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Background: 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., Methods: 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., Results: 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., Conclusions: 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.)

Background/aim: Clinical staging in the eighth edition of the Union for International Cancer Control TNM classification (TNM8) is reported to predict the prognosis of patients with gastric cancer. However, there have been no reports on using the TNM8 for prognostic stratification of patients with adenocarcinoma of the esophagogastric junction (AEG). This study aimed to investigate whether it was possible to stratify the prognosis of patients who underwent curative surgery for Siewert type II/III AEG according to the TNM8 clinical stage (cStage)., Patients and Methods: This study included patients with Siewert type II/III AEG who underwent curative surgery between 2000 and 2019 at Kanagawa Cancer Center. Those who received neoadjuvant chemotherapy were excluded. We investigated the survival of patients with AEG of each TNM8 cStage., Results: This study included 138 patients, among whom 102 (74%) had Siewert type II and 36 (26%) had Siewert type III AEG. A total of 50, 38, 43, and seven patients were classified with cStage I, II, III, and IV, respectively. The median duration of follow-up of the survivors was 54.7 months. The 5-year overall survival rate of the entire cohort was 65.8%, whereas for patients with cStage I, II, III and IV was 81.6%, 69.0%, 54.3% and 14.3%, respectively. The hazard ratio with reference to cStage I was 1.83, 3.07, and 8.13 for cStage I, III, and IV, respectively, increasing in a stepwise manner., Conclusion: TNM8 Clinical staging is able to stratify the prognosis of patients with Siewert type II/III AEG., (Copyright © 2023, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The prediction of anatomical structures within the surgical field by artificial intelligence (AI) is expected to support surgeons' experience and cognitive skills. We aimed to develop a deep-learning model to automatically segment loose connective tissue fibers (LCTFs) that define a safe dissection plane. The annotation was performed on video frames capturing a robot-assisted gastrectomy performed by trained surgeons. A deep-learning model based on U-net was developed to output segmentation results. Twenty randomly sampled frames were provided to evaluate model performance by comparing Recall and F1/Dice scores with a ground truth and with a two-item questionnaire on sensitivity and misrecognition that was completed by 20 surgeons. The model produced high Recall scores (mean 0.606, maximum 0.861). Mean F1/Dice scores reached 0.549 (range 0.335-0.691), showing acceptable spatial overlap of the objects. Surgeon evaluators gave a mean sensitivity score of 3.52 (with 88.0% assigning the highest score of 4; range 2.45-3.95). The mean misrecognition score was a low 0.14 (range 0-0.7), indicating very few acknowledged over-detection failures. Thus, AI can be trained to predict fine, difficult-to-discern anatomical structures at a level convincing to expert surgeons. This technology may help reduce adverse events by determining safe dissection planes., (© 2021. The Author(s).)

Background/aim: The changes of dietary intake (DI) after gastrectomy have not been objectively reported. It has not been clear how much DI loss is experienced after total gastrectomy (TG) in comparison to after distal gastrectomy (DG). This study quantified the changes of DI after gastrectomy, and clarified how much DI loss is experienced after TG., Patients and Methods: This was a prospective observational study. Patients who underwent gastrectomy for gastric cancer were enrolled. The DI loss was evaluated at 1 and 3 months postoperatively., Results: Thirty-three patients underwent TG, and 117 patients underwent DG. The median %DI loss of the overall study population at 1 and 3 months after surgery was -9.3% and -3.6%. The median %DI loss at 1 and 3 months postoperatively was -15.6% and -5.3% in TG group, -8.9% and -3.3% in DG group (p=0.10 and 0.49, respectively)., Conclusion: The patients experienced DI loss of approximately 10% at 1 month after gastrectomy. Patients who received TG tended to show a greater %DI loss at 1 month postoperatively., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: We hypothesised that the prognostic nutrition index (PNI) is useful for evaluating host immunity and response to immune checkpoint inhibitors. We investigated the effect of PNI on nivolumab monotherapy efficacy in advanced or recurrent gastric cancer (GC) or gastro-oesophageal junction cancer (GOC) patients., Patients and Methods: We retrospectively examined 110 patients, divided them into a high-PNI group and a low-PNI group, and compared treatment efficacy, adverse events (AEs), and survival between the groups., Results: Median overall survival (OS) was significantly longer in the high-PNI group than in the low-PNI group (205 vs. 109 days; p<0.001). Multivariate analysis revealed that low PNI was an independent risk factor for OS (hazard ratio=2.398; 95% confidence interval=1.384-4.154; p=0.002). The overall response rate and frequency of AEs were not significantly different between the groups., Conclusion: PNI could be a useful prognostic factor in GC or GOC patients undergoing nivolumab monotherapy., (Copyright© 2021, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Cancer cells are often found postoperatively at surgical resection margins (RM) in patients with gastric cancer because of submucosal infiltration or hesitation to secure adequate RM. This study was designed to evaluate risk factors for microscopic positive RM and to clarify which patients should undergo intraoperative frozen section diagnosis (IFSD)., Methods: Patients who underwent R0/1 gastrectomy for gastric adenocarcinoma between 2000 and 2018 in a single cancer center in Japan were studied. We divided the patients into a positive RM group and negative RM group according to the results of definitive histopathological examinations. We performed multivariate analysis to analyze risk factors for positive RM by and used the identified risk factors to risk stratify the patients., Results: A total of 2757 patients were studied, including 49 (1.8%) in the positive RM group. The risk factors significantly associated with positive RM were remnant gastric cancer (odds ratio [OR] 4.7), esophageal invasion (OR 6.3), tumor size ≥80 mm (OR 3.9), and a histopathological diagnosis of undifferentiated type (OR 3.6), macroscopic type 4 (OR 3.7), or pT4 disease (OR 4.6). On risk stratification analysis, the incidence of positive RM was 0.1% without any risk factors, increasing to 0.4% with one risk factor, 3.1% with two risk factors, 5.3% with three risk factors, 21.3% with four risk factors, and 85.7% with five risk factors., Conclusions: The risk of macroscopically positive RM increased in patients who have risk factors. IFSD should be performed in patients who have four or more risk factors.

Aim: We examined whether the perioperative systemic inflammation score (SIS), which describes systemic inflammation and/or malnutrition, affected the tumor recurrence and survival in advanced gastric cancer patients., Patients and Methods: The study retrospectively analyzed 160 patients with stage II/III gastric cancer who underwent curative resection at the Kanagawa Cancer Center. The SIS was evaluated before surgery, one week after surgery and one month after surgery, as determined by the serum albumin level (cut-off value=4.0 g/dl) and lymphocyte-to-monocyte ratio (cut-off value=4.44)., Results: A high SIS at one month after surgery was identified as an independent predictor for overall survival [hazard ratio (HR)=2.143, p=0.020] and showed a marginal significance for the relapse-free survival (HR=1.814, p=0.053) in multivariate analyses., Conclusion: The SIS at one month after surgery is a useful biomarker for predicting the long-term outcome in patients with advanced gastric cancer., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Introduction: Chylorrhea is a form of lymphorrhea involving digested lipid products absorbed in the small intestine. Here we report a rare case of chylorrhea after laparoscopy-assisted distal gastrectomy (LADG) with D1+ dissection that resolved following administration of a low-fat diet., Presentation of Case: A 35-year-old woman with early gastric cancer underwent LADG with D1+ dissection, and on postoperative day 4, the drain output increased and the fluid with a high triglyceride level (740mg/dL) changed from clear to milky. On postoperative day 6, oral intake of a low-fat diet was initiated after a 2-day fast, and the daily drain output decreased from postoperative day 9. The drain tube was withdrawn on postoperative day 15, and the patient was discharged on postoperative day 17., Discussion: D1+ dissection does not typically cause injury to the lymphatic trunks, cisterna chyli, or thoracic duct. The maximum output of chylous ascites was minimal, and thus, we assumed that chylorrhea occurred from slightly injured lymphatics with anatomical variation., Conclusion: Chylorrhea after LADG with D1+ dissection is very rare. The fasting of our case followed by a low-fat diet without TPN would be an effective therapy. As a result, our case recovered favorably without further therapy., (Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.)