Sensitivity and specificity of indocyanine green near-infrared fluorescence imaging in detection of metastatic lymph nodes in colorectal cancer: Systematic review and meta-analysis

The role of ureteric indocyanine green fluorescence in colorectal surgery: a retrospective cohort study

BACKGROUND

Ureteric injury (UI) is an infrequent but serious complication of colorectal surgery. Prophylactic ureteric stenting is employed to avoid UI, yet its efficacy remains debated. Intraoperative indocyanine green fluorescence imaging (ICG-FI) has been used to facilitate ureter detection. This study aimed to investigate the role of ICG-FI in identification of ureters during colorectal surgery and its impact on the incidence of UI.

METHODS

A retrospective cohort study involving 556 consecutive patients who underwent colorectal surgery between 2018 and 2023 assessed the utility of routine prophylactic ureteric stenting with adjunctive ICG-FI. Patients with ICG-FI were compared to those without ICG-FI. Demographic data, operative details, and postoperative morbidity were analyzed. Statistical analysis included univariable regression.

RESULTS

Ureteric ICG-FI was used in 312 (56.1%) patients, whereas 43.9% were controls. Both groups were comparable in terms of demographics except for a higher prevalence of prior abdominal surgeries in the ICG-FI group. Although intraoperative visualization was significantly higher in the ICG-FI group (95.3% vs 89.1%; p = 0.011), the incidence of UI was similar between groups (0.3% vs 0.8%; p = 0.585). Postoperative complications were similar between the two groups. Median stent insertion time was longer in the ICG-FI group (32 vs 25 min; p = 0.001).

CONCLUSION

Ureteric ICG-FI improved intraoperative visualization of the ureters but was not associated with a reduced UI rate. Median stent insertion time increased with use of ureteric ICG-FI, but total operative time did not. Despite its limitations, this study is the largest of its kind suggesting that ureteric ICG-FI may be a valuable adjunct to facilitate  ureteric visualization during colorectal surgery.

Preclinical evaluation of EpCAM-binding designed ankyrin repeat proteins (DARPins) as targeting moieties for bimodal near-infrared fluorescence and photoacoustic imaging of cancer

PURPOSE

Fluorescence-guided surgery (FGS) can play a key role in improving radical resection rates by assisting surgeons to gain adequate visualization of malignant tissue intraoperatively. Designed ankyrin repeat proteins (DARPins) possess optimal pharmacokinetic and other properties for in vivo imaging. This study aims to evaluate the preclinical potential of epithelial cell adhesion molecule (EpCAM)-binding DARPins as targeting moieties for near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging of cancer.

METHODS

EpCAM-binding DARPins Ac2, Ec4.1, and non-binding control DARPin Off7 were conjugated to IRDye 800CW and their binding efficacy was evaluated on EpCAM-positive HT-29 and EpCAM-negative COLO-320 human colon cancer cell lines. Thereafter, NIRF and PA imaging of all three conjugates were performed in HT-29_luc2 tumor-bearing mice. At 24 h post-injection, tumors and organs were resected and tracer biodistributions were analyzed.

RESULTS

Ac2-800CW and Ec4.1-800CW specifically bound to HT-29 cells, but not to COLO-320 cells. Next, 6 nmol and 24 h were established as the optimal in vivo dose and imaging time point for both DARPin tracers. At 24 h post-injection, mean tumor-to-background ratios of 2.60 ± 0.3 and 3.1 ± 0.3 were observed for Ac2-800CW and Ec4.1-800CW, respectively, allowing clear tumor delineation using the clinical Artemis NIRF imager. Biodistribution analyses in non-neoplastic tissue solely showed high fluorescence signal in the liver and kidney, which reflects the clearance of the DARPin tracers.

CONCLUSION

Our encouraging results show that EpCAM-binding DARPins are a promising class of targeting moieties for pan-carcinoma targeting, providing clear tumor delineation at 24 h post-injection. The work described provides the preclinical foundation for DARPin-based bimodal NIRF/PA imaging of cancer.

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.

Short-term and Mid-term Outcomes of Indocyanine Green Fluorescence Imaging-Guided Laparoscopic Right-Sided Colectomy: A Propensity Score-Matched Cohort Study

BACKGROUND

With the use of indocyanine green fluorescence imaging, intraoperative lymphatic flow assessment is possible. However, no report has indicated mid-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy.

OBJECTIVE

To analyze the mid-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy.

DESIGN

This was a retrospective, multi-institutional study that used propensity score matching.

SETTINGS

We conducted this study within the framework of the Yokohama Clinical Oncology Group in Japan.

PATIENTS

A total of 921 patients who underwent laparoscopic right-sided colectomy with lymph node dissection for colon cancer with clinical stages I to III between January 2009 and December 2020 were included. The patients were divided into 2 groups: 233 patients who underwent the lymphatic flow evaluation (indocyanine green group) and 688 patients who did not undergo lymphatic flow evaluation (non-indocyanine green group).

MAIN OUTCOMES MEASURES

The 3-year relapse-free survival after laparoscopic right-sided colectomy with and without indocyanine green fluorescence imaging were compared.

RESULTS

After propensity score matching, 231 patients were matched in each group. The numbers of dissected central lymph nodes (6 vs 4, p < 0.001), intermediate lymph nodes (7 vs 6, p = 0.03), and the total number of dissected lymph nodes (31 vs 27, p = 0.047) were significantly higher in the indocyanine green group. The median follow-up was 36.9 months. The estimated respective 3-year relapse-free survival and overall survival rates were 88.8% and 94.5% in the indocyanine green group and 89.4% and 94.7% in the non-indocyanine green group ( p = 0.721 and 0.300), respectively, with no difference between the 2 groups.

LIMITATIONS

Retrospective design of the study.

CONCLUSIONS

Indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy could increase the number of total, intermediate, and central lymph nodes. However, there was no difference in mid-term outcomes. See Video Abstract.

RESULTADOS A CORTO Y MEDIO PLAZO DE LA COLECTOMA LAPAROSCPICA DEL LADO DERECHO GUIADA POR IMGENES DE FLUORESCENCIA CON VERDE DE INDOCIANINA UN ESTUDIO DE COHORTE EMPAREJADO POR PUNTAJE DE PROPENSIN

ANTECEDENTES:Con el uso de imágenes de fluorescencia verde de indocianina, es posible la evaluación del flujo linfático intraoperatorio. Sin embargo, no hay ningún reporte que indique los resultados a medio plazo de la colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina.OBJETIVO:Examinar los resultados a mediano plazo de la colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina.DISEÑO:Estudio multiinstitucional retrospectivo con emparejamiento de puntuación de propensión.CONFIGURACIÓN:Realizado en el marco del Grupo de Oncología Clínica de Yokohama en Japón.PACIENTES:Un total de 921 pacientes sometidos a colectomía laparoscópica del lado derecho con disección de ganglios linfáticos por cáncer de colon con estadio clínico I a III entre enero de 2009 y diciembre de 2020. Los pacientes se dividieron en dos grupos: 233 pacientes sometidos a la evaluación del flujo linfático (grupo con verde de indocianina) y 688 pacientes que no sometidos a la evaluación del flujo linfático (grupo sin verde de indocianina).PRINCIPALES MEDIDAS DE RESULTADOS:Se comparó la supervivencia libre de recaídas a los 3 años después de la colectomía laparoscópica del lado derecho con y sin imágenes de fluorescencia con verde de indocianina.RESULTADOS:Después de emparejar el puntaje de propensión, 231 pacientes fueron emparejados en cada grupo. El número de ganglios linfáticos centrales disecados (6 frente a 4, p < 0,001) y de ganglios linfáticos intermedios (7 frente a 6, p = 0,03) y el número total de ganglios linfáticos disecados (31 frente a 27, p = 0,047) fueron significativamente mayor en el grupo verde de indocianina. La mediana de seguimiento fue de 36,9 meses. Las tasas respectivas estimadas de supervivencia libre de recaídas y supervivencia general a los 3 años fueron del 88,8 % y el 94,5 % en el grupo con verde de indocianina y del 89,4 % y el 94,7 % en el grupo sin verde de indocianina ( p = 0,721 y 0,300), sin diferencias entre los dos grupos.LIMITACIONES:Estudio de diseño retrospectivo.CONCLUSIONES:La colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina puede aumentar el número de ganglios linfáticos totales, intermedios y centrales. Sin embargo, no hubo diferencias en los resultados a medio plazo. (Traducción-Dr. Fidel Ruiz Healy ).

Fluorescent-guided surgery and the use of indocyanine green sentinel lymph node mapping in the pediatric and young adult oncology population

BACKGROUND

Technetium-99 (99m Tc) lymphoscintigraphy with blue dye injection is an accepted method for sentinel lymph node (SLN) mapping, but blue dye has known adverse effects, and injection of 99m Tc may increase time under anesthesia for pediatric patients. Indocyanine green (ICG) may serve as an adjunct to assist with visibility and identification of SLNs. We hypothesized that sensitivity of ICG was similar to blue dye in SLN biopsies.

METHODS

Thirty patients (36 procedures with 96 total specimens) underwent preoperative intradermal injection of 99m Tc, followed by intradermal injection of isosulfan blue and ICG. Test characteristics of blue dye, ICG, and 99m Tc included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

ICG had a sensitivity of 87% and PPV of 83% for detection of 99m Tc-hot lymph nodes; blue dye had a sensitivity of 44% and PPV of 97%. For detection of pathologically confirmed lymph nodes, ICG had a sensitivity of 84% and a positive predictive value (PPV) of 91%. 99m Tc had a sensitivity of 82% and a PPV of 94%. ICG had no significant difference in odds of being positive in pathology-confirmed lymph nodes compared to 99m Tc (odds ratio [OR], 0.818; 95% confidence interval [CI], 0.3-2.172; p = .823) and had higher odds than isosulfan blue (OR, 0.025, 95% CI, 0.001-0.148; p < .001).

CONCLUSION

This study established the efficacy of ICG as an adjunct to SLNB in the pediatric and young adult population. ICG was safe, more efficacious than blue dye, and may obviate the need for lymphoscintigraphy in selected patients resulting in reduced time under anesthesia.

A SPECT/NIR Fluorescence Dual-Modality Imaging Agent Composed of Drugs and Hospital Available Isotope for Preoperative Sentinel Lymph Node Mapping and Intraoperative Biopsy

Background

Sentinel lymph node (SLN) mapping-guided biopsy is crucial for cancer staging and treatment. Optical/nuclide dual-modality imaging agents for mapping SLN are ideal for preoperative planning and intraoperative biopsy, which are enabled by penetration-depth unlimited nuclide imaging and dynamic real-time optical imaging, respectively. However, commonly reported dual-modality imaging agents are composed of novel but safety-unproven materials, making their quick clinical translation challenging. Herein, we report a novel nanoparticle composed of facile hospital-available drugs and isotope for single-photon emission computed tomography (SPECT)/near-infrared (NIR) fluorescence imaging to detect SLNs.

Methods

Indocyanine green-human serum albumin (ICG-HSA) nanoparticles (NPs) were synthesized by ICG-induced HSA self-assembly and further 99mTc-labeling via a one-step, facile hospital-available method. After injecting 99mTc-ICG-HSA into the rats' forepaw pads, the rats' draining axillary lymph nodes were visualized by preoperative mapping with SPECT/CT and intraoperative biopsy with NIR fluorescence. The axillary lymph nodes of rats were identified by pathology and fluorescent staining after execution. Additionally, its toxicity testing and comparison with 99mTc-sulfur colloid imaging were also explored.

Results

The study reported a self-assembled 99mTc-ICG-HSA with a high radiochemical yield (85.6 ± 3.8%). Compared with conventional 99mTc-sulfur colloid, 99mTc-ICG-HSA NPs showed faster SLN identification, higher renal clearance, and lower hepatic retention. Furthermore, NIRF imaging allowed for the accurate visualization of the SLN and guided SLN biopsy intraoperatively. Notably, the 99mTc-ICG-HSA NPs were composed of hospital-available drugs and isotope, which are safe for acute toxicity evaluation by a certified institute.

Conclusion

The proposed 99mTc-ICG-HSA NPs are safe and capable of noninvasive SLN identification and biopsy guidance with multi-modal imaging strategies and could be a promising tool for clinically assisted SLN biopsy.

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.

Lymph node mapping with ICG near-infrared fluorescence imaging: technique and results

PURPOSE

Lymphadenectomy represents a fundamental step during gastrointestinal cancer resection, as the removal of an adequate number of lymph nodes is crucial to define the stage of the disease and prognosis. Lymphadenectomy during gastric and colorectal resection and adrenalectomy for cancer are technically demanding and can be associated with risk of bleeding. To date, lymphadenectomy is often performed without any visual aid. Indocyanine green fluorescence for lymph node mapping can provide better intraoperative visualization. The purpose of this review is to report the current evidence on this topic.

MATERIALS AND METHODS

A systematic research of the electronic databases Medline, Embase and Google Scholar was conducted from the inception to December 2022.

RESULTS

This review summarizes the current evidence of techniques and results of fluorescence guided lymphatic mapping during gastrointestinal and adrenal surgery.

CONCLUSION

According to this review, ICG guided lymphadenectomy for gastrointestinal tumours and adrenocortical carcinoma is feasible and safe. In gastrointestinal tumours it allows higher number of harvested lymph nodes.

Indocyanine green dye and its application in gastrointestinal surgery: The future is bright green

Indocyanine green (ICG) is a water-soluble fluorescent dye that is minimally toxic and widely used in gastrointestinal surgery. ICG facilitates anatomical identification of structures (e.g., ureters), assessment of lymph nodes, biliary mapping, organ perfusion and anastomosis assessment, and aids in determining the adequacy of oncological margins. In addition, ICG can be conjugated to artificially created antibodies for tumour markers, such as carcinoembryonic antigen for colorectal, breast, lung, and gastric cancer, prostate-specific antigen for prostate cancer, and cancer antigen 125 for ovarian cancer. Although ICG has shown promising results, the optimization of patient factors, dye factors, equipment, and the method of assessing fluorescence intensity could further enhance its utility. This review summarizes the clinical application of ICG in gastrointestinal surgery and discusses the emergence of novel dyes such as ZW-800 and VM678 that have demonstrated appropriate pharmacokinetic properties and improved target-to-background ratios in animal studies. With the emergence of robotic technology and the increasing reporting of ICG utility, a comprehensive review of clinical application of ICG in gastrointestinal surgery is timely and this review serves that aim.

Lymphatic Mapping in Colon Cancer Depending on Injection Time and Tracing Agent: A Systematic Review and Meta-Analysis of Prospective Designed Studies

An optimized lymph node yield leads to better survival in colon cancer, but extended lymphadenectomy is not associated with survival benefits. Lymphatic mapping shows several colon cancers feature aberrant drainage pathways inducing local recurrence when not resected. Currently, different protocols exist for lymphatic mapping procedures. This meta-analysis assessed which protocol has the best capacity to detect tumor-draining and possibly metastatic lymph nodes. A systematic review was conducted according to PRISMA guidelines, including prospective trials with in vivo tracer application. The risk of bias was evaluated using the QUADAS-2 tool. Traced lymph nodes, total resected lymph nodes, and aberrant drainage detection rate were analyzed. Fifty-eight studies met the inclusion criteria, of which 42 searched for aberrant drainage. While a preoperative tracer injection significantly increased the traced lymph node rates compared to intraoperative tracing (30.1% (15.4, 47.3) vs. 14.1% (11.9, 16.5), p = 0.03), no effect was shown for the tracer used (p = 0.740) or the application sites comparing submucosal and subserosal injection (22.9% (14.1, 33.1) vs. 14.3% (12.1, 16.8), p = 0.07). Preoperative tracer injection resulted in a significantly higher rate of detected aberrant lymph nodes compared to intraoperative injection (26.3% [95% CI 11.5, 44.0] vs. 2.5% [95% CI 0.8, 4.7], p < 0.001). Analyzing 112 individual patient datasets from eight studies revealed a significant impact on aberrant drainage detection for injection timing, favoring preoperative over intraoperative injection (OR 0.050 [95% CI 0.010-0.176], p < 0.001) while indocyanine green presented itself as the superior tracer (OR 0.127 [95% CI 0.018-0.528], p = 0.012). Optimized lymphatic mapping techniques result in significantly higher detection of aberrant lymphatic drainage patterns and thus enable a personalized approach to reducing local recurrence.

Simultaneous, Multi-Channel, Near-Infrared Fluorescence Visualization of Mesenteric Lymph Nodes Using Indocyanine Green and Methylene Blue: A Demonstration in a Porcine Model

Near-infrared fluorescence (NIRF) image-guided surgery is a useful tool that can help reduce perioperative complications and improve tissue recognition. Indocyanine green (ICG) dye is the most frequently used in clinical studies. ICG NIRF imaging has been used for lymph node identification. However, there are still many challenges in lymph node identification by ICG. There is increasing evidence that methylene blue (MB), another clinically applicable fluorescent dye, can also be useful in the intraoperative fluorescence-guided identification of structures and tissues. We hypothesized that MB NIRF imaging could be used for lymph node identification. The aim of this study was to evaluate the feasibility of intraoperative lymph node fluorescence detection using intravenously (IV) administered MB and compare it to ICG via a camera that has two dedicated near-infrared (NIR) channels. Three pigs were used in this study. ICG (0.2 mg/kg) was administered via a peripheral venous catheter followed by immediate administration of MB (0.25 mg/kg). NIRF images were acquired as video recordings at different time points (every 10 min) over an hour using the QUEST SPECTRUM^® 3 system (Quest Medical Imaging, Middenmeer, The Netherlands), which has two dedicated NIR channels for simultaneous intraoperative fluorescence guidance. The 800 nm channel was used to capture ICG fluorescence and the 700 nm channel was used for MB. The target (lymph nodes and small bowel) and the background (vessels-free field of the mesentery) were highlighted as the regions of interest (ROIs), and corresponding fluorescence intensities (FI) from these ROIs were measured. The target-to-background ratio (TBR) was then computed as the mean FI of the target minus the mean FI of the background divided by the mean FI of the background. In all included animals, a clear identification of lymph nodes was achieved at all time points. The mean TBR of ICG in lymph nodes and small bowel was 4.57 ± 1.00 and 4.37 ± 1.70, respectively for the overall experimental time. Regarding MB, the mean TBR in lymph nodes and small bowel was 4.60 ± 0.92 and 3.27 ± 0.62, respectively. The Mann-Whitney U test of the lymph node TBR/small bowel TBR showed that the TBR ratio of MB was statistically significantly higher than ICG. The fluorescence optical imaging technology used allows for double-wavelength assessment. This feasibility study proves that lymph nodes can be discriminated using two different fluorophores (MB and ICG) with different wavelengths. The results suggest that MB has a promising potential to be used to detect lymphatic tissue during image-guided surgery. Further preclinical trials are needed before clinical translation.

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.

Indocyanine Green Fluorescence Guided Surgery in Colorectal Surgery

BACKGROUND

Indocyanine green (ICG) imaging has been increasingly used for intraoperative guidance in colorectal surgery over the past decade. The aim of this study was to review and organize, according to different type of use, all available literature on ICG guided colorectal surgery and highlight areas in need of further research and discuss future perspectives.

METHODS

PubMed, Scopus, and Google Scholar databases were searched systematically through November 2022 for all available studies on fluorescence-guided surgery in colorectal surgery.

RESULTS

Available studies described ICG use in colorectal surgery for perfusion assessment, ureteral and urethral assessment, lymphatic mapping, and hepatic and peritoneal metastases assessment. Although the level of evidence is low, results are promising, especially in the role of ICG in reducing anastomotic leaks.

CONCLUSIONS

ICG imaging is a safe and relatively cheap imaging modality in colorectal surgery, especially for perfusion assessment. Work is underway regarding its use in lymphatic mapping, ureter identification, and the assessment of intraperitoneal metastatic disease.

Use of fluorescence imaging and indocyanine green during laparoscopic cholecystectomy: Results of an international Delphi survey

BACKGROUND

Published empirical data have increasingly suggested that using near-infrared fluorescence cholangiography during laparoscopic cholecystectomy markedly increases biliary anatomy visualization. The technology is rapidly evolving, and different equipment and doses may be used. We aimed to identify areas of consensus and nonconsensus in the use of incisionless near-infrared fluorescent cholangiography during laparoscopic cholecystectomy.

METHODS

A 2-round Delphi survey was conducted among 28 international experts in minimally invasive surgery and near-infrared fluorescent cholangiography in 2020, during which respondents voted on 62 statements on patient preparation and contraindications (n = 12); on indocyanine green administration (n = 14); on potential advantages and uses of near-infrared fluorescent cholangiography (n = 18); comparing near-infrared fluorescent cholangiography with intraoperative x-ray cholangiography (n = 7); and on potential disadvantages of and required training for near-infrared fluorescent cholangiography (n = 11).

RESULTS

Expert consensus strongly supports near-infrared fluorescent cholangiography superiority over white light for the visualization of biliary structures and reduction of laparoscopic cholecystectomy risks. It also offers other advantages like enhancing anatomic visualization in obese patients and those with moderate to severe inflammation. Regarding indocyanine green administration, consensus was reached that dosing should be on a milligrams/kilogram basis, rather than as an absolute dose, and that doses >0.05 mg/kg are necessary. Although there is no consensus on the optimum preoperative timing of indocyanine green injections, the majority of participants consider it important to administer indocyanine green at least 45 minutes before the procedure to decrease the light intensity of the liver.

CONCLUSION

Near-infrared fluorescent cholangiography experts strongly agree on its effectiveness and safety during laparoscopic cholecystectomy and that it should be used routinely, but further research is necessary to establish optimum timing and doses for indocyanine green.

Applications of Indocyanine Green-Guided Near-Infrared Fluorescence Imaging in Pediatric Minimally Invasive Surgery Urology: A Narrative Review

Background: Indocyanine green (ICG) is a fluorescent dye used for several indications in adult surgery, and, more recently, adopted also in the pediatric patients. This study aimed to review the literature published on the use of ICG near-infrared fluorescence (NIRF) in pediatric urology, to address its shortcomings and disadvantages and to detect the future perspectives. Materials and Methods: An electronic literature search of PubMed on all studies reporting use of ICG-NIRF in pediatrics was performed. We included only studies reporting ICG-NIRF application in minimally invasive surgery (MIS) for pediatric urology indications. Results: Forty-two articles reporting MIS procedures performed using ICG-NIRF in children were obtained, but only 15 studies that focused on urological applications of ICG-NIRF in children were included in this review. The included studies described use of ICG-NIRF for kidney malformations such as duplex system, kidney tumors, renal cysts, ureteral pathology, bladder malformations, varicocele, and lymph node sampling in tumors. The pediatric urological applications in which ICG-NIRF provided significant advantages included partial nephrectomy, lymphatics sparing varicocele repair, and oncological procedures. The ICG-NIRF use was clinically safe, without reported adverse systemic reactions in all pediatric series. The main drawback of this technology is the need of specific laparoscopic equipment such as camera system, light sources, and telescopes or the da Vinci Xi Robot, with the software for ICG-NIRF, Firefly^®, already integrated within. Conclusions: ICG-enhanced fluorescence-guided surgery is gaining growing popularity among pediatric surgeons due to the excellent results that have been published until now. ICG-NIRF technology has proven to be safe, easy to use, not time-consuming, cheap, and very effective to improve intraoperative view and surgical ability. Nonetheless, further evidence, including larger series, longer follow-up, and more specific assessments, is necessary to confirm the preliminary results and enlarge the applications.

Intraoperative fluorescence imaging in different surgical fields: Consensus among 140 intercontinental experts

BACKGROUND

Despite exponentially growing evidence supporting the use of intraoperative fluorescence imaging + indocyanine green dye, considerable variability exists in how and when it is used, and no published consensus guidelines exist. We have conducted Delphi surveys of international experts in the use of intraoperative fluorescence imaging covering 6 distinct surgical scenarios: laparoscopic cholecystectomy; colorectal, lymphedema, gastric cancer, and plastic surgery; and thyroid and parathyroid resections. Although each survey asked experts to vote on field-specific consensus statements, they also had 29 shared statements to permit some analysis spanning the 6 specialties. This article summarizes these results.

METHODS

Data on the 29 shared statements from 6 two-round Delphi consensus surveys were compiled to identify areas of overall consensus and compare the different specialties. As with the individual surveys, consensus was defined as ≥70% intervoter agreement.

RESULTS

Among 140 participating experts, overall consensus was achieved on 16 statements, including strong agreement that using indocyanine green is extremely safe, that it can be used even when informed written consent cannot be provided, that it significantly enhances anatomical visualization and impacts how procedures are performed, and that it significantly reduces overall procedural risk. However, indocyanine green dosing and timing are procedure-specific, with considerable variability persisting for some applications, and the overall consensus is that further research is necessary to optimize this facet of intraoperative fluorescence imaging.

CONCLUSION

Fluorescence imaging is gaining traction across multiple surgical specialties as an invaluable intraoperative tool. Its use in clinical practice and research seems destined to increase.

Use of fluorescence imaging and indocyanine green during colorectal surgery: Results of an intercontinental Delphi survey

BACKGROUND

Fluorescence imaging with indocyanine green is increasingly being used in colorectal surgery to assess anastomotic perfusion, and to detect sentinel lymph nodes.

METHODS

In this 2-round, online, Delphi survey, 35 international experts were asked to vote on 69 statements pertaining to patient preparation and contraindications to fluorescence imaging during colorectal surgery, indications, technical aspects, potential advantages/disadvantages, and effectiveness versus limitations, and training and research. Methodological steps were adopted during survey design to minimize risk of bias.

RESULTS

More than 70% consensus was reached on 60 of 69 statements, including moderate-strong consensus regarding fluorescence imaging's value assessing anastomotic perfusion and leak risk, but not on its value mapping sentinel nodes. Similarly, although consensus was reached regarding most technical aspects of its use assessing anastomoses, little consensus was achieved for lymph-node assessments. Evaluating anastomoses, experts agreed that the optimum total indocyanine green dose and timing are 5 to 10 mg and 30 to 60 seconds pre-evaluation, indocyanine green should be dosed milligram/kilogram, lines should be flushed with saline, and indocyanine green can be readministered if bright perfusion is not achieved, although how long surgeons should wait remains unknown. The only consensus achieved for lymph-node assessments was that 2 to 4 injection points are needed. Ninety-six percent and 100% consensus were reached that fluorescence imaging will increase in practice and research over the next decade, respectively.

CONCLUSION

Although further research remains necessary, fluorescence imaging appears to have value assessing anastomotic perfusion, but its value for lymph-node mapping remains questionable.

Mapping the Mesentery Using ICG

Indocyanine green (ICG) fluorescent imaging has been used in colorectal surgery to assess intraoperative blood flow to the colon. However, its use has expanded to allow imaging of the lymphatic drainage within the mesentery in cancer resections. This technique can been used for real-time visualization of lymph nodes, and the detection of sentinel lymph nodes, lateral sidewall nodes, metastatic lymph nodes, and peritoneal metastases. Ultimately, this provides a more informative map of the mesentery displaying lymphatics and blood flow. The technique is economical and easy to use by the surgeon intraoperatively. ICG lymphangiography has the potential to aid the surgeon to ensure complete lymphadenectomy is performed in cancer resections.

Applicative Limitations of Indocyanine Green Fluorescence Assistance to Laparoscopic Lymph Node Dissection in Total Gastrectomy for Cancer

BACKGROUND

Indocyanine green (ICG) fluorescence has been recently introduced as a novel imaging technique improving the accuracy of lymph node (LN) dissection in gastric cancer (GC) surgery, although procedure standardization and achievements have not been clearly defined. This study analyzed the feasibility and effectiveness of ICG-guidance for laparoscopic D2-lymphadenectomy during total gastrectomy for cancer.

METHODS

This study retrospectively analyzed a single-center series of patients who underwent laparoscopic total gastrectomy for cancer between April 2015 and August 2021. All patients underwent surgery with standard D2 LN dissection. Intraoperative ICG-fluorescence was institutionally implemented in April 2018 and was performed routinely afterward. Primary outcomes were LN harvest and ratio. Secondary endpoints included operative time and subgroup analysis to assess variables potentially affecting LN retrieval.

RESULTS

The study population included 102 patients, and ICG-fluorescence was applied in 38 (37.3%). ICG and no-ICG groups presented similar median age, gender proportions, ASA score and comorbidities (age-adjusted Charlson Comorbidity Index), body mass index, and advanced pathological stage. The median of LNs retrieved was significantly higher after the intraoperative ICG-guidance (44 vs. 32; p = 0.004), although this association was not significant after neoadjuvant therapy or among patients with positive LNs. Lymph node ratio and operative time were not significantly impacted by ICG fluorescence. Multivariate analysis identified the ICG-assistance as the only independent determinant for LN harvest (p = 0.029).

CONCLUSIONS

ICG-guidance contributes to a significantly wider LN retrieval after laparoscopic D2-lymphadenectomy during total gastrectomy for cancer. However, neoadjuvant therapy and positive LN stage appeared to limit the procedural effectiveness to ICG-assisted LN identification.

Consensus Conference Statement on the General Use of Near-infrared Fluorescence Imaging and Indocyanine Green Guided Surgery: Results of a Modified Delphi Study

BACKGROUND

In recent decades, the use of near-infrared light and fluorescence-guidance during open and laparoscopic surgery has exponentially expanded across various clinical settings. However, tremendous variability exists in how it is performed.

OBJECTIVE

In this first published survey of international experts on fluorescence-guided surgery, we sought to identify areas of consensus and nonconsensus across 4 areas of practice: fundamentals; patient selection/preparation; technical aspects; and effectiveness and safety.

METHODS

A Delphi survey was conducted among 19 international experts in fluorescence-guided surgery attending a 1-day consensus meeting in Frankfurt, Germany on September 8th, 2019. Using mobile phones, experts were asked to anonymously vote over 2 rounds of voting, with 70% and 80% set as a priori thresholds for consensus and vote robustness, respectively.

RESULTS

Experts from 5 continents reached consensus on 41 of 44 statements, including strong consensus that near-infrared fluorescence-guided surgery is both effective and safe across a broad variety of clinical settings, including the localization of critical anatomical structures like vessels, detection of tumors and sentinel nodes, assessment of tissue perfusion and anastomotic leaks, delineation of segmented organs, and localization of parathyroid glands. Although the minimum and maximum safe effective dose of ICG were felt to be 1 to 2 mg and >10 mg, respectively, there was strong consensus that determining the optimum dose, concentration, route and timing of ICG administration should be an ongoing research focus.

CONCLUSIONS

Although fluorescence imaging was almost unanimously perceived to be both effective and safe across a broad range of clinical settings, considerable further research remains necessary to optimize its use.

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.

Laparoscopic lymph node biopsy for lymphoma with a novel use of indocyanine green fluorescence in a 66-year-old male patient

Introduction

Indocyanine green (ICG) near-infrared fluorescence is primarily employed in detecting Intraoperative sentinel lymph node (SLN) mapping or to evaluate the extent of radical lymphadenectomy mainly in colo-rectal and gastric cancer. To date there are no reports indicating the use of this dye to detect pathologic lymphatic tissue when a lymph node biopsy for suspected lymphoproliferative disease is performed.

Presentation of case

A 66-year-old male patient was admitted to the hospital for severe pain of left renal colic type. A computed tomography (CT) scan and a positron emission tomography (PET) showed a left hydroureteronephrosis due to ureter compression by paraortic solid tissue of lymphomatous aspect with a standardized uptake value (SUV) of 15. Multiple lymphadenopathies on paracaval, para-aortic and common iliac sites were present as well.

Discussion

A laparoscopic lymph node biopsy (LLB) was planned for diagnostic purposes. After induction of anesthesia a ICG solution was injected Intradermally at both inguinal regions. At laparoscopy a complete visualization of the pathologic lymphnodes was achieved, enabling incisional biopsies of the lymphomatous mass. Histopathological examination showed an extranodal localization of an aggressive B-cell non-Hodgkin lymphoma.

Conclusion

ICG-fluorescence seems to offer a simple and safe method for pathologic lymph node detection. LLB in the suspicion of intra abdominal lymphoma can largely take advantage by this novel opportunity not yet tested to date. More studies with large case series are needed to confirm the efficacy of ICG-fluorescence for detecting pathologic lymph nodes.

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First report in literature concerning the use of indocyanine green (ICG) for laparoscopic lymph node biopsy

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Periaortic and iliac lymph nodes visualized at PET as pathological, at laparoscopy turned out to be stained up by ICG.

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Deep lymph nodes staining with ICG is possible by means of a preoperative injection of an ICG solution into the inguinal regions.

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ICG-fluorescence seems to offer a useful, expeditious, and easy reproductible method for pathologic lymph node [[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19]] laparoscopic lymph node biopsy (LLB).

Sentinel lymph node detection by combining nonradioactive techniques with contrast agents: State of the art and prospects

The status of sentinel lymph nodes (SLNs) has a substantial prognostic value because these nodes are the first place where cancer cells accumulate along their spreading route. Routine SLN biopsy ("gold standard") involves peritumoral injections of radiopharmaceuticals, such as technetium-99m, which has obvious disadvantages. This review examines the methods used as "gold standard" analogs to diagnose SLNs. Nonradioactive preoperative and intraoperative methods of SLN detection are analyzed. Promising photonic tools for SLNs detection are reviewed, including NIR-I/NIR-II fluorescence imaging, photoswitching dyes for SLN detection, in vivo photoacoustic detection, imaging and biopsy of SLNs. Also are discussed methods of SLN detection by magnetic resonance imaging, ultrasonic imaging systems including as combined with photoacoustic imaging, and methods based on the magnetometer-aided detection of superparamagnetic nanoparticles. The advantages and disadvantages of nonradioactive SLN-detection methods are shown. The review concludes with prospects for the use of conservative diagnostic methods in combination with photonic tools.

Lateral Pelvic Lymph Node Dissection After Neoadjuvant Chemoradiotherapy in Patients With Rectal Cancer: A Single-Center Experience and Literature Review

Purpose

We aimed to evaluate the surgicopathological outcomes of lateral pelvic lymph node dissection (LPLD) and long-term oncological outcomes of selective LPLD after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer and compare them to those of total mesorectal excision (TME) alone based on pretreatment magnetic resonance imaging (MRI).

Methods

We compared the TME-alone group (2001–2009, n=102) with the TME with LPLD group (2011–2016, n=69), both groups having lateral lymph nodes (LLNs) of ≥5 mm in short axis diameter. The surgicopathological outcomes were analyzed retrospectively. Oncological outcomes were analyzed using the Kaplan-Meier method.

Results

The rates of overall postoperative 30-day morbidity (42.0% vs. 26.5%, P=0.095) and urinary retention (13.7% vs. 10.1%, P=0.484) were not significantly different between the LPLD and TME-alone groups, respectively. Pathologically proven LLN metastasis was identified in 24 (34.8%) LPLD cases after nCRT. The LPLD group showed a lower 5-year local recurrence (LR) rate (27.9% vs. 4.6%, P<0.001) and better recurrence-free survival (RFS) (59.6% vs. 78.2%, P=0.008) than those of the TME-alone group, while the 5-year overall survival was not significantly different between the 2 groups (76.2% vs. 86.5%, P=0.094).

Conclusion

This study suggests that LPLD is a safe and feasible procedure. The oncological outcomes suggest that selective LPLD improves LR and RFS in patients with clinically suspicious LLNs on pretreatment MRI. Considering that lateral nodal disease is not common, a multicenter large-scale study is necessary.

Clinical application of indocyanine green fluorescence imaging in laparoscopic lymph node dissection for intrahepatic cholangiocarcinoma: A pilot study (with video)

BACKGROUND

Intrahepatic cholangiocarcinoma is a highly lethal malignancy characterized by lymph node metastasis. This study aimed to evaluate the efficacy of indocyanine green fluorescence for visualization of lymphatic drainage and to assess its clinical application during laparoscopic lymph node dissection for intrahepatic cholangiocarcinoma.

METHODS

All patients with intrahepatic cholangiocarcinoma who underwent laparoscopic left hepatectomy and lymph node dissection between October 2018 and January 2021 were reviewed. The patients were assigned to the indocyanine green group or non-intrahepatic cholangiocarcinoma group based on the staining technique used.

RESULTS

Of 38 patients with left hemiliver intrahepatic cholangiocarcinoma, 20 underwent intrahepatic cholangiocarcinoma tracer-guided laparoscopic radical left hepatectomy; 12 procedures were successful (indocyanine green group). During the same period, 18 patients were treated with traditional laparoscopic resection (control group). Their intraoperative factors were comparable and there were no differences in the incidence or severity of their postoperative complications 30 days after surgery (P > .05). In the indocyanine green group, more lymph nodes were harvested (mean [range]: 7.0 [6.0-8.0] vs 3.5 [3.0-5.0], P < .001) and the proportion of confirmed pathologic lymph nodes was higher (75.0%, 66.7%-87.5% vs 40%, 33.3%-50.0%, P < .001). ICG staining was observed in all (12/12, 100%) patients in the intrahepatic cholangiocarcinoma group at stations 8 and 12, and 9 (9/12, 75%) and 10 (11/12, 91.7%) patients at Stations 13 and 7, respectively.

CONCLUSION

The indocyanine green fluorescence imaging system is feasible, safe, and effective for tracing lymph nodes. It can be used to identify regional lymphatic drainage patterns and help define the scope of lymph node dissection in patients with intrahepatic cholangiocarcinoma.

Multifunctional Cyanine-Based Theranostic Probe for Cancer Imaging and Therapy

Cancer is one of the leading causes of death in the world. A cancer-targeted multifunctional probe labeled with the radionuclide has been developed to provide multi-modalities for NIR fluorescence and nuclear imaging (PET, SPECT), for photothermal therapy (PTT), and targeted radionuclide therapy of cancer. In this study, synthesis, characterization, in vitro, and in vivo biological evaluation of the cyanine-based probe (DOTA-NIR790) were demonstrated. The use of cyanine dyes for the selective accumulation of cancer cells were used to achieve the characteristics of tumor markers. Therefore, all kinds of organ tumors can be targeted for diagnosis and treatment. The DOTA-NIR790 labeled with lutetium-111 could detect original or metastatic tumors by using SPECT imaging and quantify tumor accumulation. The β-emission of ¹⁷⁷Lu-DOTA-NIR790 can be used for targeted radionuclide therapy of tumors. The DOTA-NIR790 enabled imaging by NIR fluorescence and by nuclear imaging (SPECT) to monitor in real-time the tumor accumulation and the situation of cancer therapy, and to guide the surgery or the photothermal therapy of the tumor. The radionuclide-labeled heptamethine cyanine based probe (DOTA-NIR790) offers multifunctional modalities for imaging and therapies of cancer.

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.

Role of near-infrared fluorescence in colorectal surgery

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

Performance of Indocyanine Green Fluorescence for Detecting Lymph Node Metastasis in Prostate Cancer: A Systematic Review and Meta-analysis

PURPOSE

The use of sentinel lymph node dissection in several cancers has been gaining attention with the emergence of indocyanine green fluorescence. We performed a meta-analysis to assess the diagnostic performance of indocyanine green fluorescence in detecting lymph node metastasis in prostate cancer patients.

METHODS

A literature search was conducted using PubMed, Cochrane Library, and SCOPUS on November 30, 2020, to identify eligible studies. Studies were eligible if they investigated the diagnostic performance of indocyanine green fluorescence before pelvic lymph node dissection in prostate cancer patients and reported the number of true positives, false positives, false negatives, and true negatives on lymph node-based analysis in comparison to histopathologic findings in the dissected specimen.

RESULTS

Our systematic review covered 11 studies published between 2011 and 2020, with 519 patients, and our meta-analysis included 9 studies with 479 patients. Based on lymph node analysis of indocyanine green fluorescence, the results showed pooled sensitivity and specificity at 0.75 (95% confidence interval [CI] 0.49 to 0.90) and 0.66 (95% CI 0.61 to 0.70), respectively. The diagnostic odds ratio was 6.0 (95%CI 2 to 21). Several lymphatic drainage routes also showed sentinel lymph nodes localized outside the ordinal pelvic lymph node template.

CONCLUSIONS

We noted relatively low diagnostic performance for lymph node metastasis, suggesting that indocyanine fluorescence may not currently be a viable alternative to pelvic lymph node dissection in prostate cancer patients. However, this technique shows novel lymphatic drainage routes and underscores the importance of lymph nodes not removed in ordinary dissection.

Optimal Lymphadenectomy of the Mesopancreas Based on Fluorescence Imaging During Pancreaticoduodenectomy

BACKGROUND

Excision of the mesopancreas with lymphadenectomy is an important component of pancreatoduodenectomy. However, the optimal extent of lymphadenectomy remains unclear. Furthermore, accurate description of the mesopancreatic lymphatic pathways is difficult, probably because of the complex anatomy. Intestinal derotation simplifies the anatomy and facilitates both examination of lymphatic flow and the surgical procedure. The aim of this study was to evaluate lymphatic flow in the mesopancreas using indocyanine green fluorescence imaging with an intestinal derotation technique, and to clarify the optimal extent of mesopancreas excision and lymphadenectomy in pancreatoduodenectomy.

METHODS

Indocyanine green solution (2.5 × 10^-3 mg) was injected into the pancreatic head parenchyma. After intestinal derotation, the spread of indocyanine green was observed using near-infrared imaging.

RESULTS

Participants comprised 10 patients who underwent pancreatoduodenectomy for periampullary neoplasms. With indocyanine green fluorescence imaging, 9 of the 10 patients showed lymphatic flow from the pancreatic head to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery (but not via the second and more distant arteries), with eventual drainage into the paraaortic region.

CONCLUSIONS

Lymphatic pathways from the pancreatic head were connected to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery. Excision of the mesopancreas with the inferior pancreaticoduodenal artery and first jejunal artery while preserving the second or more distant arteries appears optimal in pancreatoduodenectomy for periampullary malignancies.

Clear identification of the rare solitary external iliac lymph node metastasis of testicular cancer by using indocyanine green fluorescence guidance

INTRODUCTION

There are few reports on indocyanine green fluorescence-guided surgery in testis-related diseases.

CASE PRESENTATION

A 38-year-old man underwent orchiectomy for left testicular cancer. Pathological diagnosis was pT1 seminoma. Seven years after the surgery, solitary left external iliac lymph node metastasis was suspected. We decided to perform laparoscopic lymph node dissection combined with indocyanine green fluorescence injection. During the operation, we injected indocyanine green fluorescence into his left inner inguinal ring and found that the lymph node was directly drained from the injection point. The pathological diagnosis of the indocyanine green fluorescence-positive left external iliac lymph node was testicular cancer metastasis.

CONCLUSION

We experienced a case of solitary left external iliac lymph node recurrence in testicular cancer. Using indocyanine green fluorescence injection, we could visualize the lymphatic drainage route, which helped us identify the lymph node as the primary landing site of metastasis.

Does near-infrared fluorescent cholangiography with indocyanine green reduce bile duct injuries and conversions to open surgery during laparoscopic or robotic cholecystectomy? - A meta-analysis

BACKGROUND

Bile duct injury and conversion-to-open-surgery rates remain unacceptably high during laparoscopic and robotic cholecystectomy. In a recently published randomized clinical trial, using near-infrared fluorescent cholangiography with indocyanine green intraoperatively markedly enhanced biliary-structure visualization. Our systematic literature review compares bile duct injury and conversion-to-open-surgery rates in patients undergoing laparoscopic or robotic cholecystectomy with versus without near-infrared fluorescent cholangiography.

METHODS

A thorough PubMed search was conducted to identify randomized clinical trials and nonrandomized clinical trials with ≥100 patients. Because all near-infrared fluorescent cholangiography studies were published since 2013, only studies without near-infrared fluorescent cholangiography published since 2013 were included for comparison. Incidence estimates, weighted and unweighted for study size, were adjusted for acute versus chronic cholecystitis, and for robotic versus laparoscopic cholecystectomy and are reported as events/10,000 patients. All studies were assessed for bias risk and high-risk studies excluded.

RESULTS

In total, 4,990 abstracts were reviewed, identifying 5 near-infrared fluorescent cholangiography studies (3 laparoscopic cholecystectomy/2 robotic cholecystectomy; n = 1,603) and 11 not near-infrared fluorescent cholangiography studies (5 laparoscopic cholecystectomy/4 robotic cholecystectomy/2 both; n = 5,070) for analysis. Overall weighted rates for bile duct injury and conversion were 6 and 16/10,000 in near-infrared fluorescent cholangiography patients versus 25 and 271/10,000 in patients without near-infrared fluorescent cholangiography. Among patients undergoing laparoscopic cholecystectomy, bile duct injuries, and conversion rates among near-infrared fluorescent cholangiography versus patients without near-infrared fluorescent cholangiography were 0 and 23/10,000 versus 32 and 255/10,000, respectively. Bile duct injury rates were low with robotic cholecystectomy with and without near-infrared fluorescent cholangiography (12 and 8/10,000), but there was a marked reduction in conversions with near-infrared fluorescent cholangiography (12 vs 322/10,000).

CONCLUSION

Although large comparative trials remain necessary, preliminary analysis suggests that using near-infrared fluorescent cholangiography with indocyanine green intraoperatively sizably decreases bile duct injury and conversion-to-open-surgery rates relative to cholecystectomy under white light alone.

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

BACKGROUND

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Robotic left colectomy with double indocyanine green guidance and intracorporeal anastomoses

Radical surgery is the mainstay of treatment of colon cancer. Lymphatic drainage of splenic flexure colon cancer is variable, and the exact site of lymphatic dissection is uncertain. Hence, a true consensus of what kind of colectomy should be performed for tumours of the splenic flexure is lacking. Segmental left colectomy (splenic flexure colectomy) (extended), left colectomy as well as subtotal colectomy (extended right colectomy) all have their proponents. Robotic colectomy addresses the limitations of straight laparoscopic colon resections. We report our technique of single-docking totally robotic left hemicolectomy for splenic flexure adenocarcinoma using Da Vinci Xi^® Surgical System (Intuitive Surgical, USA) with indocyanine green near-infrared fluorescence for the assessment of both the lymph nodes and intestinal blood flow in real time.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Predictive value of the sentinel lymph node procedure in the staging of non-metastatic colorectal cancer

PURPOSE

Despite the recent growing interest of the scientific community, there is still no consensus on the actual applicability and effectiveness of sentinel lymph node (SL) procedure in colon cancers. This study aims to quantify feasibility, detection rate, negative predictive value, and accuracy of the SL identified with fluorescent dye in early colon cancers (ECC).

METHODS

This study conducted a consecutive sampling of 95 patients with non-metastatic colorectal cancer who have been treated with laparoscopic colon resection and complete mesocolic excision after a 25-mg indocyanine green peritumoral laparoscopic injection and SL identification with a near-infrared camera. The SL was later isolated and sent to ultra-staging.

RESULTS

Ninety-five patients with an average age of 71 (range 37-90) and a mean BMI of 25 (range 18-39) have been recruited. On the patient sample (92 Pts), an average of 1.49 SL (range 1-5) and a mean time of 4 min were identified. The detection rate was 96.8% and the negative predictive value and accuracy rates were 96.2% and 93.4%, respectively.

CONCLUSIONS

Mapping the SL with fluorescent dye can play an important role in the treatment of colon cancers, particularly those at early stages, and can lead to ultra-conservative surgery.

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

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

Visualization of lymphatic flow in laparoscopic colon cancer surgery using indocyanine green fluorescence imaging

Intraoperative visualization of lymphatic flow could guide surgeons performing laparoscopic colon cancer surgery on the extent of intestinal resection required. The purpose of this study was to investigate indocyanine green fluorescence imaging for intraoperative detection of lymphatic flow and nodes in such patients. All patients undergoing elective laparoscopic surgery for colorectal cancer from October 2016 to July 2017 were included in this study. Indocyanine green was injected submucosally around the tumors via a colonoscope and lymphatic flow assessed with a laparoscopic near-infrared camera system intraoperatively. Lymphatic flow was visualized perioperatively in 43 of 57 patients (75.4%). The rate of visualized lymphatic flow was significantly higher in patients with a lower clinical stage than in those with a higher clinical stage (p = 0.0103). Among the 14 patients in whom lymphatic flow was not visualized, 10 (71.4%) had cStage III or IV cancer. Our results indicate the potential role of intraoperative navigation in colon cancer surgery in early-stage colon cancers. This method allows the surgeon to clearly identify lymphatic flow during surgery and allows the determination and individualization of the lymph node dissection range.

Rectal cancer lateral pelvic sidewall lymph nodes: a review of controversies and management

BACKGROUND

The management of lateral pelvic lymphadenopathy in low rectal cancer poses an oncological and technical challenge. Interpretation of the literature is confounded by different approaches to management in the East and West, and a lack of randomized data from which to draw accurate conclusions regarding the optimal approach. Recent collaboration between Eastern and Western centres has increased the standardization of care. Despite this, significant differences in international guidelines remain. The aim of this review was to appraise the available literature and propose a management algorithm.

METHODS

A literature review of all relevant studies was performed to summarize the historical evidence, as well as establish the significance of clinically positive lateral pelvic sidewall nodes, and the role of neoadjuvant chemoradiotherapy and lateral pelvic node dissection. A management algorithm was developed based on this review of the literature.

RESULTS

The management of pelvic sidewall lymphadenopathy in rectal cancer is non-standardized, with geographical differences. The mechanism of lateral lymphatic spread is well defined; the risk increases with lower tumour height and advanced T category. Existing data indicate that acceptable disease-free and overall survival can be achieved by neoadjuvant chemoradiotherapy with selective lateral pelvic node dissection.

CONCLUSION

Suspicious lateral pelvic sidewall nodes, particularly in the internal iliac chain, should be considered as resectable locoregional disease, and surgery offered for enlarged nodes that do not respond to neoadjuvant chemoradiotherapy.

Diagnostic accuracy of sentinel lymph node biopsy using indocyanine green in lung cancer: a systematic review and meta-analysis

OBJECTIVE

The use of sentinel lymph node biopsy (SLNB) has been gaining popularity with the emergence of indocyanine green (ICG) fluorescence imaging. We aimed to systematically review the literature and perform a meta-analysis on the diagnostic accuracy of SLNB using ICG for lung cancer.

METHODS

A comprehensive search of MEDLINE, EMBASE, SCOPUS, Web of Science, and the Cochrane Library using search terms "lung/pulmonary" AND "tumor/carcinoma/cancer/neoplasm/adenocarcinoma/malignancy/squamous/carcinoid" AND "indocyanine green" was completed in June 2018. Articles were selected based on the following inclusion criteria: (1) diagnostic accuracy study design; (2) ICG injected at the tumor site with near-infrared fluorescence imaging identification of sentinel lymph nodes; (3) lymphadenectomy or sampling was performed as the gold standard.

RESULTS

Eight primary studies were included with a total of 366 patients. 43.0% of patients were females and the mean tumor size was 2.3 cm. Sentinel lymph nodes were identified with ICG in 251 patients, yielding a pooled identification rate of 0.83 (0.67-0.94). A meta-analysis of seven studies computed a diagnostic odds ratio, sensitivity, and specificity of 177.6 (45.6-691.1), 0.85 (0.71-0.94), and 1.00 (0.98-1.00), respectively. The summary receiver operator characteristic demonstrated an area under the curve of 0.963 (SE = 0.038) and a Q* of 0.91 (SE = 0.057).

CONCLUSION

Our review found suboptimal results for the diagnostic accuracy of SLNB using ICG and must be improved before routine clinical use. Further research is required to develop a robust protocol for the use SLNB with ICG for lung cancer.

Application of Fluorescent Dyes in Visceral Surgery: State of the Art and Future Perspectives

Background

Through the improvement and implementation of advanced intraoperative imaging, the indications for intraoperative fluorescence have spread to various fields of visceral surgery. Indocyanine green (ICG)-based fluorescence angiography and the imaging systems using this certain dye are currently the cornerstone of intraoperative, fluorescence-based medical imaging.

Summary

The article focuses on principles and approaches of intraoperative fluorescence in general surgery. The current clinical practice of intraoperative fluorescence and its evidence are described. Emerging new fields of application are put in a perspective. Furthermore, the technique and possible pit-falls in the performance of intraoperative ICG fluorescence angiography are described in this review article.

Key Messages

Overall growing evidence suggests that intraoperative fluorescence imaging delivers valuable additional information to the surgeon, which might help to perform surgery more exactly and reduce perioperative complications. Perfusion assessment can be a helpful tool when performing critical anastomoses. There is evidence from prospective and randomized trials for the benefit of intraoperative ICG fluorescence angiography during esophageal reconstruction, colorectal surgery, and surgery for mesenteric ischemia. Most studies suggest the administration of 2.5-10 mg of ICG. Standardized settings and documentation are essential. The benefit of ICG fluorescence imaging for gastrointestinal sentinel node detection and detection of liver tumors and colorectal metastases of the liver cannot clearly be estimated duo to the small number of prospective studies. Critical points in the use of intraoperative fluorescence imaging remain the low standardization and reproducibility of the results and the associated difficulty in comparing the results of the existing trials. Furthermore, little is known about the influence of hemodynamic parameters on the quantitative assessment of ICG fluorescence during surgery.

Noninvasive Early Detection of Calpain 2-Enriched Non-Small Cell Lung Cancer Using a Human Serum Albumin-Bounded Calpain 2 Nanosensor

Lung cancer is diagnosed at an advanced stage due to its unrecognized symptoms, resulting in high mortality. In recent decades, research into the development of an early diagnostic method for lung cancer has expanded in order to overcome the high mortality rate. Calpain 2 (CAPN2) has been suggested as a tumor marker linked to angiogenesis, cell proliferation, and migration in non-small cell lung cancer. In this study, CAPN2 enzyme-activatable near-infrared peptide sensor linked to human serum albumin (HSA-CAPN2) was developed. Intracellular localization and strong recovered fluorescence signals of HSA-CAPN2 were observed in in vitro experiments using A549-Luc cells, and signal recovery was inhibited by ALLN (a CAPN2 inhibitor). In vivo distribution and signal recovery evaluations performed using A549-Luc cell xenograft mice revealed that HSA-CAPN2 accumulated in the tumor region and produced high fluorescent signal recovery. Three-dimensional reconstructed images using single-plane illumination microscopy after tissue clarity visualized localization of HSA-CAPN2 in tumors. In addition, ALLN pretreatment showed a significant inhibitory effect on signal recovery of HSA-CAPN2, and that inhibition was induced by downregulation of CAPN2 at the gene and protein levels followed by decreases in Ca²⁺ levels. Overall, the results demonstrate the potential of HSA-CAPN2 as a sensor for CAPN2-enriched cancer.

Key clinical applications for indocyanine green fluorescence imaging in minimally invasive colorectal surgery

Near-infrared indocyanine green (ICG) fluorescence imaging has gained solid acceptance over the last years, and rightly so, as this technology has so much to offer, especially in the field of minimally invasive surgery. Firm evidence from ongoing and future studies will hopefully transform many of the applications of ICG fluorescence into the standard of care for our patients. This review examines the current status of ICG fluorescence for assessment of bowel perfusion, lymphatic mapping as well as intraoperative localisation of ureter in light of the published academic literature in English.

Preventive strategies for anastomotic leakage after colorectal resections: A review

Anastomosis is a crucial step in radical cancer surgery. Despite being a daily practice in gastrointestinal surgery, anastomotic leakage (AL) stands as a frequent postoperative complication. Because of increased morbidity, mortality, combined with longer hospital stay, the rate of re-intervention, and poor oncological outcomes, AL is considered the most feared and life-threatening complication after colorectal resections. Furthermore, poor functional outcomes with a higher rate of a permeant stoma in 56% of patients this could negatively affect the patient’s quality of life. This a narrative review which will cover intraoperative anastomotic integrity assessment and preventive measures in order to reduce AL. Although the most important prerequisites for the creation of anastomosis is well-perfused and tension-free anastomosis, surgeons have proposed several preventive measures, which were assumed to reduce the incidence of AL, including antibiotic prophylaxis, intraoperative air leak test, omental pedicle flap, defunctioning stoma, pelvic drain insertion, stapled anastomosis, and general surgical technique. However, lack of clear evidence of which preventive measures is superior over the other combined with the fact that the decision remains based on the surgeon’s choice. Despite the advances in surgical techniques, AL remains a serious health problem associated with increased morbidity, mortality with additional cost. Many preventative measures were employed with no clear evidence supporting the superiority of stapled anastomosis over hand-Sewn anastomosis, coating of the anastomosis, or pelvic drain. Defunctioning stoma, when justified it could decrease the leakage-related complications and the incidence of reoperation. MBP combined with oral antibiotics still recommended.

Sentinel Lymph Node Analysis in Colorectal Cancer Patients Using One-Step Nucleic Acid Amplification in Combination With Fluorescence and Indocyanine Green

PURPOSE

Analysis of the sentinel lymph node (SLN) in colorectal cancer (CRC) patients was proposed for more accurate staging and tailored lymphadenectomy. The aim of this study was to assess the ability to predict lymph node (LN) involvement through analysis of the SLN with a one-step nucleic acid (OSNA) technique in combination with peritumoral injection of indocyanine green (ICG) and near-infrared (NIR) lymphangiography in CRC patients.

METHODS

A total of 34 patients were enrolled. Overall, 51 LNs were analyzed with OSNA. LNs of 17 patients (50%) were examined simultaneously with hematoxylin and eosin (H&E) and OSNA.

RESULTS

SLN analysis of 17 patients examined with H&E and OSNA revealed that OSNA had a higher sensitivity (1 vs. 0.55), higher negative predictive value (1 vs. 0.66) and higher accuracy (100% vs. 76.4%) in predicting LN involvement. Overall, OSNA showed a sensitivity of 0.69, specificity of 1, accuracy of 88.2%, and stage migration of 8.8%. Compared to those who were OSNA (-), OSNA (+) patients had a greater number of LN metastases (4.8 vs. 0.16, P = 0.04), higher G3 rate (44.4% vs. 4%, P = 0.01), more advanced stage of disease (stage III: 77.8% vs. 16%; P = 0.00) and were more rapidly subjected to adjuvant chemotherapy (39.1 days vs. 50.2 days, P = 0.01).

CONCLUSION

SLN analysis with OSNA in combination with ICG-NIR lymphangiography is feasible and can detect LN involvement in CRC patients. Furthermore, it allows for more accurate staging reducing the delay between surgery and adjuvant chemotherapy.

Detection of Sentinel Lymph Nodes with Near-Infrared Imaging in Malignancies

Optical molecular imaging, a highly sensitive and noninvasive technique which is simple to operate, inexpensive, and has the real-time capability, is increasingly being used in the diagnosis and treatment of carcinomas. The near-infrared fluorescence dye indocyanine green (ICG) is widely used in optical imaging for the dynamic detection of sentinel lymph nodes (SLNs) in real time improving the detection rate and accuracy. ICG has the advantages of low scattering in tissue absorbance, low auto-fluorescence, and high signal-to-background ratio. The detection rate of axillary sentinel lymph nodes biopsy (SLNB) in breast cancers with ICG was more than 95 %, the false-negative rate was lower than 10 %, and the average detected number ranged from 1.75 to 3.8. The combined use of ICG with nuclein or blue dye resulted in a lower false-negative rate. ICG is also being used for the sentinel node detection in other malignant cancers such as head and neck, gastrointestinal, and gynecological carcinomas. In this article, we provide an overview of numerous studies that used the near-infrared fluorescence imaging to detect the sentinel lymph nodes in breast carcinoma and other malignant cancers. It is expected that with improvements in the optical imaging systems together with the use of a combination of multiple dyes and verification in large clinical trials, optical molecular imaging will become an essential tool for SLN detection and image-guided precise resection.