Fluorescence image-guided lymphadenectomy using indocyanine green and near infrared technology in robotic gastrectomy

[ICG lymph node mapping in cancer surgery of the upper gastrointestinal tract]

The importance of the assessment of the N‑status in gastric carcinoma, tumors of the gastroesophageal junction and esophageal cancer is undisputed; however, there is currently no internationally validated method for lymph node mapping in esophageal and gastric cancer. Near-infrared fluorescence imaging (NIR) is an innovative technique from the field of vibrational spectroscopy, which in combination with the fluorescent dye indocyanine green (ICG) enables intraoperative real-time visualization of anatomical structures. The ICG currently has four fields of application in oncological surgery: intraoperative real-time angiography for visualization of perfusion, lymphography for visualization of lymphatic vessels, visualization of solid tumors, and (sentinel) lymph node mapping. For imaging of the lymph drainage area and therefore the consecutive lymph nodes, peritumoral injection of ICG must be performed. Several studies have demonstrated the feasibility of peritumoral injection of ICG administered 15 min to 3 days preoperatively with subsequent intraoperative visualization of the lymph nodes. So far prospective randomized studies on the validation of the method are still lacking. In contrast, the use of ICG for lymph node mapping and visualization of sentinel lymph nodes in gastric cancer has been performed in large cohorts as well as in prospective randomized settings. Up to now, multicenter studies for ICG-guided lymph node mapping during oncological surgery of the upper gastrointestinal tract are lacking. Artificial intelligence methods can help to evaluate these techniques in an automated manner in the future as well as to support intraoperative decision making and therefore to improve the quality of oncological surgery.

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

BACKGROUND

In recent years, indocyanine green fluorescence lymphography has been introduced for lymphatic mapping in gastric cancer surgery. The aim of this study was to investigate the efficacy of ICGFL in lymph node dissection during minimally invasive surgery for gastric cancer.

METHODS

A systematic review of electronic databases including PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure was performed from the inception to January 2021 for all studies comparing ICGFL with non-ICGFL in GC patients undergoing minimal access gastrectomy. The primary outcome was the total number of harvested lymph nodes. The secondary endpoints were the number of metastatic LNs, operative time, estimated blood loss, and postoperative complications. The registration number of this protocol is PROSPERO CRD42020203443.

RESULTS

A total of 13 studies including 1882 participants were included. In this meta-analysis, the use of ICGFL was associated with a higher number of harvested LNs (40.33 vs. 33.40; MD = 6.93; 95%CI: 4.28 to 9.58; P < 0.0001; I² = 86%). No significant difference was found between the ICGFL and control groups in terms of metastatic LNs (2.63 vs. 2.42; MD = 0.21; 95%CI: -0.46 to 0.87; P = 0.54; I² = 0%). In addition, the use of ICGFL could be safely performed without increasing the operative time (P = 0.49), estimated blood loss (P = 0.26) and postoperative complications (P = 0.54).

CONCLUSION

The use of ICGFL may be a useful tool facilitating complete lymph node dissection during minimally invasive GC resection. However, more high-quality RCTs with large sample size are needed to validate this issue.

Recent advancements in peripheral nerve-specific fluorescent compounds

Nerve injury is a common complication of surgery. Accidental nerve damage or transection can lead to severe clinical symptoms including pain, numbness, paralysis and even expiratory dyspnoea. In recent years, with the rise of the field of fluorescence-guided surgery, researchers have discovered that nerve-specific fluorescent agents can serve as nerve markers in animals and can be used to guide surgical procedures and reduce the incidence of intraoperative nerve damage. Currently, researchers have begun to focus on biochemistry, materials chemistry and other fields to produce more neuro-specific fluorescent agents with physiological relevance and they are expected to have clinical applications. This review discusses the agents with potential to be used in fluorescence-guided nerve imaging during surgery.

LESSONS LEARNED ANALYZING COMPLICATIONS AFTER LAPAROSCOPIC TOTAL GASTRECTOMY FOR GASTRIC CANCER

Background:

Laparoscopic surgery has been gradually accepted as an option for the surgical treatment ofgastric cancer. There are still points that are controversial or situations that are eventually associated with intra-operative difficulties or postoperative complications.

Aim:

To establish the relationship between the difficulties during the execution of total gastrectomy and the occurrence of eventual postoperative complications.

Method:

The operative protocols and postoperative evolution of 74 patients operated for gastriccancer, who were subjected to laparoscopic total gastrectomy (inclusion criteria) were reviewed. The intraoperative difficulties recorded in the operative protocol and postoperative complications of a surgical nature wereanalyzed (inclusion criteria). Postoperative medical complications were excluded (exclusion criteria). For the discussion, an extensive bibliographical review was carried out.

Results:

Intra-operative difficulties or complications reported correspond to 33/74 and of these; 18 events (54.5%) were related to postoperative complications and six were absolutely unexpected. The more frequent were leaks of the anastomosis and leaks of the duodenal stump; however, other rare complications were observed. Seven were managed with conservative measures and 17 (22.9%) required surgical re-exploration, with a postoperative mortality of two patients (2.7%).

Conclusion:

We have learned that there are infrequent and unexpected complications; the treating team must be mindful of and, in front of suspicion of complications, anappropriate decision must be done which includes early re-exploration. Finally, after the experience reported, some complications should be avoided.

Safety and Efficacy of Indocyanine Green Tracer-Guided Lymph Node Dissection During Laparoscopic Radical Gastrectomy in Patients With Gastric Cancer: A Randomized Clinical Trial

Importance

The application of indocyanine green (ICG) imaging in laparoscopic radical gastrectomy is in the preliminary stages of clinical practice, and its safety and efficacy remain controversial.

Objective

To investigate the safety and efficacy of ICG near-infrared tracer-guided imaging during laparoscopic D2 lymphadenectomy in patients with gastric cancer.

Design, Setting, and Participants

Patients with potentially resectable gastric adenocarcinoma (clinical tumor stage cT1-cT4a, N0/+, M0) were enrolled in a prospective randomized clinical trial at a tertiary referral teaching hospital between November 2018 and July 2019. Patients were randomly assigned to the ICG group or the non-ICG group. The number of retrieved lymph nodes, rate of lymph node noncompliance, and postoperative recovery data were compared between the groups in a modified intention-to-treat analysis. Statistical analysis was performed from August to September 2019.

Interventions

The ICG group underwent laparoscopic gastrectomy using near-infrared imaging after receiving an endoscopic peritumoral injection of ICG to the submucosa 1 day before surgery.

Main Outcomes and Measures

Total number of retrieved lymph nodes.

Results

Of 266 participants randomized, 133 underwent ICG tracer-guided laparoscopic gastrectomy, and 133 underwent conventional laparoscopic gastrectomy. After postsurgical exclusions, 258 patients were included in the modified intention-to-treat analysis, which comprised 129 patients (86 men and 43 women; mean [SD] age, 57.8 [10.7] years) in the ICG group and 129 patients (87 men and 42 women; mean [SD] age, 60.1 [9.1] years) in the non-ICG group. The mean number of lymph nodes retrieved in the ICG group was significantly more than the mean number retrieved in the non-ICG group (mean [SD], 50.5 [15.9] lymph nodes vs 42.0 [10.3] lymph nodes, respectively; P < .001). Significantly more perigastric and extraperigastric lymph nodes were retrieved in the ICG group than in the non-ICG group. In addition, the mean total number of lymph nodes retrieved in the ICG group within the scope of D2 lymphadenectomy was also significantly greater than the mean number retrieved in the non-ICG group (mean [SD], 49.6 [15.0] lymph nodes vs 41.7 [10.2] lymph nodes, respectively; P < .001). The lymph node noncompliance rate of the ICG group (41 of 129 patients [31.8%]) was lower than that of the non-ICG group (74 of 129 patients [57.4%]; P < .001). The postoperative recovery process was comparable, and no significant difference was found between the ICG and non-ICG groups in the incidence (20 of 129 patients [15.5%] vs 21 of 129 [16.3%], respectively; P = .86) or severity of complications within 30 days after surgery.

Conclusions and Relevance

Indocyanine green can noticeably improve the number of lymph node dissections and reduce lymph node noncompliance without increased complications in patients undergoing D2 lymphadenectomy. Indocyanine green fluorescence imaging can be performed for routine lymphatic mapping during laparoscopic gastrectomy, especially total gastrectomy.

Trial Registration

ClinicalTrials.gov Identifier: NCT03050879.

Intraoperative angiography with indocyanine green injection for precise localization and resection of small bowel bleeding

Aim

Bleeding in the small bowel rarely occurs, and its treatment is challenging. Surgery is sometimes required in unstable patients; however, intraoperative identification of the bleeding site is extremely difficult. Many methods have been reported, but no standard strategy has been established yet. Here, we aimed to assess the safety and feasibility of intraoperative angiography with indocyanine green staining to accurately identify small bowel bleeding sites.

Methods

This retrospective study analyzed contrast‐enhanced computed tomography images of patients (n = 8) with small bowel extravasation who underwent surgery. If extravasation or other vessel abnormalities that were potential bleeding sites were detected on intraoperative angiography, a microcatheter was placed as close as possible to the extravasation site. Laparotomy was carried out, and 3–5 mL indocyanine green was injected through the microcatheter. The green‐stained segment of the small bowel was resected.

Results

Seven of the eight patients had positive angiographic findings and underwent bowel resection. The eighth patient had no abnormalities and hence did not undergo laparotomy. The rate of hemostatic success among the resected cases was 85.7% (six of seven cases). The resected specimens showed pathologic features in six of the seven patients (85.7%), all of whom achieved hemostasis. One patient had pneumonia and congestive heart failure that required longer hospital stay, but no mortality occurred.

Conclusions

Intraoperative angiography with indocyanine green injection, followed by resection for massive small bowel bleeding is effective. This can be a therapeutic option for hemodynamically unstable patients.

Advances in laparoscopic surgery for the treatment of advanced gastric cancer in China

Most gastric cancer (GC) cases are diagnosed at an advanced stage in China. Because of its high morbidity and mortality, GC remains a major health crisis in China. Surgical resection is the only potentially curative treatment for GC. Owing to being minimally invasive, laparoscopic radical gastrectomy has been widely used in various countries, especially in East Asia, since Kitano first reported the feasibility and safety of this technique. Although laparoscopic gastric surgery was introduced relatively late in China, Chinese surgeons have made unique contributions to the research and clinical practice of laparoscopic gastric surgery due to the large number of clinical cases. This review focuses on the progress in laparoscopic gastrectomy for advanced stage GC in China, including reasonable approaches in different areas and oncologic efficacy of laparoscopic surgery, and introduce advanced technology to facilitate surgeons to rapidly overcome the learning curve in clinical practice.

Near-infrared fluorescence-guided surgery using indocyanine green facilitates secure infrapyloric lymph node dissection during laparoscopic distal gastrectomy

PURPOSE

We aimed to investigate the usefulness of near-infrared indocyanine green (ICG)-enhanced fluorescence guidance for infrapyloric LN dissection in laparoscopic distal gastrectomy.

METHODS

This study enrolled patients with early gastric cancer scheduled for laparoscopic distal gastrectomy. After intraoperative submucosal injection of ICG (0.1 mg/mL), LN dissection was conducted under near-infrared ICG fluorescence guidance. The operation time, bleeding events during infrapyloric LN dissection were analyzed. Cases were retrospectively 1:3 propensity-score matched to patients who underwent laparoscopic distal gastrectomy without ICG injection.

RESULTS

The mean time from midline omentectomy to exposure of the right gastroepiploic vein was significantly shorter in the ICG group (n = 20) than in the non-ICG group (n = 60) (13.05 ± 5.77 vs 18.68 ± 7.92 min; p = 0.001), and the incidence of bleeding during infrapyloric LN dissection was lower in the ICG group (20% vs 68.3%, p < 0.001). The two groups did not differ significantly regarding the number of LNs retrieved from the infrapyloric area (p = 0.434).

CONCLUSIONS

Near-infrared ICG fluorescence guidance facilitates safe and fast infrapyloric LN dissection in laparoscopic distal gastrectomy.