MicBall800-coated metal clip as a novel fluorescent marker for image-guided laparoscopic surgery.

Accurate tumor localization is crucial for the success of minimally invasive surgery, as it minimizes the resection of normal tissues surrounding tumors. Traditional methods for marking gastrointestinal (GI) tumors, such as ink tattooing, intraoperative gastroscopy or colonoscopy, and placement of metal clips, have major drawbacks in their application in laparoscopic surgery. Therefore, the development of safe and easy-to-operate marking methods for accurate and real-time detection of GI tumors during laparoscopic surgery remains an ongoing challenge. Here, we propose a new fluorescent metal clip (MicBall800 clip) for noninvasive and precise fluorescence marking of GI tumors. First, we prepared a poly(methyl methacrylate) microball with small, multiple, and separated pores in its internal structure, and near-infrared fluorescence dye (IRDye800CW) and human serum albumin complex were loaded into the pores. This near-infrared-dye-loaded poly(methyl methacrylate) microball (MicBall800) was then coated onto the surface of the metal clips to produce a highly fluorescent MicBall800 clip. Safety and biocompatibility tests of the MicBall800 clip were conducted by the Korea Testing Certification Institute. The MicBall800 clip was evaluated in vivo using a porcine model. The MicBall800 clip passed safety and biocompatibility tests. The MicBall800 clip could be easily marked at the target sites without causing any side effects and was detected in real time during the laparoscopic operation. The data obtained from the safety and biocompatibility tests and the in vivo animal study indicate that the MicBall800 clip can be an important advancement in minimally invasive and precision surgery for GI cancers.

A pilot clinical study to evaluate feasibility of using single patient classifier as a prognostic test in stage II-III gastric cancer patients.

Objective: Precision medicine approaches emphasize the importance of reliable prognostic tools for guiding individualized therapy decisions. In this study, we evaluated the clinical feasibility of the single patient classifier (SPC) test, a new clinical-grade prognostic assay, in stage II-III gastric cancer patients. Methods: A prospective multicenter study was conducted, involving 237 patients who underwent gastrectomy between September 2019 and August 2020 across nine hospitals. The SPC test was employed to stratify patients into risk groups, and its feasibility and performance were evaluated. The primary endpoint was the proportion of the cases in which the test results were timely delivered before selecting postoperative treatment. Furthermore, 3-year disease-free survivals of risk groups were analyzed. Results: The SPC test met the primary endpoint criteria. The 99.5% of SPC tests were timely delivered to hospitals before the postoperative treatment started. In a clinical setting, the median time from the specimen transfer to laboratory to the result delivery to hospital was 4 d. Furthermore, 3-year disease-free survivals were significantly different between risk groups classified with SPC tests. Conclusions: This study highlights the SPC test's feasibility in offering crucial information timely delivered for making informed decisions regarding postoperative treatment strategies. It also provides evidence to support the implementation of a future prospective clinical trial aimed at evaluating the clinical utility of the SPC test in guiding personalized treatment decisions for gastric cancer patients.

Laparoscopic Pylorus Preserving Gastrectomy vs Distal Gastrectomy for Early Gastric Cancer; A Multicenter Randomized Controlled Trial (KLASS-04).

OBJECTIVE: To evaluate the long-term outcomes of laparoscopic pylorus preserving gastrectomy (LPPG) with laparoscopic distal gastrectomy (LDG) for early gastric cancer (EGC). SUMMARY BACKGROUND DATA: PPG is considered as a function preserving surgery for EGC. However, there has been no multicenter randomized controlled trial comparing PPG with DG until now. METHODS: A multicenter randomized controlled trial (KLASS-04) with 256 patients with cT1N0M0 gastric cancer located in the mid portion of the stomach was conducted. The primary endpoint was the incidence of dumping syndrome at postoperative 1 year. Secondary endpoints included survival and recurrence, gallstone formation, nutritional parameters, gastroscopic findings, and quality of life (QOL) for 3 years. RESULTS: In the intention-to-treat analyses, there was no difference in the incidence of dumping syndrome at one year postoperatively (13.2% in LPPG vs. 15.8% in LDG, P=0.622). Gallstone formation after surgery was significantly lower in LPPG than in LDG (2.33% vs. 8.66%, P=0.026). Hemoglobin (+0.01 vs. -0.76 gm/dL, P<0.001) and serum protein (-0.15 vs. -0.35 gm/dL, P=0.002) were significantly preserved after LPPG. However, reflux esophagitis (17.8% vs. 6.3%, P=0.005) and grade IV delayed gastric emptying (16.3% vs. 3.9%, P=0.001) were more common in LPPG. Changes in body weight and postoperative QOL were not significantly different between groups. Three-year overall survival and disease-free survival were not different (1 case of recurrence of in each group, P=0.98). CONCLUSIONS: LPPG can be used as an alternative surgical option for cT1N0M0 gastric cancer in the mid portion of the stomach.

Feasibility of Regional Lymphadenectomy for Stomach-Preserving Surgery in Early Gastric Cancer Omitting Sentinel Node Navigation: A Post Hoc Analysis of the SENORITA Trial.

BACKGROUND: Sentinel node navigation (SNN) has been known as the effective treatment for stomach-preserving surgery in early gastric cancer; however, SNN presents several technical difficulties in real practice. OBJECTIVE: This study aimed to evaluate the feasibility of regional lymphadenectomy omitting SNN, using the post hoc analysis of a randomized controlled trial. METHODS: Using data from the SENORITA trial that compared laparoscopic standard gastrectomy with lymphadenectomy and laparoscopic SNN, 237 patients who underwent SNN were included in this study. Tumor location was divided into longitudinal and circumferential directions. According to the location of the tumor, the presence or absence of lymph node (LN) metastases between sentinel and non-sentinel basins were analyzed. Proposed regional LN stations were defined as the closest area to the primary tumor. Sensitivities, specificities, positive predictive values, and negative predictive values (NPV) of SNN and regional lymphadenectomy were compared. RESULTS: Metastasis to non-sentinel basins with tumor-free in sentinel basins was observed in one patient (0.4%). The rate of LN metastasis to non-regional LN stations without regional LN metastasis was 2.5% (6/237). The sensitivity and NPV of SNN were found to be significantly higher than those of regional lymphadenectomy (96.8% vs. 80.6% [p = 0.016] and 99.5% vs. 97.2% [p = 0.021], respectively). CONCLUSIONS: This study showed that regional lymphadenectomy for stomach-preserving surgery, omitting SNN, was insufficient; therefore, SNN is required in stomach-preserving surgery.

Quality of Life and Nutritional Outcomes of Stomach-Preserving Surgery for Early Gastric Cancer: A Secondary Analysis of the SENORITA Randomized Clinical Trial.

Importance: The Sentinel Node Oriented Tailored Approach (SENORITA) randomized clinical trial evaluated quality of life (QoL) and nutritional outcomes between the laparoscopic sentinel node navigation surgery (LSNNS) and laparoscopic standard gastrectomy (LSG). However, there has been no report on the QoL and nutritional outcomes of patients who underwent stomach-preserving surgery among the LSNNS group. Objective: To compare long-term QoL and nutritional outcomes between patients who underwent stomach-preserving surgery and those who underwent standard gastrectomy and to identify factors associated with poor QoL outcomes in patients who underwent stomach-preserving surgery. Design, Setting, and Participants: This study is a secondary analysis of the SENORITA trial, a randomized clinical trial comparing LSNNS with LSG. Patients from 7 tertiary or general hospitals across the Republic of Korea were enrolled from March 2013 to December 2016, with follow-up through 5 years. Data were analyzed between August and September 2022. Among trial participants, patients who underwent actual laparoscopic standard gastrectomy in the LSG group and those who underwent stomach-preserving surgery in the LSNNS group were included. Patients who did not complete the baseline or any follow-up questionnaire were excluded. Intervention: Stomach-preserving surgery vs standard gastrectomy. Main Outcomes and Measures: Overall European Organization for Research and Treatment of Cancer QoL Questionnaire Core 30 (EORTC QLQ-C30) and stomach module (STO22) scores, body mass index, hemoglobin, protein, and albumin levels. Results: A total of 194 and 257 patients who underwent stomach-preserving surgery and standard gastrectomy, respectively, were included in this study (mean [SD] age, 55.6 [10.6] years; 249 [55.2%] male). The stomach-preserving group had better QoL scores at 3 months postoperatively in terms of physical function (87.2 vs 83.9), dyspnea (5.9 vs 11.2), appetite loss (13.1 vs 19.4), dysphagia (8.0 vs 12.7), eating restriction (10.9 vs 18.2), anxiety (29.0 vs 35.2), taste change (7.4 vs 13.0), and body image (19.5 vs 27.2). At 1 year postoperatively, the stomach-preserving group had significantly higher body mass index (23.9 vs 22.1, calculated as weight in kilograms divided by height in meters squared) and hemoglobin (14.3 vs 13.3 g/dL), albumin (4.3 vs 4.25 g/dL), and protein (7.3 vs 7.1 g/dL) levels compared to the standard group. Multivariable analyses showed that tumor location (greater curvature, lower third) was favorably associated with global health status (ß, 10.5; 95% CI, 3.2 to 17.8), reflux (ß, -8.4; 95% CI, -14.7 to -2.1), and eating restriction (ß, -5.7; 95% CI, -10.3 to -1.0) at 3 months postoperatively in the stomach-preserving group. Segmental resection was associated with risk of diarrhea (ß, 40.6; 95% CI, 3.1 to 78.1) and eating restriction (ß, 15.1; 95% CI, 1.1 to 29.1) at 3 years postoperatively. Conclusions and Relevance: Stomach-preserving surgery after sentinel node evaluation was associated with better long-term QoL and nutritional outcomes than standard gastrectomy. These findings may help facilitate decision-making regarding treatment for patients with early-stage gastric cancer. Trial Registration: ClinicalTrials.gov Identifier: NCT01804998.

Real-world Nationwide Outcomes of Minimally Invasive Surgery for Advanced Gastric Cancer Based on Korean Gastric Cancer Association-Led Survey.

PURPOSE: The study aimed to investigate real-world surgical outcomes of minimally invasive surgery (MIS) for advanced gastric cancer using Korean Gastric Cancer Association (KGCA)-led nationwide data. MATERIALS AND METHODS: A nationwide survey of patients who underwent surgical treatment for gastric cancer in 2019 was conducted by the KGCA. A total of 14,076 patients from 68 institutions underwent surgery, and 4,953 patients diagnosed with pathological stages IB-III gastric cancer were included. Among them, 1,689 patients who underwent MIS (MIS group) and 1,689 who underwent the open approach (open group) were matched using propensity score in a 1:1 ratio. Surgical outcomes were compared, and multivariate analysis was performed to identify the independent factors for overall morbidity. RESULTS: The MIS group had a lower proportion of D2 lymphadenectomy, total omentectomy, and combined resection. However, the number of harvested lymph nodes was higher in the MIS group. Better surgical outcomes, including less blood loss and shorter hospital stay, were observed in the MIS group, and the overall morbidity rate was significantly lower in the MIS group (17.5% vs. 21.9%, P=0.001). The mortality rates did not differ significantly between the 2 groups. In the multivariate analysis, the minimally invasive approach was a significant protective factor against overall morbidity (odds ratio, 0.799; P=0.006). CONCLUSIONS: Based on the Korean nationwide data, MIS for stage IB-III gastric cancer had better short-term outcomes than the open approach, including lower rates of wound complications, intra-abdominal abscesses, and cardiac problems.

Feasibility of intraoperative pathologic examination for sentinel lymph nodes during sentinel node navigation surgery in early gastric cancer: results of pathologic protocol for SENORITA trial.

BACKGROUND: During sentinel node navigation surgery in patients with gastric cancer, intraoperative pathologic examination of sentinel nodes is crucial in determining the extent of surgery. In this study, we evaluated the feasibility and accuracy of intraoperative pathologic protocols using data from a prospective, multicenter, randomized trial. METHODS: A retrospective analysis was conducted using data from the SEntinel Node ORIented Tailored Approach trials from 2013 to 2016. All sentinel lymph nodes were evaluated during surgery with hematoxylin-eosin (HE) staining using a representative section at the largest plane for lymph nodes. For permanent histologic evaluation, sentinel basin nodes were stained with HE and cytokeratin immunohistochemistry in formalin-fixed, paraffin-embedded (FFPE) sections and examined with HE for three deeper-step sections at 200-µm intervals. The failure rate of identification by frozen section and the metastasis rate in non-sentinel basins were investigated. RESULTS: Of the 237 patients who underwent sentinel node basin dissection, 30 had lymph node metastases on permanent pathology. Thirteen patients had macrometastasis confirmed in frozen sections as well as FFPE sections (failure rate: 0%). Patients with negative sentinel nodes in frozen sections but micrometastasis in FFPE sections had no lymph node recurrence during the follow-up period (0%, 0/6). However, in cases with tumor-positive nodes in frozen sections, metastases in non-sentinel basins were detected in the paraffin blocks (8.3%, 2/24). CONCLUSIONS: The single-section HE staining method is sufficient for detecting macrometastasis via intraoperative pathological examination. If a negative frozen-section result is confirmed, sentinel basin dissection can be performed safely. Otherwise, standard surgery is required.

Clinical Efficacy of Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: 5-year Results of the SENORITA Trial.

OBJECTIVE: This study aimed to compare laparoscopic standard gastrectomy (LSG) and laparoscopic sentinel node navigation surgery (LSNNS) for EGC in terms of 5-year long-term oncologic outcomes. SUMMARY BACKGROUND DATA: The oncological safety of LSNNS for early gastric cancer (EGC) has not been confirmed. Three-year disease-free survival (DFS), which is the primary endpoint of the phase III multicenter randomized controlled clinical trial (SEntinel Node ORIented Tailored Approach [SENORITA] trial), did not show the non-inferiority of LSNNS relative to LSG. METHODS: The SENORITA trial, a multicenter randomized clinical trial, was designed to show that LSNNS is non-inferior to LSG in terms of 3-year DFS. In the present study, we collected 5-year follow-up data from 527 patients recruited in the SENORITA trial as the full analysis set (FAS). Disease-free survival (DFS), overall survival (OS), disease-specific survival (DSS), and recurrence patterns were evaluated using the FAS of both LSG (n=269) and LSNNS (n=258). RESULTS: The 5-year DFS was not significantly different between the LSG and LSNNS groups (P=0.0561). During the 5-year follow-up, gastric cancer-related events, such as metachronous cancer, were more frequent in the LSNNS group than in the LSG group. However, ten recurrent cancers in the remnant stomach of both groups were curatively resected by additional gastrectomy and one by additional endoscopic resection. Two of the 198 patients who underwent local resection for stomach preservation based on the LSNNS results developed distant metastasis. However, there was no statistically significant difference in the 5-year OS and DSS (P=0.7403 and P=0.9586, respectively) between the two groups. CONCLUSION: The 5-year DFS, DSS and OS did not differ significantly between the two groups. Considering the benefits of LSNNS on postoperative quality of life, LSNNS could be recommended as an alternative treatment option for EGC.

Effect of Vitamin B12 Replacement Intervals on Clinical Symptoms and Laboratory Findings in Gastric Cancer Patients after Total Gastrectomy.

The management of patients with vitamin B12 deficiency after total gastrectomy (TG) remains controversial. We aimed to evaluate the effect of vitamin B12 replacement intervals on the clinical characteristics in these patients. The data from patients who received vitamin B12 supplementation after TG between 2007 and 2018 at the National Cancer Center, Korea, were retrospectively evaluated. Vitamin B12 deficiency was defined as a serum vitamin B12 level of <200 pg/mL or urine methylmalonic acid level > 3.8 mg/gCr. The patients were divided into a regular replacement group (patients received an intramuscular injection or oral medication regularly), and a lab-based replacement group (patients received vitamin B12 intermittently after checking the level). The symptoms and biochemical parameters were compared between these groups. The regular and lab-based replacement groups included 190 and 216 patients, respectively. The median vitamin B12 replacement intervals were 1 and 9 months, respectively (p < 0.001). After replacement, the regular replacement group had higher vitamin B12 levels than the lab-based replacement group (p < 0.001). However, the serum hemoglobin level showed no significant changes. After replacement, there was no significant difference in the proportion of the symptomatic patients between the groups. Replacing vitamin B12 with a lab-based protocol may be sufficient for TG patients.

Stomach tissue classification using autofluorescence spectroscopy and machine learning.

BACKGROUND AND OBJECTIVES: Determination of stomach tumor location and invasion depth requires delineation of gastric histological structure, which has hitherto been widely accomplished by histochemical staining. In recent years, alternative histochemical evaluation methods have been pursued to accelerate intraoperative diagnosis, often by bypassing the time-consuming step of dyeing. Owing to strong endogenous signals from coenzymes, metabolites, and proteins, autofluorescence spectroscopy is a favorable candidate technique to achieve this aim. MATERIALS AND METHODS: We investigated stomach tissue slices and block specimens using a fast fluorescence imaging scanner. To obtain histological information from broad and structureless fluorescence spectra, we analyzed tens of thousands of spectra with multiple machine-learning algorithms and built a tissue classification model trained with dissected gastric tissues. RESULTS: A machine-learning-based spectro-histological model was built based on the autofluorescence spectra measured from stomach tissue samples with delineated and validated histological structures. The scores from a principal components analysis were employed as input features, and prediction accuracy was confirmed to be 92.0%, 90.1%, and 91.4% for mucosa, submucosa, and muscularis propria, respectively. We investigated the tissue samples in both sliced and block forms using a fast fluorescence imaging scanner. CONCLUSION: We successfully demonstrated differentiation of multiple tissue layers of well-defined specimens with the guidance of a histologist. Our spectro-histology classification model is applicable to histological prediction for both tissue blocks and slices, even though only sliced samples were trained.

Risk prediction model of peritoneal seeding in advanced gastric cancer: A decision tool for diagnostic laparoscopy.

BACKGROUND: Selective diagnostic laparoscopy in gastric cancer patients at high risk of peritoneal metastasis is essential for optimal treatment planning. In this study available clinicopathologic factors predictive of peritoneal seeding in advanced gastric cancer (AGC) were identified, and this information was translated into a clinically useful tool. METHODS: Totally 2833 patients underwent surgery for AGC between 2003 and 2013. The study identified clinicopathologic factors associated with the risk of peritoneal seeding for constructing nomograms using a multivariate logistic regression model with backward elimination. A nomogram was constructed to generate a numerical value indicating risk. Accuracy was validated using bootstrapping and cross-validation. RESULTS: The proportion of seeding positive was 12.7% in females and 9.6% in males. Of 2833 patients who underwent surgery for AGC, 300 (10.6%) were intraoperatively identified with peritoneal seeding. Multivariate analysis revealed the following factors associated with peritoneal seeding: high American Society of Anesthesiologists score, fibrinogen, Borrmann type 3 or 4 tumors, the involvement of the middle, anterior, and greater curvature, cT3 or cT4cN1 or cN2 or cN3, cM1, and the presence of ascites or peritoneal thickening or plaque or a nodule on the peritoneal wall on computed tomography. The bootstrap analysis revealed a robust concordance between mean and final parameter estimates. The area under the ROC curve for the final model was 0.856 (95% CI, 0.835-0.877), which implies good performance. CONCLUSIONS: This nomogram provides effective risk estimates of peritoneal seeding from gastric cancer and can facilitate individualized decision-making regarding the selective use of diagnostic laparoscopy.

Gastric cancer surgery in South Korea: Past, present, and future.

Gastric cancer remains a significant global health concern and its surgical management approaches have undergone significant changes in South Korea and worldwide. Subtotal or total gastrectomy with D2 lymph node dissection is well established as a standard surgical procedure for gastric cancer. With the active implementation of cancer screening in South Korea, the proportion of early gastric cancer cases has significantly increased over the past few decades, leading to a steady increase in the survival rate among patients. Furthermore, recent advances in surgical instruments and techniques have made minimally invasive surgery increasingly prevalent, not only for early but also for advanced gastric cancer. We aim to provide a comprehensive overview of the evolution and current status of gastric cancer surgery in South Korea.

An early interactive human coaching via a mobile application to improve quality of life in patients who underwent gastrectomy for gastric cancer: Design and protocol of a randomized controlled trial.

BACKGROUND: After gastrectomy, patients may experience the postgastrectomy syndrome and face difficulties adapting to everyday diet. Recently, human health coaching via a mobile application (app) has been used for obese patients or patients with chronic diseases, with significant improvements in clinical outcomes. The aim of this study is to evaluate and compare the effects of human health coaching via a mobile app and conventional face-to-face counseling in patients who underwent gastrectomy for gastric cancers. METHODS: This study is a single-institution, prospective randomized controlled trial comparing the mobile health and face-to-face counselling groups. After randomization, participants assigned to the mobile health coaching group will receive health coaching via a mobile app for 3 months after discharge, and the assigned coaches will provide personalized advice based on the self-recorded health data. Participants in the face-to-face group will have 1- and 3-months postoperative dietary consultations with a clinical dietitian. The primary endpoint is the food restriction score on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-STO22, and secondary endpoints included all other quality of life scale scores and nutritional parameters. The calculated sample size is 180, and the outcomes will be measured until 1-year post-surgery. SIGNIFICANCE: This study will show the efficacy of human health coaching via a mobile app on dietary adaptation in patients who underwent gastrectomy. A relational approach based on personal data and timely intervention using a mobile platform could reduce patients' trial and error and improve quality of life. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04394585, Registered 19 May, 2020 -Retrospectively registered, http://clinicaltrials.gov/ct2/show/NCT040394585.

Risks and benefits of additional surgery for early gastric cancer in the upper third of the stomach meeting non-curative resection criteria after endoscopic submucosal dissection.

BACKGROUND: Additional surgery is recommended after non-curative endoscopic submucosal dissection for early gastric cancer. However, it is not easy to recommend for tumors located in the upper third of the stomach, because it would be a total or proximal gastrectomy. This study aimed to evaluate the actual risks and benefits of additional gastrectomy for upper third tumors. METHODS: We reviewed the clinicopathological data of patients who underwent total or proximal gastrectomy for early gastric cancer in the upper third of the stomach between March 2002 and January 2021. The incidence of lymph node metastasis and postoperative complications were calculated, and risk factors for lymph node metastasis were identified using logistic regression analysis. Survival rates were analyzed using the Kaplan-Meier method and log-rank test. RESULTS: A total of 523 patients underwent total or proximal gastrectomy for early gastric cancer; 379 of them had tumors meeting the non-curative resection criteria for endoscopic submucosal dissection. The overall lymph node metastasis rate was 9.5%, and lymphovascular invasion was the only significant risk factor for lymph node metastasis (p < 0.001). The most common sites of lymph node metastasis were stations 1, 3, and 7, with their rates being 3.2%, 3.7%, and 3.2%, respectively. Overall and severe (Clavien-Dindo grade III or higher) postoperative complication rates were 21.1% and 14.0%, respectively, while postoperative mortality was 0.5% (2/379). The 5-year overall survival rates for patients with and without lymph node metastasis were 96.1% and 81.1%, respectively (p = 0.076). CONCLUSIONS: Before planning an additional gastrectomy after non-curative endoscopic resection for the upper third tumor, we should consider both the benefit of the 9.5% curability for lymph node metastasis and the risks of the 21% postoperative complications and 0.5% mortality.

Postoperative Complications and Their Risk Factors of Completion Total Gastrectomy for Remnant Gastric Cancer Following an Initial Gastrectomy for Cancer.

PURPOSE: Completion total gastrectomy (CTG) for remnant gastric cancer (RGC) is a technically demanding procedure and associated with increased morbidity. The present study aimed to evaluate postoperative complications and their risk factors following surgery for RGC after initial partial gastrectomy due to gastric cancer excluding peptic ulcer. MATERIALS AND METHODS: We retrospectively reviewed the data of 107 patients who had previously undergone an initial gastric cancer surgery and subsequently underwent CTG for RGC between March 2002 and December 2020. The postoperative complications were graded using the Clavien-Dindo classification. Logistic regression analyses were used to determine the risk factors for complications. RESULTS: Postoperative complications occurred in 34.6% (37/107) of the patients. Intra-abdominal abscess was the most common complication. The significant risk factors for overall complications were multi-visceral resections, longer operation time, and high estimated blood loss in the univariate analysis. The independent risk factors were multi-visceral resection (odds ratio [OR], 2.832; 95% confidence interval [CI], 1.094-7.333; P=0.032) and longer operation time (OR, 1.005; 95% CI, 1.001-1.011; P=0.036) in the multivariate analysis. Previous reconstruction type, minimally invasive approach, and current stage were not associated with the overall complications. CONCLUSIONS: Multi-visceral resection and long operation time were significant risk factors for the occurrence of complications following CTG rather than the RGC stage or surgical approach. When multi-visceral resection is required, a more meticulous surgical procedure is warranted to improve the postoperative complications during CTG for RGC after an initial gastric cancer surgery.

A Comprehensive and Comparative Review of Global Gastric Cancer Treatment Guidelines.

Countries differ in their treatment expertise and research results regarding gastric cancer; hence, treatment guidelines are diverse based on evidence and medical situations. A comprehensive and comparative review of each country's guidelines is imperative to understand the similarities and differences among countries. We reviewed and compared five gastric cancer treatment guidelines in terms of endoscopic, surgical, perioperative, and palliative systemic treatment based on evidence levels and recommendation grades, as well as the postoperative follow-up strategies for each guideline. The Korean, Chinese, and European guidelines provided evidence and grading of the recommendations. The United States guidelines suggested categories for evidence and consensus. The Japanese guidelines suggested evidence and recommendations only for systemic treatment. The Korean and Japanese guidelines described endoscopic treatment, surgery, and lymphadenectomy in detail. The Chinese, United States, and European guidelines more intensively considered perioperative chemotherapy. In particular, the indications for chemotherapy and the regimens recommended by each guideline differed slightly. Considering their medical situations, each guideline had some diversity in terms of adopting evidence, which resulted in heterogeneous recommendations. This review will help medical personnel to comprehensively understand the diversity in gastric cancer treatment guidelines for each country in terms of evidence and recommendations.

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.

Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: A Randomized Clinical Trial.

PURPOSE: To compare postoperative complications, long-term survival, and quality of life (QOL) after laparoscopic sentinel node navigation surgery (LSNNS) and laparoscopic standard gastrectomy (LSG). METHODS: Five hundred eighty patients with preoperatively diagnosed stage IA gastric adenocarcinoma (≤ 3 cm) were assigned to undergo either LSG or LSNNS. Observers were not blinded to patient grouping. The primary outcome was 3-year disease-free survival (3y-DFS). Secondary outcomes included postoperative complications, QOL, 3-year disease-specific survival (3y-DSS), and 3-year overall survival (3y-OS). RESULTS: In total, 527 patients were included in the modified intention-to-treat analysis population for the primary outcome (LSG, 269; LSNNS, 258). Stomach-preserving surgery was performed in 210 patients (81%) in the LSNNS group. During the median follow-up duration, the 3y-DFS rates in the LSG and LSNNS groups were 95.5% and 91.8%, respectively (difference: 3.7%; 95% CI, -0.6 to 8.1). Three patients with recurrence and five with metachronous gastric cancer in the LSNNS group underwent standard surgery. Two patients with distant metastasis in both groups were treated with palliative chemotherapy. The 3y-DSS and 3y-OS rates in the LSG and LSNNS groups were 99.5% and 99.1% (P = .59) and 99.2% and 97.6% (P = .17), respectively. Postoperative complications occurred in 19.0% of the LSG group and 15.5% of the LSNNS group (P = .294). The LSNNS group showed better physical function (P = .015), less symptoms (P < .001), and improved nutrition than the LSG group. CONCLUSION: LSNNS did not show noninferiority to LSG for 3y-DFS, with a 5% margin. However, the 3y-DSS and 3y-OS were not different after rescue surgery in cases of recurrence/metachronous gastric cancer, and LSNNS had better long-term QOL and nutrition than LSG.

Short and Long-Term Surgical Outcomes of Laparoscopic Total Gastrectomy Compared with Open Total Gastrectomy in Gastric Cancer Patients.

This study aimed to compare the efficacy of laparoscopic total gastrectomy (LTG) with that of open total gastrectomy (OTG) in terms of postoperative complications and long-term survival. We retrospectively reviewed the clinicopathological data of 560 patients, who underwent total gastrectomy between 2012 and 2016 at the National Cancer Center, Korea. Propensity-score matching (PSM) was performed to correct for discrepancies between the two groups. Matched variables included sex, age, body mass index, American Society of Anesthesiologists score, and pathological Tumor-Node-Metastasis stage. After PSM, 238 patients were included in this analysis. The rate of D2 lymph node dissection was significantly higher in the OTG group than in the LTG group. The estimated blood loss was significantly lower in the LTG group than in the OTG group. The overall complication rate was not significantly different between the two groups. There was no significant difference in the 3-year disease-free and 5-year overall survival rates between the two groups. LTG and OTG had comparable efficacies in gastric cancer patients regarding short- and long-term surgical outcomes. This study suggests that LTG could be an alternative approach to the OTG.

Ergonomic effects of medical augmented reality glasses in video-assisted surgery.

BACKGROUND: The aim of this study was to objectively compare medical augmented reality glasses (ARG) and conventional monitors in video-assisted surgery and to systematically analyze its ergonomic benefits. METHODS: Three surgeons (thoracic, laparoscopic, and thyroid surgeons) participated in the study. Six thoracoscopic metastasectomies, six subtotal laparoscopic gastrectomies, and six thyroidectomies were performed with and without ARG. The subjective experience was evaluated using a questionnaire-based NASA-Task Load Index (NASA-TLX). Postures during surgeries were recorded. The risk of musculoskeletal disorders associated with video-assisted surgery was assessed using rapid entire body assessment (REBA). Surface electromyography (EMG) was recorded. Muscle fatigue was objectively measured. RESULTS: NASA-TLX scores of three surgeons were lower when ARG was used compared to those with conventional monitor (66.4 versus 82.7). Less workload during surgery was reported with ARG. The laparoscopic surgeon exhibited a substantial decrease in mental and physical demand [- 21.1 and 12.5%)] and the thyroid surgeon did (- 40.0 and - 66.7%).Total REBA scores decreased with ARG (8 to 3.6). The risk of musculoskeletal disorders was improved in regions of the neck and shoulders. Root mean square (RMS) of the EMG signal decreased from 0.347 ± 0.150 to 0.286 ± 0.130 (p = 0.010) with usage of ARG; a decrease was observed in all surgeons. The greatest RMS decrease was observed in trapezius and sternocleidomastoid muscles. The decrease in brachioradialis muscle was small. CONCLUSION: ARG assisted with correction of bad posture in surgeons during video-assisted surgery and reduced muscular fatigue of the upper body. This study highlights the superior ergonomic efficiency of ARG in video-assisted surgery.