Risky surgical manipulations that can cause postoperative intra-abdominal infections (IAICs) have not been identified in gastric cancer surgery. We conducted a study to evaluate surgical videos and identify risky surgical maneuvers.

This was a multicenter case-control study. Patients who underwent laparoscopic gastrectomy with lymph node dissection for gastric adenocarcinoma were enrolled in this study. Patients who developed IAICs after surgery were defined as cases, and a control group adjusted for patient background characteristics was selected using propensity score matching. Using an 11-item rating scale specific to gastric cancer surgery developed by experts, two raters blinded to the outcome scored the unedited surgical videos on a five-point scale. The mean difference in the scores for each item was evaluated to identify risky manipulations. We also evaluated the Objective Structured Assessment of Technical Skills (OSATS) as a general evaluation instrument.

After excluding patients for whom a video evaluation was not possible, 121 cases and 114 controls were included in this analysis. Risky surgical maneuvers strongly associated with the occurrence of IAICs were identified, including accidental pancreatic injury during peri-pancreatic lymph node dissection, bleeding from the pancreas, improper hemostatic manipulation, and blunt compression of the pancreas. The reconstructive manipulations were not at risk, and all OSATS items were also significantly better in the control group than in the case group.

We identified the risk of surgical manipulation associated with postoperative complications in this case-control study, with strict adjustment for patient risk factors.

Postoperative pancreatic fistula (POPF) is one of the potentially serious complications after gastrectomy for gastric cancer (GC). Drain amylase level is a predictor of POPF in open and laparoscopic gastrectomy, but no study has focused on minimally invasive surgery (MIS), including robotic gastrectomy (RG). This study assesses the effect of drain amylase levels for POPF in MIS and develop a prediction model in the MIS era.

This single-institutional retrospective study, conducted from January 2011 to December 2021, included 1,353 who underwent standard MIS for GC. We placed a drain in all patients undergoing MIS gastrectomy and measured the drain amylase level on the first postoperative day (D1Amy). The predictive accuracy of D1Amy for POPF was assessed. Additionally, the entire cohort was randomly categorized into the training (1,048 patients) and validation sets (305 patients) to establish the nomogram.

Of the 1353 patients, 530 underwent a robotic approach. POPF and intraabdominal infectious complications of Clavien-Dindo classification grade ≥ II were observed in 80 (5.9%) and 145 (10.7%) patients, respectively. Median D1Amy was 812 U/L. The receiver operating characteristic analysis of D1Amy for POPF revealed an area under the curve (AUC) of 0.888. Multivariate analysis revealed age, tumor location, splenectomy, and D1Amy as significant risk factors for POPF. The AUC of the nomogram was 0.8960, validated with AUC of 0.9259.

We revealed the utility of D1Amy in predicting POPF in MIS gastrectomy. Furthermore, the nomogram, incorporating D1Amy and other clinical factors, was additionally used as a predictive model for POPF.

To compare the short- and long-term outcomes of laparoscopic and open abdominal lymph node dissection using propensity score matching (PSM) analysis.

The subjects of this retrospective analysis were 459 patients who underwent curative resection for esophageal squamous cell carcinoma (ESCC) between May, 2005 and December, 2019, at our hospital. Patients were divided into two groups: the Laparoscopic (Lap group) and the Open (Open group). Post-PSM, 139 patients from each group were selected for the analysis to compare the short- and long-term outcomes between the groups.

The Lap group experienced fewer Clavien-Dindo (CD) Grade ≥ 2 complications (28.1% vs. 40.3%, P = 0.04) and lower rates of abdominal surgical site infections (SSI) (2.9% vs. 7.9%, P = 0.02) than the Open group. The number of lymph nodes harvested was similar in the Lap and Open groups (14.8 ± 7.5 vs. 15.7 ± 8.6, P = 0.34). There was no significant difference in 3-year overall survival rates (81.2% vs. 69.5%, P = 0.12) or relapse-free survival rates (61.1% vs. 58.2%, P = 0.54) between the groups.

Laparoscopic abdominal lymph node dissection for ESCC can be performed safely and appears to be beneficial.

Following laparoscopic gastrectomy (LG), one of the critical complications that can arise is a pancreatic fistula (PF). The inability to promptly prevent, diagnose, and manage this condition can lead to severe complications and potentially be life-threatening for the patient. The incidence of PF post-LG in gastric cancer treatment is related to factors such as surgical approach, surgical instruments, characteristics of the pancreas itself, tumor stage, and the surgeon's experience. Currently, the diagnosis of postoperative PF is mainly based on the definition and diagnostic criteria consensus established by the International Study Group of Pancreatic Surgery. Gastrointestinal surgeons should be aware of the risk factors for PF, perform LG for gastric cancer with great care and precision, avoid pancreatic injury, and actively work to reduce the risk of postoperative PF.

This study aimed to investigate the laparoscopic gastrectomy (LG) performance of non-Endoscopic Surgical Skill Qualification System (ESSQS)-qualified surgeons under the ESSQS-qualified surgeon guidance and compare oncological outcomes of gastric cancer to LG performed by the ESSQS-qualified surgeons.

This study enrolled 1,030 patients diagnosed with both clinical and pathological stage ≤ III gastric cancer and undergoing LG from January 2009 to June 2019. ESSQS-qualified surgeons served as the operator or the instructive assistant in all LG procedures involving them. A propensity score-matched analysis was used to retrospectively compare the long-term outcomes between the ESSQS-qualified and non-ESSQS-qualified surgeons.

Each group included 315 pairs after propensity score matching. The 3-year recurrence-free survival rates were 84.4% and 81.7% in the non-ESSQS and ESSQS groups, respectively. The difference was 2.7% (95% confidence interval: - 3.20%-8.44%, P < 0.001), and the non-ESSQS group statistically demonstrated noninferiority as the lower 95% confidence limit was greater than the prespecified margin of -10%, indicating the achieved primary endpoint. No significant differences in 5-year recurrence-free survival (non-ESSQS: 78.5% vs. ESSQS: 77.4%, P = 0.627) and 5-year overall survival (non-ESSQS: 80.9% vs. ESSQS: 79.3%, P = 0.475) were found between the two groups. The oncological outcomes stratified according to the presence of pathological stage I, II, and III disease did not significantly differ between the two groups.

LG performed by non-ESSQS-qualified surgeons achieved comparable oncological outcomes to the ESSQS-qualified surgeons, as long as ESSQS-qualified surgeons provided intraoperative instructions, in a high-volume center.

Postoperative pancreatic fistula (POPF) is a critical complication of laparoscopic gastrectomy (LG). However, there are no widely recognized anatomical landmarks to prevent POPF during LG. This study aimed to identify anatomical landmarks related to POPF occurrence during LG for gastric cancer and to develop an artificial intelligence (AI) navigation system for indicating these landmarks.

Dimpling lines (DLs)-depressions formed between the pancreas and surrounding organs-were defined as anatomical landmarks related to POPF. The DLs for the mesogastrium, intestine, and transverse mesocolon were named DMP, DIP, and DTP, respectively. We included 50 LG cases to develop the AI system (45/50 were used for training and 5/50 for adjusting the hyperparameters of the employed system). Regarding the validation of the AI system, DLs were assessed by an external evaluation committee using a Likert scale, and the pancreas was assessed using the Dice coefficient, with 10 prospectively registered cases.

Six expert surgeons confirmed the efficacy of DLs as anatomical landmarks related to POPF in LG. An AI system was developed using a semantic segmentation model that indicated DLs in real-time when this system was synchronized during surgery. Additionally, the distribution of scores for DMP was significantly higher than that of the other DLs (p < 0.001), indicating the relatively high accuracy of this landmark. In addition, the Dice coefficient of the pancreas was 0.70.

The DLs may be used as anatomical landmarks related to POPF occurrence. The developed AI navigation system can help visualize the DLs in real-time during LG.

Magnetorheological fluids (MRFs) are functional fluids that exhibit rapid and reproducible rheological responses to external magnetic fields. An MRF has been utilized to develop a haptic device with precise haptic feedback for teleoperative surgical systems. To achieve this, we developed several types of compact MRF clutches for haptics (H-MRCs) and integrated them into a twin-driven MRF actuator (TD-MRA). The first TD-MRA prototype was successfully used to generate fine haptic feedback for operators. However, undesirable torque ripples were observed due to shaft misalignment and the low rigidity of the structure. Additionally, the detailed torque control performance was not evaluated from both static and dynamic current inputs. The objective of this study is to develop a second prototype to reduce torque ripple by improving the structure and evaluating its static and dynamic torque performance. Torque performance was measured using both constant and stepwise current inputs. The coefficient of variance of the torque was successfully reduced by half due to the structural redesign. Although the time constants of the H-MRC were less than 10 ms, those of the TD-MRA were less than 20 ms under all conditions. To address the slower downward output response, we implemented an improved input method, which successfully halved the response time.

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.

Gastric cancer is the fifth most prevalent malignancy globally and the fourth major contributor to cancer-related mortality. The comparative effectiveness of robotic gastrectomy (RG) versus laparoscopic gastrectomy (LG) at different stages of gastric cancer is unclear regarding surgical and survival outcomes. We compared surgical and survival outcomes between RG and LG in early-stage (cStage I) and advanced (cStage II/III) gastric cancers to elucidate the difference in the efficacy of RG across various stages of gastric cancer.

We identified 299 patients (LG, 170; RG, 129) with cStage II/III disease and 569 (LG, 455; RG, 114) with cStage I disease who underwent either LG or RG. Following propensity score matching for RG and LG, 118 pairs were selected for cStage II/II and 113 pairs for cStage I. Surgical and survival outcomes of LG and RG were separately compared for cStage II/III and cStage I.

In cStage II/III, RG showed significantly fewer intra-abdominal complications of Clavien-Dindo (C.D.) Grade ≥ III in the RG group than in the LG group (LG = 8.5 vs. RG = 1.7%, P = 0.033). Multivariate analysis identified LG as an independent risk factor for intra-abdominal complications of C.D. Grade ≥ III (OR 5.69, 95% CI 1.17-27.70, P = 0.031). However, in cStage I, no difference in surgical outcomes between LG and RG was observed. No differences were observed in survival outcomes between LG and RG in both cStage I or cStage II/III.

The real benefit of RG was demonstrated in surgical outcomes, especially for advanced-stage gastric cancer.

Pancreatic fistula (PF) is one of the most serious postoperative complications of gastrectomy. Misidentification of the boundary between the pancreas and the dissected fat is a primary concern. In this study, we focused on differences in the appearance of the pancreas and the dissected fat in actual surgical images and statistically analyzed the relationship between the pancreas and the dissected fat.

We analyzed data from 109 gastric cancer patients who underwent curative gastrectomy between November 2018 and March 2023. Intraoperative images were taken from videos of lymph node dissections of Nos.6 and 8a regions, and the mean gray value of the areas was measured using ImageJ software for analysis. The visceral fat area (VFA) was evaluated by preoperative axial CT at the umbilical level using Ziostation software.

A significant correlation was observed between the fat/pancreas gray value ratio in the No.8a lymph node region and the drain/serum amylase ratio (P < 0.001). The fat/pancreas gray value ratio in the No.6 lymph node region correlated with VFA (P < 0.001). The VFA and drain/serum amylase ratio were significantly higher in the group with intra-abdominal complications (P = 0.004).

We revealed significant relationships between the fat/pancreas gray value ratio with drain/serum amylase and VFA. Detecting differences in gray values between the pancreas and the dissected fat may lead to a decrease in the drain/serum amylase ratio and PF.

While pharmaceutical companies aim to leverage real-world data (RWD) to bridge the gap between clinical drug development and real-world patient outcomes, extant research has mainly focused on the use of social media in a post-approval safety-surveillance setting. Recent regulatory and technological developments indicate that social media may serve as a rich source to expand the evidence base to pre-approval and drug development activities. However, use cases related to drug development have been largely omitted, thereby missing some of the benefits of RWD. In addition, an applied end-to-end understanding of RWD rooted in both industry and regulations is lacking.

We aimed to investigate how social media can be used as a source of RWD to support regulatory decision making and drug development in the pharmaceutical industry. We aimed to specifically explore the data pipeline and examine how social-media derived RWD can align with regulatory guidance from the US Food and Drug Administration and industry needs.

A machine learning pipeline was developed to extract patient insights related to anticoagulants from X (Twitter) data. These findings were then analysed from an industry perspective, and complemented by interviews with professionals from a pharmaceutical company.

The analysis reveals several use cases where RWD derived from social media can be beneficial, particularly in generating hypotheses around patient and therapeutic area needs. We also note certain limitations of social media data, particularly around inferring causality.

Social media display considerable potential as a source of RWD for guiding efforts in pharmaceutical drug development and pre-approval settings. Although further regulatory guidance on the use of social media for RWD is needed to encourage its use, regulatory and technological developments are suggested to warrant at least exploratory uses for drug development.

The appropriateness of laparoscopic gastrectomy (LG) for super-geriatric patients with locally advanced gastric cancer (LAGC) is inconclusive, and the prognostic factors are also yet to be elucidated. Herein, we aimed to investigate the surgical and oncological outcomes of LG versus open gastrectomy (OG) for geriatric patients with LAGC who have outlived the average lifespan of the Chinese population (≥ 78 years).

This is a monocentric, retrospective, comparative study. A 1:1 propensity score matching (PSM) was performed to minimize selection bias and ensure well-balanced characteristics. The primary endpoint of interest was 3-year overall survival, while secondary endpoints included procedure-related variables, postoperative recovery indices, and complications. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify unfavorable prognostic factors.

Of 196 eligible individuals, 107 underwent LG and 89 underwent OG, with a median age (interquartile range [IQR]) of 82 [79, 84] years. PSM yielded 61 matched pairs, with comparable demographic and tumor characteristics. The LG group had a significantly lower overall complication rate than the OG group (31.1% vs. 49.2%, P = 0.042), as well as shorter duration of postoperative hospital stay [12 (11, 13) vs. 13 (12, 15.5) d, P < 0. 001], less intraoperative blood loss [95 (75, 150) vs. 230 (195, 290) mL, P < 0.001], but a longer operative time [228 (210, 255.5) vs. 196 (180, 219.5) min, P < 0.001]. The times to first aerofluxus, defecation, liquid diet, and half-liquid diet were comparable. Kaplan-Meier analyses revealed no significant difference in 3-year overall survival between the groups, either in the entire cohort or in subgroups with different TNM staging. Moreover, Age-adjusted Charlson Comorbidity Index scores of > 6 [hazard ratio (HR) 4.003; P = 0.021] and pathologic TNM stage III (HR 3.816, P = 0.023) were independent unfavorable prognostic factors for long-term survival.

LG performed by experienced surgeons offers the benefits of comparable or better surgical and oncological safety profiles than OG for super-geriatric patients with LAGC.

In this editorial we comment on the article by Zhang et al published in a recent issue of the World Journal of Gastrointestinal Surgery. Gastrectomy with appropriate lymph node dissection is still standard curative treatment in locally advanced gastric cancer. Several studies point out that gastric cancer surgery is a complex procedure that leads to a high risk of morbidity and mortality. Many factors can contribute to the onset of complications with consequent effects on prognosis and increased mortality. The complications can be divided in complications related to anastomosis, to motility and to surgical site infection. The study presented by Zhang B et al represent an interesting analysis on the possibility to prevent postoperative morbidity. The study was performed on 131 patients with distal gastric cancer who underwent gastrectomy with D2 lymph node dissection. Of these patients, 16% developed early postoperative complications. The univariate analysis showed that prealbumin level, hypertension, diabetes, history of abdominal surgery, R0 resection, and blood transfusion were factors influencing early postoperative complications after distal gastrectomy. Moreover, the inclusion of the above significant variables in the logistic regression analysis revealed that hypertension, diabetes, a history of abdominal surgery, and blood transfusion were independent predictors of postoperative complications. In conclusion, preoperative and intraoperative factors can be used to establish an early postoperative nomogram model. The results of the study presented by Zhang et al suggest that the prediction model can be used to guide the detection of postoperative complications and has clinical reference value.

Robotic distal gastrectomy (RDG) has been widely performed throughout Japan since it became insured in 2018. This study aimed to evaluate the short-term outcomes of RDG and laparoscopic distal gastrectomy (LDG) for gastric cancer using real-world data.

A total of 4161 patients who underwent LDG (n = 3173) or RDG (n = 988) for gastric cancer between April 2018 and October 2022 were identified through the Japanese Diagnosis Procedure Combination Database, which covers 42 national university hospitals. The primary outcome was postoperative in-hospital mortality rate. The secondary outcomes were postoperative complication rates, time to diet resumption, and postoperative length of stay (LOS).

In-hospital mortality and postoperative complication rates in the RDG group were comparable with those in the LDG group (0.1% vs. 0.0%, p = 1.000, and 8.7% vs. 8.2%, p = 0.693, respectively). RDG was associated with a longer duration of anesthesia (325 vs. 262 min, p < 0.001), similar time to diet resumption (3 vs. 3 days, p < 0.001), and shorter postoperative LOS (10 vs. 11 days, p < 0.001) compared with LDG.

RDG was performed safely and provided shorter postoperative LOS, since it became covered by insurance in Japan.

Prevention of pancreas-related complications after gastric cancer surgery is critical. Polyglycolic acid (PGA) mesh reduces postoperative pancreatic fistula formation following pancreatic resection. However, the clinical efficacy of PGA mesh in gastric cancer surgery has not been adequately investigated.

This retrospective study compared the short-term outcomes between two groups: patients who underwent minimally invasive R0 gastrectomy for gastric cancer with the use of a PGA mesh (PGA group) and those without the use of a PGA mesh (non-PGA group) at the Cancer Institute Hospital, Tokyo, between January 2019 and May 2023. Propensity score matching (PSM) was performed to adjust for the possible confounding factors.

A total of 834 patients were initially included, of whom 614 (307 in each group) remained after PSM. The amylase levels in the drained abdominal fluid on postoperative days 1 and 3 were similar between the PGA and non-PGA groups. The PGA group had a significantly lower incidence of pancreas-related complications of Clavien-Dindo grade ≥2 than that in the non-PGA group (6.8% vs. 2.9%, P=0.025). In subgroup analyses, the odds ratio for pancreas-related complications appeared to be better in the PGA group than in the non-PGA group in patients with American Society of Anesthesiologists Physical Status Classification score of 2 or 3, those operated via a laparoscopic approach, and those undergoing procedures other than proximal gastrectomy.

The use of PGA mesh significantly reduced pancreas-related complications after minimally invasive surgery for gastric cancer and might thus benefit patients at risk of such complications.

Abdominal surgical infectious complications (ASIC) after gastrectomy for gastric cancer impair patients' survival and quality of life. JCOG0912 was conducted to compare laparoscopy-assisted distal gastrectomy with open distal gastrectomy for clinical stage IA or IB gastric cancer. The present study aimed to identify risk factors for ASIC using prospectively collected data.

We performed a post-hoc analysis of the risk factors for ASIC using the dataset from JCOG0912. All complications were evaluated according to the Clavien-Dindo classification (CD). ASIC was defined as CD grade I or higher anastomotic leakage, pancreatic fistula, abdominal abscess, and wound infection. Analyses were performed using the logistic regression model for univariable and multivariable analyses.

A total of 910 patients were included (median age, 63 years; male sex, 61 %). Among them, ASIC occurred in 5.8 % of patients. In the univariable analysis, male sex (odds ratio [OR] 2.855, P = 0.003), diabetes (OR 2.565, P = 0.029), and Roux-en-Y (R-Y) reconstruction (vs. Billroth Ⅰ, OR 2.707, P = 0.002) were significant risk factors for ASIC. In the multivariable analysis, male sex (OR 2.364, P = 0.028) and R-Y reconstruction (vs. Billroth Ⅰ, OR 2.310, P = 0.015) were independent risk factors for ASIC.

Male sex and R-Y reconstruction were risk factors for ASIC after distal gastrectomy. Therefore, when performing surgery on male patients or when R-Y reconstruction is selected after gastrectomy for gastric cancer, surgeons should pay special attention to prevent ASIC.

This study aimed to determine the safety and feasibility of minimally invasive gastrectomy in patients who underwent preoperative chemotherapy for highly advanced gastric cancer.

Preoperative chemotherapy was indicated for patients with advanced large tumors (≥ cT3 and ≥ 5 cm) and/or bulky node metastasis (≥ 3 cm × 1 or ≥ 1.5 cm × 2). Between January 2009 and March 2022, 150 patients underwent preoperative chemotherapy followed by gastrectomy with R0 resection, including conversion surgery (robotic, 62; laparoscopic, 88). The outcomes of these patients were retrospectively examined.

Among them, 41 and 47 patients had stage IV disease and underwent splenectomy, respectively. Regarding operative outcomes, operative time was 475 min, blood loss was 72 g, morbidity (grade ≥ 3a) rate was 12%, local complication rate was 10.7%, and postoperative hospital stay was 14 days (Interquartile range: 11-18 days). Fifty patients (33.3%) achieved grade ≥ 2 histological responses. Regarding resection types, total/proximal gastrectomy plus splenectomy (29.8%) was associated with significantly higher morbidity than other types (distal gastrectomy, 3.2%; total/proximal gastrectomy, 4.9%; P < 0.001). Specifically, among splenectomy cases, the rate of postoperative complications associated with the laparoscopic approach was significantly higher than that associated with the robotic approach (40.0% vs. 0%, P = 0.009). In the multivariate analysis, splenectomy was an independent risk factor for postoperative complications [odds ratio, 8.574; 95% confidence interval (CI), 2.584-28.443; P < 0.001].

Minimally invasive gastrectomy following preoperative chemotherapy was feasible and safe for patients with highly advanced gastric cancer. Robotic gastrectomy may improve surgical safety, particularly in the case of total/proximal gastrectomy combined with splenectomy.

Laparoscopic gastrectomy is widely used as a curative treatment for gastric cancer. Although delta-shaped anastomosis is commonly used for Billroth I anastomosis after totally laparoscopic distal gastrectomy (TLDG), it has some drawbacks. The book-binding technique (BBT) was developed as an alternative, and this study aimed to examine its short-term results in 188 consecutive cases.

This retrospective study included patients who underwent BBT reconstruction after TLDG for gastric malignancy between 2011 and 2020. BBT is a technique for intracorporeal gastroduodenostomy, which is a triangular anastomosis with a linear stapler that does not require additional dissection or rotation of the duodenum. The short-term outcomes of BBT reconstruction and postoperative endoscopic findings were analyzed.

This study evaluated 188 patients who underwent TLDG and BBT reconstruction. Anastomotic stenosis and leakage occurred in 1.1% and 0.5% of the patients, respectively. The median time to the first diet was 3.1 days, and the median postoperative hospital stay was 11.9 days. BBT anastomoses were performed by 19 surgeons and took an average of 32.8 minutes to complete, with completion times decreasing as the surgical team became more proficient. On endoscopy performed 1 year postoperatively, 5.2% had reflux esophagitis (grade A or higher), 67.8% had gastritis (grade 1 or higher), 37.4% had residual food (grade 1 or higher), and 37.4% had bile reflux (grade 1).

BBT is a safe and feasible method for intracorporeal gastroduodenostomy in TLDG for patients with gastric malignancy and demonstrates good surgical outcomes.

Laparoscopic gastrectomy (LG) indications have been extended to advanced gastric cancer requiring expansive lymph node dissection. Despite the huge benefits of this minimally invasive surgery, major complications such as postoperative pancreatic fistula (POPF) remain a concern. With technical advances in surgical procedures, the treatment outcomes of gastric cancer surgery have improved. However, effective methods for preventing POPF have not yet been established. Herein, we examined the usefulness of polyglycolic acid (PGA) sheets for preventing POPF after LG.

We retrospectively assessed 142 patients who underwent curative LG at our institution between January 2017 and August 2022. The 142 patients were divided into 2 groups; PGA group (n = 61): the site of lymph node dissection at the superior margin of the pancreas and pancreatic head was covered with PGA sheets, and nPGA group (n = 81): the site was not covered. We retrospectively compared the short-term surgical outcomes including POPF incidence.

There was no significant difference in the background factors between the 2 groups and in the incidence of Grade II or higher postoperative complications according to the Clavien-Dindo (CD) classification. However, the incidence of CD Grade II or higher POPF was significantly lower in the PGA group than in the nPGA group (.0% vs 2.3%, respectively, P = .007).

There was no POPF in any of the 61 patients in the PGA group. This outcome suggests that POPF incidence may be reduced by covering the lymph node dissection site with PGA sheets after LG.

Postoperative pancreatic fistula (POPF) is a common and serious consequence of gastrectomy. The prevalence of POPF among patients with gastric cancer varies greatly, and the risk factors and outcomes of POPF are also controversial. The meta-analysis aims to comprehensively assess the risk factors for POPF in gastric cancer patients.

PubMed, Web of Science, the Cochrane Library, Embase, and Chinese databases (SinoMed, CNKI, WanFang, and VIP Databases) were searched to identify relevant studies (from inception to May 2023). Two researchers evaluated the literature quality and extracted data individually. The Review Manager 5.4 program was used to analyze all of the data.

In our meta-analysis, 22 studies totaling 11,647 patients were analyzed. Male sex (OR = 3.06), older age (OR = 3.22), body mass index (BMI) ≥ 25 kg/m2 (OR = 2.58), visceral fat area (VFA) ≥ 100 cm2 (OR = 3.65), pTNM Ⅲ-Ⅳ (OR = 2.47), the number of lymphlode dissections (OR = 1.04), neoadjuvant chemotherapy (NAC) (OR = 2.91), the application of LigaSure (OR = 3.30), open surgery (OR = 3.23), intraoperative combined organ resection (OR = 4.11), drainage amylase concentration on the first postoperative day (OR = 5.73) and C-reactive protein on the 3rd postoperative day ≥20 mg/dL (OR = 7.29) were the risk factors for POPF in gastric cancer patients. On the other hand, the operation time (OR = 1.34) was not a risk factor for POPF.

The frequency of POPF in people undergoing gastrectomy was determined by a variety of risk factors. Medical professionals should identify risk factors early and impose interventions to prevent them to lower the incidence of POPF in gastric cancer patients.

Laparoscopic gastrectomy (LG) is considered a standard treatment for clinical stage I gastric cancer. Nevertheless, LG has some drawbacks, such as motion restriction and difficulties in spatial perception. Robot-assisted gastrectomy (RG) overcomes these drawbacks by using articulated forceps, tremor-filtering capability, and high-resolution three-dimensional imaging, and it is expected to enable more precise and safer procedures than LG for gastric cancer. However, robust evidence based on a large-scale randomized study is lacking.

We are performing a randomized controlled phase III study to investigate the superiority of RG over LG for clinical T1-2N0-2 gastric cancer in terms of safety. In total, 1,040 patients are planned to be enrolled from 46 Japanese institutions over 5 years. The primary endpoint is the incidence of postoperative intra-abdominal infectious complications, including anastomotic leakage, pancreatic fistula, and intra-abdominal abscess of Clavien-Dindo (CD) grade ≥ II. The secondary endpoints are the incidence of all CD grade ≥ II and ≥ IIIA postoperative complications, the incidence of CD grade ≥ IIIA postoperative intra-abdominal infectious complications, relapse-free survival, overall survival, the proportion of RG completion, the proportion of LG completion, the proportion of conversion to open surgery, the proportion of operation-related death, and short-term surgical outcomes. The Japan Clinical Oncology Group Protocol Review Committee approved this study protocol in January 2020. Approval from the institutional review board was obtained before starting patient enrollment in each institution. Patient enrollment began in March 2020. We revised the protocol to expand the eligibility criteria to T1-4aN0-3 in July 2022 based on the results of randomized trials of LG demonstrating non-inferiority of LG to open surgery for survival outcomes in advanced gastric cancer.

This is the first multicenter randomized controlled trial to confirm the superiority of RG over LG in terms of safety. This study will demonstrate whether RG is superior for gastric cancer.

The protocol of JCOG1907 was registered in the UMIN Clinical Trials Registry as UMIN000039825 ( http://www.umin.ac.jp/ctr/index.htm ). Date of Registration: March 16, 2020. Date of First Participant Enrollment: April 1, 2020.

This study investigated indocyanine green (ICG) as an intraoperative tool for improving lymph node dissection quality in radical robotic distal gastrectomy (RDG) for gastric cancer by comparing the rate of lymph node (LN) noncompliance with or without use of the Firefly™ system.

Patients with potentially resectable gastric cancer including cT1-T4a, N0/ + , M0 were registered in a prospective nonrandomized cohort study at our institution between March 2019 and December 2022. Patients were assigned to the da Vinci surgical system with Firefly system (F group) or that without Firefly system (non-F group). F group patients received endoscopic peritumoral injection of ICG to the submucosa one day before surgery. Rate of LN noncompliance, number of harvested LNs, and short-term outcomes were compared.

Of the 94 patients in this study, 55 underwent Firefly system-guided RDG and 39 underwent conventional RDG. The mean [SD] total number of harvested lymph nodes in F group, 31.2 [10.2], was significantly higher than that harvested in non-F group (25.6 [12.6]; p = 0.026). The LN noncompliance rate in F group was lower than that in non-F group (32.7% vs. 61.5%, p = 0.006). The mean number of LNs harvested in F group was significantly higher than that harvested in non-F group (31.2 [10.2] vs. 25.7 [12.6], p = 0.02). Significant differences were found between the F vs. non-F groups in blood loss and postoperative hospital stay (83.9 [75.1] vs. 301.9 [766.7] mL; p = 0.003 and 13.4 vs. 17.4 days, p = 0.049).

The Firefly system-assisted ICG tracer improved LN dissection quality without compromising safety.

Radical gastrectomy with D2 lymphadenectomy can trigger a high incidence of postoperative pancreatic fistula (POPF), which produces a poor clinical prognosis. We sought to evaluate the effect of somatostatin analogs (SSA) on POPF and clinical prognosis after radical gastrectomy.

A total of 123 patients with a high risk of POPF after radical gastrectomy (drainage fluid amylase concentration on a postoperative day [POD] 1 > 3 times the upper limit of normal serum amylase value) were randomly divided into the SSA group (n = 61) and the control group (n = 62). The former received continuous intravenous SSA (0.3 mg/8 h) for 3 days from POD1, and the latter normal saline. The primary outcome was the incidence of POPF.

The incidence of POPFs in the SSA group was significantly lower than that in the control group (3.3% vs. 14.5%, P = 0.029). The incidence of short-term postoperative complications was significantly lower in the SSA group than in the control group (9.8% vs. 24.2%, P = 0.034). The median white blood cell counts, neutrophil counts, and the percentage of neutrophils on POD4 were significantly lower in the SSA group than in the control group (all P < 0.05). The SSA group had a shorter mean time to the first liquid diet (87.33 ± 17.92 h vs. 93.97 ± 17.29 h, P = 0.039). And the SSA group had less median daily drainage volume (96.33 mL vs. 119.67 mL, P = 0.025) and shorter drainage duration (7.0 days vs. 10.0 days, P = 0.013).

Postoperative treatment with a somatostatin analog reduced the incidence of POPF and short-term complications after radical gastrectomy. (TRN: ChiCTR2200056201, Reg. Date: 2022/2/1).

Laparoscopic gastrectomy is more frequently associated with postoperative pancreatic fistula than is open gastrectomy. We assumed that compression of the pancreas with various devices to obtain a proper operative view is associated with the higher incidence of PF in LG and that the extent of the compression differs depending on the anatomical position of the pancreas. The present study aimed to elucidate the correlation between the anatomical position of the pancreas and PF after LG for gastric cancer.

Patients who underwent LG for gastric cancer from 2005 to 2019 were retrospectively reviewed. Two anatomical parameters representing the height of the slope looking down the celiac artery from the top of the pancreas (P-A length) and the steepness of the slope (UP-CA angle) were measured in computed tomography sagittal projections. The correlation between PF and (1) P-A length, (2) UP-CA angle, and (3) other clinicopathological factors was analyzed using a logistic regression model.

Among 3485 patients, grade ≥ II PF was observed in 140 (4.0%) patients. The UP-CA angle [odds ratio (OR), 2.472; 95% confidence interval (CI), 1.725-3.543; P < 0.001], a high BMI (OR 2.339; 95% CI 1.634-3.348; P < 0.001), and male sex (OR 2.602; 95% CI 1.590-4.257; P < 0.001) were independently correlated with grade ≥ II PF.

The present study identified a significant correlation between anatomical position of the pancreas and PF after LG. High BMI and male sex were also significantly correlated with PF after LG.

Robot-assisted gastrectomy (RG) for gastric cancer is still not well standardized. This study aimed to explore the feasibility and effectiveness of solo surgery in robot-assisted gastrectomy (SRG) for gastric cancer compared to laparoscopic gastrectomy (LG).

This was a single-center retrospective comparative study between SRG and conventional LG. Between April 2015 and December 2022, 510 patients underwent gastrectomy, and data from a prospectively collected database were analyzed. We identified 372 patients who underwent LG (n = 267) and SRG (n = 105) and the remaining 138 patients were excluded because of remnant gastric cancer, esophagogastric junction cancer, open gastrectomy, concurrent surgery for concomitant malignancies, RG before starting SRG, or cases in which the author was unable to perform or supervise gastrectomy. Propensity score matching was performed at a ratio of 1:1 to reduce bias from confounding patient-related variables, and short-term outcomes were compared between the groups.

After propensity score matching, 90 pairs of patients who underwent LG and SRG were selected. In the propensity-matched cohort, the operation time was significantly shorter in the SRG group than that in the LG group (SRG = 305.7 ± 74.0 min vs. LG = 340.3 ± 91.65 min, p < 0.0058), less estimated blood loss was observed in the SRG group than that in the LG group (SRG = 25.6 ± 50.6 mL vs. LG = 76.1 ± 104.2 mL, p < 0.0001) and postoperative hospital stay was shorter in the SRG group than that in the LG group (SRG = 7.1 ± 0.8 days vs. LG = 9.1 ± 7.7 days, p = 0.015).

We found that SRG for gastric cancer was technically feasible and effective with favorable short-term outcomes, including shorter operative time, less estimated blood loss, shorter hospital stays, and lower postoperative morbidity than those in LG.

Evidence of implementation of laparoscopic gastrectomy for locally advanced gastric cancer is currently insufficient, as the primary end point in previous prospective studies was evaluated at a median follow-up time of 3 years. More robust evidence is necessary to verify noninferiority of laparoscopic gastrectomy.

To compare 5-year survival outcomes between laparoscopy-assisted distal gastrectomy (LADG) and open distal gastrectomy (ODG) with D2 lymph node dissection for locally advanced gastric cancer.

This was a multicenter, open-label, noninferiority, prospective randomized clinical trial. Between November 26, 2009, and July 29, 2016, eligible patients with histologically proven gastric carcinoma from 37 institutes in Japan were enrolled. Two interim analyses and final analysis were performed in October 2014, May 2018, and November 2021, respectively.

Patients were randomly assigned (1:1) to either the ODG or LADG group. The procedures were performed exclusively by qualified surgeons.

The primary end point was 5-year relapse-free survival, and the noninferiority margin for the hazard ratio (HR) was set at 1.31. The secondary end points were 5-year overall survival and safety.

A total of 502 patients were included in the full-analysis set: 254 (50.6%) in the ODG group and 248 (49.4%) in the LADG group. Patients in the ODG group had a median (IQR) age of 67 (33-80) years and included 168 males (66.1%). Patients in the LADG group had a median (IQR) age of 64 (34-80) years and included 169 males (68.1%). No significant differences were observed in severe postoperative complications between the 2 groups in the safety analysis (ODG, 4.7% [11 of 233] vs LADG, 3.5% [8 of 227]; P = .64). The median (IQR) follow-up for all patients after randomization was 67.9 (60.3-92.0) months. The 5-year relapse-free survival was 73.9% (95% CI, 68.7%-79.5%) and 75.7% (95% CI, 70.5%-81.2%) for the ODG and LADG groups, respectively, and the HR was 0.96 (90% CI, 0.72-1.26; noninferiority 1-sided P = .03). Further, no significant difference was observed in overall survival time between the 2 groups, and the HR was 0.83 (95% CI, 0.57-1.21; P = .34). The pattern of recurrence was similar between the 2 groups.

Results of this study show that on the basis of 5-year follow-up data, LADG with D2 lymph node dissection for locally advanced gastric cancer, when performed by qualified surgeons, was proved noninferior to ODG. This laparoscopic approach could become a standard treatment for locally advanced gastric cancer.

UMIN Clinical Trial Registry: UMIN000003420.

Despite technical advances in minimally invasive gastrectomy for gastric cancer, an increased incidence of postoperative pancreatic fistula (POPF) has been reported. POPF can cause infectious and bleeding complications, which could lead to surgery-related death; therefore, reduction of the post-gastrectomy POPF risk is crucial. This study aimed to investigate the importance of pancreatic anatomy as a predictor of POPF in patients undergoing laparoscopic or robotic gastrectomy.

Data were collected from 331 consecutive patients who underwent laparoscopic or robotic gastrectomy for gastric cancer. The thickness of the pancreas anterior to the most ventral level of the splenic artery (TPS) was measured. The correlation between TPS and POPF incidence was investigated using univariate and multivariate analyses.

The cutoff value of TPS was 11.8 mm, which predicted a high drain amylase concentration on postoperative day 1, and patients were categorized into thin (Tn group) and thick TPS groups (Tk group). There was no significant difference in the background characteristics between the two groups, except for sex (P = 0.009) and body mass index (P < 0.001). The incidences of POPF grade B or higher (2% vs. 16%, P < 0.001), all postoperative complications of grade II or higher (12% vs. 28%, P = 0.004), and postoperative intra-abdominal infections of grade II or higher (4% vs. 17%, P = 0.001) were significantly higher in the Tk group. Multivariable analysis identified that high TPS was the only independent risk factor for grade B or higher POPF and grade II or higher postoperative intra-abdominal infectious complications.

The TPS is a specific predictive factor for POPF and postoperative intra-abdominal infectious complications in patients undergoing laparoscopic or robotic gastrectomy. Careful pancreatic manipulation during suprapancreatic lymphadenectomy is necessary for patients with increased TPS (> 11.8 mm) to avoid postoperative complications.

The frequency of lymph node metastases per lymph node site in early gastric cancer has not been well clarified from the data based on prospective studies. This exploratory analysis aimed to determine the frequency and location of lymph node metastases in clinical T1 gastric cancer using the data from JCOG0912 to investigate the validity of the extent of standard lymph node dissection defined in Japanese guidelines.

This analysis included 815 patients with clinical T1 gastric cancer. The proportion of pathological metastasis was identified for each lymph node site per tumor location (middle third and lower third) and four equal parts of the gastric circumference. The secondary aim was identification of the risk factor for lymph node metastasis.

Eighty-nine patients (10.9%) had pathologically positive lymph node metastases. Although the overall frequency of metastases was low (0.3-5.4%), metastases were widely located in each lymph node sites when primary lesion was in the middle third of the stomach. No. 4sb and 9 showed no metastasis when primary lesion was in the lower third of the stomach. Lymph node dissection of metastatic nodes resulted in a 5-year survival in more than 50% of patients. A tumor greater than 3 cm and a T1b tumor were associated with lymph node metastasis.

This supplementary analysis demonstrated that nodal metastasis from early gastric cancer is widely and disorderly not depending on the location. Thus, systematic lymph node dissection is necessary to cure the early gastric cancer.

Advanced bipolar devices (ABD; e.g., LigaSure™) have a lower blade temperature than ultrasonically activated devices (USAD; e.g., Harmonic® and Sonicision™) during activation, potentially enabling accurate lymph node dissection with less risk of postoperative pancreatic fistula (POPF) due to pancreatic thermal injury in laparoscopic gastrectomy. Therefore, we compared the efficacy and safety of ABD and USAD in laparoscopic gastrectomy for gastric cancer patients.

A retrospective cohort study was conducted on patients who underwent laparoscopic distal gastrectomy (LDG) between August 2008 and September 2020. A total of 371 patients were enrolled, and short-term surgical outcomes, including the incidence of ISGPF grades B and C POPF, were compared between ABD and USAD. The risk factors for POPF in LDG were investigated by univariate and multivariate analyses.

A propensity score-matching algorithm was used to select 120 patients for each group. The POPF rate was significantly lower (0.8 vs. 9.2%, p < 0.001), the morbidity rate was lower (13.3 vs. 28.3%, p < 0.001), the length of postoperative hospitalization was shorter (14 vs. 19 days, p < 0.001), and the lymph node retrieval rate was higher (34 vs. 26, p < 0.001) with an ABD than with a USAD. There were no mortalities in either group. A multivariate analysis showed that a USAD was the only independent risk factor with a considerably high odds ratio for the occurrence of POPF (USAD/ABD, odds ratio 8.38, p = 0.0466).

An ABD may improve the safety of laparoscopic gastrectomy for gastric cancer patients.

The Japanese operative-rating scale for laparoscopic distal gastrectomy (JORS-LDG) was developed through cognitive task analysis together with the Delphi method to measure intraoperative performance during laparoscopic distal gastrectomy. This study aimed to investigate the value of this rating scale as an educational tool and a surgical outcome predictor in laparoscopic distal gastrectomy.

The surgical performance of laparoscopic distal gastrectomy was assessed by the first assistant, through self-evaluation in the operating room and by video raters blind to the case. We evaluated inter-rater reliability, internal consistency, and correlations between the JORS-LDG scores and the evaluation methods, patient characteristics, and surgical outcomes.

Fifty-four laparoscopic distal gastrectomy procedures performed by 40 surgeons at 16 institutions were evaluated in the operating room and with video recordings using the proposed rating scale. The video inter-rater reliability was > 0.8. Participating surgeons were divided into the low, intermediate, and high groups based on their total scores. The number of laparoscopic surgeries and laparoscopic gastrectomy procedures performed differed significantly among the groups according to laparoscopic distal gastrectomy skill levels. The low, intermediate, and high groups also differed in terms of median operating times (311, 266, and 229 min, respectively, P < 0.001), intraoperative complication rates (27.8, 11.8, and 0%, respectively, P = 0.01), and postoperative complication rates (22.2, 0, and 0%, respectively, P = 0.002).

The JORS-LDG is a reliable and valid measure for laparoscopic distal gastrectomy training and could be useful in predicting surgical outcomes.

To perform laparoscopic gastrectomy safely, we aimed to comprehensively re-evaluate perigastric vessel anatomies using a three-dimensional angiography reconstructed from enhanced multidetector-row computed tomography data.

Perigastric vessel anatomy was preoperatively analyzed using a multidetector-row computed tomography-based three-dimensional angiography reconstructed in 127 patients undergoing gastric surgery.

Of the 67 left gastric veins that ran along the dorsal side of the arteries, 59 (88.1%) ran along the dorsal side of the common hepatic artery and flowed into the portal vein. In 18 cases, a common trunk of one to three left gastric arteries and the replaced left hepatic artery was observed. The left inferior phrenic artery ramified from the left gastric artery in 5.5% of the cases. The right gastric artery was classified into distal (73.2%), caudal (18.1%), and proximal (8.7%) types. The infra-pyloric artery was also classified into distal (64.6%), caudal (26.0%), and proximal (9.4%) types. The posterior gastric artery branched as a common trunk with the superior polar artery in the proximal (37.9%) and distal (18.4%) regions of the splenic artery. The left gastroepiploic artery ramified from the splenic (18.1%) and inferior terminal arteries (81.9%). No, one, and two gastric branches of the left gastroepiploic artery, which ramified between the roots of the left gastroepiploic artery and its omental branch, were found in 36.5%, 49.2%, and 14.3% of the cases, respectively.

Preoperative 3D angiography is useful for the precise evaluation of perigastric vessel anatomies, and may help us to perform laparoscopic gastrectomy and robotic surgery safely.

We have developed a novel technique for safe and precise lymph-node dissection during robotic gastrectomy for gastric cancer using monopolar curved scissors with soft coagulation. This technique is called the soft coagulation scissors technique. The technical details of this technique are as follows: a long bipolar grasper in the first arm and monopolar curved scissors in the third arm are primarily used for lymph-node dissection, maximizing the use of the robotic arm articulation. The monopolar curved scissors were energized in the soft coagulation mode of the Valleylab™ FT10 energy platform or in the forced coagulation mode of the ERBE VIO^®dV with an effect 1/power limit of 15 W. This limit was confirmed to be equivalent to the soft coagulation mode in preliminary experiments, and a long bipolar grasper applied adequate tension to the surgical site without strongly grasping the tissue or applying traction. The peak temperatures of our devices were more than 100 °C lower than those of the Harmonic ACE and the Maryland bipolar forceps with the forced coagulation mode. Overall, 80 patients with gastric cancer, including 36 (45.0%) with stage III or IV cancers, underwent robotic distal gastrectomy with this technique. The median estimated blood loss was 10 g. There were only four surgical complications (5.0%): two paralytic ileus, one intra-abdominal abscess, and one duodenal stump leakage. Robotic distal gastrectomy for gastric cancer is made possible by the soft coagulation scissors technique, which allows for safe and precise lymph-node dissection.

The safety of robotic gastrectomy (RG) for gastric cancer in daily clinical settings and the process by which surgeons are introduced and taught RG remain unclear. This study aimed to evaluate the safety of RG in daily clinical practice and assess the learning process in surgeons introduced to RG.

Patients who underwent RG for gastric cancer at Kyoto University and 12 affiliated hospitals across Japan from January 2017 to October 2019 were included. Any morbidity with a Clavien-Dindo classification grade of II or higher was evaluated. Moreover, the influence of the surgeon's accumulated RG experience on surgical outcomes and surgeon-reported postoperative fatigue were assessed.

A total of 336 patients were included in this study. No conversion to open or laparoscopic surgery and no in-hospital mortality were observed. Overall, 50 (14.9%) patients developed morbidity. During the study period, 14 surgeons were introduced to robotic procedures. The initial five cases had surprisingly lower incidence of morbidity compared to the following cases (odds ratio 0.29), although their operative time was longer (+ 74.2 min) and surgeon's fatigue scores were higher (+ 18.4 out of 100 in visual analog scale).

RG was safely performed in actual clinical settings. Although the initial case series had longer operative time and promoted greater levels of surgeon fatigue compared to subsequent cases, our results suggested that RG had been introduced safely.

Cell sheet technology is one of the most successful methodologies in regenerative medicine. Various applications of cell sheets have been introduced in first-in-human studies in several clinical fields. When transplanting a cell sheet into internal organs, a relatively large incision is required for delivery due to difficulty handling the sheet. We developed a laparoscopic delivery procedure for safe and easy transplantation of cell sheets in a porcine model.

Pneumoperitoneum was established by inflation with CO2. First, to increase the strength during handling, fibrin was sprayed onto the surface of the cell sheet, and then a myoblast sheet was placed onto the newly developed carrier. The sheets were pinched with laparoscopic forceps to insert into the abdominal cavity through the laparoscopic port. Myoblast sheets were then applied to the surface of the liver, colon, small intestine, and stomach, and procedure times were measured. At three days post transplantation, a histopathological examination was performed to confirm engraftment of the sheet. The function and engraftment were also analyzed in a duodenal endoscopic submucosal dissection (ESD) model.

The fibrin-processed myoblast sheet was able to be managed with conventional laparoscopic forceps without breaking. Despite the drastic change in air pressure by passing through the laparoscopic port, the sheets suffered no apparent damage. The transplantation procedure times did not markedly differ among transplant sites. A histopathological examination revealed thin-layered, desmin-positive cells at each transplant site. With transplantation following ESD, the engrafted myoblast sheets effectively prevented delayed perforation.

Our procedure is simple, and the system involves a carrier made of medically fit silicon, commercially available fibrin glue and conventional laparoscopic forceps. Our procedure is a powerful tool for laparoscopical cell sheet transplantation.