Lymphadenectomy (LND) is a crucial component of the curative surgical treatment of gastric cancer (GC). The LND serves to both accurately stage the disease and offer therapeutic benefits. At the time of "curative-intent" gastrectomy, D2 LND is the optimal treatment for patients with locally advanced GC due to its survival benefits and acceptable morbidity. Mastery of the technical aspects of LND, especially D2, requires significant training, adequate case volume, and expertise. This review discusses key aspects of D2 LND, including its status as the standard treatment for locally advanced GC, definition and anatomic borders, technical details, and controversial topics such as splenic hilar dissection and omentectomy. The application of indocyanine green (ICG) fluorescence imaging to elucidate the drainage patterns of GC and to facilitate lymph node (LN) identification is briefly reviewed. Finally, GC standardization and centralization, including surgical treatment, are discussed.© 2024. Society of Surgical Oncology.

The aim of this study is to categorize splenic artery and vein configurations, and examine their influence on suprapancreatic lymph node (LN) dissection in laparoscopic gastrectomy.Digital Imaging and Communications in Medicine images from 169 advanced cancer patients who underwent laparoscopic gastrectomy with D2 dissection were used to reconstruct perigastric vessels in 3D using a volume rendering program (VP Planning). Splenic artery and vein configuration were classified depending on the relative position of their lowest part in regard to the pancreas. Number of resected LNs and surgical outcomes were analyzed.The splenic artery was categorized as superficial (36.7%), middle (49.1%), and concealed (14.2%), and the splenic vein was categorized as superior (6.5%), middle (42.0%), and inferior to the pancreas (51.5%). The number of resected LNs around the proximal half of the splenic artery (#11p) and the proportion of the splenic vein located inferiorly to the pancreas were significantly higher in splenic arteries of concealed types. LN metastasis of station #7 was an independent risk factor of LN metastasis in station #11p (p = 0.010). Concealed types showed a tendency towards longer operating times, more blood loss, longer hospital stays, and a higher postoperative morbidity.Concealed types of splenic artery are associated with an increased difficulty in the dissection of LN station #11p around the splenic artery. A 3D volume rendering program is a useful tool to rapidly and intuitively identify individual anatomical variations, to plan a tailored surgical strategy, and to predict potential challenges.

To date, no large population-based studies have compared complications and short-term outcomes between neoadjuvant chemotherapy and upfront surgery in gastric cancer. More nationwide studies with standardized reporting on complications are needed to enable international comparison between studies. This study aimed to compare postoperative complications between neoadjuvant therapy and upfront surgery after gastrectomy for gastric adenocarcinoma in a population-based setting.

Visceral adipose tissue index (VAI) and visceral-to-subcutaneous adipose tissue area ratio (VSR) are indices related to visceral fat mass, and intramuscular adipose tissue content (IMAC) is an index related to intramuscular fat. We investigated the impact of fat mass-related indices on the incidence of postoperative complications.Patients who underwent radical laparoscopic gastrectomy for c-stage I primary gastric cancer between April 2014 and December 2020 were included. We investigated the relationship between both VAI, VSR, IMAC and postoperative complications. For each value, the median was used as a cut-off point, the patients were divided into high- and low-fat groups, and background adjustments using propensity score matching analysis were used to compare these two groups.Of the 490 patients, 245 (50.0%) were in the high-VAI group, 243 (49.6%) in the high-VSR group, and 239 (48.8%) in the high-IMAC group. After matching, intra-abdominal abscess and pancreatic fistula were greater in the high-VAI group than those in the low-VAI group (p=0.081 and p=0.081, respectively), and were also significantly greater in the high-VSR group (p=0.012 and p=0.025, respectively). However, anastomotic leakage was greater in the high-IMAC group than in the low-IMAC group (p=0.050).VAI and VSR, which reflect visceral fat mass, were useful in predicting intra-abdominal infections, whereas IMAC, which reflects intramuscular fat, was useful in predicting anastomotic leakage. Preoperative prediction using a combination of these factors may aid clinical assessment of complication risk.Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Obesity is associated with a wide range of complications, including type 2 diabetes mellitus, cardiovascular disease, hypertension and nonalcoholic fatty liver disease. Obesity also increases the incidence and progression of cancers, autoimmunity and infections, as well as lowering vaccine responsiveness. A unifying concept across these differing diseases is dysregulated immunity, particularly inflammation, in response to metabolic overload. Herein, we review emerging mechanisms by which obesity drives inflammation and autoimmunity, as well as impairing tumour immunosurveillance and the response to infections. Among these mechanisms are obesity-associated changes in the hormones that regulate immune cell metabolism and function and drive inflammation. The cargo of extracellular vesicles derived from adipose tissue, which controls cytokine secretion from immune cells, is also dysregulated in obesity, in addition to impairments in fatty acid metabolism related to inflammation. Furthermore, an imbalance exists in obesity in the biosynthesis and levels of polyunsaturated fatty acid-derived oxylipins, which control a range of outcomes related to inflammation, such as immune cell chemotaxis and cytokine production. Finally, there is a need to investigate how obesity influences immunity using innovative model systems that account for the heterogeneous nature of obesity in the human population.© 2023. Springer Nature Limited.

Laparoscopic gastrectomy (LG) requires a long learning curve because of the complicated surgical procedures. Infrapyloric (No. 6) lymph node dissection (LND) is one of the difficult procedures in LG, especially for trainees. This study investigated the impact of the prediction of the difficulty of No. 6 LND.We retrospectively reviewed the preoperative computed tomography (CT) images and individual operative video records of 57 patients who underwent LG with No. 6 LND to define and predict the No. 6 LND difficulty. To evaluate whether prediction of the difficulty of No. 6 LND could improve surgical outcomes, 48 patients who underwent laparoscopic distal gastrectomy were assessed (30 patients without prediction by a qualified surgeon and 18 patients with prediction by a trainee).The anatomical characteristic that LND required > 2 cm of dissection along the right gastroepiploic vein was defined as difficulty of No. 6 LND. Of the 57 LG patients, difficulty was identified intraoperatively in 21 patients (36.8%). Among the several evaluated anatomical parameters, the length between the right gastroepiploic vein and the right gastroepiploic artery in the maximum intensity projection in contrast-enhanced CT images was significantly correlated with the intraoperative difficulty of No. 6 LND (p < 0.0001). Surgical outcomes, namely intraoperative minor bleeding, postoperative pancreatic fistula, and drain amylase concentration were not significantly different between LG performed by a trainee with prediction compared with that by a specialist without prediction.Preoperative evaluation of the difficulty of No. 6 LND is useful for trainees, to improve surgical outcomes.© 2024. The Author(s).

A postoperative pancreatic fistula (POPF) is a critical complication of radical gastrectomy for gastric cancer, mainly because surgeons occasionally misrecognize the pancreas and fat during lymphadenectomy. Therefore, this study aimed to develop an artificial intelligence (AI) system capable of identifying and highlighting the pancreas during robot-assisted gastrectomy.A pancreas recognition algorithm was developed using HRNet, with 926 training images and 232 validation images extracted from 62 scenes of robot-assisted gastrectomy videos. During quantitative evaluation, the precision, recall, intersection over union (IoU), and Dice coefficients were calculated based on the surgeons' ground truth and the AI-inferred image from 80 test images. During the qualitative evaluation, 10 surgeons answered two questions related to sensitivity and similarity for assessing clinical usefulness.The precision, recall, IoU, and Dice coefficients were 0.70, 0.59, 0.46, and 0.61, respectively. Regarding sensitivity, the average score for pancreas recognition by AI was 4.18 out of 5 points (1 = lowest recognition [less than 50%]; 5 = highest recognition [more than 90%]). Regarding similarity, only 54% of the AI-inferred images were correctly differentiated from the ground truth.Our surgical AI system precisely highlighted the pancreas during robot-assisted gastrectomy at a level that was convincing to surgeons. This technology may prevent misrecognition of the pancreas by surgeons, thus leading to fewer POPFs.© 2024. The Author(s) under exclusive licence to The International Gastric Cancer Association and The Japanese Gastric Cancer Association.

The usability of a new surgical navigation system that provides patient-specific vascular information for robotic gastrectomy in gastric cancer remains unexplored for laparoscopic gastrectomy owing to differences in surgical environments. This study aimed to evaluate the applicability and safety of this navigation system in laparoscopic gastrectomy and to compare the post-operative outcomes between procedures with and without its use.Between June 2022 and July 2023, 38 patients across 2 institutions underwent laparoscopic gastrectomy using a navigation system (navigation group). The technical feasibility, safety, and accuracy of detecting variations in vascular anatomy were measured. The perioperative outcomes were compared with 114 patients who underwent laparoscopic gastrectomy without a navigation system (non-navigation group) using 1:3 propensity score matching during the same study period.In all patients in the navigation group, no adverse events associated with the navigation system occurred during surgery in any patient in the navigation group. No accidental vessel injuries necessitate auxiliary procedures. All vessels encountered during the gastrectomy were successfully reconstructed and visualized. Patient demographics and operative data were comparable between the 2 groups. The navigation group exhibited a significantly lower overall complication rate (10.5%) than the non-navigation group (26.3%, P=0.043). Notably, pancreas-related complications were absent in the navigation group but occurred in eight cases in the non-navigation group (7.0%, P=0.093), although the difference was not statistically significant.The patient-specific surgical navigation system demonstrated clinical feasibility and safety for laparoscopic gastrectomy for gastric cancer, potentially reducing complication rates compared with laparoscopic gastrectomy without its use.Copyright © 2024. Korean Gastric Cancer Association.

Proficiency of the operating surgeon is one of the most critical factors potentially associated with reductions in complications and surgery-related mortality. With video-rating systems having shown potential for assessing laparoscopic surgeons' proficiency, the Endoscopic Surgical Skill Qualification System (ESSQS) was developed by the Japan Society for Endoscopic Surgery to subjectively assess the proficiency of laparoscopic surgeons by rating applicants' non-edited case videos. We conducted a study to evaluate how ESSQS skill-qualified (SQ) surgeon involvement influences short-term outcomes of laparoscopic gastrectomy performed for gastric cancer.Data from the National Clinical Database regarding laparoscopic distal and total gastrectomy performed for gastric cancer between January 2016 and December 2018 were analyzed. Operative mortality, defined as 30-day mortality or 90-day in-hospital mortality, and anastomotic leakage rates were compared per involvement vs. non-involvement of an SQ surgeon. Outcomes were also compared per involvement of a gastrectomy-, colectomy-, or cholecystectomy-qualified surgeon. The association between the area of qualification and operative mortality/anastomotic leakage was also analyzed with a generalized estimating equation logistic regression model used to account for patient-level risk factors and institutional differences.Of 104,093 laparoscopic distal gastrectomies, 52,143 were suitable for inclusion in the study; 30,366 (58.2%) were performed by an SQ surgeon. Of 43,978 laparoscopic total gastrectomies, 10,326 were suitable for inclusion; 6501 (63.0%) were performed by an SQ surgeon. Gastrectomy-qualified surgeons outperformed non-SQ surgeons in terms of both operative mortality and anastomotic leakage. They also outperformed cholecystectomy- and colectomy-qualified surgeons in terms of operative mortality or anastomotic leakage in distal and total gastrectomy, respectively.The ESSQS appears to discriminate laparoscopic surgeons who can be expected to achieve significantly improved gastrectomy outcomes.© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Gastric surgery involves numerous surgical phases; however, its steps can be clearly defined. Deep learning-based surgical phase recognition can promote stylization of gastric surgery with applications in automatic surgical skill assessment. This study aimed to develop a deep learning-based surgical phase-recognition model using multicenter videos of laparoscopic distal gastrectomy, and examine the feasibility of automatic surgical skill assessment using the developed model.Surgical videos from 20 hospitals were used. Laparoscopic distal gastrectomy was defined and annotated into nine phases and a deep learning-based image classification model was developed for phase recognition. We examined whether the developed model's output, including the number of frames in each phase and the adequacy of the surgical field development during the phase of supra-pancreatic lymphadenectomy, correlated with the manually assigned skill assessment score.The overall accuracy of phase recognition was 88.8%. Regarding surgical skill assessment based on the number of frames during the phases of lymphadenectomy of the left greater curvature and reconstruction, the number of frames in the high-score group were significantly less than those in the low-score group (829 vs. 1,152, P < 0.01; 1,208 vs. 1,586, P = 0.01, respectively). The output score of the adequacy of the surgical field development, which is the developed model's output, was significantly higher in the high-score group than that in the low-score group (0.975 vs. 0.970, P = 0.04).The developed model had high accuracy in phase-recognition tasks and has the potential for application in automatic surgical skill assessment systems.© 2023. The Author(s) under exclusive licence to The International Gastric Cancer Association and The Japanese Gastric Cancer Association.