Efficacy of intraoperative gastroscopy for tumor localization in totally laparoscopic distal gastrectomy for cancer in the middle third of the stomach

Chinese national clinical practice guidelines on the prevention, diagnosis, and treatment of early gastric cancer

BACKGROUND

Gastric cancer is one of the most common malignant tumors in the digestive system in China. Few comprehensive practice guidelines for early gastric cancer in China are currently available. Therefore, we created the Chinese national clinical practice guideline for the prevention, diagnosis, and treatment of early gastric cancer.

METHODS

This clinical practice guideline (CPG) was developed in accordance with the World Health Organization's recommended process and with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in assessing evidence quality. We used the Evidence to Decision framework to formulate clinical recommendations to minimize bias and increase transparency in the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guidelines to ensure completeness and transparency of the CPG.

RESULTS

This CPG contains 40 recommendations regarding the prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer based on available clinical studies and guidelines. We provide recommendations for the timing of Helicobacter pylori eradication, screening populations for early gastric cancer, indications for endoscopic resection and surgical gastrectomy, follow-up interval after treatment, and other recommendations.

CONCLUSIONS

This CPG can lead to optimum care for patients and populations by providing up-to-date medical information. We intend this CPG for widespread adoption to increase the standard of prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer; thereby, contributing to improving national health care and patient quality of life.

Release of liposomally formulated near-infrared fluorescent probes included in giant cluster vesicles by ultrasound irradiation

Detection of tumors and regional lymph nodes during surgery has been proposed in the diagnosis of lymphatic metastasis and the surgical treatment of malignant diseases. Giant cluster vesicles (GCVs), including liposomally formulated indocyanine green (LP-ICG) derivatives, are a possible candidate for agents to realize the two contradictory properties, i.e., retention in tissue for lesion-marking and trace for sentinel lymph nodes (SLNs) identification. We attempted to release the LP-ICG derivatives from GCVs using ultrasound contrast agents (UCAs) under ultrasound irradiation. An absorption spectrophotometer quantitatively evaluated the amounts of released LP-ICG derivatives. As a result, we demonstrated that it depended on conditions for sound pressure, burst length, and number density of UCAs, and had a sound pressure threshold independent of burst length and number density of UCAs. The results will aid to determine appropriate conditions to maximize the released amount of LP-ICG derivatives while keeping safety.

Experimental Study on Gastric Labeling by Magnetic Detector Combined With Magnetic Bead

OBJECTIVE

Preoperative labeling of gastric cancer is an important means to determine the surgical margin. At present, there are many commonly used labeling methods. However, which is more accurate and has fewer complications remains to be studied. Through animal experiments, this study explored the feasibility, accuracy, and safety of a magnetic detector combined with magnetic beads for the preoperative labeling of gastric cancer.

METHODS

A total of 10 beagle dogs were included in the study. Each dog was randomly labeled with magnetic beads in the gastric body and antrum. After labeling, the magnetic detector was used to explore the gastric serosa surface, and the positioning titanium clip was released at the detected magnetic bead. The main monitoring index was to measure the distance between the labeled magnetic beads and the positioning titanium clamped. The secondary indexes were detection time, magnetic induction intensity, magnetic bead shedding rate, mucosal injury rate, bleeding, and leukocyte and C-reactive protein levels before and 24 hours after the operation.

RESULTS

All 10 beagle dogs completed the marking and exploration successfully. The average distance between the magnetic beads and the positioning titanium clip in 20 cases was 5.90±2.36 mm. The average detection time was 1.60±0.69 min, and the average magnetic induction intensity was 3.76±1.11 mT. No magnetic beads were found to fall off, 1 case had a mild mucosal injury, and 2 cases had a small amount of bleeding when releasing the positioning titanium clip. The white blood cells before and 24 hours after the operation were 7.43±0.94(×10 9 /L) versus 7.79±0.67(×10 9 /L) ( P =0.34). The C-reactive protein before and 24 hours after the operation were 5.24±0.97 µg/mL versus 5.95±1.02 µg/mL ( P =0.13).

CONCLUSION

A magnetic detector combined with magnetic beads for gastric cancer labeling is feasible, accurate, and safe. It is expected to be further applied in the clinic.

The First Systematic Gastroscopy Training Program for Surgeons in Korea

BACKGROUND

Endoscopic evaluation of the stomach is essential for preoperative planning and post-surgical surveillance for various diseases of the stomach, including malignancy. The gastroscopy education program for surgeons is currently in its infancy and is not systematically organized in Korea. This study aimed to introduce the first systematic gastroscopy education program for surgeons in Korea.

METHODS

The gastroscopy education program entitled "Gastroscopy School for Surgeons (GSS)" comprised of theoretical education, dry lab hands-on training, and clinical practice. All participants were beginners without any gastroscopy experience. Clinical practice started after the completion of the theoretical and dry lab training. The gastroscopy practices utilized simple luminal observation, biopsy, localization using clips or dye injection, and limited therapeutic gastroscopy. The educational performances and surveys from 33 participants were analyzed.

RESULTS

The participants consisted of surgical residents, general surgeons, gastrointestinal-specialized surgeons, and physicians. Participants performed a total of 2,272 gastroscopies, 2,008 of which were post-gastrectomy cases. Currently, of the 33 participants, 7 (21.2%) of the participants performed gastroscopy regularly, and 7 (21.2%) occasionally. According to the self-reported survey, one participant assessed their current gastroscopic technique to be at the expert level, and 25 (75.8%) at a proficient level. All participants considered gastroscopy education for surgeons to be necessary, and 28 (84.8%) stated that systematic education is not currently provided in Korea.

CONCLUSION

We introduced the first systematic gastroscopy education program for surgeons in Korea, namely the GSS, which is practical and meets clinical needs. More training centers are needed to expand gastroscopy training among Korean surgeons.

Safety and efficacy of preoperative indocyanine green fluorescence marking in laparoscopic gastrectomy for proximal gastric and esophagogastric junction adenocarcinoma (ICG MAP study)

PURPOSE

The incidence of adenocarcinoma of the esophagogastric junction (AEG) and proximal gastric cancer (PGC) is rising worldwide. Recently, the use of indocyanine green (ICG) tracer-guided surgery has been reported; however, its efficacy for total/proximal gastrectomy has not been clarified. We evaluated the feasibility and safety of ICG fluorescent marking for tumor localization in AEG/PGC treatment by laparoscopic surgery.

METHODS

We enrolled patients with AEG/PGC from October 2016 to March 2019 from a prospectively registered database. On the day before surgery, ICG markings were made at four locations just at the edge of the tumor by gastrointestinal fiberscope examination. Surgery was performed while viewing the fluorescence image of ICG, and the proximal portions of the esophagus and the distal portion of the stomach were resected at the edge of the area where ICG had spread.

RESULTS

We enrolled 130 patients with AEG/PGC. Overall, 107 patients were eventually included in the study: AEG n = 64 (60%) and PGC n = 43 (40%). ICG markings were detected intraoperatively in all cases, and cancer invasion into the resection lines of the esophagus and stomach, performed based on ICG fluorescence images, was negative in all cases. The median visible range of ICG fluorescence was 22.5 mm. ICG diffusion expanded 20 mm proximal for AEG. There were no adverse events associated with endoscopic ICG injection.

CONCLUSION

ICG fluorescence imaging is feasible and safe and can potentially be used as a tumor-marking agent for determining the surgical resection line for total/proximal gastrectomy in AEG and PGC treatment.

Surgical and oncological outcomes of distal gastrectomy compared to total gastrectomy for middle‑third gastric cancer: A systematic review and meta‑analysis

Distal gastrectomy (DG) and total gastrectomy (TG) are the most common types of radical surgery for patients with middle-third gastric cancer (MTGC). However, the indications and benefits of the two procedures still remain controversial. The present meta-analysis aimed to compare the surgical and oncological outcomes of DG and TG in the treatment of MTGC. A rigorous literature review was performed in the databases of PubMed, Embase, Web of Science, China National Knowledge Infrastructure and Chinese BioMedical Literature to retrieve studies published up to February 2022. The Newcastle-Ottawa Scale was used to assess the quality of included studies and a meta-analysis was performed using RevMan 5.3 software. A total of 12 retrospective studies performing comparisons of DG and TG were included in the present meta-analysis. For patients who underwent DG, a lower rate of overall post-operative complications, anastomosis leakage and intro-abdominal infection was determined. No significant difference was observed between DG and TG in the 5-year overall survival when the proximal resection margin ranged from 3 to 5 cm. Although DG was associated with a higher 5-year overall survival rate when compared to TG, there was no significant difference in the stratified analyses by TNM stage. In conclusion, the prognosis of MTGC did not depend on the extent of gastrectomy. With lower complications and acceptable oncological outcomes, DG was a safe and feasible surgical procedure for MTGC when a negative proximal margin was confirmed.

Intraoperative Tumor Identification During Laparoscopic Distal Gastrectomy: a Novel Fluorescent Clip Marking Versus Metal Clip Marking and Intraoperative Gastroscope

BACKGROUND

In complete laparoscopic distal gastrectomy, the gastric resection line is difficult to determine due to a lack of tactile sensation. The use of intraoperative gastroscopy and intraoperative radiography has been reported, but the burden on personnel and technical complexity present impediments. In our department, based on lesion extent determined with preoperative gastroscopy, a fluorescent clip is used to mark the oral side of the lesion, which is resected after confirmation with a fluorescent laparoscopic system. In this study, we investigated the efficacy of fluorescent clip marking (FCM) in achieving an accurate resection line and reducing the operative time.

METHODS

Fifty-six patients with gastric cancer who underwent complete laparoscopic distal gastrectomy from January 2018 to March 2021 were divided into two groups: the FCM group (n = 32) and the conventional metal clip marking and intraoperative gastroscopy (MCMG) group (n = 24). Short-term outcomes, including the resection margins, gastric resection time, and operative time, were compared and examined.

RESULTS

The fluorescent clips were visible in all cases, and all stumps were negative according to permanent preparations. The operative times for FCM and MCMG were 350 (216-533) vs. 373.5 (258-651) min, respectively, with no significant difference (p = 0.316), while the gastric resection times were 636.5 (321-2572) vs. 1457.5 (843-4973) s, respectively, and were significantly shorter in the FCM group (p < 0.0001).

CONCLUSIONS

FCM shortened the gastric resection time and could possibly shorten the operative time. FCM is feasible and safe and can potentially be used as a tumor-marking agent to determine accurate surgical resection lines.

CLINICAL TRIAL REGISTRATION

Examination of Gastric Cancer, Research Ethics Committee of the Kawaguchi Municipal Medical Centre (Saitama, Japan), approval number: 2019-33. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

Effectiveness of Intraoperative Endoscopy for Localization of Early Gastric Cancer during Laparoscopic Distal Gastrectomy

INTRODUCTION

Intraoperative localization of tumors has been considered crucial in determining adequate resection margins during laparoscopic gastrectomy for early gastric cancer (EGC). This study has evaluated the effectiveness of intraoperative endoscopy for localization of EGC during the totally laparoscopic distal gastrectomy.

METHODS

Patients with EGC who received totally laparoscopic distal gastrectomy from January 2018 to March 2020 were included in this study. Except the tumors located in the antrum, the patients were categorized into two groups: no localization procedure (n = 144) and intraoperative endoscopy (n = 65). To evaluate the effectiveness of the localization procedure, proximal resection margin (PRM) involvement by the tumor and approximation of optimal PRM were compared, including their postoperative outcomes.

RESULTS

There were 3 patients (2.1%) with tumor involvement of the PRM at the initial gastric resection in the no localization group. Distance from the tumor to the PRM was determined to be not significantly different between the no localization group and intraoperative endoscopy group. The PRM distribution pattern and reconstruction method were also not significantly different between the two groups.

DISCUSSION/CONCLUSION

Intraoperative endoscopy for localization of EGC is an effective method to avoid tumor involvement at the resection margin during the laparoscopic gastrectomy with intracorporeal gastric resection and reconstruction.

Short- and long-term oncological outcomes of totally laparoscopic gastrectomy versus laparoscopy-assisted gastrectomy for clinical stage I gastric cancer

BACKGROUND

Totally laparoscopic gastrectomy (TLG), which involves a complete intracorporeal gastric transection and the creation of an anastomosis, has been gradually adopted. However, a potential limitation of intracorporeal transection is the lack of tactile feedback, and whether this limitation influences oncological outcomes is unclear. The aim of this study is to evaluate the short- and long-term oncological safety of TLG using endoscopy-guided intracorporeal gastric transection for clinical stage (cStage) I gastric cancer.

METHODS

A total of 1875 consecutive patients who underwent laparoscopic gastrectomy for cStage I gastric cancer between January 2007 and March 2015 were enrolled in this study. Marking clips were preoperatively placed and a transection line was determined by perceiving it tactually in laparoscopy-assisted gastrectomy (LAG) or endoscopically in TLG. After propensity score matching, 1366 patients (683 each for LAG and TLG groups) were selected to primarily test the non-inferiority of TLG to that of LAG for relapse-free survival (RFS).

RESULTS

In the propensity-matched population, the 5-year RFS rates of the LAG and TLG groups were 94.3% (95% confidence interval (CI) 92.2-95.8%), and 95.6% (95% CI 93.8-96.9%), respectively. The hazard ratio (TLG/LAG) was 0.77 (95% CI 0.48-1.24, P for non-inferiority < 0.01). There were no significant differences in the recurrence profiles. The incidence of the remnant of marking clips or tumor tissue did not differ (LAG: 1.0% vs. TLG: 1.9%, P = 0.177).

CONCLUSIONS

TLG using preoperative markings and intraoperative endoscopic guidance provides cStage I gastric cancer patients with comparable oncological outcomes to the conventional method.

Transpyloric optic navigation of tumor using a laparoscope during totally laparoscopic distal gastrectomy for gastric cancer

Purpose

Methods

Results

Conclusion

Clinical Significance of Intra-operative Gastroscopy for Tumor Localization in Totally Laparoscopic Partial Gastrectomy

BACKGROUND

Tumor localization during totally laparoscopic gastrectomy is challenging owing to the invisibility of tumors on the serosal surface. We aimed to evaluate the clinical significance of intra-operative gastroscopy in totally laparoscopic partial gastrectomy.

METHODS

We reviewed 1084 gastric cancer patients who underwent either intra- or extracorporeal partial gastrectomy between 2014 and 2018. The intracorporeal group with intra-operative gastroscopy (intra-operative gastroscopy group, n = 187), the intracorporeal group without intra-operative gastroscopy (non-intra-operative gastroscopy group, n = 267), and the extracorporeal group (n = 630) were evaluated for the adequacy of surgical resection margins. We assessed whether total gastrectomy could be avoided according to the performance of intra-operative gastroscopy if the tumor was located within 3-5 cm away from the gastroesophageal junction.

RESULTS

The proximal margin positivity was lesser in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (0% versus 2.2%; P = 0.045) but similar to that in the extracorporeal group (0% versus 0.6%; P = 0.579). The number of cases with proximal resection margins < 1 cm was lower in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (3.7% versus 9.4%; P = 0.025) but comparable with that in the extracorporeal group (3.7% versus 4.1%; P = 0.815). Among 94 patients with lesions located within 3-5 cm apart from the gastroesophageal junction, the intra-operative gastroscopy group (n = 47) had fewer patients who underwent total gastrectomy than the non-intra-operative gastroscopy group (n = 47) (12.8% versus 44.7%; P = 0.001). Intra-operative gastroscopy was the only independent factor that prevented total gastrectomy (P = 0.001).

CONCLUSION

Intra-operative gastroscopy can provide margin safety during intracorporeal partial gastrectomy, avoiding unnecessary total gastrectomy.

Intraoperative Tumor Localization of Early Gastric Cancers

Recently, endoscopic screening systems have enabled the diagnosis of gastric cancer in the early stages. Early gastric cancer (EGC) is typically characterized by a shallow invasion depth and small size, which can hinder localization of EGC tumors during laparoscopic surgery. Here, we review nine recently reported tumor localization methods for the laparoscopic resection of EGCs. Preoperative dye or blood tattooing has the disadvantage of spreading. Preoperative 3-dimensional computed tomography reconstruction is not performed in real time during laparoscopic gastrectomy. Thus, they are considered to have a low accuracy. Intraoperative portable abdominal radiography and intraoperative laparoscopic ultrasonography methods can provide real-time feedback, but these methods require expertise, and it can be difficult to define the clips in some gastric regions. Despite a few limitations, intraoperative gastrofibroscopy provides real-time feedback with high accuracy. The detection system using an endoscopic magnetic marking clip, fluorescent clip, and radio-frequency identification detection system clip is considered highly accurate and provides real-time feedback; we expect a commercial version of this setup to be available in the near future. However, there is not yet an easy method for accurate real-time detection. We hope that improved devices will soon be developed and used in clinical settings.

Intraoperative gastroscopy to determine proximal resection margin during totally laparoscopic gastrectomy for patients with upper third gastric cancer

Background

In totally laparoscopic gastrectomy (TLG), it is usually difficult to determine the proximal margin. Therefore, the present study evaluated the usefulness of intraoperative gastroscopy for direct marking of the tumor proximal margin during TLG for cancer in the upper third of the stomach.

Methods

This retrospective cohort study included 52 patients with gastric cancer who underwent TLG from January 2018 to May 2020. The proximal margin of tumors was determined by intraoperative gastroscopic methods.

Results

Patients were divided into short (1 cm) and long (2 cm) groups according to the distance to the proximal margin of the tumor. Participants consisted of 41 males and 11 females with a median age of 63.5 years. Tumors involving the esophagogastric junction (EGJ) occurred in 27 patients. Siewert type II and III tumors were present in 42 and 10 patients, respectively. The median operative time was 244 min. The long group had a statistically significant lower frequency of positive margin than the short group (0% vs. 17.4%, P=0.033). Total gastrectomy was performed in 35 patients, and 17 patients received proximal gastrectomy. No complications associated with the procedure occurred in any patient.

Conclusions

Intraoperative endoscopic views for tumor proximal localization can be used effectively during TLG for patients with upper third gastric cancer. Our results indicate that a distance of ≥2 cm from the proximal resection margin to the tumor was necessary to achieve a negative resection margin. In the future, this may be used as an alternative to frozen section diagnosis.

Application of Near-Infrared Fluorescence Imaging with Indocyanine Green in Totally Laparoscopic Distal Gastrectomy

Purpose

Recently, totally laparoscopic gastrectomy has been gradually accepted by surgeons worldwide for gastric cancer treatment. Complete dissection of the lymph nodes and the establishment of the surgical margin are the most important considerations for curative gastric cancer surgery. Previous studies have demonstrated that indocyanine green (ICG)-traced laparoscopic gastrectomy significantly improves the completeness of lymph node dissection. However, it remains difficult to identify the tumor location intraoperatively for gastric cancers that are staged ≤T3. Here, we investigated the feasibility of ICG fluorescence for lymph node mapping and tumor localization during totally laparoscopic distal gastrectomy.

Materials and Methods

Preoperative and perioperative data from consecutive patients with gastric cancer who underwent a totally laparoscopic distal gastrectomy were collected and analyzed. The patients were categorized into the ICG (n=61) or the non-ICG (n=75) group based on whether preoperative endoscopic mucosal ICG injection was performed.

Results

The ICG group had a shorter operation time and less intraoperative blood loss. Moreover, significantly more lymph nodes were harvested in the ICG group than the non-ICG group. No pathologically positive margin was found and there was no significant difference in either the proximal or distal surgical margins between the 2 groups.

Conclusions

Near-infrared fluorescence imaging with ICG can be successfully used in totally laparoscopic distal gastrectomy, and it contributes to both the completeness of D2 lymph node dissection and confirmation of the gastric transection line. Well-designed prospective randomized studies are needed in the future to fully validate our findings.

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.

Detection of indocyanine green fluorescence to determine tumor location during laparoscopic gastrectomy for gastric cancer: Results of a prospective study

INTRODUCTION

In laparoscopic gastrectomy, a method to locate the margin of an early-stage cancerous lesion that is invisible from the serosal surface and impalpable during laparoscopic procedures is needed to determine an appropriate transection line. We conducted a prospective study to develop a new marking method using preoperative submucosal injection of indocyanine green (ICG).

METHODS

Patients undergoing laparoscopic gastrectomy for T1 gastric cancer were recruited. The first 11 patients comprised the learning set and the subsequent 18 patients the validation set. ICG was endoscopically injected in the submucosal layer of the stomach approximately 1 cm away from the tumor edge 1 or 3 days before surgery. The diameters of the visualized ICG were compared with those of a conventional marking method using India ink in 10 historical controls.

RESULTS

In the learning set, the optimal amount of ICG was determined to be 0.1 mL at a concentration of 0.5 mg/mL. In the validation set, the same procedure was repeated. No technical problems or adverse reactions related to ICG injection were observed. In all cases, ICG was successfully detected, and negative surgical margins were pathologically confirmed. The mean long diameter of the visualized ICG fluorescence measured at the mucosal surface of the stomach was significantly smaller in the current study than in the historical controls in whom India ink was used (21 vs 52 mm, P < 0.0001).

CONCLUSIONS

The preoperative submucosal ICG marking was safely performed and successfully detected without excessive blurring during laparoscopic gastrectomy.

An advanced RFID-based system to localize gastric and colon cancers during laparoscopic surgery

BACKGROUND

We aimed to improve the tumor localization system using radiofrequency identification (RFID) technology used during laparoscopic surgery for gastric and colorectal cancer. To this end, we developed a detection algorithm and designed improvement for the RFID clip.

METHODS

To evaluate the proposed system, a swine-based animal study was conducted, followed by experiments on porcine stomachs and colons using the EASIE-R simulator. The success rates of endoscopic clipping, detection time, and detection accuracy, which is the distance between the detection point and RFID tag, were measured.

RESULTS

Results of the in vivo swine animal study showed success in all three clippings and detections of the RFID clips. Results of the 60 RFID endoclip attempts using the EASIE-R simulator showed a total clipping success rate of 85.0% (n = 51/60; stomach, 83.3%, n = 25/30; colon, 86.7%, n = 26/30). The median detection times were 29.2 s for the stomach and 25.5 s for the colon. The median detection accuracy was 4.0 mm for the stomach and 4.5 mm for the colon.

CONCLUSIONS

We confirmed that the proposed RFID-based system showed improvements over the system of a previous study. This RFID-based system is effective at localizing gastric and colorectal tumors.

The Feasibility and Safety of Preoperative Fluorescence Marking with Indocyanine Green (ICG) in Laparoscopic Gastrectomy for Gastric Cancer

BACKGROUND

Securing the surgical margin is the most essential and important task in curative surgery. However, it is difficult to accurately identify the tumor location during laparoscopic surgery for gastric cancer, and existing methods, such as preoperative endoscopic marking with tattooing and clipping, have multiple disadvantages.

AIMS

We investigated the feasibility and safety of indocyanine green (ICG) fluorescence marking for determining the tumor location during laparoscopic gastrectomy.

METHODS

We retrospectively analyzed preoperative and perioperative data from consecutive patients with gastric cancer undergoing planned laparoscopic distal gastrectomy. Data was maintained in a prospectively compiled surgical database, and patients were categorized into ICG (n = 84) or non-ICG (n = 174) groups based on whether they underwent preoperative endoscopic mucosal ICG injection. One-to-one propensity score matching (PSM) was performed to compare outcomes between the two groups.

RESULTS

We included 84 patient pairs after PSM, and there were no significant differences in preoperative patient characteristics. The ICG group had shorter procedure time (p < 0.001), lower estimated blood loss (p = 0.005), and significantly shorter postoperative hospital stay (p < 0.001). Positive resection margins were confirmed in five cases (6.0%) in the non-ICG group, whereas there were none in the ICG group (p = 0.008). Real-time confirmation was possible during laparoscopy, and the injected ICG did not affect the surgical procedure or result in adverse events.

CONCLUSION

ICG fluorescence imaging is feasible and safe and can potentially be used as a tumor-marking agent for determining the surgical resection line.

Are the indications for postoperative radiotherapy in the NCCN guidelines for patients with gastric adenocarcinoma too broad? A study based on the SEER database

Background

The types of patients with gastric adenocarcinoma (GA) for whom postoperative radiotherapy can improve the disease-specific survival rate (DSS) remain controversial. This study aims to explore the ideal indications.

Methods

Patients in the Surveillance, Epidemiology, and End Results (SEER) database with T3–4Nx or TxN+ GA from January 1988 to December 2012 were included and divided into a postoperative chemoradiotherapy group (Group R) and a postoperative chemotherapy group (Group C). We established a nomogram to predict DSS and then divided entire patient cohort into low-risk and high-risk groups based on the DSS predicted by the nomogram.

Results

The Cox multiple regression analysis demonstrated that various risk factors affected DSS for Group R. Based on these risk factors, a nomogram for predicting DSS was established. The decision curve indicated that the best clinical effect could be obtained when the threshold probability was 0–58%. The patients were then divided into low-risk (< 69 points) and high-risk (≥ 69 points) groups according to the five-year DSS predicted. DSS was significantly better for Group R than for Group C for high-risk patients (P < 0.001) but was similar for low-risk patients (P = 0.732).

Conclusion

At present, the National Comprehensive Cancer Network (NCCN) guidelines may include an overly broad range of indications for postoperative radiotherapy for patients with GA. For intestinal GA patients with a postoperative pathologic stage of T1 N1 who are younger than 65 years, have had more than 15 lymph nodes dissected, and have received postoperative chemotherapy, postoperative radiotherapy should not be recommended.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4957-6) contains supplementary material, which is available to authorized users.

Role of preoperative endoscopic clipping in laparoscopic distal gastrectomy for early gastric cancer

In this study, we evaluate the usefulness of preoperative endoscopic clipping for early gastric cancer (EGC) localization in laparoscopic distal gastrectomy.We retrospectively screened all consecutive patients who underwent laparoscopic distal gastrectomy for EGC by 1 surgeon at Chungnam National University Hospital between January 2014 and December 2016. Patients who underwent combined surgery and patients who had tumors at the lower third of the stomach were excluded. Endoscopic clipping was performed prior to surgery by specialized endoscopists. During the operation, endoscopic metal clips were found using surgical devices, and laparoscopic vessel clips were attached on the presumed site; thereafter, intraoperative radiographs were obtained for confirmation.We analyzed a total of 196 patients; of them, 101 were classified into the clipping group (CG) and 95 into the non clipping group (NCG). The 2 groups were comparable regarding their demographic characteristics. The CG showed less additional resection (2 of 101 patients [2.0%] vs 9 of 95 patients [9.4%], P = .021) and better outcomes in terms of the operation time (P = .000), duration of hospital stay (P = .036), and postoperative atelectasis (P = .001) than the NCG.Preoperative endoscopic clipping was helpful in determining the exact resection margin in laparoscopic distal gastrectomy for EGC.

Tumor localization using radio-frequency identification clip marker: experimental results of an ex vivo porcine model

PURPOSE

With the widespread use of minimally invasive surgery, tumor detection is becoming more difficult. We present the experimental results of a radio-frequency identification (RFID) lesion detection system in an ex vivo porcine model.

METHODS

The efficacy and feasibility of a newly developed RFID lesion detection system were examined. It was applied to the stomach and colon of pigs weighing 40 kg. The RFID clip was attached to the upper and lower mucosal sides of the stomach. Colon specimens with thin and thick walls were used. The clipped sites were marked on the serosa by a pin. The longest distance from the pin the RFID tag could be detected was measured 25 times in each direction.

RESULTS

In the upper gastric wall, the RFID tag detection distance was 4.5 ± 0.9 mm, 5.6 ± 0.7 mm, 12.5 ± 0.7 mm, and 5.3 ± 0.5 mm in the four directions, respectively (right, left, upper, and lower). In the antrum, the RFID tag detection distance was 5.8 ± 0.7 mm, 6.9 ± 0.5 mm, 5.6 ± 0.5 mm, and 3.7 ± 0.5 mm in the four directions. In the thin colon, the RFID tag detection distance was 6.3 ± 0.5 mm, 5.0 ± 0.5 mm, 9.7 ± 0.7 mm, and 6.4 ± 0.4 mm in the four directions. In the thick colon, the RFID tag detection distance was 3.5 ± 0.8 mm, 6.6 ± 0.5 mm, 8.4 ± 0.6 mm, and 9.8 ± 0.5 mm in the four directions. The area of detection was smallest for the antrum (83.7 mm²) and similar for the other sites (150.6, 154.7 and 157.7 mm² for the upper body, thin colon, and thick colon, respectively).

CONCLUSIONS

The distance at which the RFID tag was detected was usually within 10 mm. These results indicate the feasibility of the clinical application of the add-on clip and RFID tag as a marker for identifying the location of various gastrointestinal tumors.

Advanced Endoscopic Navigation: Surgical Big Data, Methodology, and Applications

Interventional endoscopy (e.g., bronchoscopy, colonoscopy, laparoscopy, cystoscopy) is a widely performed procedure that involves either diagnosis of suspicious lesions or guidance for minimally invasive surgery in a variety of organs within the body cavity. Endoscopy may also be used to guide the introduction of certain items (e.g., stents) into the body. Endoscopic navigation systems seek to integrate big data with multimodal information (e.g., computed tomography, magnetic resonance images, endoscopic video sequences, ultrasound images, external trackers) relative to the patient's anatomy, control the movement of medical endoscopes and surgical tools, and guide the surgeon's actions during endoscopic interventions. Nevertheless, it remains challenging to realize the next generation of context-aware navigated endoscopy. This review presents a broad survey of various aspects of endoscopic navigation, particularly with respect to the development of endoscopic navigation techniques. First, we investigate big data with multimodal information involved in endoscopic navigation. Next, we focus on numerous methodologies used for endoscopic navigation. We then review different endoscopic procedures in clinical applications. Finally, we discuss novel techniques and promising directions for the development of endoscopic navigation.

Real-time detection system for tumor localization during minimally invasive surgery for gastric and colon cancer removal: In vivo feasibility study in a swine model

BACKGROUND AND OBJECTIVES

During minimally invasive surgery (MIS), it is impossible to directly detect marked clips around tumors via palpation. Therefore, we developed a novel method and device using Radio Frequency IDentification (RFID) technology to detect the position of clips during minimally invasive gastrectomy or colectomy.

METHODS

The feasibility of the RFID-based detection system was evaluated in an animal experiment consisting of seven swine. The primary outcome was to successfully detect the location of RFID clips in the stomach and colon. The secondary outcome measures were to detect time (time during the intracorporeal detection of the RFID clip), and accuracy (distance between the RFID clip and the detected site).

RESULTS

A total of 25 detection attempts (14 in the stomach and 11 in the colon) using the RFID antenna had a 100% success rate. The median detection time was 32.5 s (range, 15-119 s) for the stomach and 28.0 s (range, 8-87 s) for the colon. The median detection distance was 6.5 mm (range, 4-18 mm) for the stomach and 6.0 mm (range, 3-13 mm) for the colon.

CONCLUSIONS

We demonstrated favorable results for a RFID system that detects the position of gastric and colon tumors in real-time during MIS.

Stomach resection with intraoperative fluoroscopy in laparoscopic distal gastrectomy for early gastric cancer

Background:

In Japan, laparoscopic distal gastrectomy (LDG) is common for early gastric cancer. Formerly, we used to verify the location of the marking clip to decide the proximal incisional line with our hand, through a small epigastric incision. In 2015, we introduced intracorporeal reconstruction and started to decide the incisional line using intraoperative fluoroscopy. Herein, we aimed to evaluate the efficacy and safety of intraoperative fluoroscopy in LDG.

Patients and Methods:

A total of 19 patients were included in this retrospective observational study. On the day before operation, we endoscopically clipped several points located 2 cm proximal to the tumour edge to cover about half of the tumour. After lymph node dissection, we incised the stomach with an endoscopic linear stapling device, including the previously placed clips, guided by intraoperative fluoroscopy. Reconstruction was performed in all patients who underwent Billroth I and Roux-en-Y procedures.

Results:

No complications were observed during pre-operative endoscopic clipping or intraoperatively. On pathological examination, all resected specimens had negative margins, and the mean distance from the tumour edge was 28.5 ± 16.5 (13–60) mm.

Conclusion:

Stomach resection with intraoperative fluoroscopic guidance was safe and effective.

Use of endoscopy to determine the resection margin during laparoscopic gastrectomy for cancer

Background

It can be difficult to determine the transection line during totally laparoscopic surgery for early gastric cancer owing to lack of tactile feedback. This retrospective cohort study aimed to assess the role of intraoperative endoscopy in determining the resection margin in totally laparoscopic gastrectomy.

Methods

Consecutive patients with histologically confirmed gastric cancer who underwent laparoscopic gastrectomy between March 2012 and July 2015 were eligible. Preoperative placement of marking clips and intraoperative endoscopy were performed to determine the resection margin. Frozen-section analyses were also performed to confirm the absence of cancer cells at the surgical margin. Success was defined as the proportion of specimens with all clips present and by the proportion of resections with a negative surgical margin following initial transection.

Results

Total laparoscopic gastrectomy with intraoperative endoscopy was performed in 522 patients; a total of 662 surgical margins were analysed. The overall success rate was 99·8 per cent (661 of 662 margins). The success rate of achieving a negative surgical margin during the initial transection was 98·9 per cent (550 of 556 margins).

Conclusion

Preoperative placement of marking clips and intraoperative endoscopy is helpful in the determination of a safe surgical margin in patients with gastric cancer who undergo laparoscopic gastrectomy.

A Promising Method for Tumor Localization during Total Laparoscopic Distal Gastrectomy: Preoperative Endoscopic Clipping based on Negative Biopsy and Selective Intraoperative Radiography Findings

PURPOSE

Precise localization of tumors and creation of sufficient proximal resection margins are complicated processes during total laparoscopic distal gastrectomy (TLDG) for clinical T1/T2 gastric cancers. Various solutions to this problem have also yielded many disadvantages. In this study, we reviewed a preoperative endoscopic clipping method based on the results of negative biopsy and selective intraoperative radiography.

MATERIALS AND METHODS

A retrospective review of 345 consecutive patients who underwent TLDG and preoperative endoscopic clipping for tumor localization was conducted. During preoperative endoscopy, the endoscopists performed negative biopsies just 1-2 cm selectively above the tumor's upper limit. After confirming the biopsy results, endoscopic metal clips were applied just proximal to the negative biopsy site the day before surgery. Selective intraoperative tumor localization using portable abdominal radiography was performed only when we could not ensure a precise resection line.

RESULTS

Negative biopsy was performed in 244 patients. Larger tumor size (P=0.008) and more distally located tumors (P=0.052) were observed more frequently in the negative biopsy group than in the non-negative biopsy group. The non-negative biopsy group had significantly higher frequencies of differentiated tumor types than the negative biopsy group (P=0.003). Of the 244 patients who underwent negative biopsies, 6 had cancer cells in their biopsy specimens. We performed intraoperative radiography in 12 patients whose tumors had difficult-to-determine proximal margins. No tumors were found in the proximal resection margins of any patients.

CONCLUSIONS

Our tumor localization method is a promising and accurate method for securing a sufficient resection margin during TLDG.

Robotic gastrectomy for gastric cancer: Current evidence

The robotic system has gained wide acceptance in specialties such as urological and gynecological surgery. It has also been applied in the field of upper gastrointestinal surgery. Since the first implementation of the robotic system for the treatment of gastric adenocarcinoma, the procedure has been found to be safe and feasible. Although robotic gastrectomy does not meet our expectations and yield better results than laparoscopic gastrectomy, this procedure seems to provide several advantages over laparoscopy such as reduced blood loss, shorter learning curves and increased number of retrieved lymph nodes. However, as many case series, including a recent multicenter study, have revealed, higher cost and longer operation time are the major limitations of robotic gastrectomy. Furthermore, there are no results from well-designed randomized clinical trials comparing the two procedures. New procedures in much more technically demanding cases will test the genuine benefits of robotic gastrectomy.

Simple and reliable method for tumor localization during totally laparoscopic gastrectomy: intraoperative laparoscopic ultrasonography combined with tattooing

We have developed a new method to localize a tumor during totally laparoscopic gastrectomy that uses intraoperative laparoscopic ultrasonography combined with preoperative clipping and tattooing. One or 2 days before the surgery, endoscopic clipping was performed just proximal to the tumor, followed by tattooing with India ink at the clipping site. Examination by intraoperative laparoscopic ultrasonography was performed at the tattooed site to detect the clips. The resection line of the stomach was determined with use of the detected clips as a marker of the proximal margin of the tumor. This method was attempted in 14 patients who underwent totally laparoscopic gastrectomy, and the clips were successfully identified in all patients. The clips were visualized as several layers of a hyperechoic bar, which was termed a "ladder sign." The mean time from insertion of the laparoscopic probe to identification of the clips was 2 min. The ladder sign is an important finding in this method.

A comparison between two methods for tumor localization during totally laparoscopic distal gastrectomy in patients with gastric cancer

Purpose

The aim of this study was to compare two methods of tumor localization during totally laparoscopic distal gastrectomy (TLDG) in patients with gastric cancer.

Methods

From March 2014 to November 2014, patients in whom TLDG had been engaged for middle third gastric cancer enrolled in this study. The patients were allocated to either the radiography or endoscopy group based on the type of tumor localization technique. Clinicopathologic outcomes were compared between the 2 groups.

Results

The accrual was suspended in November 2014 when 39 patients had been enrolled because a failed localization happened in the radiography group. The radiography and endoscopy groups included 17 (43.6 %) and 22 patients (56.4 %), respectively. Mean length of the proximal resection margin did not differ between the radiography and endoscopy groups (4.0 ± 2.6 and 2.8 ± 1.2 cm, respectively; P = 0.077). Mean localization time was longer in the radiography group than in the endoscopy group (22.7 ± 11.4 and 6.9 ± 1.8 minutes, respectively, P < 0.001). There were no statistically significant differences in the incidence of severe complications between the 2 groups (5.9% and 4.5%, respectively, P = 0.851).

Conclusion

As an intraoperative tumor localization for TLDG, radiologic method was unsafe even though other comparable parameters were not different from that of endoscopy group. Moreover, intraoperative endoscopic localization may be advantageous because it is highly accurate and contributes to reducing operation time.

Linear-shaped gastroduodenostomy (LSGD): safe and feasible technique of intracorporeal Billroth I anastomosis

BACKGROUND

Although delta-shaped gastroduodenostomy (DSGD) is used increasingly as an intracorporeal Billroth I anastomosis after distal gastrectomy, worries about anatomical distortion always exist in twisting stomach and making an oblique incision on duodenum. We developed a new method of intracorporeal gastroduodenostomy, the linear-shaped gastroduodenostomy (LSGD), in which anastomosis is done using endoscopic linear staplers only without any complicated rotation. In this report, we introduced LSGD and compared its short-term and long-term outcomes with DSGD.

METHODS

We analyzed 261 consecutive gastric cancer patients who underwent the intracorporeal gastroduodenostomy between January 2009 and May 2014 (LSGD: 190, DSGD: 71), retrospectively. All of them underwent a laparoscopic or robotic distal gastrectomy with regional lymph node dissection. Early surgical outcomes such as operation time, postoperative complications, days until soft diet began, length of hospital stay, and endoscopic findings in postoperative 6 and 12 months were evaluated.

RESULTS

Although the proportion of robotic approach and D2 lymphadenectomy were significantly higher in LSGD group, the rates for overall complications (13.2 % [LSGD] vs. 9.9 % [DSGD], p = 0.470) and major complications (5.8 vs. 5.6 %, p = 1.0) were similar between two groups. There were no differences in anastomotic bleeding (1.1 vs. 1.4 %, p = 1.0), stenosis (3.2 vs. 2.8 %, p = 1.0), and leakage (0.5 vs. 0.0 %, p = 1.0). Endoscopy performed 6 months postoperatively showed that residual food (p = 0.022), gastritis (p = 0.018), and bile reflux (42.0 vs. 63.2 %, p = 0.003) were significantly decreased in LSGD and there were no significant differences in postoperative 12 months.

CONCLUSION

LSGD is an innovative reconstruction technique with comparable short-term outcomes to DSGD. In addition, reduced residual food, gastritis, and bile reflux were seen in LSGD.

Robotic gastrectomy for gastric cancer

Robotic surgery for gastric cancer overcomes technical difficulties with laparoscopic gastrectomy. Its benefits include reduced intraoperative bleeding and shorter hospital stays; it is also easier to learn. Because accuracy increases during lymphadenectomy, a larger number of lymph nodes is likely to be retrieved using robotic gastrectomy. Higher costs and longer operation times have hindered the widespread adaptation and use of robotic surgery. In this review, we summarize the current status and issues regarding robotic gastrectomy.

Three-dimensional fusion images combining CT gastrography and CT angiography for early gastric cancer: pilot experiences of preoperative simulation prior to totally laparoscopic gastrectomy

We herein report two cases of gastric cancer in which preoperative 3-D CT gastrography and CT angiography fusion images enabled totally laparoscopic gastrectomy. Case 1 involved a 60-year-old woman with a superficial depressed lesion on the greater curvature of the middle gastric body. Case 2 involved a 64-year-old woman with a superficial depressed lesion on the posterior wall of the upper gastric body. In both cases, 3-D fusion images were prepared from enhanced CT scans after the area near the lesions was clipped under preoperative gastroendoscopy. Based on the relative position between the clips and nearby vessels, a resection line was preoperatively determined in each case. Totally laparoscopic distal gastrectomy and totally laparoscopic proximal gastrectomy were performed in cases 1 and 2, respectively, with safe surgical margins. Three-dimensional fusion images can help in preoperative simulation of totally laparoscopic gastrectomy.

Laparoscopic gastric surgery for cancer: Where do we stand?

Gastric cancer poses a significant public health problem, especially in the Far East, due to its high incidence in these areas. Surgical treatment and guidelines have been markedly different in the West, but nowadays this debate is apparently coming to an end. Laparoscopic surgery has been employed in the surgical treatment of gastric cancer for two decades now, but with controversies about the extent of resection and lymphadenectomy. Despite these difficulties, the apparent advantages of the laparoscopic approach helped its implementation in early stage and distal gastric cancer, with an increase on the uptake for distal gastrectomy for more advanced disease and total gastrectomy. Nevertheless, there is no conclusive evidence about the laparoscopic approach yet. In this review article we present and analyse the current status of laparoscopic surgery in the treatment of gastric cancer.

A noble method for intraoperative fine localization during laparoscopic gastric local resection: endoscopic submucosal cutting and light transmission

BACKGROUND

The main requirements when performing laparoscopic local resection for early mucosal tumors of the stomach are a clearly defined cancer-free margin and precise tumor localization. In this study, a novel method for precise intraoperative tumor localization and appropriate resection in a porcine model is introduced: endoscopic submucosal cutting and light transmission (ESCLT).

METHODS

A total of 15 cases of laparoscopic local resection were performed in 6 pigs. The size of the target lesions was approximately 20 mm. The imaginary lesions were located in the high body anterior wall, posterior wall, lower body posterior wall, angle, and antrum anterior wall of the stomach. Mucosal marking around the lesions, mucosal precutting surrounding the marking, and submucosal cutting along the precutting line using white light endoscopy were sequentially performed. Next, an endoscopic light source was placed directly in front of the lesion. Exact oval-shaped submucosal cutting margins were identified via laparoscopy. Laparoscopic local resection was performed after the minimal distance from the stapler line to the submucosal cutting line was confirmed. The sizes of the mucosal marking, submucosal cutting line, and the entire resected mucosa and serosa were measured.

RESULTS

The procedure was completed successfully in all pigs. Local resection was completed on all of the lesions. The mean endoscopic and laparoscopic procedure times were 26.1 and 12.7 min, respectively. The mean size of the resected specimens was: (i) marking lesion, 22 × 19.5 mm; (ii) submucosal cutting line, 26.7 × 23.2 mm; (iii) entire resected mucosa, 37 × 31 mm; and (iv) entire resected serosa, 41.7 × 33.1 mm. There was no intraoperative morbidity.

CONCLUSION

ESCLT provides a precise and useful method of intraoperative tumor localization during laparoscopic local resection of the stomach in terms of minimizing the resection of normal stomach tissue and guaranteeing adequate mucosal safety margins.

Development of a non-blurring, dual-imaging tissue marker for gastrointestinal tumor localization

BACKGROUND

Knowing the exact location of gastrointestinal tumors both preoperatively and intraoperatively is essential for planning and performing laparoscopic surgery. Different techniques have been introduced to ascertain tumor locations during surgery, but none of these are fully satisfactory at establishing the minimum margins for organ resection while retaining curability. A new, non-blurring tissue marker, detectable by both X-ray computed tomography (CT) and near-infrared (NIR) fluorescence laparoscopy, has been developed, and we here examine its utility using an animal model.

METHODS

Liposomes, comprised phospholipids and an NIR fluorescent dye (an indocyanine green derivative), and emulsions, consisting of phospholipids and oily radiographic contrast medium, were combined with polyglycerol-polyricinoleate to form giant cluster-like vesicles. This vesicular dispersion (300 μl) was administered into the porcine gastric submucosa using a gastroendoscope, and the detectability of the marker was examined using X-ray CT and NIR fluorescence laparoscopy.

RESULTS

One hour after the administration of the vesicular dispersion, X-ray CT identified four individual injection sites, each at a 1-cm radius of a metal hemostasis clip. NIR fluorescence laparoscopy detected individual fluorescent spots 18 hours after the administration of the vesicular dispersion.

CONCLUSION

We anticipate that this newly developed tissue marker will contribute to the preoperative simulation of laparoscopic gastrointestinal cancer surgery and its intraoperative navigation.

Development of a novel marking system for laparoscopic gastrectomy using endoclips with radio frequency identification tags: feasibility study in a canine model

BACKGROUND

Intraoperative identification of early gastric cancer is difficult to conduct during laparoscopic procedures. In this study, we investigated the feasibility and accuracy of a newly developed marking system using endoclips with radio frequency identification (RFID) tags in a canine model.

METHODS

RFID is a wireless near field communication technology. Among the open frequency bands available for medical use, 13.56 MHz is suitable for a surgical marking system because of the similar and linear signal decay both in air and in biological tissues. The proposed system consists of four parts: (a) endoclips with RFID tags, (b) endo-clip applier equipment, (c) laparoscopic locating probe, and (d) signal processing units with audio interface. In the experimental setting using canine models, RFID-tagged endoclips were applied to the mucosa of each dog's stomach. During the subsequent operation, the clips with RFID tags placed in five dogs were located by the detection of the RFID signal from the tag (RFID group), and the conventional clips in the other six dogs were located by finger palpation (FP group). The detected sites were marked by ablation on the serosal surface. Distance between the clips and the metal pin needles indicating ablated sites were measured with X-ray radiographs of the resected specimen.

RESULTS

All clips were successfully detected by the marking system in the RFID group (10/10) and by finger palpation in the FP group (17/17). The medians of detection times were 31.5 and 25.0 s, respectively; the distances were 5.63 and 7.62 mm, respectively. The differences were not statistically significant. No adverse event related to the procedures was observed.

CONCLUSIONS

Endoclips with RFID tags were located by our novel marking system in an experimental laparoscopic setting using canine stomachs with substantial accuracy comparable to conventional endoclips located by finger palpation through an open approach.

Application of a novel near infrared-fluorescence giant vesicle- and polymerasome-based tissue marker for endoscopic and laparoscopic navigation

In this study, we describe the development of a novel tissue marker that can be injected from within the digestive tract by using an endoscopic instrument, and visualized using near-infrared (NIR) fluorescence imaging. The marker was prepared in three steps, (i) mixing NIR-fluorescent indocyanine green (ICG) with giant vesicles (GVs) of lecithin, (ii) suspending the ICG-containing giant vesicles (ICG-GV) in an oil phase dissolving polyglycerol-polyricinoleate (PGPR), and (iii) centrifugation of the suspension layered on a buffered solution to obtain a giant polymer vesicle (polymerasome) containing ICG-GV. We injected the tissue marker into the inner gastric surface of an anesthetized pig using an endoscopic syringe, and observed the injection site using a fluorescence laparoscopic camera. The diameter of the spot blur was approximately 2 cm over a 5-h period, demonstrating the utility of this procedure as a tissue marker for tumor marking, and suggesting its potential for assisting navigation during surgical procedures.