Assessment of indocyanine green fluorescence lymphography on lymphadenectomy during minimally invasive gastric cancer surgery: a systematic review and meta-analysis

Assessment of Laparoscopic Indocyanine Green Tracer-guided Lymphadenectomy After Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer: A Randomized Controlled Trial

OBJECTIVE

To assess the effectiveness of indocyanine green (ICG)-guided lymph node (LN) dissection during laparoscopic radical gastrectomy after neoadjuvant chemotherapy (NAC) in patients with locally advanced gastric cancer (LAGC).

BACKGROUND

Studies on ICG imaging use in patients with LAGC on NAC are rare.

METHODS

Patients with gastric adenocarcinoma (clinical T2-4NanyM0) who received NAC were randomly assigned to receive ICG-guided laparoscopic radical gastrectomy or laparoscopic radical gastrectomy alone. Here, we reported the secondary endpoints including the quality of lymphadenectomy (total retrieved LNs and LN noncompliance) and surgical outcomes.

RESULTS

Overall, 240 patients were randomized. Of whom, 236 patients were included in the primary analysis (118 in the ICG group and 118 in the non-ICG group). In the ICG group, the mean number of LNs retrieved was significantly higher than in the non-ICG group within the D2 dissection (48.2 vs 38.3, P < 0.001). The ICG fluorescence guidance significantly decreased the LN noncompliance rates (33.9% vs 55.1%, P = 0.001). In 165 patients without baseline measurable LNs, ICG significantly increased the number of retrieved LNs and decreased the LN noncompliance rate ( P < 0.05). For 71 patients with baseline measurable LNs, the quality of lymphadenectomy significantly improved in those who had a complete response ( P < 0.05) but not in those who did not ( P > 0.05). Surgical outcomes were comparable between the groups ( P > 0.05).

CONCLUSIONS

ICG can effectively improve the quality of lymphadenectomy in patients with LAGC who underwent laparoscopic radical gastrectomy after NAC.

Laparoscopic versus open gastrectomy for nonmetastatic T4a gastric cancer: a meta-analysis of reconstructed individual participant data from propensity score-matched studies

BACKGROUND

​The applicability of laparoscopy to nonmetastatic T4a patients with gastric cancer remains unclear due to the lack of high-quality evidence. The purpose of this study was to compare the survival rates of laparoscopic gastrectomy (LG) versus open gastrectomy (OG) for these patients through a meta-analysis of reconstructed individual participant data from propensity score-matched studies.

METHODS

PubMed, Embase, Web of Science, Cochrane library and CNKI were examined for relevant studies without language restrictions through July 25, 2023. Individual participant data on overall survival (OS) and disease-free survival (DFS) were extracted from the published Kaplan-Meier survival curves. One-stage and two-stage meta-analyses were performed. In addition, data regarding surgical outcomes and recurrence patterns were also collected, which were meta-analyzed using traditional aggregated data.

RESULTS

Six studies comprising 1860 patients were included for analysis. In the one-stage meta-analyses, the results demonstrated that LG was associated with a significantly better DFS (Random-effects model: P = 0.027; Restricted mean survival time [RMST] up to 5 years: P = 0.033) and a comparable OS (Random-effects model: P = 0.135; RMST up to 5 years: P = 0.053) than OG for T4a gastric cancer patients. Two-stage meta-analyses resulted in similar results, with a 13% reduced hazard of cancer-related death (P = 0.04) and 10% reduced hazard of overall mortality (P = 0.11) in the LG group. For secondary outcomes, the pooled results showed an association of LG with less estimated blood loss, faster postoperative recovery and more retrieved lymph nodes.

CONCLUSION

Laparoscopic surgery for patients with nonmetastatic T4a disease is associated with a potential survival benefit and improved surgical outcomes.

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.

Impact of tumor stage and neoadjuvant chemotherapy in fluorescence-guided lymphadenectomy during laparoscopic gastrectomy for gastric cancer: A propensity score-matched study in a western center

BACKGROUND

The use of indocyanine green fluorescence has been shown to be a safe and effective method for improving lymph node retrieval in patients with gastric cancer. However, previous studies have focused on early-stage tumors and/or the Asian population and excluded patients who received neoadjuvant treatment.

METHODS

In this study, 142 patients with gastric adenocarcinoma underwent laparoscopic gastrectomy at a Spanish hospital between January 2017 and December 2022. Of these, 42 patients received preoperative indocyanine green injection to guide lymphadenectomy. Their outcomes were compared to a retrospective cohort of 42 patients after 1:1 propensity score matching.

RESULTS

The feasibility of indocyanine green lymphatic mapping was 95.5%. No complications associated with indocyanine green injection were observed. The indocyanine green group had a significantly higher number of retrieved lymph nodes than the non-indocyanine green group (32.67 vs 25.14; P = .013). This statistically significant difference was maintained across subgroups of neoadjuvant treatment, non-obese patients, pT0 to 2 stage, and pN0 stage. In 47.6% of patients from the indocyanine green group, lymphadenectomy was extended outside the standard D2 dissection area based on indocyanine green uptake, but none of the retrieved lymph nodes were metastatic. There were no differences in postoperative complications and length of hospital stay between the 2 groups.

CONCLUSION

Indocyanine green-guided lymphadenectomy is safe and feasible and increases the number of retrieved lymph nodes compared to conventional lymphatic dissection, as well as in patients receiving neoadjuvant chemotherapy. The use of indocyanine green should be routine if available for guiding lymph node dissection in gastric cancer, regardless of tumor stage or previous neoadjuvant treatment. However, further studies are needed to determine the impact of this technique on disease-free and overall survival.

Indocyanine green fluorescence in gastrointestinal surgery: Appraisal of current evidence

Applying indocyanine green (ICG) fluorescence in surgery has created a new dimension of navigation surgery to advance in various disciplines. The research in this field is nascent and fragmented, necessitating academic efforts to gain a comprehensive understanding. The present review aims to integrate diverse perspectives and recent advances in its application in gastrointestinal surgery. The relevant articles were selected by using the appropriate keyword search in PubMed. The angiography and cholangiography property of ICG fluorescence is helpful in various hepatobiliary disorders. In gastroesophageal and colorectal surgery, the lymphangiography and angiography property of ICG is applied to evaluate bowel vascularity and guide lymphadenectomy. The lack of objective parameters to assess ICG fluorescence has been the primary limitation when ICG is used to evaluate bowel perfusion. The optimum dose and timing of ICG administration need to be standardized in some new application areas in gastrointestinal surgery. Binding tumor-specific ligands with fluorophores can potentially widen the fluorescence application to detect primary and metastatic gastrointestinal tumors. The narrative review outlines prior contributions, limitations, and research opportunities for future studies across gastrointestinal sub-specialty. The findings of the present review would be helpful for scholars and practitioners to explore and progress in this exciting domain of gastrointestinal surgery.

Indocyanine Green in Bariatric Surgery: a Systematic Review

Indocyanine green (ICG) is a fluorescent dye that can be used intraoperatively to assess tissue perfusion, as well as perform leak testing. This study aims to summarize published manuscripts on outcomes of ICG use and reduction of complications compared to traditional leak test and tissue perfusion evaluation. A PubMed search using "ICG and bariatric surgery," "ICG and gastric sleeve," "ICG and gastric bypass," and "ICG and revisional bariatric surgery" was performed. The proportion of patients who underwent an intraoperative decision change due to ICG was 3.8% (95% CI: 2.0 to 7.2%). ICG fluorescent imaging in bariatric surgery is a valuable tool, and further studies are needed to confirm its utility for routine use in both standard or complex cases (PROSPERO #418126).

Indocyanine Green (ICG) in Robotic Gastrectomy: A Retrospective Review of Lymphadenectomy Outcomes for Gastric Cancer

Radical gastrectomy is essential for gastric cancer treatment. While guidelines advise dissecting at least 16 lymph nodes, some research suggests over 30 nodes might be beneficial. This study assessed ICG-guided robotic gastrectomy's effectiveness in thorough lymph node dissection. We analyzed data from 393 stage II or III gastric cancer patients treated at Seoul St. Mary's Hospital from 2016-2022. Patients were categorized into conventional laparoscopy (G1, n = 288), ICG-guided laparoscopy (G2, n = 61), and ICG-guided robotic surgery (G3, n = 44). Among 391 patients, 308 (78.4%) achieved proper lymphadenectomy. The ICG-robotic group (G3) showed the highest success rate at 90.9%. ICG-guided robotic surgery was a significant predictor for achieving proper lymphadenectomy, with an odds ratio of 3.151. In conclusion, ICG-robotic gastrectomy improves lymphadenectomy outcomes in selected gastric cancer cases, indicating a promising surgical approach for the future.

Prognostic significance of the pretreatment pan-immune-inflammation value in cancer patients: an updated meta-analysis of 30 studies

Background

The pan-immune-inflammation value (PIV) has been reported as a promising prognostic biomarker in multiple cancers but still remains inconclusive. The objective of this study is to systematically investigate the association of the pretreatment PIV with survival outcomes in cancer patients, based on available literature.

Methods

Online databases including PubMed, Embase and the Web of Science were thoroughly searched for studies evaluating the prognostic role of the pretreatment PIV in cancers from the inception to June 2023. Hazard ratios (HRs) with 95% confidence intervals (CIs) were always assessed using a random-effects model. Statistical analyses were performed using Stata 12.0.

Results

Thirty studies were finally included after comprehensively study searching. In total, 8,799 cancer patients were enrolled in this meta-analysis. The pooled results demonstrated that patients in the high PIV group had a significantly poorer overall survival (HR = 2.07; 95%CI: 1.77-2.41; I2 = 73.0%) and progression-free survival (HR = 1.83; 95%CI: 1.37-2.45; I2 = 98.2%) than patients in the low PIV group. The prognostic significance of the PIV score on overall survival and progression-free survival was observed across various geographical regions, tumor stages and treatment strategies. Sensitivity analyses supported the stability of the above combined results.

Conclusion

This meta-analysis demonstrated that the pretreatment PIV could be a non-invasive and efficacious prognostic biomarker for cancer patients.

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.

Effect of indocyanine green near-infrared light imaging technique guided lymph node dissection on short-term clinical efficacy of minimally invasive radical gastric cancer surgery: a meta-analysis

Objective

In recent years, the utilization of indocyanine green near-infrared (ICG NIR) light imaging-guided lymph node dissection in the context of minimally invasive radical gastric cancer has emerged as a novel avenue for investigation. The objective of this study was to assess the influence of employing this technique for guiding lymph node dissection on the short-term clinical outcomes of minimally invasive radical gastric cancer surgery.

Methods

The present study conducted a comprehensive search for short-term clinical outcomes, comparing the group undergoing ICG NIR light imaging-guided lymph node dissection with the control group, by thoroughly examining relevant literature from the inception to July 2023 in renowned databases such as PubMed, Embase, Web of Science, and Cochrane Library. The primary endpoints encompassed postoperative complications, including abdominal infection, abdominal bleeding, pneumonia, anastomotic fistula, and overall incidence of complications (defined as any morbidity categorized as Clavien-Dindo class I or higher within 30 days post-surgery or during hospitalization). Additionally, secondary outcome measures consisted of the time interval until the initiation of postoperative gas and food intake, as well as various other parameters, namely postoperative hospital stay, operative time, intraoperative blood loss, total number of harvested lymph nodes, and the number of harvested metastatic lymph nodes. To ensure methodological rigor, the Cochrane Collaboration Risk of Bias Tool and the Newcastle-Ottawa Scale (NOS) were employed to assess the quality of the included studies, while statistical analyses were performed using Review Manager 5.4 software and Stata, version 12.0 software.

Results

A total of 19 studies including 3103 patients were ultimately included (n=1276 in the ICG group and n=1827 in the non-ICG group). In this meta-analysis, the application of ICG near-infrared light imaging in minimally invasive radical gastric cancer surgery effectively improved the occurrence of postoperative Clavien-Dindo grade II or higher complications in patients (RR=0.72, 95% CI 0.52 to 1.00) with a statistically significant P=0.05; in reducing intraoperative blood loss and shortening While reducing intraoperative blood loss and shortening postoperative hospital stay, it could ensure the thoroughness of lymph node dissection in minimally invasive radical gastric cancer surgery (MD=5.575, 95% CI 3.677-7.473) with significant effect size (Z=5.76, p<0.00001).

Conclusion

The utilization of indocyanine green near-infrared light imaging technology in the context of minimally invasive radical gastric cancer surgery demonstrates notable efficacy in mitigating the occurrence of postoperative complications surpassing Clavien-Dindo grade II, while concurrently augmenting both the overall quantity of lymph node dissections and the identification of positive lymph nodes, all the while ensuring the preservation of surgical safety. Furthermore, the implementation of this technique proves particularly advantageous in the realm of robotic-assisted radical gastric cancer surgery, thus bearing significance for enhancing the short-term prognostic outcomes of patients.

Endoscopic fluorescent lymphography for gastric cancer

Lymphography by radioisotope or dye is a well-known technique for visualizing the lymphatic drainage pattern in a neoplastic lesion and it is in use in gastric cancer. Indocyanine green (ICG) more recently has been validated in fluorescent lymphography studies and is under evaluation as a novel tracer agent in gastric cancer. The amount and dilution of ICG injected as well as the site and the time of the injection are not standardized. In our unit, endoscopic submucosal injections of ICG are made as 0.5 mg in 0.5 mL at four peritumoral sites the day before surgery (for a total of 2.0 mg in 2.0 mL). Detection instruments for ICG fluorescence are evolving. Near-infrared systems integrated into laparoscopic or robotic instruments (near-infrared fluorescence imaging) have shown the most promising results. ICG fluorescence recognizes the node that receives lymphatic flow directly from a primary tumor. This is defined as the sentinel lymph node, and it has a high predictive negative value at the cT1 stage, able to reduce the extent of gastrectomy and lymph node dissection. ICG also enhances the number of lymph nodes detected during extended lymphadenectomy for advanced gastric cancer. Nevertheless, the practical effects of ICG use in a single patient are not yet clear. Standardization of the technique and further studies are needed before fluorescent lymphography can be used extensively worldwide. Until then, current guidelines recommend an extensive lymphadenectomy as the standard approach for gastric cancer with suspected metastasis.

The primary application of indocyanine green fluorescence imaging in surgical oncology

Background

Indocyanine green (ICG) is a nontoxic, albumin-bound, liver-metabolized fluorescent iodide dye that has been widely utilized in clinical applications since the mid-1950s. However, after the 1970s, in-depth research on the fluorescence properties of ICG greatly expanded its application in the medical field.

Methods

In our mini-review, we searched the relevant literature on common oncology surgeries from PubMed, including lung cancer, breast cancer, gastric cancer, colorectal cancer, liver cancer, and pituitary tumors, using keywords such as indocyanine green, fluorescence imaging technology, and near-infrared fluorescence imaging. In addition, the application of targeted ICG photothermal technology in tumor therapy is briefly mentioned.

Results

In this mini-review, we analyzed studies on ICG fluorescence imaging in common surgical oncology and offered a thorough analysis of each form of cancer or tumor.

Conclusion

ICG has demonstrated significant potential in the detection and treatment of tumors in current clinical practice, although many applications are still in the preliminary stages, and multicenter studies are still required to more precisely define its indications, effectiveness, and safety.

Efficacy and safety of indocyanine green tracer-guided lymph node dissection in minimally invasive radical gastrectomy for gastric cancer: A systematic review and meta-analysis

Background

The implementation of indocyanine green (ICG) tracer-guided lymph node dissection is still in the preliminary stages of laparoscopic surgery, and its safety and efficacy for gastric cancer remain unclear.

Methods

A systematic review was conducted in PubMed, Embase, Web of Science, the Cochrane Library, and Scopus to identify relevant subjects from inception to June 2022. The core indicators were the total number of harvested lymph nodes and the safety of the laparoscopic gastrectomy with ICG. A meta-analysis was performed to estimate the pooled weighted mean difference (WMD) and 95% confidence interval (CI).

Results

Thirteen studies and 2,027 participants were included (642 for the ICG-group and 1,385 for the non-ICG group). The mean number of lymph nodes dissected in the ICG group was significantly greater than that in the non-ICG group (WMD = 6.24, 95% CI: 4.26 to 8.22, P <0.001). However, there was no significant difference in the mean number of positive lymph nodes dissected between the ICG and the non-ICG groups (WMD = 0.18, 95% CI: −0.70 to 1.07, P = 0.879). Additionally, ICG gastrectomy did not increase the risk in terms of the operative time, estimated blood loss, and postoperative complications.

Conclusion

ICG tracer with favorable safety increases the number of harvested lymph nodes but not the number of positive lymph nodes in laparoscopic gastrectomy. More high-quality, large-sample-size randomized controlled trials are still needed to enhance this evidence.

Robotic versus Laparoscopic Gastrectomy for Gastric Cancer: An Updated Systematic Review

Background and Objectives: Gastrectomy with D2 lymphadenectomy is the standard surgical treatment with curative intent for patients with gastric cancer (GC). Over the last three decades, surgeons have been increasingly adopting laparoscopic surgery for GC, due to its better short-term outcomes. In particular, laparoscopic gastrectomy (LG) has been routinely used for early gastric cancer (EGC) treatment. However, LG suffers from technical limitations and drawbacks, such as a two-dimensional surgical field of view, limited movement of laparoscopic tools, unavoidable physiological tremors and discomfort for operating surgeon. Therefore, robotic surgery has been developed to address such limitations. Materials and Methods: We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines in order to investigate the benefits and harms of robotic gastrectomy (RG) compared to the LG. PubMed/MEDLINE, Scopus, Cochrane Library (Cochrane Database of Systematic Re-views, Cochrane Central Register of Controlled Trials-CENTRAL) and Web of Science (Science and Social Science Citation Index) databases were used to search all related literature. Results: The 7 included meta-analyses covered an approximately 20 years-study period (2000-2020). Almost all studies included in the meta-analyses were retrospective ones and originated from Asian countries (China and Korea, in particular). Examined overall population ranged from 3176 to 17,712 patients. If compared to LG, RG showed both operative advantages (operative time, estimated blood loss, number of retrieved lymph nodes) and perioperative ones (time to first flatus, time to restart oral intake, length of hospitalization, overall complications, Clavien-Dindo (CD) ≥ III complications, pancreatic complications), in the absence of clear differences of oncological outcomes. However, costs of robotic approach appear significant. Conclusions: It is impossible to make strong recommendations, due to the statistical weakness of the included studies. Further randomized, possibly multicenter trials are strongly recommended, if we want to have our results confirmed.