First case of non-exposed endoscopic wall-inversion surgery with sentinel node basin dissection for early gastric cancer

Non-exposed endoscopic wall-inversion surgery for a gastrointestinal stromal tumor of the stomach: A case report

Complete surgical resections are crucial for permanently curing patients with gastrointestinal stromal tumors (GISTs). Laparoscopic wedge resection is a widely accepted surgical treatment, but identifying the tumor margin from a serosal laparoscopic view is challenging when using this technique. Non-exposed endoscopic wall-inversion surgery (NEWS) for patients with gastric GISTs is a novel, minimally invasive surgical technique that may aid in complete resection of the tumor margin by endoscopy and laparoscopy methods, removing the whole layer of the gastric wall and the entire tumor, with decreased risk of peritoneal contamination or tumor spread to the peritoneum. To the best of our knowledge, the present study reports the first use of NEWS for a patient with small gastric GIST in Thailand. A 61-year old female presented with jaundice and was diagnosed with acute viral hepatitis A. At 4 months, the severity of the symptoms had decreased but the serum transaminase in the liver function tests remained elevated. The computed tomography scans incidentally demonstrated a gastric mass that protruded into the lumen. Endoscopic examination revealed a 2.5×2.0-cm sub-epithelial tumor located in the posterior wall of the upper gastric body. The patient was informed and consented to undergo NEWS. No intraoperative or immediate postoperative complications were detected. The patient was discharged 5 days following the surgery. In a follow-up visit 4 weeks subsequent to the surgery, the patient was healthy and without complications.

Novel approach of laparoscopic and endoscopic cooperative surgery (LECS) for cholecystectomy

BACKGROUND

Endoscopic submucosal dissection (ESD) techniques, such as generating an artificial space between digestive tract layers for safer dissection, were thought to be safer for the resection of organs in cholecystectomy. We investigated whether combinations of endoscopic techniques and laparoscopic techniques could be performed more safely and rapidly.

MATERIAL AND METHODS

Laparoscopic and endoscopic cooperative-cholecystectomy (LEC-chole) and conventional laparoscopic cholecystectomy (Lapa-chole) were performed in six dogs. Operation time was defined as the time from the creation of the first port to the retrieval of the resected gallbladder (GB); and GB bed dissection time was the time from local injection of natural saline to the clipping of the cystic duct. The main roles of the endoscope in LEC-chole were to obtain a sufficient cutting space via local injection of natural saline to the GB bed and to monitor the operative view without laparoscopic camera, thus omitting the umbilical port.

RESULTS

The operation times were 60 ± 18.3 minutes for LEC-chole and 95 ± 7.0 for Lapa-chole (p = .036). The GB bed dissection times were 31 ± 8.54 minutes in LEC-chole and 50.6 ± 7.37 minutes in Lapa-chole (p = 0.048). There were significant differences in liver damage and bleeding (p = 0.116), but there were no significant differences in one-month survival.

CONCLUSIONS

The application of LEC-chole may be expanded to cholecystectomy.

Feasibility and diagnostic performance of dual-tracer-guided sentinel lymph node biopsy in cT1-2N0M0 gastric cancer: a systematic review and meta-analysis of diagnostic studies

BACKGROUND

Dual-tracer-guided sentinel lymph node (SLN) biopsy may provide a promising diagnostic tool to assess accurately the status of lymph node metastasis in the surgical operation and assure the oncologic safety of the function or stomach preserving surgery. The diagnostic performance of this technology in recent studies varied. Thus, we conducted this meta-analysis.

METHODS

This systematic review and meta-analysis was registered at the PROSPERO. Eligible studies were searched in the PubMed, EMBASE, Web of Knowledge, and Cochrane Library databases. A random-effect model was used to pool the data. Summary receiver operator characteristic curves, analysis for publication bias, meta-regression, and subgroup analysis were also performed.

RESULTS

The pooled SLN identification rate and sensitivity were 0.97 and 0.89. ^99mTc-human serum albumin with indocyanine green (ICG), ^99mTc-antimony sulfur colloid with ICG, performing SLN biopsy ≥15 min after dye injection, an SLN ≥5, the basin dissection, laparoscopic surgery, in studies conducted in Japan and studies published after 2012, were associated with higher sensitivity. CT1 stage, performing SLN biopsy ≥15 min after dye injection, in studies conducted in Japan and studies published after 2012, were related with a higher identification rate.

CONCLUSIONS

Dual tracer is promising in SLN biopsy in gastric cancer, and the clinical application of SLN biopsy should be limited to the patients of cT1N0M0 gastric cancer. The combination of ^99mTc-human serum albumin and ICG as well as the combination of ^99mTc-antimony sulfur colloid and ICG may be the optimal tracer combination. However, it seems not justified to put this technique into routine clinical application recently. Some factors that might enhance diagnostic value are identified.

Laparoscopic endoscopic cooperative surgery (LECS) for the upper gastrointestinal tract

We developed the laparoscopic and endoscopic cooperative surgery (LECS) technique, which combines endoscopic submucosal dissection (ESD) and laparoscopic gastric resection to resect gastric submucosal tumors (SMTs). Many researchers have reported LECS to be a feasible technique for gastric submucosal tumor resection regardless of tumor location, including the esophagogastric junction (EGJ). Recently, the Japanese National Health Insurance system approved LECS for insurance coverage, and it is now widely applied for gastric submucosal tumor resection. Initially, we applied LECS to gastric SMTs without ulcerative lesions due to concern about the possibility of tumor cells seeding into the peritoneal cavity, in a procedure termed "classical LECS". To expand the indication of LECS for gastric epithelial neoplasms, modified LECS procedures such as inverted LECS, non-exposed endoscopic wall-inversion surgery (NEWS), combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique (CLEAN-NET), and closed laparoscopic and endoscopic cooperative surgery (closed-LECS) have been developed and applied to patients with gastric epithelial neoplasms. As a future perspective of LECS, we plan to combine the modified LECS procedure and sentinel node (SN) navigation surgery (SNNS) for clinical (c)Stage IA gastric cancer resection. This strategy could be a minimally invasive surgical technique for cStage IA early gastric cancer.

Nonexposure laparoscopic and endoscopic cooperative surgery (closed laparoscopic and endoscopic cooperative surgery) for gastric submucosal tumor

Laparoscopic and endoscopic cooperative surgery (LECS) is increasingly applied for gastric submucosal tumors (SMTs) such as gastrointestinal stromal tumors. However, the conventional LECS procedure has the potential risk that gastric contents and even tumor cells could spread into the abdominal cavity because the gastric wall has to be opened during the resection. To avoid this problem, we have developed a modified LECS procedure named "closed LECS." Ten patients underwent closed LECS for the resection of gastric SMTs. Closed LECS consists of the following steps: endoscopic submucosal layer dissection around the tumor, laparoscopic marking of a resection line on the serosal surface along submucosal dissection line, seromuscular suturing with the marked lesion inverted into the inside of the stomach, endoscopic circumferential seromuscular dissection, and peroral retrieval. In three of the initial five cases, the closed LECS procedure was not completed as planned because of the tumor size and endoscopic inappropriate seromuscular dissection. After modification of the procedure, the entire procedure was successful in all five cases. The mean resected tumor diameter was 24.1 ± 7.6 mm. The mean operation time was 253 ± 45 min. One patient experienced an intra-abdominal abscess potentially related to delayed perforation as a postoperative complication. The closed LECS procedure for gastric SMTs can theoretically be applied without contamination and tumor cell dissemination into the abdominal cavity.

Updated evidence on endoscopic resection of early gastric cancer from Japan

BACKGROUND

Endoscopic resection for early gastric cancer (EGC) plays a central role in the treatment of EGC in Japan. However, there is still room for improvement, and it is necessary to summarize the recently obtained knowledge from Japan for further improvement.

METHODS

We conducted a PubMed search to select relevant articles in the 5 years until September 18, 2016, using the keywords "gastric cancer" and "endoscopic treatment," "endoscopic submucosal dissection," "endoscopic mucosal resection," or "polypectomy" and filtering article types as "clinical study" or "clinical trial."

RESULTS

Among the 329 articles selected automatically from the keywords "polypectomy" (1 article), "endoscopic mucosal resection" (29 articles), "endoscopic submucosal dissection" (77 articles), and "endoscopic treatment" (222 articles) in combination with "gastric cancer," 32 relevant articles from Japanese investigators were chosen. Seven articles were categorized into "equipment," 4 into "preparation and sedation," 17 into "complications and their prevention," and 4 into "therapeutic outcomes." Among them, CO₂ insufflation, propofol sedation, and how to prevent post-endoscopic submucosal dissection (ESD) ulcer bleeding and achieve post-ESD ulcer healing were intensively investigated. Long-term outcomes of endoscopic mucosal resection and ESD were also reported as favorable outcomes.

CONCLUSIONS

Endoscopic resection for EGC is still developing toward an ideal form, pursuing a more reliable, safer, and faster minimally invasive treatment.

Current Status of Exposed Endoscopic Full-Thickness Resection and Further Development of Non-Exposed Endoscopic Full-Thickness Resection

Endoscopic full-thickness resection (EFTR) is a procedure that makes it possible to access the lesions that are on the wall of the digestive tract via the shortest distance through the mouth. Because of the ultra-minimal invasive nature of the treatment, pure EFTR is a highly promising surgical procedure that allows the radical excision of full-thickness layers of digestive tract tumors using only a flexible endoscope. There are 2 types of EFTR methods: exposed and non-exposed. Considering the risks of contracting infection and intraperitoneal dissemination of tumor cells, non-exposed EFTR is an ideal method. However, a number of issues remain unresolved, including the method for performing a full-thickness suture under endoscopic view and the challenge of securing the operating field in the case of gastrointestinal tract collapse. Moreover, advances in the development of equipment such as full-thickness suturing devices would be helpful to make this therapeutic procedure the most minimally invasive endoscopic surgery ever.

Sentinel node navigation in gastric cancer: new horizons for personalized minimally invasive surgical oncology?

Complete (R0) resection and regional lymph nodes (LNs) dissection represent undoubtedly the basic surgical tools for patients with gastric cancer. It is reported that the LN metastasis rate in patients with early gastric cancer (EGC) is approximately 15-20%. Therefore, the innovative clinical application of sentinel node navigation surgery (SNNS) for EGC might be able to prevent unnecessary LN dissection as well as to reduce significantly the volume of gastric resection. Recent evidence suggests that double tracer methods appear superior compared to single tracer techniques. However, the researchers' interest is now focused on the identification of new LN detection methods utilizing sophisticated technology such as infrared ray endoscopy, fluorescence imaging and near-infrared technology. Despite its notable limitations, hematoxylin-eosin is still considered the mainstay staining for assessing the metastatic status of LNs. In this review, we summarize the current evidences and we provide the latest scientific information assessing safety, efficacy and potential limitations of the innovative sentinel node (SN) navigation technique for gastric cancer. We try also to provide a "view" towards a future potential application of personalized minimally invasive surgery in gastric cancer field.

Clinical significance of the anterosuperior lymph nodes along the common hepatic artery identified by sentinel node mapping in patients with gastric cancer

BACKGROUND

The sentinel node (SN) concept is safely applied and validated in early gastric cancer. Gastric lymph nodes are divided into five basins with the main gastric arteries, and the anterosuperior lymph nodes with the common hepatic artery (No. 8a) are classified in the right gastric artery (r-GA) basin. Although No. 8a are considered to have lymphatic flow from the r-GA basin, there might be additional multiple lymphatic flows into No. 8a. The aim of this study is to analyze the lymphatic flows to No. 8a and to investigate the clinical significance of No. 8a as a sentinel node (SN No. 8a).

METHODS

Four hundred and twenty-nine patients with cT1N0 or cT2N0 gastric cancer underwent SN mapping. We used technetium-99 tin colloid solution and blue dye as a tracer.

RESULTS

We detected SN No. 8a in 35 (8.2 %) patients. In these patients, we detected SN No. 8a with SNs that belonged to the left gastric artery (l-GA) basin (66 %), right gastroepiploic artery (r-GEA) basin (54 %), and right gastric artery (r-GA) basin (46 %). In addition, celiac artery lymph nodes were detected as SNs significantly more frequently. Function-preserving surgery was performed significantly less often in patients with SN No. 8a (p =0.018).

CONCLUSIONS

We found that SN No. 8a seemed to have lymphatic flow not only from the r-GA basin, but also from the l-GA basin or r-GEA basin. When SN No. 8a are detected, we should be careful to perform function-preserving surgery, even in SN-negative cases.

Non-Exposed Endoscopic Wall-Inversion Surgery for Gastrointestinal Stromal Tumor of the Stomach: First Case Report in Korea

Laparoscopic wedge resection of the stomach is a widely accepted treatment for primary resectable gastrointestinal stromal tumors (GISTs). However, it is difficult to determine the appropriate incision line from outside of the stomach, and many attempts have been made to avoid unnecessary resection of unaffected gastric tissues. Recently a technique called non-exposed endoscopic wall-inversion surgery (NEWS) was introduced to avoid exposure of GIST to the peritoneum. Here, we describe the first published case of NEWS for GIST of the stomach practiced in Korea.

Risk factors for lymph node metastasis and long-term outcomes of patients with early gastric cancer after non-curative endoscopic submucosal dissection

BACKGROUND

The long-term outcomes after non-curative gastric endoscopic submucosal dissection (ESD) are still unknown. We aimed to clarify the pathological risk factors for lymph node metastasis (LNM) of early gastric cancer (EGC) and the long-term outcomes among patients who were judged to have had non-curative ESD.

METHODS

From September 2002 to December 2012, 506 patients who were judged to have had non-curative gastric ESD were enrolled and classified into two groups: (1) those who subsequently underwent additional surgical resection (surgical group, n = 323) and (2) those followed up without additional surgical resection (nonsurgical group, n = 183). We analyzed pathological risk factors for LNM of EGC in the surgical group. Additionally, we compared long-term outcomes in the two groups.

RESULTS

LNM was found pathologically in 9.3 % of the surgical group (30/323) at the additional surgical resection after non-curative ESD. In the multivariate logistic regression analysis, lymphovascular invasion (LVI) was an independent risk factor for LNM in the surgical group (odds ratio 8.57, 95 % confidence interval 2.76-38.14, P < 0.0001). The 5-year cause-specific survival rate was similar in the surgical and nonsurgical groups (98.7 and 96.5 %, respectively; log-rank test, P = 0.07). In contrast, the 5-year cause-specific survival rate of patients with LVI in the surgical group was better than that in the nonsurgical group (98.2 and 79.1 %, respectively; log-rank test, P < 0.0001).

CONCLUSIONS

A detailed assessment of LVI is essential to the pathological evaluation of endoscopically resected specimens. An additional surgical resection should be strongly recommended for patients with LVI.

Feasibility of laparoscopic and endoscopic cooperative surgery for gastric submucosal tumors (with video)

BACKGROUND AND AIMS

Laparoscopic gastric resection is widely used for gastric submucosal tumors (SMTs). However, determining an appropriate resection line using only the laparoscopic approach is difficult. We developed a laparoscopic and endoscopic cooperative surgery (LECS) technique by combining laparoscopic gastric resection with endoscopic submucosal dissection, and we have used this procedure to resect gastric SMTs. In this study, the procedure is presented and its safety and feasibility for resecting gastric SMTs are evaluated.

METHODS

This retrospective study included 100 patients who underwent LECS for SMTs at the Department of Gastroenterological Surgery, Cancer Institute, between June 2006 and November 2014. The demographics, tumor histopathologic characteristics, and operative and follow-up data were reviewed.

RESULTS

Complete resection with negative surgical margins was achieved in all patients, and LECS was performed regardless of tumor location. The mean operation time was 174.3 minutes, with an estimated blood loss of 16.3 mL. In addition, the mean time until the initiation of oral intake was 1.4 days, and the mean postoperative hospital stay was 8.4 days. Moreover, no local or distant tumor recurrence was observed. The only severe adverse event was leakage, which was observed in 1 patient.

CONCLUSIONS

LECS was performed with a reasonable operation time, low blood loss, and minimal adverse events. Therefore LECS is safe and feasible for resecting gastric SMTs.

Hybrid surgery for early gastric cancer

Endoscopic submucosal dissection (ESD) is the most suitable treatment option in terms of minimally invasive treatment for potential node-negative early gastric cancers (EGCs). Furthermore, making the resection area of the primary lesion as small as possible is ideal for the patient's quality of life, even for potential node-positive EGC. An endoluminal approach is a reasonable option with which to minimize stomach resection area, because this procedure can be accurately demarcated from the inside. From this point of view, endoscopic full-thickness resection (EFTR) may be optimal, while laparoscopic assistance would be more desirable to create a more secure procedure. However, hybrid EFTR for EGCs has two limitations, which must be solved. First, concerns regarding iatrogenic tumor seeding via transluminal communication between the inside and outside of the tract exist. The second limitation relates to the determination of lymphadenectomy. Conventional lymphadenectomy, which involves the removal of the majority of feeding arteries, can lead to necrosis of the remaining gastric wall. Therefore, the resection area of lymphadenectomy should also be carefully determined. To address these two problems, a non-exposed hybrid EFTR combined with sentinel node navigation surgery (SNNS) would be the most ideal method of minimally invasive surgery for EGCs.

Endoscopic Submucosal Dissection (ESD) and Related Techniques as Precursors of "New Notes" Resection Methods for Gastric Neoplasms

Endoscopic full-thickness resection for subepithelial tumors is one of the more attractive proposed methods for less-invasive transluminal surgery but remains challenging in terms of safety and feasibility. Currently, laparoscopic endoscopic cooperative surgery is thought to be a more clinically acceptable approach. In targeting cancers, however, more advanced nonexposure techniques are required to avoid the risk of iatrogenic tumor seeding. By combining these techniques with possible regional lymphadenectomy using sentinel node navigation surgery, an ideal minimally invasive, function-preserving gastric resection can be achieved even in possible node-positive cancers. Further development for this type of advanced endoscopic surgery is expected.

Minimally invasive function-preserving surgery based on sentinel node concept in early gastric cancer

Recent meta-analyses and a prospective multicenter trial of sentinel node (SN) mapping for early gastric cancer have shown acceptable SN detection rates and accuracy of determination of lymph node status. A dual-tracer method that employs radioactive colloids and blue dyes is currently considered the most reliable method for the stable detection of SNs in patients with early gastric cancer. However the new technologies such as indocyanine green (ICG) infrared or fluorescence imaging may revolutionize the SN mapping procedures in gastric cancer. For early stage gastric cancer, the establishment of individualized, minimally invasive treatments based on SN concept can retain the patients' quality of life (QOL). The combination of non-exposed endoscopic wall-inversion surgery (NEWS) with SN biopsy is expected to become a promising, ideal minimally invasive, function-preserving surgery to cure cases of cN0 early gastric cancer.

Sentinel lymph node navigation surgery for gastric cancer: Does it really benefit the patient?

Sentinel lymph node (SLN) navigation surgery is accepted as a standard treatment procedure for malignant melanoma and breast cancer. However, the benefit of reduced lymphadenectomy based on SLN examination remains unclear in cases of gastric cancer. Here, we review previous studies to determine whether SLN navigation surgery is beneficial for gastric cancer patients. Recently, a large-scale prospective study from the Japanese Society of Sentinel Node Navigation Surgery reported that the endoscopic dual tracer method, using a dye and radioisotope for SLN biopsy, was safe and effective when applied to cases of superficial and relatively small gastric cancers. SLN mapping with SLN basin dissection was preferred for early gastric cancer since it is minimally invasive. However, previous studies reported that limited gastrectomy and lymphadenectomy may not improve the patient’s postoperative quality of life (QOL). As a result, the benefit of SLN navigation surgery for gastric cancer patients, in terms of their QOL, is limited. Thus, endoscopic and laparoscopic limited gastrectomy combined with SLN navigation surgery has the potential to become the standard minimally invasive surgery in early gastric cancer.

Cooperative laparoscopic endoscopic and hybrid laparoscopic surgery for upper gastrointestinal tumors: Current status

AIM

To investigate the cooperative laparoscopic and endoscopic techniques used for the resection of upper gastrointestinal tumors.

METHODS

A systematic research of the literature was performed in PubMed for English and French language articles about laparoscopic and endoscopic cooperative, combined, hybrid and rendezvous techniques. Only original studies using these techniques for the resection of early gastric cancer, benign tumors and gastrointestinal stromal tumors of the stomach and the duodenum were included. By excluding case series of less than 10 patients, 25 studies were identified. The study design, number of cases, tumor pathology size and location, the operative technique name, the endoscopy team and surgical team role, operative time, type of closure of visceral wall defect, blood loss, complications and length of hospital stay of these studies were evaluated. Additionally all cooperative techniques found were classified and are presented in a systematic approach.

RESULTS

The studies identified were case series and retrospective cohort studies. A total of 706 patients were operated on with a cooperative technique. The tumors resected were only gastrointestinal stromal tumors (GIST) in 4 studies, GIST and various benign submucosal tumors in 22 studies, early gastric cancer (pT1a and pT1b) in 6 studies and early duodenal cancer in 1 study. There was important heterogeneity between the studies. The operative techniques identified were: laparoscopic assisted endoscopic resection, endoscopic assisted wedge resection, endoscopic assisted transgastric and intragastric surgery, laparoscopic endoscopic cooperative surgery (LECS), laparoscopic assisted endoscopic full thickness resection (LAEFR), clean non exposure technique and non-exposed endoscopic wall-inversion surgery (NEWS). Each technique is illustrated with the roles of the endoscopic and laparoscopic teams; the indications, characteristics and short term results are described.

CONCLUSION

Along with the traditional cooperative techniques, new procedures like LECS, LAEFR and NEWS hold great promise for the future of minimally invasive oncologic procedures.

Cutting edge of endoscopic full-thickness resection for gastric tumor

Recently, several studies have reported local full-thickness resection techniques using flexible endoscopy for gastric tumors, such as gastrointestinal stromal tumors, gastric carcinoid tumors, and early gastric cancer (EGC). These techniques have the advantage of allowing precise resection lines to be determined using intraluminal endoscopy. Thus, it is possible to minimize the resection area and subsequent deformity. Some of these methods include: (1) classical laparoscopic and endoscopic cooperative surgery (LECS); (2) inverted LECS; (3) combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique; and (4) non-exposed endoscopic wall-inversion surgery. Furthermore, a recent prospective multicenter trial of the sentinel node navigation surgery (SNNS) for EGC has shown acceptable results in terms of sentinel node detection rate and the accuracy of nodal metastasis. Endoscopic full-thickness resection with SNNS is expected to become a treatment option that bridges the gap between endoscopic submucosal dissection and standard surgery for EGC. In the future, the indications for these procedures for gastric tumors could be expanded.

Estimation of subepithelial lateral extent in submucosal early gastric cancer: retrospective histological analysis

BACKGROUND

Endoscopic full-thickness resection (EFTR) is expected to make possible minimally invasive local resection of early gastric cancer (EGC). However, no consensus exists regarding how far an optimal safety margin should be set in determining the resection area by endoscopy. We aimed to investigate the optimal lateral margin of EGC which could be a candidate for EFTR by measuring the subepithelial extent (SE) of tumors.

METHODS

In 60 surgically resected submucosal EGCs 4 cm or smaller, 595 prepared slides which showed lateral tumor borders both on the epithelial surface and on the subepithelial layer were assessed. The distance between the epithelial and the subepithelial tumor edge was measured under microscopic observation, followed by analyses of the relationship between the measured SE and the histological characteristics.

RESULTS

The average and the median SE were 1.1 mm (standard deviation 1.8 mm) and 0.3 mm (range 0-12.3 mm), respectively. The 99th percentile was 8.8 mm. With regard to the histological type, the median SE was significantly greater in diffuse-type tumor than in intestinal-type tumor (0.9 mm vs 0 mm, p < 0.0001). With regard to the location of the subepithelilal tumor edge, the median SE was significantly greater in the submucosal layer than in the mucosal layer (2.6 mm vs 0.3 mm, p < 0.0001).

CONCLUSIONS

In most lesions, the SE was less than 1 cm. A safety margin may be set at 1 cm in EFTR of submucosal EGC.

Single skip metastasis in sentinel lymph node: In an early gastric cancer

Lymph node status is considered a key prognostic and predictive factor in patients with gastric cancer (GC). Although there is a practical approach to the intraoperative detection of sentinel lymph nodes (SLNs), such a procedure is not included in the European surgical protocol. In this report, we present a practical approach to SLN mapping in a representative case with early gastric cancer (EGC). A 74-year-old female was hospitalized with an endoscopically observed, superficially ulcerated tumor located in the antral region. Subtotal gastrectomy with D2 lymphadenectomy and SLN mapping was performed by injecting methylene blue dye into the peritumoral submucosal layer. An incidentally detected blue-stained lymph node located along the middle colic artery was also removed. This was detected 40 min after injection of the methylene blue. Histopathologic examination showed a pT1b-staged well-differentiated HER-2-negative adenocarcinoma. All of the 41 LNs located at the first, third, and fifth station of the regional LN compartments were found to be free of tumor cells. The only lymph node with metastasis was located along the middle colic artery and was considered a non-regional lymph node. This incidentally identified skip metastasis indicated stage IV GC. A classic chemotherapy regimen was given, and no recurrences were observed six months after surgery. In this representative case, low-cost SLN mapping, with a longer intraoperative waiting time, totally changed the stage of the tumor in a patient with EGC.