Genomic Landscape of Adenocarcinomas Across the Gastroesophageal Junction: Moving on from the Siewert Classification.

OBJECTIVE: To investigate how the Siewert classification of gastroesophageal junction adenocarcinomas correlates with genomic profiles. SUMMARY/BACKGROUND DATA: Current staging and treatment guidelines recommend that tumors with an epicenter less than 2 cm into the gastric cardia be treated as esophageal cancers, while tumors with epicenter greater than 2 cm into the cardia be staged and treated as gastric cancers. To date, however, few studies have compared the genomic profiles of the 3 Siewert classification groups to validate this distinction. METHODS: Using targeted tumor sequencing data on patients with adenocarcinoma of the gastroesophageal junction previously treated with surgery at our institution, we compared genomic features across Siewert classification groups. RESULTS: A total of 350 patients were included: 121 had Siewert type I, 170 type II, and 59 type III. Comparisons by Siewert location revealed that Siewert type I and II were primarily characterized as the chromosomal instability (CIN) molecular subtype and displayed Barrett's metaplasia and p53 and cell cycle pathway dysregulation. Siewert type III tumors, by contrast, were more heterogeneous, including higher proportions of microsatellite instability (MSI) and genomically stable (GS) tumors and more frequently displayed ARID1A and somatic CDH1 alterations, signet ring cell features, and poor differentiation. Overall, Siewert type I and II tumors demonstrated greater genomic overlap with lower esophageal tumors, while Siewert type III tumors shared genomic features with gastric tumors. CONCLUSIONS: Overall, our results support recent updates in treatment and staging guidelines. Ultimately, however, molecular rather than anatomic classification may prove more valuable in determining staging, treatment, and prognosis.

Safety and feasibility of minimally invasive gastrectomy following preoperative chemotherapy for highly advanced gastric cancer.

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

Standardized procedure for preventing late intestinal complications following minimally invasive total gastrectomy for gastric cancer: a single-center retrospective cohort study.

BACKGROUND: Although minimally invasive total gastrectomy for gastric cancer is commonly performed, reports regarding late complications are limited. We have made several improvements each time we experienced severe late complications since 2009. This study aimed to evaluate the clinical efficacy of these improved procedures in preventing late complications. METHODS: Between January 2009 and December 2019, 302 patients who underwent laparoscopic or robotic total gastrectomy for gastric cancer were enrolled. The patients were divided into two groups: Period-I (2009-2013, before established standardization of procedure, 166 patients) and Period-II (2014-2019, after established standardization of procedure, 136 patients). The standardized procedure comprised four major steps, including closure of the mesentery defects and diaphragm crus, circumferential fixation of the anastomotic site into the diaphragm, and linearization around the anastomotic site of esophagojejunostomy. The incidence of late complications was retrospectively compared between the two groups. RESULTS: Late overall complications that occurred over 30 days after surgery were observed in 19 (6.3%) patients. In all, 14 of 24 (58.3%) patients admitted due to late intestinal complications eventually required reoperation for treatment. The most frequent complication was nonstenotic outlet obstruction of the distal jejunal limb. The incidence of late overall complications was significantly lower in Period-II than in Period-I (2.9 vs 9.0%, p = 0.030). Intestinal complications were reduced considerably in Period-II. The 3-year cumulative incidence rate of late overall complications was significantly lower in Period-II than in Period-I (0.03 vs 0.10, p = 0.035). Period-I as the only independent risk factor for the development of late intestinal complications. CONCLUSION: Late complications after laparoscopic total gastrectomy sometimes occurred, and more than half of the patients with intestinal complications required reoperation. Our standardized procedure was associated with a lower risk of late intestinal complications after minimally invasive total gastrectomy followed by intracorporeal esophagojejunostomy using linear staplers in a cohort of patients with gastric cancer.

First clinical experiences of robotic gastrectomy for gastric cancer using the hinotori™ surgical robot system.

BACKGROUND: Although the da Vinci™ Surgical System is the most predominantly used surgical robot worldwide, other surgical robots are being developed. The Japanese surgical robot hinotori™ Surgical Robot System was launched and approved for clinical use in Japan in November 2022. We performed the first robotic gastrectomy for gastric cancer using hinotori in the world. Here, we report our initial experience and evaluation of the feasibility and safety of robotic gastrectomy for gastric cancer using hinotori. METHODS: A single-institution retrospective study was conducted. Between November 2022 and October 2023, 24 patients with gastric cancer underwent robotic gastrectomy with hinotori. Five ports, including one for an assistant, were placed in the upper abdomen, and gastric resection with standard lymphadenectomy and intracorporeal reconstruction were performed. The primary endpoint was the postoperative complication rate within 30 days after surgery. The secondary outcomes were surgical outcomes, including intraoperative adverse events, operative time, blood loss, and the number of dissected nodes. RESULTS: Of the 24 patients, 16 (66.7%) were male. The median age and body mass index were 73.5 years and 22.9 kg/m2, respectively. Twenty-three patients (95.8%) had tumors in the middle to lower stomach. Sixteen (66.7%) and seven (29.2%) patients had clinical stage I and II diseases, respectively. Twenty-three (95.8%) patients underwent distal gastrectomy. No patient had postoperative complications of Clavien-Dindo classification IIIa or higher, whereas two (8.3%) had the grade II complications (enteritis and pneumonia). No intraoperative adverse events, including conversion to other approaches, were observed. All patients received R0 resection. The median operative and console times were 400 and 305 min, respectively. The median blood loss was 14.5 mL, and the number of lymph nodes dissected was 51.5. CONCLUSIONS: This study found that robotic gastrectomy with standard lymphadenectomy for gastric cancer using hinotori can be safely performed.

Distinct Differences in Gastroesophageal Junction and Gastric Adenocarcinoma in 2194 Patients: In Memory of Rebecca A. Carr, February 24, 1988-January 19, 2021.

OBJECTIVE: We sought to compare gastroesophageal junction (GEJ) cancer and gastric cancer (GC) and identify clinicopathological and oncological differences. SUMMARY BACKGROUND DATA: GEJ cancer and GC are frequently studied together. Although the treatment approach for each often differs, clinico-pathological and oncological differences between the 2 have not been fully evaluated. METHODS: We retrospectively identified patients with GEJ cancer or GC who underwent R0 resection at our center between January 2000 and December 2016. Clinicopathological characteristics, disease-specific survival (DSS), and site of first recurrence were compared. RESULTS: In total, 2194 patients were analyzed: 1060 (48.3%) with GEJ cancer and 1134 (51.7%) with GC. Patients with GEJ cancer were younger (64 vs 66 years; P < 0.001), more often received neoadjuvant treatment (70.9% vs 30.2%; P < 0.001), and had lower pathological T and N status. Five-year DSS was 62.2% in patients with GEJ cancer and 74.6% in patients with GC ( P < 0.001). After adjustment for clinicopathological factors, DSS remained worse in patients with GEJ cancer (hazard ratio, 1.78; 95% confidence interval, 1.40-2.26; P < 0.001). The cumulative incidence of recurrence was approximately 10% higher in patients with GEJ cancer ( P < 0.001). The site of first recurrence was more likely to be hematogenous in patients with GEJ cancer (60.1% vs 31.4%; P < 0.001) and peritoneal in patients with GC (52.9% vs 12.5%; P < 0.001). CONCLUSIONS: GEJ adenocarcinoma is more aggressive, with a higher incidence of recurrence and worse DSS, compared with gastric adenocarcinoma. Distinct differences between GEJ cancer and GC, especially in patterns of recurrence, may affect evaluation of optimal treatment strategies.

Risk of Lymph Node Metastasis in T1b Gastric Cancer: An International Comprehensive Analysis from the Global Gastric Group (G3) Alliance.

OBJECTIVE: We sought to define criteria associated with low lymph node metastasis risk in patients with submucosal (pT1b) gastric cancer from 3 Western and 3 Eastern countries. SUMMARY BACKGROUND DATA: Accurate prediction of lymph node metastasis risk is essential when determining the need for gastrectomy with lymph node dissection following endoscopic resection. Under present guidelines, endoscopic resection is considered definitive treatment if submucosal invasion is only superficial, but this is not routinely assessed. METHODS: Lymph node metastasis rates were determined for patient groups defined according to tumor pathological characteristics. Clinicopathological predictors of lymph node metastasis were determined by multivariable logistic regression and used to develop a nomogram in a randomly selected subset that was validated in the remainder. Overall survival was compared between Eastern and Western countries. RESULTS: Lymph node metastasis was found in 701 of 3166 (22.1%) Eastern and 153 of 560 (27.3%) Western patients. Independent predictors of lymph node metastasis were female sex, tumor size, distal stomach location, lymphovascular invasion, and moderate or poor differentiation. Patients fulfilling the National Comprehensive Cancer Network guideline criteria, excluding the requirement that invasion not extend beyond the superficial submucosa, had a lymph node metastasis rate of 8.9% (53/594). Excluding moderately differentiated tumors lowered the rate to 3.4% (10/296). The nomogram's area under the curve was 0.690. Regardless of lymph node status, overall survival was better in Eastern patients. CONCLUSIONS: The lymph node metastasis rate was lowest in patients with well differentiated tumors that were ≤3 cm and lacked lymphovascular invasion. These criteria may be useful in decisions regarding endoscopic resection as definitive treatment for pT1b gastric cancer.

Survival of Locally Advanced MSI-high Gastric Cancer Patients Treated With Perioperative Chemotherapy: A Retrospective Cohort Study.

OBJECTIVE: To evaluate the efficacy of chemotherapy in patients with microsatellite instability (MSI)-high gastric cancer. BACKGROUND: Although MSI-high gastric cancer is associated with a superior prognosis, recent studies question the benefit of perioperative chemotherapy in this population. METHODS: Locally advanced gastric adenocarcinoma patients who either underwent surgery alone or also received neoadjuvant, perioperative, or adjuvant chemotherapy between 2000 and 2018 were eligible. MSI status, determined by next-generation sequencing or mismatch repair protein immunohistochemistry, was determined in 535 patients. Associations among MSI status, chemotherapy administration, overall survival (OS), disease-specific survival, and disease-free survival were assessed. RESULTS: In 535 patients, 82 (15.3%) had an MSI-high tumor and ∼20% better OS, disease-specific survival, and disease-free survival. Grade 1 (90%-100%) pathological response to neoadjuvant chemotherapy was found in 0 of 40 (0%) MSI-high tumors versus 43 of 274 (16%) MSS. In the MSI-high group, the 3-year OS rate was 79% with chemotherapy versus 88% with surgery alone ( P =0.48). In the MSS group, this was 61% versus 59%, respectively ( P =0.96). After multivariable interaction analyses, patients with MSI-high tumors had superior survival compared with patients with MSS tumors whether given chemotherapy (hazard ratio=0.53, 95% confidence interval: 0.28-0.99) or treated with surgery alone (hazard ratio=0.15, 95% confidence interval: 0.02-1.17). CONCLUSIONS: MSI-high locally advanced gastric cancer was associated with superior survival compared with MSS overall, despite worse pathological chemotherapy response. In patients with MSI-high gastric cancer who received chemotherapy, the survival rate was ∼9% worse compared with surgery alone, but chemotherapy was not significantly associated with survival.

Efficacy of minimally invasive proximal gastrectomy followed by valvuloplastic esophagogastrostomy using the double flap technique in preventing reflux oesophagitis.

BACKGROUND: Valvuloplastic esophagogastrostomy (VEG) using the double flap technique (DFT) after proximal gastrectomy (PG) represents a promising procedure for the prevention of reflux oesophagitis. We aimed to retrospectively investigate the efficacy of minimally invasive PG followed by VEG-DFT in preventing reflux oesophagitis among patients who require intra-mediastinal anastomosis. METHODS: A total of 80 patients who underwent reconstruction with DFT after LPG from November 2013 to January 2021 were enrolled in the present study. Data were obtained through a review of our prospectively maintained database. At 1 year after surgery, multivariate analyses were performed to identify risk factors for gastroesophageal reflux disease of Los Angeles (LA) classification grade B or higher. RESULTS: The incidence of LA grade B or higher reflux oesophagitis 1 year after surgery was 10%. Multivariate analyses revealed that the longitudinal length of the resected oesophagus of > 20 mm was the only significant risk factor for reflux oesophagitis. Patients with a longitudinal length of the resected oesophagus > 20 mm (group-L, n = 35) had a significantly longer total operative time and a higher rate of complications within 30 days of surgery than those with a length of ≤ 20 mm (group-S, n = 45). LA grade B or higher reflux oesophagitis was significantly higher in group-L than in group-S (20% vs. 2.2%; P = 0.011). CONCLUSIONS: There is a need for surgical procedures with improved efficacy for the prevention of reflux oesophagitis in patients requiring oesophageal resection of > 20-mm.

Muscle mass ratio in male gastric cancer patients as an independent predictor of postoperative complications after minimally invasive distal gastrectomy.

BACKGROUND: The current study aimed to investigate the relationship between muscle mass proportion and the incidence of total complications in male gastric cancer (GC) patients after minimally invasive distal gastrectomy (MIDG). METHODS: Between March 2017 and March 2020, 152 male GC patients with clinical stage III or lower GC who underwent MIDG were enrolled in this study. The muscle mass ratio (MMR) was calculated by dividing the total muscle weight obtained from bioelectrical impedance analysis by the whole-body weight. Thereafter, the association between MMR and surgical outcomes was determined. RESULTS: Based on the optimal MMR cutoff value of 0.712 obtained using the receiver operating characteristic (ROC) curve, patients were divided into two groups (69 and 83 patients in the MMR-L and MMR-H groups). The MMR-L group had a significantly higher total complication rate compared to the MMR-H group (MMR-L, 24.6% vs. MMR-H, 7.2%; P = 0.005). Multivariate analysis also identified MMR-L as a significant independent risk factor for total complications and intra-abdominal infectious complications after MIDG. CONCLUSIONS: The MMR calculated using bioelectrical impedance analysis can be a useful predictor for postoperative complications after MIDG in male GC patients.

Robotic esophagectomy with outermost layer-oriented dissection for esophageal cancer: technical aspects and a retrospective review of a single-institution database.

BACKGROUND: Systematic lymph node dissection in patients with gastric cancer could be sufficiently and reproducibly achieved along the outermost layer of the autonomic nerves and similar concept has been extensively used for robotic esophagectomy (RE) since 2018. This study aimed to determine the surgical and oncological safety of RE using the outermost layer-oriented approach for esophageal cancer (EC). METHODS: Sixty-six patients who underwent RE with total mediastinal lymphadenectomy for primary EC between April 2018 and December 2021 were retrospectively reviewed. All underwent the outermost layer-oriented approach with intraoperative nerve monitoring (IONM). Postoperative complications within 30 days were analyzed. RESULTS: Among the patients, 51 (77.3%) were male. The median age was 64 years, and the body mass index was 21.8 kg/m2. Furthermore, 58 (87.9%) patients had squamous cell carcinoma and eight (12.1%) patients had adenocarcinoma. Clinical stages I, II, and III were seen in 23 (34.8%), 23 (34.8%), and 16 (24.2%) patients, respectively. Thirty-four (51.5%) patients received preoperative treatment. No patient shifted to conventional thoracoscopic or open procedure intraoperatively. The median operative time was 716 min with 119 mL of blood loss. Additionally, 64 (97%) patients underwent R0 resection. The morbidity rates based on Clavien-Dindo grades ≥ II and ≥ IIIa were 30.3% and 10.6%, respectively, within 30 postoperative days. None died within 90 days postoperatively. Three (4.5%) patients exhibited recurrent laryngeal nerve (RLN) palsy (CD grade ≥ II). The sensitivity and specificity of IONM for RLN palsy were 50% and 98.3% at the right RLN and 33.3% and 98.0% at the left RLN, respectively. CONCLUSION: RE with the outermost layer-oriented approach can provide safe short-term outcomes.

Three-year outcomes of robotic gastrectomy versus laparoscopic gastrectomy for the treatment of clinical stage I/II gastric cancer: a multi-institutional retrospective comparative study.

BACKGROUND: Oncological benefits of robotic gastrectomy (RG) remain unclear. We aimed to determine and compare the 3-year outcomes of RG and laparoscopic gastrectomy (LG) for the treatment of gastric cancer. METHODS: This was a multi-institutional retrospective study of patients who prospectively underwent RG in a previous study (UMIN000015388) and historical controls who underwent LG. Operable patients with cStage I/II primary gastric cancer were enrolled. The inverse probability of treatment weighting method based on propensity scores was used to balance patient demographic factors and surgeon volume between the RG and LG groups. The primary outcome measure was the 3-year overall survival rate (3yOS). RESULTS: Of the 1,127 patients in the previous study, 326 and 752 patients in the RG and LG groups, respectively, completed the study. The standardized difference of all confounding factors was reduced to 0.09 or less after weighting. In the weighted population, 3yOS was 96.3% and 89.6% in the RG and LG groups, respectively (hazard ratio [HR] 0.34 [0.15, 0.76]; p = 0.009), whereas there was no difference in 3-year recurrence-free survival rate (3yRFS) between the two groups (HR 0.58 [0.32, 1.05]; p = 0.073). Sub-analyses showed that RG improved 3yOS (HR 0.05 [0.01, 0.38]; p = 0.004) and 3yRFS (HR 0.05 [0.01, 0.34]; p = 0.003) in patients with pStage IA disease. Recurrence rates and patterns were similar between the RG and LG groups. RG did not improve the morbidity rate, however, it attenuated some of the adverse events, including anastomotic leakage and intra-abdominal abscess. RG improved estimated blood loss and duration of postoperative hospitalization. CONCLUSION: This study showed surgical and oncological safety of RG for cStage I/II gastric cancer considering the 3-year outcomes, compared with those of LG.

Incidence and clinical relevance of postoperative diarrhea after minimally invasive gastrectomy for gastric cancer: a single institution retrospective study of 1476 patients.

PURPOSE: Postoperative diarrhea (PD) remains one of the significant complications. Only a few studies focused on PD after minimally invasive surgery. We aimed to investigate PD after minimally invasive gastrectomy for gastric cancer. METHODS: A total of 1476 consecutive patients with gastric cancer undergoing laparoscopic or robotic gastrectomy between 2009 and 2019 at our institution were retrospectively reviewed. PD was defined as continuous diarrhea for ≥ 2 days, positive stool culture, or positive clostridial antigen test. The incidence, causes, and related clinical factors were analyzed. RESULTS: Of the 1476 patients, the median age was 69 years. Laparoscopic and robotic approaches were performed in 1072 (72.6%) and 404 (27.4%), respectively. Postoperative complications with Clavien-Dindo classification grade of ≥ IIIa occurred in 108 (7.4%) patients. PD occurred in 89 (6.0%) patients. Of the 89 patients with PD, Clostridium difficile, enteropathogenic Escherichia coli, and methicillin-resistant Staphylococcus aureus were detected in 24 (27.0%), 16 (33.3%), and 7 (14.6%) patients, respectively. Multivariate analysis revealed that age ≥ 75 years (OR 1.62, 95% CI [1.02-2.60], p = 0.042) and postoperative complications (OR 6.04, 95% CI [3.54-10.32], p < 0.001) were independent risk factors for PD. In patients without complications, TG (OR 1.88) and age of ≥ 75 years(OR 1.71) were determined as independent risk factors. CONCLUSION: The incidence of PD following minimally invasive gastrectomy for gastric cancer was 6.0%. Older age and TG were obvious risk factors in such a surgery, with the latter being a significant risk even in the absence of complications.

Safe implementation of robotic distal gastrectomy performed by non-endoscopic surgical skill qualification system-qualified surgeons.

PURPOSE: Robotic gastrectomy (RG) for gastric cancer (GC) was approved for national medical insurance coverage in April, 2018, since when its use has increased dramatically throughout Japan. However, the safety of RG performed by surgeons who are not Endoscopic Surgical Skill Qualification System (ESSQS)-qualified has yet to be established. We conducted this study to verify the short-term outcomes of the initial series of RG procedures performed by non-ESSQS-qualified surgeons. METHODS: Between January, 2020 and December, 2021, 30 patients with clinical Stage I and II GC underwent RG performed by four non-ESSQS-qualified surgeons according to the Japan Society for Endoscopic Surgery guideline. We evaluated, retrospectively, the morbidity rates according to Clavien-Dindo (CD) classification grade II or higher. RESULTS: Each operating surgeon completed all procedures without any serious intraoperative adverse events. The median operative time, console time, and estimated blood loss were 413 (308-547) min, 361 (264-482) min, and 25.5 (4-167) mL, respectively. No patient required conversion to laparoscopic or open surgery. Three (10%) patients suffered CD grade II complications postoperatively. The median postoperative hospitalization was 11 (8-51) days. CONCLUSION: Non-ESSQS-qualified surgeons trained by expert RG surgeons could perform robotic distal gastrectomy safely for initial cases.

Circular-stapled esophagogastrostomy using the keyhole procedure after radical esophagectomy for esophageal cancer.

BACKGROUND: Anastomotic leakage of cervical esophagogastrostomy following radical esophagectomy for esophageal cancer has reduced over time; however, postoperative anastomotic stricture still occurs at a considerably high rate. We developed a novel method of circular-stapled esophagogastrostomy by employing the keyhole procedure, which uses a linear stapler to enlarge the anastomotic opening made with a circular stapler (CS). METHODS: We retrospectively reviewed 70 patients with esophageal cancer who underwent transthoracic esophagectomy and reconstruction via cervical CS-mediated anastomosis with or without the keyhole procedure between 2018 and 2020. The primary outcome was postoperative anastomotic stricture incidence within 180 days after surgery. RESULTS: Among 70 patients, 22 underwent the keyhole procedure (CS + K group) and the remaining did not (CS group). No differences were observed in patients' age, sex, body mass index, performance status, American Society of Anesthesiologists physical status, Charlson's comorbidity index, tumor histological type, tumor location, clinical stage, or preoperative treatment. A smaller stapler was used in the CS + K group (p < 0.001). Incidence of anastomotic stricture was significantly different (CS vs. CS + K, 18.8 vs. 0%, p = 0.049), especially when a 21 or 23 mm CS was used (CS vs. CS + K, 50.0 vs. 0%, p = 0.005). Univariate analysis confirmed that CS ≤ 23 without keyhole was a significant risk factor (p = 0.001). CONCLUSIONS: The keyhole procedure could be a simple and useful alternative technique that reduces the risk of stricture formation in cervical esophagogastric anastomosis, especially when using the smaller-sized CS.

Clinical advantage of standardized robotic total gastrectomy for gastric cancer: a single-center retrospective cohort study using propensity-score matching analysis.

BACKGROUND: Although recent studies have shown that robotic gastrectomy offers clinical advantages over laparoscopic gastrectomy in decreasing gastric cancer (GC) morbidity, studies focusing on robotic total gastrectomy (RTG) remain limited. The current study aimed to clarify whether the use of a robotic system could clinically improve short-term outcomes. METHODS: Between January 2009 and June 2021, 371 patients diagnosed with both clinical and pathological Stage III or lower GC and underwent RTG or laparoscopic total gastrectomy (LTG) were enrolled in this study. The primary outcome was the incidence of intra-abdominal infectious complications over Clavien-Dindo classification grade IIIa. Demographic characteristics of those who underwent the RTG and LTG were matched using propensity-score matching (PSM), after which short-term outcomes were compared retrospectively. RESULTS: After PSM, 100 patients were included in each group. The RTG group had a significantly shorter duration of hospitalization following surgery [RTG 13 (11-16) days vs. LTG 14 (11-19) days; p = 0.032] and a greater number of dissected LNs [RTG 48 (39-59) vs. LTG 43 (35-54) mL; p = 0.025], despite having a greater total operative time [RTG 511 (450-646) min vs. LTG 448 (387-549) min; p < 0.001]. In addition, the RTG group had significantly fewer total complications (3% vs. 13%, p = 0.019) and intra-abdominal infectious complications (1% vs. 9%; p = 0.023). CONCLUSIONS: The current study showed that robotic surgery might improve short-term outcomes following minimally invasive radical total gastrectomy by reducing intra-abdominal infectious complications.

Impact of routine preoperative sonographic screening with early intervention for deep venous thrombosis in lower extremities on preventing postoperative venous thromboembolism in patients with gastric cancer scheduled for minimally invasive surgery.

PURPOSE: This study aimed to investigate the clinical efficacy of lower-extremity ultrasonography screening with early intervention for deep venous thrombosis (DVT) on the incidence of venous thromboembolism (VTE) after minimally invasive surgery (MIS) for gastric cancer (GC). METHODS: Between January 2012 and December 2019, 1070 patients were diagnosed with both clinical and pathological stage I-III GC and underwent MIS at our institution. Routine ultrasonographic screening for DVT in lower extremities is performed before MIS. Patients diagnosed with DVT were preoperatively administered anticoagulant therapy. Enoxaparin was routinely administrated after surgery irrespective of the presence of DVT. The incidence of postoperative symptomatic VTE was examined retrospectively. RESULTS: A total of 74 (6.9%) patients were preoperatively diagnosed with DVT. Multivariate analyses revealed that age > 70 years (p = 0.015), female sex (p < 0.001), and positive serum D-dimer test (p < 0.001) were significant and independent risk factors for preoperative DVT. The incidence of symptomatic postoperative VTE was 1 (0.09%); symptomatic VTE developed in one patient among patients without DVT, whereas no patient with DVT developed VTE. CONCLUSIONS: Preoperative DVT screening using lower-extremity ultrasonography followed by preoperative anticoagulant therapy should be considered as a useful strategy to safely perform MIS for GC without increasing the incidence of VTE.

Establishment of a new practical telesurgical platform using the hinotori™ Surgical Robot System: a preclinical study.

AIM: The recent development of new surgical robots and network telecommunication technology has opened new avenues for robotic telesurgery. Although a few gastroenterological surgeries have been performed in the telesurgery setting, more technically demanding procedures including gastrectomy with D2 lymphadenectomy and intracorporeal anastomosis have never been reported. We examined the feasibility of telesurgical robotic gastrectomy using the hinotori™ Surgical Robot System in a preclinical setting. METHODS: First, the suturing time in the dry model was measured in the virtual telesurgery setting to determine the latency time threshold. Second, a surgeon cockpit and a patient unit were installed at Okazaki Medical Center and Fujita Health University, respectively (approximately 30 km apart), and connected using a 10-Gbps leased optic-fiber network. After evaluating the feasibility in the dry gastrectomy model, robotic distal gastrectomies with D2 lymphadenectomy and intracorporeal B-I anastomosis were performed in two porcine models. RESULTS: The virtual telesurgery study identified a latency time threshold of 125 ms. In the actual telesurgery setting, the latency time was 27 ms, including a 2-ms telecommunication network delay and a 25-ms local information process delay. After verifying the feasibility of the operative procedures using a gastrectomy model, two telesurgical gastrectomies were successfully completed without any unexpected events. No fluctuation was observed across the actual telesurgeries. CONCLUSION: Short-distance telesurgical robotic surgery for technically more demanding procedure may be safely conducted using the hinotori Surgical Robot System connected by high-speed optic-fiber communication.

[Robot-Assisted Surgery for Stage â £ Gastric Cancer with Liver Metastases-Report of a Case].

We report a successful case of robot-assisted surgery for Stage Ⅳ gastric cancer with liver metastasis. A 70s man diagnosed with advanced gastric cancer with S3 solitary liver metastasis, and received a chemotherapy with S-1 and cisplatin. After 4 courses of chemotherapy, liver metastatic lesion was disappeared. Thus, robotic distal gastrectomy and partial liver resection were performed. Operating time was 391 minutes, and amount of intraoperative blood loss was 11 mL. The postoperative course was uneventful, and the patient was discharged 11 days after surgery. Histologic examination revealed no viable malignant cells in the resected liver, with a diagnosis of ypT2N1M0, ypStage ⅡA. The patient is alive with no recurrence 12 months after surgery, without adjuvant chemotherapy.

[A Case of Gastric Granular Cell Tumor Resected by a Surgical Robot].

A 46-year-old man was referred to further treatment for a 20 mm submucosal tumor at the gastric angle found during a medical check-up. Endoscopic ultrasonography and chest abdominal contrast-enhanced CT revealed the tumor was located at the 4th(proper muscular)layer of the posterior wall of the gastric antrum and slightly enhanced. No metastasis was found. Although a biopsy failed to reveal an accurate diagnosis, GIST was clinically suspected. A robotic distal gastrectomy was planned to manage the residual gastric stricture. The intraoperative findings indicated possible passage of the remnant stomach; therefore, local resection was performed. The patient's postoperative course was uneventful, and he was discharged on postoperative day 9. A histopathological examination confirmed the diagnosis of a PAS-positive, S100-positive granular cell tumor with no nuclear atypia. These findings suggest that use of the robotic approach could help determine the stomach resection extent.

[A Case of Curative Resection for Gastric Cancer with Single Giant Lymph Node Metastasis].

A 79-year-old male presented with epigastric discomfort and appetite loss. A type 1 advanced gastric tumor was detected by upper gastrointestinal endoscopy. Contrast-enhanced CT revealed a 7 cm mass with contrast effect at the greater curvature of the lower body of the stomach. No distant metastases were found. Staging laparoscopy confirmed gastric cancer with single giant lymph node metastasis, which was resectable, although the metastatic node possibly invaded the transverse colon. We performed total gastrectomy and partial colectomy. Pathological examination revealed the tumor was pT3N1; the mass was #4sa lymph node metastasis of gastric cancer. The postoperative course was uneventful. No tumor recurrence has been found for 12 months postoperatively.