Clinical Application of Indocyanine Green Fluorescence Technology in Laparoscopic Radical Gastrectomy

Vagus Nerve Preservation for Early Distal Gastric Cancer With Monitoring and Indocyanine Green Labeling: A Randomized Clinical Trial

Importance

Radical gastric cancer surgery can cause functional and physiological disorders due to the resection of perigastric vagus nerves. Few studies have used intraoperative neurophysiological monitoring and indocyanine green (ICG) labeling to preserve the perigastric vagus nerve and to evaluate the corresponding effects.

Objective

To assess the feasibility and effects of vagus nerve preservation using neurophysiologic monitoring and ICG labeling during laparoscopic distal gastrectomy in patients with early distal gastric cancer.

Design, Setting, and Participants

This open-label, prospective randomized clinical trial initially enrolled 285 patients with clinical stage cT1N0M0 distal gastric cancer from May 2022 to May 2023. This trial was conducted at Qilu Hospital of Shandong University in Jinan, China, and enrolled patients aged 18 to 80 years with histologically proven gastric adenocarcinoma scheduled for distal gastrectomy. The final follow-up examination was performed May 1, 2024.

Interventions

Eligible participants were randomly assigned 1:1 to vagus nerve preservation distal gastrectomy (VPG) or vagus nerve resection distal gastrectomy (VRG).

Main Outcomes and Measures

The primary outcome was the incidence of postsurgical gastroparesis. Secondary outcomes included postoperative gallstone formation, quality of life, morbidity, mortality, overall survival, and disease-free survival up to 12 months postoperatively. All analyses were based on both intention-to-treat and per-protocol analyses.

Results

Of 264 patients included in the intention-to-treat analysis, the median (IQR) patient age was 58.0 (52.0-67.0) years, and 67 patients (25.4%) were female. Both the VPG and VRG groups included 132 patients. Postoperative gastroparesis occurred in 1 patient (0.8%) in the VPG group and in 10 patients (7.6%) in the VRG group. Gallstones developed in 0 patients in the VPG group and in 9 patients (6.8%) in the VRG group. As assessed by mean (SD) score on the 30-item European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, the VRG group experienced more nausea and vomiting at 6 months postsurgery (19.38 [7.62]) than the VPG group (17.15 [9.21]) (P = .03) and had significantly higher rates of persistent appetite loss, reflux symptoms, and eating difficulties at both 6 months and 12 months than the VPG group. Differences in postoperative complications and metastasis were not significant.

Conclusions and Relevance

Neurophysiologic monitoring and ICG labeling during distal laparoscopic gastrectomy for vagus nerve preservation in patients with early distal gastric cancer are safe and feasible. Preserving the perigastric vagus nerve may retain the function of the remnant stomach and improve quality of life.

Trial Registration

Chictr.org.cn Identifier: ChiCTR2200059489.

Indocyanine green and near-infrared fluorescence-guided surgery for gastric cancer: a narrative review

In recent years, indocyanine green (ICG) and near-infrared (NIR) fluorescence-guided surgery has become a versatile and well-researched tool for gastric cancer treatment. Our narrative review aims to explore the applications, benefits, and challenges that are associated with this technique. Initially used to detect sentinel lymph nodes in early gastric cancer, its scope has broadened to include several clinical applications. Its most notable advantages are the ability to guide standard lymphadenectomy, intraoperatively localize tumors and define tumor margins. Despite these advantages, there are still ongoing discussions regarding its accuracy, lack of standardized administration, and oncologic safety in sentinel node navigation surgery. The limited tumor specificity of ICG has been especially put into question, hindering its ability to accurately differentiate between malignant and healthy tissue. With ongoing innovations and its integration into newer endoscopic and robotic systems, ICG-NIR fluorescence imaging shows promise in becoming a standard tool in the surgical treatment of gastric cancer.

Effect of visceral obesity on outcomes of fluorescence-guided lymphadenectomy during laparoscopic gastrectomy for gastric cancer: Post hoc analysis of a randomized phase 3 trial

Objective

To explore the impact of visceral fat area (VFA) on the short- and long-term efficacy of indocyanine green (ICG)-guided D2 lymphadenectomy for gastric cancer (GC).

Methods

A post hoc analysis was performed in patients who participated in a phase 3 randomized clinical trial of ICG-guided laparoscopic radical gastrectomy vs. conventional laparoscopic radical gastrectomy from November 2018 to July 2019. The VFA was calculated based on preoperative computed tomography images. Short-term efficacy included the quality of lymph node (LN) dissection and surgical outcomes, while long-term efficacy included overall survival (OS) and recurrence-free survival (RFS).

Results

This study included 126 patients each in the ICG (high-VFA, n=43) and non-ICG groups (high-VFA, n=38). Compared with the non-ICG group, the ICG group had significantly more retrieved LNs (low-VFA: 50.1 vs. 43.9, P=0.001; high-VFA: 49.6 vs. 37.5, P<0.001) and a significantly lower LN noncompliance rate (low-VFA: 32.5% vs. 50.0%, P=0.020; high-VFA: 32.6% vs. 73.7%, P<0.001), regardless of the VFA. The ICG group had a shorter postoperative hospital stay and fewer intra-abdominal infections than the ICG group in the high-VFA patients (P=0.025 and P=0.020, respectively) but not in the low-VFA patients. Regardless of the VFA, the 3-year OS (RFS) was better in the ICG group than in the non-ICG group [low-VFA: 83.1% (76.9%) vs. 73.9% (67.0%); high-VFA: 90.7% (90.7%) vs. 73.7% (73.5%); P for interaction =0.474 (0.547)].

Conclusions

The short- and long-term efficacies of ICG tracing were not influenced by visceral obesity.

Prognostic impact of fluorescent lymphography on gastric cancer

BACKGROUND

Fluorescent lymphography-guided lymphadenectomy (FL) for gastric cancer is gaining popularity. However, its impact on prognosis is not known. This study aimed to assess the prognostic impact of FL in gastric cancer patients.

MATERIALS AND METHODS

This study retrospectively analyzed 5678 gastric cancer patients who underwent gastrectomy from 2013 to 2017. The survival was compared between the FLFL group and the conventional lymphadenectomy (non-FL group) using 1:1 propensity score matching after exclusion. Patients in the FL group underwent gastrectomy with systematic lymphadenectomy after endoscopic peritumoral injection of indocyanine green the day before surgery.

RESULTS

After propensity score matching, the FL and non-FL groups each had 1064 patients with similar demographic and clinicopathological characteristics. All matched variables had a standardized mean difference under 0.1. The FL group showed a significantly higher number of retrieved lymph nodes (56.2±20.1) than the non-FL group (46.2±18.2, P <0.001). The FL group also had more stage III patients ( P= 0.044) than the non-FL group. The FL group demonstrated higher overall survival ( P= 0.038) and relapse-free survival ( P= 0.036) in stage III compared with the non-FL group. However, no significant differences in overall and relapse-free survival were observed between the two groups for stages I ( P= 0.420 and P= 0.120, respectively) and II ( P= 0.200 and P= 0.280, respectively).

CONCLUSION

FL demonstrated a higher survival in stage III gastric cancer patients by the more accurate staging resulting from larger lymph node retrieval. Thus, given its potential to improve prognostication by enhancing staging accuracy, it is recommended as an option to consider the use of FL in clinical practice.

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.

Clinical effect and follow-up of laparoscopic radical proximal gastrectomy for upper gastric carcinoma

Objective

To evaluate the safety and clinical effect of tubular esophagogastric anastomosis in laparoscopic radical proximal gastrectomy.

Methods

A retrospective analysis was conducted involving 191 patients who underwent laparoscopic radical proximal gastrectomy in the Department of Gastrointestinal Surgery, Qilu Hospital of Shandong University from January 2017 to October 2020. Patients were divided into tubular esophagogastric anastomosis group (TG group) and traditional esophagogastric anastomosis group (EG group) according to the digestive tract reconstruction. Their intraoperative conditions, perioperative recovery and postoperative follow-up were compared. Patients were also divided into indocyanine green group and non-indocyanine green group according to whether or not indocyanine green tracer technology was used during the operation. Their intraoperative condition and perioperative recovery were compared and analyzed after propensity score matching.

Results

The operation was successfully completed in all patients. Compared with the EG group, the TG group had less volume of gastric tube drainage, shorter gastric tube drainage time and proton pump inhibitors application time, and lower reuse rate of proton pump inhibitors. However, the TG group had a higher anastomotic stenosis at three months after surgery, as measured using anastomotic width and dysphagia score. Nevertheless, the incidence of reflux esophagitis and postoperative quality of life score in the TG group were lower compared with the EG group at 1st and 2nd year after surgery. In the indocyanine green analysis, the indocyanine green group had significantly shorter total operation time and lymph node dissection time and less intraoperative blood loss compared with the non-indocyanine green group. However, compared with the non-indocyanine green group, more postoperative lymph nodes were obtained in the indocyanine green group.

Conclusion

Laparoscopic radical proximal gastrectomy is safe and effective treatment option for upper gastric cancer. Tubular esophagogastric anastomosis has more advantages in restoring postoperative gastrointestinal function and reducing reflux, but it has a higher incidence of postoperative anastomotic stenosis compared with traditional esophagogastrostomy. The application of indocyanine green tracer technique in laparoscopic radical proximal gastrectomy has positive significance.

Tracers in Gastric Cancer Surgery

The treatment of gastric cancer mainly depends on radical gastrectomy. Determination of appropriate surgical margins and adequate lymph node (LN) resection are two major surgical steps that directly correlate with prognosis in gastric cancer. Due to the expanding use of minimally invasive procedures, it is no longer possible to locate tumors and LNs through touch. As an alternative, tracers have begun to enter the field due to their capacities for intraoperative visualization. Herein, we summarize the application of contemporary tracers in gastric cancer surgery, including isosulfan blue, methylene blue, patent blue, indocyanine green, carbon particles, and radioactive tracers. Their mechanisms, administration methods, detection efficiency, and challenges, as well as perspectives on them, are also outlined.

Efficacy of indocyanine green fluorescence imaging-guided lymphadenectomy in radical gastrectomy for gastric cancer: A systematic review and meta-analysis

Background

Indocyanine green (ICG) imaging-guided lymphadenectomy has been introduced in gastric cancer (GC) surgery and its clinical value remains controversial. The aim of this study is to evaluate the efficacy of ICG fluorescence imaging-guided lymphadenectomy in radical gastrectomy for GC.

Methods

Studies comparing lymphadenectomy in radical gastrectomy between use and non-use of ICG fluorescence imaging up to July 2022 were systematically searched from PubMed, Web of Science, Embase and Cochrane Library. A pooled analysis was performed for the available data regarding the baseline features, the number of retrieved lymph nodes (LNs), the number of metastatic LNs and surgical outcomes as well as oncological outcomes. RevMan 5.3 software was used to perform the statistical analysis. Quality evaluation and publication bias were also conducted.

Results

17 studies with a total of 2274 patients (1186 in the ICG group and 1088 in the control group) undergoing radical gastrectomy and lymphadenectomy were included. In the pooled analysis, the baseline features were basically comparable. However, the number of retrieved LNs in the ICG group was significantly more than that in the control group (MD = 7.41, 95% CI = 5.44 to 9.37, P < 0.00001). No significant difference was found between the ICG and control groups in terms of metastatic LNs (MD = -0.05, 95% CI = -0.25 to 0.16, P = 0.65). In addition, the use of ICG could reduce intraoperative blood loss (MD = -17.96, 95% CI = -27.89 to -8.04, P = 0.0004) without increasing operative time (P = 0.14) and overall complications (P = 0.10). In terms of oncological outcomes, the use of ICG could reduce the overall recurrence rate (OR = 0.50; 95% CI 0.28-0.89; P = 0.02) but could not increase the 2-year overall survival rate (OR = 1.25; 95% CI 0.72-2.18; P = 0.43).

Conclusions

ICG imaging-guided lymphadenectomy is valuable for complete LNs dissection in radical gastrectomy for GC. However, more high-quality randomized controlled trials are needed to confirm this benefit.

Clinicopathological features and management strategy for superficial nonampullary duodenal tumors: a multi-center retrospective study

Purpose

We investigated the clinicopathological features and management for superficial nonampullary duodenal tumors (SNADTs). The safety and feasibility of laparoscopic management, especially laparoscopic endoscopic cooperative surgery (LECS), were evaluated.

Methods

A total of 59 patients with SNADTs who underwent operations from January 2009 to December 2018 at all 8 institutions of the Catholic Medical Center were identified in our comprehensive multi-institutional database. Clinicopathological and surgical data on the 4 anatomical regions of the duodenum were collected and compared. Characteristics of conventional laparoscopic procedure (laparoscopy-only) and LECS procedures were also compared.

Results

There were significantly more asymptomatic patients with tumors in the first and second vs. third and fourth duodenal regions. Gastrointestinal stromal tumors (GISTs), carcinoids, and ectopic pancreatic tumors were identified in 32, 12, and 5 cases, respectively. Forty-two patients (71.2%) underwent laparoscopy. Of patients undergoing laparoscopy, the LECS group exhibited significantly more endophytic features and smaller tumor sizes (P < 0.001 and P < 0.001, respectively). Although no significant difference in the wedge resection or postoperative complication rate was seen between the 2 groups (P = 0.096 and P = 0.227, respectively), the wedge resection rate was higher, and the complication rate lower, in the LECS group than the conventional laparoscopic surgery group.

Conclusion

Most of the SNADTs located in proximal duodenum were detected incidentally. GISTs were the most common diagnoses of SNADTs in all locations. In treating these tumors, laparoscopic resection is safe and feasible. Especially, LECS may be ideal for treating small endophytic tumors, minimizing over-resection and postoperative complications.