Safety and efficacy of indocyanine green tracer-guided robotic segmental gastrectomy in early gastric cancer: A case report

Abstract

BACKGROUND

Robotic surgery has been widely used in pylorus-preserving gastrectomy (PPG). Segmental gastrectomy (SG) is a classic surgical method in PPG. Indocyanine green (ICG) can increase the number of lymph nodes dissected.

CASE SUMMARY

We report ICG tracer-guided SG using a robotic system in a 62-year-old female patient with early gastric cancer. It took 23 minutes for robotic setup, 130 minutes for dissection, and 60 minutes for digestive tract reconstruction. There were no postoperative complications such as abdominal infection, delayed gastric emptying, or gastroesophageal reflux. The patient was discharged on postoperative day 9. The pathological staging was pT1bN0M0.

CONCLUSION

This report indicates that ICG tracer-guided robotic SG is feasible and safe for some patients with early gastric cancer.

Key Words: Robotic surgery; Pylorus-preserving Gastrectomy; Segmental gastrectomy; Indocyanine green tracer-guided; Gastric cancer; Case report

Core Tip: We report indocyanine green (ICG) tracer-guided segmental gastrectomy (SG) using a robotic system in a 62-year-old female patient with early gastric cancer. There were no postoperative complications such as abdominal infection, delayed gastric emptying, or gastroesophageal reflux. This report indicates that ICG-tracer-guided robotic SG is feasible and safe for some patients with early gastric cancer.

INTRODUCTION

According to the Global Cancer Statistics Report, gastric cancer is the fifth most common cancer worldwide and the third leading cause of cancer-related death[1]. For patients with early gastric cancer, cohort studies and systematic analyses have shown that pylorus-preserving gastrectomy (PPG) can significantly improve postoperative quality of life and nutritional status, and the recurrence and survival rates are not significantly different from those with traditional distal gastrectomy (DG)[2,3]. Therefore, PPG has received increased attention in recent years. Segmental gastrectomy (SG) is a classic surgical method in PPG.

Robotic surgical systems provide three-dimensional (3D) visualization, higher accuracy, and greater operating flexibility. Studies have confirmed that robotic surgery is safe and feasible in DG and PPG, and does not increase the postoperative recurrence rate of tumors when compared to laparoscopic surgery[4,5]. In gastric cancer surgery, application of indocyanine green (ICG) significantly increases the number of lymph nodes dissected, without complications, and is safe and effective[6]. However, there are few reports of its application in PPG. The purpose of this study was to describe the clinical experience of performing SG using a robotic surgical system, with application of ICG for lymph node dissection and margin identification, and to report on its feasibility and safety.

The robotic system used in this operation was the Condo Surgical Robot System (SR2000; Harbin Sagebot Intelligent Medical Equipment Co., Ltd., China), which has been widely used in colonic and ovarian surgery in China. This paper reports the first application of this robotic system in ICG-tracer-guided SG.

CASE PRESENTATION

Chief complaints

A 62-year-old female patient was diagnosed with moderately differentiated adenocarcinoma in the anterior wall of the middle gastric body by gastroscopy during physical examination (Figure 1).

Figure 1  Lesion in the middle gastric body under gastroscopy (black circle).

History of present illness

A 62-year-old female patient was diagnosed moderately differentiated adenocarcinoma in the anterior wall of the middle gastric body by gastroscopy during physical examination (Figure 1).

History of past illness

Body mass index was 26.8 kg/m². The patient had a history of laparoscopic cholecystectomy, right breast cancer surgery, and hypertension.

Personal and family history

The patient had no family history of gastric cancer.

Physical examination

Physical examination revealed no positive signs such as abdominal tenderness.

Laboratory examinations

The laboratory tests showed that routine indicators of blood and liver function were normal, and the tumor markers were also within the normal range.

Imaging examinations

Total abdominal computed tomography confirmed no distant metastasis. The preoperative clinical stage was cT1N0M0. The gastroenterologist assessed that endoscopic submucosal dissection was not feasible for resection. Therefore, we planned to perform robotic SG with D1 lymph node dissection, in accordance with the 5^th edition of the Japanese Treatment Guidelines for Gastric Cancer. Informed consent for surgery was obtained from the patient. This study was approved by the Ethics Committee of Lishui Central Hospital, Approval No. 2025(I)-033-01.

FINAL DIAGNOSIS

The pathological diagnosis was a 1.5-cm highly to moderately differentiated intestinal adenocarcinoma, infiltrating the submucosa, with negative margins. Six gastric lesser curvature lymph nodes and seven gastric greater curvature lymph nodes were dissected, and no tumor metastasis was found. The pathological stage was pT1bN0M0.

TREATMENT

A gastroenterologist performed endoscopic tumor localization 4 hours before surgery. ICG was injected at three points in the margin of the tumor (Figure 2). After induction of general anesthesia, the pneumoperitoneum pressure was set at 13 mmHg. During the operation, the surgeon dissociated the mid-section gastric wall that was expected to be resected and completed D1 lymph node dissection, then switched the display screen to fluorescent mode to determine the resection range. The tumor area was clearly displayed in fluorescent mode compared with the normal mode (Figure 3). The surgeon cut off the stomach with a linear cutter at 5 cm from both sides of the tumor, then made a small incision in the posterior and anterior wall of the great curvature and performed a side-to-side anastomosis (Figures 4 and 5). Finally, an abdominal drainage tube was placed, and the surgical specimen was removed.

Figure 2  Injection of indocyanine green in the margin of the tumor (three black circles).

Figure 3 Tumor area in fluorescent mode and normal mode. A: Fluorescent mode; B: Normal mode.

Figure 4 Digestive tract reconstruction. A: Side-to-side anastomosis by linear cutter; B: Suture of common opening.

Figure 5  Brief schematic drawing of the intervention.

OUTCOME AND FOLLOW-UP

The operation time was approximately 3.5 hours, including 130 minutes for dissection, 60 minutes for digestive tract reconstruction, and 23 minutes for assembly, connection, and adjustment of the robotic system. Surgical bleeding was approximately 50 mL. The patient was able to drink water on postoperative day 1, consumed a liquid diet on day 3, and a semi-fluid diet on day 6. She was discharged on postoperative day 9 and was well after 4 months’ follow-up.

DISCUSSION

The current development direction of gastric cancer surgery is to be safer, more precise, and function-preserving, to accelerate short-term recovery and long-term quality of life. With its advantages of 3D magnifying field of view, tremor filtering, and free robotic arms, the robotic surgical system overcomes the limitations of traditional laparoscopic surgery and improves surgical accuracy. Studies have demonstrated the superiority of robotic gastrectomy. A meta-analysis including 258 patients showed that robotic gastrectomy has the advantages of less intraoperative blood loss and shorter hospital stay compared with laparoscopic gastrectomy. The complication rates and long-term recurrence rate of both are similar, which is related to the more precise operation under robotic surgery and the better protection of the vascular arch and vagus nerve of the stomach[5]. Compared with traditional DG, PPG can improve long-term survival. A multicenter randomized controlled trial, involving 256 patients with early gastric cancer, found that compared with the laparoscopic DG group, the laparoscopic PPG group had a lower rate of postoperative gallstone formation (2.33% vs 8.66%, P = 0.026), less decline in postoperative hemoglobin (+0.01 vs -0.76 gm/dL, P < 0.001) and serum protein (-0.15 vs -0.35 gm/dL, P = 0.002), and there was no difference in 3-year overall survival rate and disease-free survival[7]. A study involving 79 patients with early gastric cancer analyzed the operation time, blood loss, number of lymph nodes retrieved, postoperative hospital stay, and early complications of robotic PPG surgery, indicating that robotic PPG is feasible[4]. High-level evidence on robotic SG is still limited globally, and more prospective, multicenter randomized controlled trials are needed to prove its long-term oncological efficacy and functional outcomes.

ICG is a fluorescent dye, which can visually identify the location of lymph nodes in real time during gastric cancer surgery; especially lymph nodes that are small and hidden in adipose tissue, thereby achieving more complete surgical resection and more accurate postoperative staging[8]. A randomized clinical trial involving 266 patients showed that the total number of lymph nodes dissected in ICG-tracer-guided laparoscopic radical gastrectomy was significantly higher than that in the non-ICG group (average: 50.5 vs 42.0), and the unqualified rate of lymph nodes was significantly reduced[6]. Because of the small size of early gastric cancer, it is impossible to accurately determine the resection range during surgery. In this case, we localized the tumor under gastroscopy 4 h before surgery, and injected ICG at three points in 1 week to help locate the tumor precisely. One drawback of this operation was that the gastroenterologist injected too much ICG, resulting in widespread distribution of ICG during the operation and reduced accuracy of tumor positioning. Another application of ICG is to assess the blood supply to the anastomosis. Before digestive tract reconstruction, surgeons intravenously inject ICG, then use fluorescence imaging to monitor the blood supply of the gastric wall in real time during the operation to ensure good blood supply of the anastomosis to reduce the risk of anastomotic leakage[9]. In this operation, we injected ICG before surgery, so we could not judge the blood supply of the anastomosis. In the future, the effect of ICG-tracer-guided surgery will be improved by studying the unified injection dose, timing, and site of ICG. Meanwhile, the FUTURE-01 (NCT05229874) prospective randomized controlled trial is under way to explore the most suitable lymph node tracer by comparing the efficacy and safety of lymph node dissection guided by carbon nanoparticle suspension and ICG[10].

CONCLUSION

This report indicates that ICG-tracer-guided robotic SG is feasible and safe for some patients with early gastric cancer. The advantage lies in its ability to precisely determine the resection range, but its effectiveness still needs to be verified in large-scale studies.

ACKNOWLEDGEMENTS

We thank all the doctors and nurses who participated in the surgery and rehabilitation of the patients.