed by placing the electrode array on the colon prior to and following mesenteric artery ligation, just prior to colonic resection. Results: In human isolated colon, the amplitude, duration, and frequency of contractions were inhibited during hypoxia by >80% for each measurement, compared to control values and time-matched oxygenated muscle. Intraoperative (N = 5; mean age, 64.8 years; range, 54-74 years; 60% females) myoelectric signal assessment revealed a decline in spike rate following arterial ligation, with a mean reduction of 112.64 to 51.13 spikes/min (p < 0.0008). No adverse events were observed during the study, and the device did not substantially alter the surgical procedure. Conclusions: The electrical and contraction force of the human colon was reduced by ischemia, both in vitro and in vivo. These preliminary findings also suggest the potential of the xBar system to measure such changes during intraoperative and possibly postoperative periods to predict the risk of anastomotic viability as a surrogate of evolving dehiscence.

[Anastomotic leaks in colorectal surgery]

A leakage of a colorectal anastomosis represents a severe complication in visceral surgery. An anastomotic insufficiency (AI) is a potentially life-threatening complication for patients that carries a high risk of subsequent complications and long-term stoma care. Numerous factors influence the risk of AI. Knowing and being able to estimate these factors are essential for successful treatment in colorectal surgery as they help determine the surgical strategy. The recognition of an AI can be challenging for practitioners due to the variability in the clinical presentation. If the presence of AI is suspected appropriate diagnostic measures must therefore be taken. If an AI has occurred a colorectal specialist should definitely be involved in the treatment as this can significantly reduce further complications and the rate of permanent stomas.

Detection of wound healing disorders after major amputations by measurements of the microcirculation: A prospective single-center study

Introduction

Although major amputations can often be avoided due to evolving methods of endovascular and surgical revascularizations techniques, in patients with chronic limb-threatening ischemia, it is still necessary in some cases. Aim of this study was the detection of wound healing disorders through intraoperative microcirculation measurements in major limb amputations.

Materials and methods

In this single-center clinical study, patients with an indication for major amputation were enrolled prospectively. Cause of amputation, patients' comorbidities including cardiovascular risk profile were assessed. Macrocirculation, as well as microcirculation were assessed. Microcirculation measurements were performed by fluorescence angiography with the administration of indocyanine green. A preoperative measurement was obtained at the amputation level, followed by three additional measurements of the amputation stump postoperatively. Wound healing was monitored and correlated with the microcirculatory findings, based on the perfusion parameters ingress and ingress rate, calculated in the indocyanine green fluorescence video sequences of the amputation stumps.

Results

Forty-five patients were enrolled, including 19 (42%) below-the-knee amputations and 26 (58%) above-the-knee amputations. When considering the need for revision, a change in the microperfusion parameters was observed postoperatively. The mean value for ingress was significantly lower directly postoperatively in stumps requiring revisions (5 ± 0 A.U. versus 40.5 ± 42.5 A.U., p < 0.001). The mean value of ingress rate behaved similarly (0.15 ± 0.07 A.U./s versus 2.8 ± 5.0 A.U./s, p = 0.005). The evaluation of indocyanine green measurements when wound healing disorders occurred also showed nonsignificant differences in the mean values.

Conclusion

Fluorescence angiography after major lower limb amputations appears to be an option of depicting microperfusion. Especially, the early postoperative detection of reduced perfusion can indicate a subsequent need for revision. Therefore, this method could possibly serve as a tool for intraoperative quality control after major limb amputation.

Quantitative analysis of intestinal perfusion with indocyanine green (ICG) and methylene blue (MB) using a single clinically approved fluorescence imaging system: a demonstration in a porcine model

BACKGROUND

Near-infrared fluorescence (NIRF) angiography with intraoperative administration of indocyanine green (ICG) has rapidly disseminated in clinical practice. Another clinically approved, and widely available dye, methylene blue (MB), has up to now not been used for this purpose. Recently, we demonstrated promising results for the real-time evaluation of intestinal perfusion using this dye. The primary aim of this study was to perform a quantitative analysis of bowel perfusion assessment for both ICG and MB.

METHODS

Four mature female Landrace pigs underwent laparotomy under general anesthesia. An ischemic bowel loop with five regions of interest (ROIs) with varying levels of perfusion was created in each animal. An intravenous (IV) injection of 0.25 mg/kg-0.50 mg/kg MB was administered after 10 min, followed by NIRF imaging in MB mode and measurement of local lactate levels in all corresponding ROIs. This procedure was repeated in ICG mode (IV dose of 0.2 mg/kg) after 60 min. The quest spectrum fluorescence camera (Quest Medical Imaging, Middenmeer, The Netherlands) was used for NIRF imaging of both MB and ICG.

RESULTS

Intraoperative NIRF imaging of bowel perfusion assessment with MB and ICG was successful in all studied animals. Ingress (i/s) levels were calculated and correlated with local lactate levels. Both MB and ICG ingress values showed a significant negative correlation (r = - 0.7709; p =  < 0.001; r = - 0.5367, p = 0.015, respectively) with local lactate levels. This correlation was stronger for MB compared to ICG, although ICG analysis showed higher absolute ingress values.

CONCLUSION

Our fluorescence quantification analysis validates the potential to use MB for bowel perfusion assessment besides the well-known and widely used ICG. Further human studies are necessary to translate our findings to clinical applications.

Impact of indocyanine green angiography on anastomotic dehiscence rate in colorectal surgery: a systematic review and meta-analysis of randomized studies

Anastomotic dehiscence, a feared complication in colorectal surgery, motivates the search for effective strategies to mitigate its risk. This meta-analysis encompasses all published randomized trials investigating and comparing the impact of indocyanine green (ICG) angiography on this complication. With four studies and 1,109 patients, the intraoperative ICG angiography group demonstrated a significant reduction in the overall rate of anastomotic dehiscence compared to the non-angiography group (7.3% vs. 11.5%; OR: 0.6; 95% CI: 0.4-0.9; p = 0.03). These differences were maintained in rectal surgery subgroup, with no prolongation of surgical time or increase in morbidity and mortality. There were no differences in the left colon surgery group. The evidence provided by this meta-analysis would support the effectiveness of ICG angiography in reducing the incidence of anastomotic leakage in colorectal surgery, advocating for its integration into routine surgical practice.

The colon does not reach! A technical note with tricks to avoid colorectal anastomoses under tension

AIM

We describe two options for colorectal anastomosis suitable in cases when the colon would reach the pelvis under tension.

METHOD

Deloyers procedure and the retro-ileal colorectal anastomosis are presented, focusing on practical tips and tricks to perform them. Insights on patients who underwent the procedures are provided to demonstrate the advantages and feasibility of the techniques.

RESULTS

Each step of both techniques is detailed. Ten patients underwent Deloyers procedure and nine underwent retro-ileal anastomosis at our unit. A minimally invasive approach was attempted in 13 patients, of whom five required conversion to open surgery due to the technical complexity of the abdominal procedure. Colorectal anastomosis was successfully performed in all patients. There were no major intra-operative complications, although five patients had postoperative complications requiring further treatment.

CONCLUSIONS

Both techniques are effective in patients at risk of receiving a colorectal anastomosis under tension, and a minimally invasive approach can be used. However, owing to the complexity of surgery in this group of patients, the perioperative morbidity is not negligible. Careful postoperative management is advisable, and patients should be informed of the risks. In expert hands, the outcomes are acceptable, avoiding an ileorectal anastomosis and its constraints.

Current applications of indocyanine green (ICG) in abdominal, gynecologic and urologic surgery: a meta-review and quality analysis with use of the AMSTAR 2 instrument

BACKGROUND

Indocyanine green (ICG) is an injectable fluorochrome that has recently gained popularity as a means of assisting intraoperative visualization during laparoscopic and robotic surgery. Many systematic reviews and meta-analyses have been published. We conducted a meta-review to synthesize the findings of these studies.

METHODS

PubMed and Embase were searched to identify systematic reviews and meta-analyses coping with the uses of ICG in abdominal operations, including Metabolic Bariatric Surgery, Cholecystectomy, Colorectal, Esophageal, Gastric, Hepato-Pancreato-Biliary, Obstetrics and Gynecology (OG), Pediatric Surgery, Surgical Oncology, Urology, (abdominal) Vascular Surgery, Adrenal and Splenic Surgery, and Interdisciplinary tasks, until September 2023. We submitted the retrieved meta-analyses to qualitative analysis based on the AMSTAR 2 instrument.

RESULTS

We identified 116 studies, 41 systematic reviews (SRs) and 75 meta-analyses (MAs), spanning 2013-2023. The most thoroughly investigated (sub)specialties were Colorectal (6 SRs, 25 MAs), OG (9 SRs, 15 MAs), and HPB (4 SRs, 12 MAs). Interestingly, there was high heterogeneity regarding the administered ICG doses, routes, and timing. The use of ICG offered a clear benefit regarding anastomotic leak prevention, particularly after colorectal and esophageal surgery. There was no clear benefit regarding sentinel node detection after OG. According to the AMSTAR 2 tool, most meta-analyses ranked as "critically low" (34.7%) or "low" (58.7%) quality. There were only five meta-analyses (6.7%) that qualified as "moderate" quality, whereas there were no "high" quality reviews.

CONCLUSIONS

Regardless of the abundance of pertinent literature and reviews, surgeons should be cautious when interpreting their results on ICG use in abdominal surgery. Future reviews should focus on ensuring methodological vigor; establishing clear protocols of ICG dose, route of administration, and timing; and improving reporting quality. Other sources of data (e.g., registries) and novel methods of data analysis (e.g., machine learning) might also contribute to an enhanced role of ICG as a decision-making tool in surgery.

Optimizing Indocyanine Green Dosage for Near-Infrared Fluorescence Perfusion Assessment in Bowel Anastomosis: A Prospective, Systematic Dose-Ranging Study

BACKGROUND

Indocyanine green (ICG) near-infrared fluorescence (NIRF) has emerged as a promising technique for visualizing tissue perfusion. However, within the wide range of dosages and imaging conditions currently being applied, the optimal dosage of ICG remains unclear. This study aimed to investigate the feasibility and implications of implementing lower dosages of ICG than commonly used for visual and quantitative perfusion assessment in a standardized setting.

METHODS

A prospective single-center cohort study was conducted on patients undergoing ileostomy reversal by hand-sewn anastomosis. ICG-NIRF visualization was performed before (T1) and after (T2) anastomosis with one of four different dosages of ICG (5 mg, 2.5 mg, 1.25 mg, or 0.625 mg) and recorded. Postoperatively, each visualization was evaluated for signal strength, completeness, and homogeneity of fluorescence. Additionally, perfusion graphs were generated by a software-based quantitative perfusion assessment, allowing an analysis of perfusion parameters. Statistical analysis comparing the effect of the investigated dosages on these parameters was performed.

RESULTS

In total, 40 patients were investigated. Visual evaluation demonstrated strong, complete, and homogeneous fluorescence signals across all dosages. Perfusion graph assessment revealed a consistent shape for all dosages (ingress followed by egress phase). While the average signal intensity decreased with dosage, it was sufficient to enable perfusion assessment even at the lowest dosages of 1.25 mg and 0.625 mg of ICG. The baseline intensity at T2 (the second intraoperative visualization) significantly decreased with dosage. The slope of the egress phase steepened with decreasing dosage.

CONCLUSIONS

Lower dosages of ICG were sufficient for intraoperative perfusion assessment, while causing lower residual fluorescence and quicker egress in subsequent visualizations.

Progress of near-infrared-II fluorescence in precision diagnosis and treatment of colorectal cancer

Colorectal cancer is a malignant tumour with high incidence and mortality worldwide; therefore, improving the early diagnosis of colorectal cancer and implementing a targeted "individualized treatment" strategy is of great concern. NIR-II fluorescence imaging is a large-depth, high-resolution optical bioimaging tool. Around the NIR-II window, researchers have developed a variety of luminescent probes, imaging systems, and treatment methods with colorectal cancer targeting capabilities, which can be visualized and image-guided in clinical surgery. This article aims to overcome the difficulties in diagnosing and treating colorectal cancer. The present review summarizes the latest results on using NIR-II fluorescence for targeted colorectal cancer imaging, expounds on the application prospects of NIR-II optical imaging for colorectal cancer, and discusses the imaging-guided multifunctional diagnosis and treatment platforms.

The Role of Carbon Nanoparticles as Lymph Node Tracers in Colorectal Cancer: A Systematic Review and Meta-Analysis

Colorectal malignancies are the third-most common malignancies worldwide, with a rising incidence. Surgery remains the treatment of choice and adequate lymph node dissection is required for accurate staging. The objective of this study is to assess the use of carbon nanoparticles in lymph node tracing and resection in cases of colorectal cancer. For that purpose, we conducted a systematic review and meta-analysis of studies included in Medline, Scopus, Embase, Cochrane Library, and Google Scholar databases. In the end, ten studies with a total number of 1418 patients were included in the final statistical analysis. The meta-analysis carried out showed that the use of carbon nanoparticles results in an increased number of lymph nodes harvested (WMD 6.15, 95% CI 4.14 to 8.16, p < 0.001) and a higher rate of cases with more than 12 lymph nodes harvested (OR 9.57, 95% CI 2.87 to 31.96, p = 0.0002). As a consequence, we suggest that carbon nanoparticles are used on a wider scale and that future research focuses on assessing the association between their use and overall patient survival. This study is limited by the fact that all included studies originate from China and by the fact that certain oncologic parameters and long-term outcomes have not been taken into account in the analysis.

Assessment of gastric pouch blood supply with indocyanine green fluorescence in conversional and revisional bariatric surgery: a prospective comparative study

Our study aimed to evaluate the usefulness of indocyanine green (ICG) angiography during conversional or revisional bariatric surgery. We prospectively enrolled all patients scheduled for reoperative bariatric surgery with gastric pouch resizing and ICG assessment and we compared them with a retrospective series of similar patients who did not receive ICG. The primary outcome was the rate of intraoperative change in the surgical strategy due to the ICG test. We included 32 prospective patients receiving intraoperatively an ICG perfusion test and 48 propensity score-matched controls. The mean age was 50.7 ± 9.7 years, 67 (83.7%) patients were female, and the mean BMI was 36.8 ± 5.3 kg/m2. The patient characteristics were similar in both groups. The ICG angiography was successfully conducted in all patients, and no change of the surgical strategy was necessary. Postoperative complications were similar in both groups (6.2% vs. 8.3%, p = 0.846), as well as operative time (125 ± 43 vs. 133 ± 47 min, p = 0.454) and length of hospital stay (2.8 ± 1.0 vs. 3.3 ± 2.2 days, p = 0.213). Our study suggested that ICG fluorescence angiography might not have been useful for assessing the blood supply of the gastric pouch in patients who underwent reoperative bariatric surgery. Therefore, it remains uncertain whether the application of this technique is indicated.

Laparoscopic D3 lymph node dissection with left colic artery and first sigmoid artery preservation in rectal cancer

BACKGROUND

D3 lymph node dissection with left colic artery (LCA) preservation in rectal cancer surgery seems to have little effect on reducing postoperative anastomotic leakage. So we first propose D3 lymph node dissection with LCA and first sigmoid artery (SA) preservation. This novel procedure deserves further study.

METHODS

Rectal cancer patients who underwent laparoscopic D3 lymph node dissection with LCA preservation or with LCA and first SA preservation between January 2017 and January 2020 were retrospectively assessed. The patients were categorized into two groups: the preservation of the LCA group and the preservation of the LCA and first SA group. A 1:1 propensity score-matched analysis was performed to decrease confounding.

RESULTS

Propensity score matching yielded 56 patients in each group from the eligible patients. The rate of postoperative anastomotic leakage in the preservation of the LCA and first SA group was significantly lower than that in the LCA preservation group (7.1% vs. 0%, P=0.040). No significant differences were observed in operation time, length of hospital stay, estimated blood loss, length of distal margin, lymph node retrieval, apical lymph node retrieval, and complications. A survival analysis showed patients' 3-year disease-free survival (DFS) rates of group 1 and group 2 were 81.8% and 83.5% (P=0.595), respectively.

CONCLUSION

D3 lymph node dissection with LCA and first SA preservation for rectal cancer may help reduce the incidence of anastomotic leakage without compromising oncological outcomes compare with D3 lymph node dissection with LCA preservation alone.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Artificial Intelligence in Colorectal Cancer Surgery: Present and Future Perspectives

Artificial intelligence (AI) and computer vision (CV) are beginning to impact medicine. While evidence on the clinical value of AI-based solutions for the screening and staging of colorectal cancer (CRC) is mounting, CV and AI applications to enhance the surgical treatment of CRC are still in their early stage. This manuscript introduces key AI concepts to a surgical audience, illustrates fundamental steps to develop CV for surgical applications, and provides a comprehensive overview on the state-of-the-art of AI applications for the treatment of CRC. Notably, studies show that AI can be trained to automatically recognize surgical phases and actions with high accuracy even in complex colorectal procedures such as transanal total mesorectal excision (TaTME). In addition, AI models were trained to interpret fluorescent signals and recognize correct dissection planes during total mesorectal excision (TME), suggesting CV as a potentially valuable tool for intraoperative decision-making and guidance. Finally, AI could have a role in surgical training, providing automatic surgical skills assessment in the operating room. While promising, these proofs of concept require further development, validation in multi-institutional data, and clinical studies to confirm AI as a valuable tool to enhance CRC treatment.

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.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NCT04712032; NL7502.

Intestinal perfusion assessed by quantitative fluorescence angiography in piglets with necrotizing enterocolitis

BACKGROUND

Reduced intestinal perfusion is thought to be a part of the pathogenesis in necrotizing enterocolitis (NEC). This study aims to evaluate the intestinal perfusion assessment in NEC-lesions by quantitative fluorescence angiography with indocyanine green (q-ICG) during laparoscopy and open surgery.

METHODS

Thirty-four premature piglets were delivered by cesarean section and fed with parenteral nutrition and increasing infant formula volumes to induce NEC. During surgery, macroscopic NEC-lesions were evaluated using a validated macroscopic scoring system (1-6 for increasing NEC severity). The intestinal perfusion was assessed by q-ICG and quantified with a validated pixel intensity computer algorithm.

RESULTS

Significantly higher perfusion values were found in healthy areas of the colon (score 1) compared to those with NEC scores of 4, 5, and 6 (p < 0.05). Similarly, in the small intestine, perfusion was higher in the intestine with areas scored 1 compared to scores of 3 and 4 (p < 0.05). A cut-off value was found between NEC score of 1-2 vs. 3-4 for the small intestine at 117 and for colon at 107 between NEC scores 12 vs. scores of 36 with an area less than the curve value at 0.9 (p < 0.05).

CONCLUSIONS

q-ICG seems to be a feasible and valuable technique to evaluate the perfusion of tissue with NEC-lesions. We found a cut-off between intestine with scores 1-2 and intestine with NEC scores 3-6 in colon, and NEC score 3-4 in the small intestine.

LEVEL OF EVIDENCE

II.

Effect of Indocyanine Green Fluorescence Angiography on Anastomotic Leakage in Patients Undergoing Colorectal Surgery: A Meta-Analysis of Randomized Controlled Trials and Propensity-Score-Matched Studies

Background

Meta-analyses have demonstrated that indocyanine green (ICG) can effectively prevent anastomotic leakage (AL) after colorectal surgery. However, recent evidence from large randomized controlled trial (RCT) has suggested that ICG fluorescence angiography does not reduce the incidence of AL in colorectal surgery. This study was conducted to evaluate the value of ICG for the prevention of AL following colorectal surgery.

Methods

Up to September 16, 2021, PubMed, Embase, China National Knowledge Infrastructure, Web of Science, Scopus, Cochrane Library, and VIP databases were searched for RCTs and propensity-score matched (PSM) studies evaluating the use of ICG for prevention of AL after colorectal surgery. Mean differences (MDs) or odds ratios (ORs) and 95% confidence intervals (CI) were calculated.

Results

Twenty studies (5 RCTs and 15 PSM studies) with a total of 5,125 patients were included. ICG did not reduce the reoperation rate (OR, 0.71; 95% CI, 0.38, 1.30), conversion rates (OR, 1.34; 95% CI, 0.65, 2.78), or mortality (OR, 0.50; 95% CI, 0.13, 1.85), but ICG did reduce the incidence of AL (OR, 0.46; 95% CI, 0.36, 0.59) and symptomatic AL (OR, 0.48; 95% CI, 0.33, 0.71), and reduced the length of hospital stay (MD,-1.21; 95% CI,-2.06,-0.35) and intraoperative blood loss (MD,-9.13; 95% CI,-17.52,-0.74). In addition, ICG use did not increase the incidence of total postoperative complications (OR, 0.93; 95% CI, 0.64, 1.35), postoperative ileus (OR, 1.26; 95% CI, 0.53, 2.97), wound infection (OR, 0.76; 95% CI, 0.44, 1.32), urinary tract infection (OR, 0.87; 95% CI, 0.30, 2.59), pulmonary infection (OR, 0.23; 95% CI, 0.04, 1.45), urinary retention (OR, 1.08; 95% CI, 0.23, 5.04), anastomotic bleeding (OR, 1.53; 95% CI, 0.27, 8.60), anastomotic stricture (OR, 0.74; 95% CI, 0.24, 2.29), or operative time (MD,-9.64; 95% CI,-20.28, 1.01).

Conclusions

ICG can effectively reduce the incidence of AL, without prolonging the operation time or increasing postoperative complications in colorectal surgery.

Systematic Review Registration

www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42021279064.

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.

Indocyanine green fluorescence angiography after full-thickness bowel resection for rectosigmoid endometriosis: A multicentric experience with quantitative analysis

OBJECTIVE

To evaluate effectiveness and reproducibility of qualitative and quantitative near-infrared indocyanine green (NIR-ICG) analyses as a tool for anastomotic perfusion assessment after full-thickness bowel resection for rectosigmoid endometriosis (RSE).

METHODS

Symptomatic women with RSE undergoing minimally invasive full-thickness surgical excision of RSE and NIR-ICG evaluation from November 2019 to July 2020 were included. Study outcomes were the accuracy of qualitative and quantitative NIR-ICG analyses in predicting bowel fistula and their reproducibility. NIR-ICG predictive accuracy was assessed by calculating sensitivity, specificity, and area under the curve on receiver operating characteristic curves with 95% confidence intervals (CI). NIR-ICG reproducibility was assessed through Cohen's k coefficient to determine interoperator agreement between two observers.

RESULTS

Of 33 patients, 2 (6%) developed bowel fistula. In predicting bowel fistula, qualitative and quantitative NIR-ICG evaluations showed sensitivity of 100% and 100%, specificity of 71% and 93%, and area under the curve of 0.86 (95% CI 0.67-1.00) and 0.96 (95% CI 0-1.00), respectively. Regarding interoperator agreement rate, it was reported as excellent for the qualitative analysis and very good for the quantitative analysis.

CONCLUSION

Qualitative and quantitative NIR-ICG evaluations might be effective and reproducible tools for anastomotic perfusion assessment after discoid or segmental resection for RSE. Quantitative evaluation might be even more effective than qualitative evaluation in predicting bowel fistula.

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

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

Enhancing colorectal anastomotic safety with indocyanine green fluorescence angiography: An update

Reducing anastomotic leak (AL) continues to be a main focus in colorectal research. Several new technologies have been developed with an aim to reduce this from mechanical devices to advanced imaging techniques. Fluorescence angiography (FA) with indocyanine green (ICG) in colorectal surgery is now a well-established technique and may have a role in reducing AL. By using FA, we are able to have a visual representation of perfusion which aids intraoperative decision making. The main impact is change in the level of bowel transection at the proximal side of an anastomosis and provide a more objective and confident assessment of bowel perfusion. Previous studies have shown that routine FA use is safe and reproducible. Recent results from randomized control trials and meta-analyses show that FA use reduces the rate of anastomotic leak. The main limitation of FA is its lack of ability to quantify perfusion. Novel technologies are being developed that will quantify tissue perfusion and oxygenation. Overall, FA is a safe and feasible technique which may have a role in reducing AL.

Indocyanine Green Fluorescence Angiography after Full-thickness Bowel Resection for Rectosigmoid Endometriosis-A Feasibility Study

STUDY OBJECTIVE

To evaluate feasibility of near-infrared (NIR)-indocyanine green (ICG) imaging for bowel vascularization assessment after full-thickness bowel resection for rectosigmoid endometriosis (RSE).

DESIGN

This is a prospective, single-center, preliminary study on consecutive patients who were symptomatic submitted to discoid or segmental resection for RSE and NIR-ICG evaluation for vascular assessment of the anastomotic line from May 2018 to January 2020.

SETTING

Tertiary university hospital.

PATIENTS

Thirty-two women with RSE meeting eligibility criteria were included for study analysis.

INTERVENTIONS

NIR-ICG evaluation of anastomotic line vascularization after RSE removal.

MEASUREMENTS AND MAIN RESULTS

Fluorescence degree of the anastomotic line was assessed with a 0 to 2 Likert scale, as follows: 0 or "absent" (no fluorescence observed), 1 or "irregular" (not uniform distribution or weak fluorescence), and 2 or "regular" (uniform distribution of fluorescence and similar to the proximal colon). In all the patients included in the study (100%), NIR-ICG imaging allowed the evaluation of fluorescence degree of the anastomotic line. No adverse reaction related to ICG use was recorded. The protocol did not greatly lengthen operating time (median, 4 [range, 3-5] minutes). Excellent interoperator agreement was observed. Most of the patients (31 of 32, 96.9%) showed regular fluorescence on the anastomotic line; in 1 patient with irregular fluorescence at NIR-ICG after discoid excision, the anastomotic suture was reinforced through interrupted stitches. We had 1 case of anastomotic leakage after segmental resection with intraoperative good fluorescence at NIR-ICG evaluation.

CONCLUSION

NIR-ICG imaging for anastomotic perfusion assessment after discoid or segmental resection for RSE seems to be a feasible, safe, and reproducible method.