Non-robotic minimally invasive gastrectomy as an independent risk factor for postoperative intra-abdominal infectious complications: A single-center, retrospective and propensity score-matched analysis

Possibility of preventing intra-abdominal infection by lymph node mapping with indocyanine green in robotic gastrectomy

BACKGROUND

Intra-abdominal infection can be an onerous and fatal complication of radical gastrectomy for gastric cancer. High drain amylase levels are closely related to pancreatic damage and intra-abdominal infection. We aimed to investigate whether robotic radical gastrectomy with lymph node mapping by indocyanine green tracer reduces drain amylase levels.

METHODS

Between March 2019 and July 2024, patients at our institution with clinical tumor stage cT1-T4a, N0/+, M0, and possibly treatable gastric cancer were enrolled in this study and divided into the indocyanine green group or the non-indocyanine green group based on the use of indocyanine green. One day before surgery, the patients in the indocyanine green group underwent endoscopic peritumoral injection of indocyanine green into the submucosa. Drain amylase levels on postoperative days 1 and 3, postoperative intra-abdominal infection, and perioperative outcomes were compared between the 2 groups.

RESULTS

There were no significant differences in patient background and pathologic factors between the 2 groups. Drain amylase levels on postoperative days 1 and 3 were significantly lower in the indocyanine green group than in the non-indocyanine green group, and postoperative hospital stay was shorter. The incidence of intra-abdominal infection was also significantly lower in the indocyanine green group than in the non-indocyanine green group. However, multivariate analysis of intra-abdominal infection showed a drain amylase level of 200 IU/L or higher on postoperative day 3 to be an independent risk factor for postoperative intra-abdominal infection, whereas indocyanine green use was not.

CONCLUSION

This study showed the clinical usefulness of robotic radical gastrectomy with lymph node mapping by indocyanine green. This procedure can reduce drain amylase levels and consequently may reduce the incidence of intra-abdominal infection.

Safety and feasibility of laparoscopic stomach-partitioning gastrojejunostomy combined with neoadjuvant chemotherapy followed by minimally invasive gastrectomy for resectable gastric cancer with gastric outlet obstruction

BACKGROUND

Advanced gastric cancer with gastric outlet obstruction (GOO) causes malnutrition and medication adherence issues, leading to a poor prognosis. We developed a novel multimodal, less invasive treatment approach for gastric cancer patients with symptomatic GOO: laparoscopic stomach-partitioning gastrojejunostomy (LSPGJ) combined with neoadjuvant chemotherapy (NAC), followed by minimally invasive gastrectomy with reuse of gastrojejunostomy. This study is a retrospective analysis of the safety and feasibility of our treatment strategy.

METHODS

In this single-institution retrospective study, we enrolled 54 patients (NAC group, n = 26; upfront gastrectomy group, n = 28) who achieved R0 resection through a minimally invasive approach between 2007 and 2020 and evaluated their short- and long-term outcomes.

RESULTS

After LSPGJ, the Gastric Outlet Obstruction Scoring System score significantly improved (p < 0.001). The median relative dose intensity of NAC was 88.2%. Regarding short-term outcomes, there were no differences in postoperative complications, length of postsurgical hospital stay, and adjuvant chemotherapy administration. Although overall survival and relapse-free survival showed trends toward improvement in the NAC group, these differences were not statistically significant. The cumulative incidence curve for recurrence in the NAC group was significantly lower than that of the upfront gastrectomy group (p = 0.041). Recurrence and hematogenous metastasis were significantly lower in the NAC group (p = 0.031 and 0.041, respectively) than in the upfront gastrectomy group. A forest plot revealed that NAC yielded favorable outcomes, particularly for patients with a body mass index (BMI) < 18.5 kg/m2, cT4, or cN1.

CONCLUSIONS

LSPGJ combined with NAC followed by minimally invasive gastrectomy was a safe and feasible treatment strategy for patients with advanced gastric cancer with symptomatic GOO. This procedure may contribute to the early recovery of oral intake and help maintain NAC dose intensity, potentially improving prognosis, particularly for patients with low BMI and advanced-stage disease.

Predictive model for pancreatic fistula in minimally invasive surgery for gastric cancer

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Evaluating the Role of Robotic Surgery Gastric Cancer Treatment: A Comprehensive Review by the Robotic Global Surgical Society (TROGSS) and European Federation International Society for Digestive Surgery (EFISDS) Joint Working Group

INTRODUCTION

Robot-assisted minimally invasive gastrectomy (RAMIG) represents a significant advancement in the surgical management of gastric cancer, offering superior dexterity, enhanced visualization, and improved ergonomics compared to laparoscopic gastrectomy (LG). This review systematically evaluates the current evidence on perioperative outcomes, oncological efficacy, learning curves, and economic considerations, providing insights into RAMIG's potential role in modern gastric cancer surgery.

METHODS

A thorough analysis of retrospective, prospective, and meta-analytic studies was conducted to compare RAMIG with LG. Key outcomes, including operative time, intraoperative blood loss, lymph node retrieval, postoperative complications, learning curve duration, and cost-effectiveness, were assessed. Emphasis was placed on both short-term and long-term oncological outcomes to determine the clinical value of RAMIG.

RESULTS

Evidence indicates that RAMIG is associated with reduced intraoperative blood loss, lower morbidity rates, and a shorter learning curve, with proficiency achieved after 11-25 cases compared to 40-60 cases for LG. The robotic platform's articulated instruments and enhanced three-dimensional visualization enable more precise lymphadenectomy, particularly in complex anatomical regions. Despite these advantages, operative time remains longer, and costs remain higher due to system acquisition, maintenance, and consumable expenses. However, emerging data suggest a gradual narrowing of cost disparities. While short-term outcomes are favorable, further high-quality, multicenter studies are needed to validate long-term oncological efficacy and survival outcomes.

CONCLUSION

RAMIG offers significant technical and clinical advantages over conventional LG, particularly in terms of precision and learning efficiency. However, the long-term oncological benefits and economic feasibility require further validation. Future research should focus on cost optimization, advanced technological integration such as near-infrared fluorescence and artificial intelligence, and multicenter trials to solidify RAMIG's role as a standard approach for gastric cancer surgery.

Robotic Versus Laparoscopic Gastrectomy for Gastric Cancer: The Largest Systematic Reviews of 68,755 Patients and Meta-analysis

BACKGROUND

This meta-analysis aimed to compare the efficacy of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) in treating gastric cancer (GC).

PATIENTS AND METHODS

A comprehensive literature search across PubMed, MEDLINE, and Web of Science identified 86 eligible studies, including 68,755 patients (20,894 in the RG group and 47,861 in the LG group).

RESULTS

The analysis revealed that RG was associated with superior outcomes in several areas: more lymph nodes were harvested, intraoperative blood loss was reduced, postoperative hospital stays were shorter, and the time to first flatus and oral intake was shortened (all p < 0.001). Additionally, RG resulted in lower incidences of conversion to open surgery (OR = 0.62, p = 0.004), reoperation (OR = 0.68, p = 0.010), overall postoperative complications (OR = 0.82, p < 0.001), severe complications (OR = 0.65, p < 0.001), and pancreatic complications (OR = 0.60, p = 0.004). However, RG had longer operative times and higher costs (both p < 0.001). No significant differences were found between RG and LG in terms of resection margin distance, mortality, anastomotic leakage, or recurrence rates.

CONCLUSIONS

RG is a safe and effective surgical option for patients of GC, but further improvements in operative duration and costs are needed.

Trends of minimally invasive surgery in the primary treatment of cervical cancer

Minimally invasive surgery (MIS), including laparoscopic and robot-assisted procedures, has rapidly advanced in the treatment of gynecologic malignancies worldwide. However, its adoption and insurance coverage in AOFOG countries remain limited, particularly for advanced uterine and ovarian cancers. This limitation poses a challenge to the widespread use of MIS, highlighting the need for a more comprehensive evaluation of its role and the skills required by gynecologic oncologists to ensure safe and effective treatment. Furthermore, the Laparoscopic Approach to Cervical Cancer trial significantly impacted perceptions of MIS, revealing higher recurrence rates and inferior overall survival for minimally invasive radical hysterectomy (MIS-RH) compared to abdominal radical hysterectomy. Subsequent studies confirmed these findings, raising questions about the suitability of MIS-RH, particularly in centers with limited experience. Key issues affecting MIS outcomes include surgical expertise and tumor spillage prevention. As the landscape of cervical cancer treatment evolves, the integration of radiotherapy, chemotherapy, and immune therapies has challenged the traditional reliance on surgical monotherapy. There also exists ongoing debate over the optimal use of MIS in primary treatment and salvage surgery for cervical cancer to refine MIS techniques and explore their role in preserving fertility and managing residual disease post-chemoradiotherapy. For ensuring MIS as a viable treatment option, it is continuously necessary accumulating real-world data and reassessing surgical strategies to balance efficacy, safety, and patient preferences.

Impact of the endoscopic surgical skill qualification system on the oncological safety of laparoscopic gastrectomy for gastric cancer: A single-center retrospective cohort study

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Robotic gastrectomy is more beneficial for advanced than early-stage gastric cancer: a comparison with laparoscopic gastrectomy using propensity score matching

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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

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.

Short-term outcomes of laparoscopic and robotic distal gastrectomy for gastric cancer: Real-world evidence from a large-scale inpatient database in Japan

BACKGROUND AND OBJECTIVES

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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

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.

Laparoscopic gastrectomy for remnant gastric cancer: A single-center retrospective study

BACKGROUND

Laparoscopic gastrectomy (LG) for remnant gastric cancer (RGC) remains controversial because of its rarity and heterogeneity of clinical characteristics. Based on our experience, we posited that our established methodology in LG could be applied to the laparoscopic procedure for RGC surgery and introduced LG for RGC at our institution in 2004.

METHODS

This study enrolled 46 patients who underwent LG for RGC between January 2004 and December 2017. Data were obtained through a review of our prospectively maintained database. Laparoscopic total gastrectomy (LTG) was the standard surgical procedure for RGC. Laparoscopic subtotal gastrectomy (LsTG) was performed as an alternative procedure for patients with RGC located near the anastomotic site after primary gastrectomy. The technical and oncological feasibility and safety of LG for RGC were evaluated.

RESULTS

LTG for RGC was performed on 36 patients. LsTG for RGC was performed on 10 patients. All patients completed LG procedure and succeeded R0 resection. Complications of Clavien-Dindo classification grade ≥ IIIa occurred in 4 (8.7%) patients. The retrospective video reviews showed that the time for adhesiotomy around the suprapancreatic area and the lesser curvature of the remnant stomach was significantly shorter in the primary-benign group than in the primary-malignant group. With the median follow-up period of 40 months, the 3-year recurrence-free survival and 3-year overall survival rates were 72.3% and 80.2%, respectively.

CONCLUSION

LG for RGC represents a safe and feasible surgical option with favorable short-term and long-term outcomes in patients with RGC.

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.

Laparoscopic Versus Robotic Gastric Cancer Surgery: Short-Term Outcomes-Systematic Review and Meta-Analysis of 25,521 Patients

Background: Gastric cancer has the third highest cancer-related mortality worldwide. There is no consensus regarding the optimal surgical technique to perform curative resection surgery. Objective: Compare laparoscopic gastrectomy (LG) and robotic gastrectomy (RG) regarding short-term outcomes in patients with gastric cancer. Materials and Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the following topics: "Gastrectomy," "Laparoscopic," and "Robotic Surgical Procedures." The included studies compared short-term outcomes between LG and RG. Individual risk of bias was assessed with the Methodological Index for Non-Randomized Studies (MINORS) scale. Results: There was no significant difference between RG and LG regarding conversion rate, reoperation rate, mortality, overall complications, anastomotic leakage, distal and proximal resection margin distances, and recurrence rate. However, mean blood loss (mean difference [MD] -19.43 mL, P < .00001), length of hospital stay (MD -0.50 days, P = .0007), time to first flatus (MD -0.52 days, P < .00001), time to oral intake (MD -0.17 days, P = .0001), surgical complications with a Clavien-Dindo grade ≥III (risk ratio [RR] 0.68, P < .0001), and pancreatic complications (RR 0.51, P = .007) were significantly lower in the RG group. Furthermore, the number of retrieved lymph nodes was significantly higher in the RG group. Nevertheless, the RG group showed a significantly higher operation time (MD 41.19 minutes, P < .00001) and cost (MD 3684.27 U.S. Dollars, P < .00001). Conclusion: This meta-analysis supports the choice of robotic surgery over laparoscopy concerning relevant surgical complications. However, longer operation time and higher cost remain crucial limitations. Randomized clinical trials are required to clarify the advantages and disadvantages of RG.

Impact of gastrectomy on body composition within 1 month in patients with gastric cancer

PURPOSE

The present study examined the changes in and risk factors for body composition (BC) during the first postoperative month when dynamic biological reactions occur.

METHODS

We retrospectively assessed 202 patients who underwent gastrectomy. The BC was assessed using a bioelectrical impedance analysis and evaluated within 1 month preoperatively, 1 week postoperatively, and 1 month postoperatively. Multiple regression analyses were performed to identify predictive factors for BC change.

RESULTS

The mean reduction rate in BC at 1 month postoperatively was - 6.0, - 10.5, - 5.6, - 1.1, - 10.1, and + 1.2% for body weight, body fat, skeletal muscle, bone mineral, extracellular water/total body water, and the whole-body phase angle, respectively. A multiple regression analysis revealed that independent risk factors for weight loss were complications, operative time, and type of gastrectomy (P = 0.004, 0.011, 0.015, respectively), and those for skeletal muscle loss were complications and gastrectomy type (P = 0.002, 0.010, respectively). A segmental lean mass analysis revealed that the lower limbs were markedly reduced at 1 week postoperatively (- 8.0%), and these independent risk factors were the female sex and Stage II/III disease (P = 0.008, 0.036, respectively).

CONCLUSION

Detailed analyses of BC might help elucidate the mechanisms underlying postoperative physical changes, which might be useful for perioperative management.

Solo surgery in robot-assisted gastrectomy versus laparoscopic gastrectomy for gastric cancer: a propensity score-matched analysis

BACKGROUND

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).

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Relationship of preoperative Th1/Th2 ratio, TNF-α, and ALB with pulmonary infection in elderly patients after radical surgery for gastric cancer and predictive efficacy of a nomogram based on these factors

BACKGROUND

The immune system and the inflammatory response play an important role in the development of lung infections in the elderly population after radical gastric cancer surgery. Helper T cell 1 (Th1)/helper T cell 2 (Th2) phenotype reflects the dynamic immune homeostasis. Preoperative Th1/Th2 ratio and inflammatory response-related factors may have predictive value for postoperative lung infection.

AIM

To investigate the relationship of Th1/Th2 ratio, tumor necrosis factor-α (TNF-α), and albumin (ALB) with pulmonary infection in elderly patients after radical gastrectomy for gastric cancer and their predictive efficacy for postoperative pulmonary infection.

METHODS

A total of 135 patients with lung infection after radical gastric cancer surgery (infection group) and 135 uninfected patients (control group) admitted to our hospital from April 2020 to June 2022 were included in this study. The general demographic data, surgery-related conditions, combined diseases, and preoperative serum Th1/Th2 ratio, TNF-α, and ALB levels were compared between the two groups. R was used to draw a nomogram for predicting lung infection after radical gastrectomy in elderly patients, and the concordance index (C-index) of the nomogram was obtained to evaluate its prediction ability. The bootstrap method was used to draw the prediction curve, calibration curve, and ideal curve to evaluate the consistency between the nomogram and the actual observation results, and decision curve analysis (DCA) was performed to evaluate the clinical efficacy of the nomogram.

RESULTS

The infection group had longer operative time and postoperative gastric tube indwelling time, higher intraoperative bleeding, and more diabetic patients than the control group (P < 0.05). Preoperative Th1/Th2 ratio and ALB were lower and TNF-α was higher in the infection group than in the control group (P < 0.05). Binary logistic regression analysis showed that operative time, intraoperative bleeding, diabetes mellitus, postoperative gastric tube indwelling time, and TNF-α were risk factors for pulmonary infection in elderly patients after radical surgery for gastric cancer, and Th1/Th2 ratio and ALB were protective factors (P < 0.05). A nomogram for predicting postoperative pulmonary infection was developed, and its C-index reached 0.985, which was at a high level. External validation showed that the calibration degree of the nomogram was 0.826, and there was good agreement between the model and the actual observation. DCA showed that the nomogram had obvious positive net benefit and possessed good clinical utility in predicting postoperative infection.

CONCLUSION

Preoperative Th1/Th2 ratio, TNF-α, and ALB are associated with pulmonary infection in elderly patients after radical surgery for gastric cancer. The nomogram developed based on baseline correlation data with the above three indicators has good predictive ability and clinical utility, and can be used as a potential tool to predict postoperative infection and guide clinical management in the perioperative period.

Robotic gastrectomy for gastric cancer: systematic review and future directions

BACKGROUND

Robotic gastrectomy (RG) using the da Vinci Surgical System for gastric cancer was approved for national medical insurance coverage in Japan in April 2018, and its number has been rapidly increasing since then.

AIM

We reviewed and compared current evidence on RG and conventional laparoscopic gastrectomy (LG) to identify the differences in surgical outcomes.

METHODS

Three independent reviewers systematically reviewed the data collected from a comprehensive literature search by an independent organization, focusing on the following nine endpoints: mortality, morbidity, operative time, estimated blood loss volume, length of postoperative hospital stay, long-term oncologic outcome, quality of life, learning curve, and cost.

RESULTS

Compared to LG, RG has lower intraoperative blood loss volume, shorter length of hospital stay, and shorter learning curve, but both procedures have similar mortality. Contrarily, its disadvantages include longer procedural time and higher costs. Although the morbidity rate and long-term outcomes are almost comparable, RG showed superior potentials. Currently, the outcomes of RG are considered comparable to or better than LG.

CONCLUSION

RG might be applicable to all gastric cancer patients who fulfill the indication of LG at institutions that meet specific criteria and are approved to claim the National Health Insurance costs for the use of the surgical robot in Japan.

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.

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.

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.

What is necessary to shorten the operative time in initial introduction of robotic gastrectomy for gastric cancer?

INTRODUCTION

Robotic gastrectomy (RG) is a good alternative to laparoscopic gastrectomy, as it improves treatment outcomes and reduces the burden of technical difficulties; however, prolonged operative time may be a disadvantage. This study aimed to identify measures to shorten the operative time during the initial introduction of RG at an institution.

METHODS

We assessed 33 patients with gastric cancer who underwent radical distal gastrectomy with Billroth-I reconstruction and divided them into three groups: laparoscopic distal gastrectomy (LDG), robotic distal gastrectomy in the early phase (RDG-E), and in the late phase (RDG-L). Operative time, six technical steps, and junk time, including the roll-in/roll-out, docking/undocking, and instrument exchange times, were compared among the groups.

RESULTS

The median (range) overall operative times of LDG, RDG-E, and RDG-L were 248 (179-323), 304 (249-383), and 263 (220-367) min, respectively, but no significant differences were observed. For each surgical step of RG, RDG-L in suprapancreatic lymph node dissection was significantly shorter than that in RDG-E. The median (range) junk times of LDG, RDG-E, and RDG-L were 16.7 (12.7-26.4), 48.3 (38.6-67.7), and 42.0 (35.4-49.2) min, respectively. Junk time was significantly longer in RDG-L than in LDG (p = 0.003), but not significant between RDG-E and RDG-L. The learning curve effect of overall, console, and junk times were achieved in four cases of RDG.

CONCLUSION

Junk time is a major factor in prolonging RDG operative time. However, to reduce the time after initial introduction, measures to promote robot-specific standardization and more effective use of robotic instruments are essential.

Robotic Versus Laparoscopic Gastrectomy for Gastric Cancer: A Mega Meta-Analysis

Background

Laparoscopic gastrectomy and robotic gastrectomy are the most widely adopted treatment of choice for gastric cancer. To systematically assess the safety and effectiveness of robotic gastrectomy for gastric cancer, we carried out a systematic review and meta-analysis on short-term and long-term outcomes of robotic gastrectomy.

Methods

In order to find relevant studies on the efficacy and safety of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) in the treatment of gastric cancer, numerous medical databases including PubMed, Medline, Cochrane Library, Embase, Google Scholar, and China Journal Full-text Database (CNKI) were consulted, and Chinese and English studies on the efficacy and safety of RG and LG in the treatment of gastric cancer published from 2012 to 2022 were screened according to inclusion and exclusion criteria, and a meta-analysis was conducted using RevMan 5.4 software.

Results

The meta-analysis inlcuded 48 literatures, with 20,151 gastric cancer patients, including 6,175 in the RG group and 13,976 in the LG group, respectively. Results of our meta-analysis showed that RG group had prololonged operative time (WMD = 35.72, 95% CI = 28.59–42.86, P < 0.05) (RG: mean ± SD = 258.69 min ± 32.98; LG: mean ± SD = 221.85 min ± 31.18), reduced blood loss (WMD = −21.93, 95% CI = −28.94 to −14.91, P < 0.05) (RG: mean ± SD = 105.22 ml ± 62.79; LG: mean ± SD = 127.34 ml ± 79.62), higher number of harvested lymph nodes (WMD = 2.81, 95% CI = 1.99–3.63, P < 0.05) (RG: mean ± SD = 35.88 ± 4.14; LG: mean ± SD = 32.73 ± 4.67), time to first postoperative food intake shortened (WMD = −0.20, 95% CI = −0.29 to −0.10, P < 0.05) (RG: mean ± SD = 4.5 d ± 1.94; LG: mean ± SD = 4.7 d ± 1.54), and lower length of postoperative hospital stay (WMD = −0.54, 95% CI = −0.83 to −0.24, P < 0.05) (RG: mean ± SD = 8.91 d ± 6.13; LG: mean ± SD = 9.61 d ± 7.74) in comparison to the LG group. While the other variables, for example, time to first postoperative flatus, postoperative complications, proximal and distal mar gin, R₀ resection rate, mortality rate, conversion rate, and 3-year overall survival rate were all found to be statistically similar at P > 0.05.

Conclusions

In the treatment of gastric cancer, robotic gastrectomy is a safe and effective procedure that has both short- and long-term effects. To properly evaluate the advantages of robotic surgery in gastric cancer, more randomised controlled studies with rigorous research methodologies are needed.

Da Vinci Robot-Assisted Video Image Processing under Artificial Intelligence Vision Processing Technology

This research was aimed to explore the application value of intelligent algorithm-based digital images in Da Vinci robot-assisted treatment of patients with gastric cancer surgery. 154 patients were included as the research objects, with 89 cases in the control group underwent laparoscopic surgery, and 65 cases in the experimental group underwent robotic surgery. According to the propensity score, the patients in two groups were pair matched (1: 1), of which 104 cases (52 cases in each group) were successfully matched. The general data of patients, the changes in the images before and after the algorithm processing, the intraoperative and postoperative conditions, the pathological examination results, and the follow-up information were observed after matching. Compared with the original images, the images processed by the thread image edge detection algorithm had the significantly improved clarity, as well as highly reduced artifacts and noises. The sensitivity, specificity, and accuracy of image-assisted diagnosis were improved remarkably, showing the differences of statistical significance ( $P<0.05$ ). The total time of surgery, intraoperative bleeding, CRP (1d and 3d after surgery), and postoperative total abdominal drainage showed the significant differences as well ( $P<0.05$ ). The surgeries of patients in both groups met R0 resection (no tumor infiltration within 1 mm of the surgical margin), but there was a significant difference in the number of lymph node dissections ( $P<0.05$ ). The overall survival rates of patients in the experimental group and the control group were 83.0% and 76.1%, respectively, 2 years after surgery, with no significant difference ( $P>0.05$ ). The thread image edge detection algorithm produced a better processing effect on the images, which greatly improved the diagnostic sensitivity, specificity, and accuracy. Compared with endoscopic surgery, robotic surgery has better postoperative recovery, safety and reliability, and obvious advantages of minimally invasive surgery.

Predictive value of prognostic nutritional index on infection after radical gastrectomy: a retrospective study

BACKGROUND

The prognostic nutritional index (PNI) is a useful tool to evaluate nutritional status, which is associated with postoperative complications and prognosis of patients with cancer. Recent studies have shown that PNI has important predictive value for postoperative infection in cancer patients. However, the role and clinical value of PNI in infection after radical gastrectomy remains unclear. This study investigated the relationship between PNI and infection after radical surgery for gastric cancer (GC), focusing on the predictive value of PNI.

METHODS

A total of 1,111 patients with primary gastric cancer who underwent radical surgery in our hospital from December 2010 to December 2020 were included in this retrospective study. The demographic and clinicopathological data of all patients were acquired through hospital information system (HIS). Preoperative serum albumin (ALB) level and peripheral blood lymphocyte count were obtained for PNI calculation. We selected 812 patients by propensity score matching to reduce biases due to the different distributions of co-variables among the comparable groups. The factors influencing postoperative infection in the matched patients were explored using univariate and multivariate analyses.

RESULTS

Baseline characteristics significantly differed among patients with different PNI scores. After one-to-one matching, the clinicopathological data of the 2 groups were comparable, and 812 patients were included for further analysis. Among these patients, 101 developed infections, with an infection rate of 12.4%, which were mainly caused by gram-negative bacteria. The incidence of infection was significantly higher in the low PNI group than in the high PNI group. Univariate and multivariate analyses identified body mass index (BMI) ≥25 kg/m2 [odds ratio (OR) =2.314, P=0.004], diabetes mellitus (OR =1.827, P=0.042), PNI score <45 (OR =2.138, P=0.037), combined multi-organ resection (OR =2.946, P<0.001), operation time ≥240 minutes (OR =2.744, P=0.023), and perioperative blood transfusion (OR =2.595, P=0.025) as risk factors for infection after radical surgery for GC.

CONCLUSIONS

Infection is the most common complication after radical gastrectomy for GC, and a low preoperative PNI score is a risk factor for postoperative infection.

Advantages of a robotic approach compared with laparoscopy gastrectomy for patients with high visceral fat area

BACKGROUND

Gastric cancer surgery for obese patients is regarded as a technically challenging procedure. The morbidity after gastrectomy has been reported to be significantly higher in patients with high visceral fat area (VFA). Robotic gastrectomy (RG) is expected to be advantageous for complicated operations. However, whether RG is superior to conventional laparoscopic gastrectomy (LG) for patients with visceral fat obesity remains unclear. The present study aimed to clarify the impact of RG on the short- and long-term outcomes of patients with high VFAs.

METHODS

This study included 1306 patients with clinical stage I/II gastric cancer who underwent minimally invasive gastrectomy between January 2012 and December 2020. The patients were subclassified according to VFA. The short- and long-term outcomes of RG were compared with those of LG in two VFA categories.

RESULTS

This study included 394 (high-VFA, 151; low-VFA, 243) and 882 patients (high-VFA, 366; low-VFA, 516) in the RG and LG groups, respectively. RG was associated with a significantly longer operative time than LG (high-VFA, P < 0.001; low-VFA, P < 0.001). The incidence rates of overall and intra-abdominal infectious complications in the high-VFA patients were lower in the RG group than in the LG group (P = 0.019 and P = 0.048, respectively) but not significantly different from those in the low-VFA patients. In the multivariate analysis, LG was identified as the only independent risk factor of overall (odds ratio [OR] 3.281; P = 0.012) and intra-abdominal infectious complications (OR 3.462; P = 0.021) in the high-VFA patients. The overall survival of high-VFA patients was significantly better in the RG group than in the LG group (P = 0.045).

CONCLUSIONS

For patients with visceral fat obesity, RG appears to be advantageous to LG in terms of reducing the risk of complications and better long-term survival.

Safe implementation of robotic gastrectomy for gastric cancer under the requirements for universal health insurance coverage: a retrospective cohort study using a nationwide registry database in Japan

BACKGROUND

Robotic gastrectomy (RG) has increased since being covered by universal health insurance in 2018. However, to ensure patient safety the operating surgeon and facility must meet specific requirements. We aimed to determine whether RG has been safely implemented under the requirements for universal health insurance in Japan.

METHODS

Data of consecutive patients with primary gastric cancer who underwent minimally invasive total or distal gastrectomy-performed by a surgeon certified by the Japan Society for Endoscopic Surgery (JSES) endoscopic surgical skill qualification system (ESSQS) between October 2018 and December 2019-were extracted from the gastrointestinal surgery section of the National Clinical Database (NCD). The primary outcome was morbidity over Clavien-Dindo classification grade IIIa. Patient demographics and hospital volume were matched between RG and laparoscopic gastrectomy (LG) using propensity score-matched analysis (PSM), and the short-term outcomes of RG and LG were compared.

RESULTS

After PSM, 2671 patients who underwent RG and 2671 who underwent LG were retrieved (from a total of 9881), and the standardized difference of all the confounding factors reduced to 0.07 or less. Morbidity rates did not differ between the RG and LG patients (RG, 4.9% vs. LG, 3.9%; p = 0.084). No difference was observed in 30-day mortality (RG, 0.2% vs. LG, 0.1%; p = 0.754). The reoperation rate was greater following RG (RG, 2.2% vs. LG, 1.2%; p = 0.004); however, the duration of postoperative hospitalization was shorter (RG, 10 [8-13] days vs. LG, 11 [9-14] days; p < 0.001).

CONCLUSIONS

Insurance-covered RG has been safely implemented nationwide.

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.

Comparison of Long-Term and Perioperative Outcomes of Robotic Versus Conventional Laparoscopic Gastrectomy for Gastric Cancer: A Systematic Review and Meta-Analysis of PSM and RCT Studies

Background

To investigate the perioperative and oncological outcomes of gastric cancer (GC) after robotic versus laparoscopic gastrectomy (RG versus LG), we carried out a meta-analysis of propensity score matching (PSM) studies and randomized controlled study (RCT) to compare the safety and overall effect of RG to LG for patients with GC.

Methods

PubMed, Web of Science, EMBASE, and Cochrane Central Register were searched based on a defined search strategy to identify eligible PSM and RCT studies before July 2021. Data on perioperative and oncological outcomes were subjected to meta-analysis.

Results

Overall, we identified 19 PSM studies and 1 RCT of RG versus LG, enrolling a total of 13,446 patients (6,173 and 7,273 patients underwent RG and LG, respectively). The present meta-analysis revealed nonsignificant differences in tumor size, proximal resection margin distance, distal resection margin distance, abdominal bleeding, ileus, anastomosis site leakage, duodenal stump leakage rate, conversion rate, reoperation, overall survival rate, and long-term recurrence-free survival rate between the two groups. Alternatively, comparing RG with LG, RG has a longer operative time (p < 0.00001), less blood loss (p <0.0001), earlier time to first flatus (p = 0.0003), earlier time to oral intake (p = 0.0001), shorter length of stay (p = 0.0001), less major complications (p = 0.0001), lower overall complications (p = 0.0003), more retrieved lymph nodes (P < 0.0001), and more cost (p < 0.00001).

Conclusions

In terms of oncological adequacy and safety, RG is a feasible and effective treatment strategy for gastric cancer but takes more cost in comparison with LG.

The safe performance of robotic gastrectomy by second-generation surgeons meeting the operating surgeon's criteria in the Japan Society for Endoscopic Surgery guidelines

BACKGROUND

Robotic gastrectomy (RG) for gastric cancer (GC) has gradually gained nationwide prominence following 2011 guidelines from the Japan Society for Endoscopic Surgery (JSES), including the surgeons' criteria and the proctor system. In this retrospective study, we examined the short-term outcomes of the initial series of RGs performed by second-generation operating surgeons trained within our institute.

METHODS

Between January 2017 and April 2020, five surgeons each performed RG in 20 patients with clinical stage III or lower GC in accordance with the JSES guidelines. We evaluated both the rate of Clavien-Dindo grade II or higher morbidities and the console time required to reach the learning plateau via cumulative summation (CUSUM) analysis.

RESULTS

We observed no mortality and 3% of morbidity following RG. Both the operative time (430 vs 387.5 min, P = 0.019) and console time (380 vs . 331.5 min, P = 0.009) were significantly shorter in the second 10 cases than in the initial 10 cases. We observed a remarkable trend in cases of distal gastrectomy (DG), in which the total operative time and console time were significantly shorter in the later cases. Our CUSUM analysis revealed that seven cases were required to achieve a learning plateau in RG when confined to DG.

CONCLUSIONS

Non-expert RG surgeons meeting the operating surgeon's criteria from the JSES who had trained under an expert RG surgeon safely performed RG in an initial 20 cases.

Impact of the Endoscopic Surgical Skill Qualification System on the safety of laparoscopic gastrectomy for gastric cancer

BACKGROUND

We hypothesized that the Endoscopic Surgical Skill Qualification System (ESSQS) can shorten operative time, resulting in a decrease in postoperative morbidity. Here, we aimed to clarify whether ESSQS-qualified surgeons could decrease the incidence of complications.

METHODS

Between January 2009 and June 2019, 1042 patients diagnosed with both clinical and pathological Stage ≤ III gastric cancer and undergoing LG were enrolled. In all LG procedures involving ESSQS-qualified surgeons, these served as the operator or the instructive assistant. The short-term outcomes were retrospectively compared between the ESSQS-qualified and the non-ESSQS-qualified surgeons using a propensity-score matched analysis.

RESULTS

After propensity-score matching, 321 patients were included in each group. No significant differences were observed in morbidity rate, and length of hospitalization following surgery, although the non-ESSQS-qualified surgeon group had a significantly longer total operative time (Non-ESSQS-qualified group, 368 [170-779] min vs. ESSQS-qualified group, 316 [147-772] min; p < 0.001), and larger estimated blood loss (Non-ESSQS-qualified group, 28 [0-702] mL vs. ESSQS-qualified group 25, [0-1069] mL; p = 0.042). Multivariate analysis revealed that operative time ≥ 360 min (OR 1.818 [1.069-3.094], p = 0.027) was identified as the only significant independent risk factor determining morbidity.

CONCLUSIONS

The incidence of postoperative morbidity did not differ between patients operated by the qualified and nonqualified surgeons, as long as ESSQS-qualified surgeons provide intraoperative instructions.

Challenges in improving the minimal invasiveness of the surgical treatment for gastric cancer using robotic technology

The number of operations performed using the da Vinci Surgical System® (DVSS) has been increasing worldwide in the past decade. We introduced robotic gastrectomy for gastric cancer (GC) in January 2009 to overcome the disadvantage of conventional laparoscopic gastrectomy. Initially, we experienced some troubles in the technical aspect and cost of robotic surgery. After extensive trial and error, we were able to develop the "double bipolar method" and the "da Vinci's plane theory" to use DVSS effectively. We then conducted "Senshiniryo B," which was a multi-institutional prospective single-arm study to determine the safety, feasibility, and effectiveness of robotic gastrectomy for GC in 2014. In that study, we demonstrated that the morbidity rate in the robotic group (2.45%) was significantly lower than that in the historical control group (6.4%). As a consequence of that clinical trial, 12 procedures, including robotic gastrectomy for GC, have been covered under the Japanese national insurance in 2018. An additional seven procedures were newly covered in April 2020. In the first half of this article, we describe the history of robotic surgery in the world and Japan and demonstrate the "double bipolar method" and "da Vinci's plane theory." In the latter half, we explain the Japanese systems for the safe dissemination of robotic surgery and state our efforts to solve some problems in robotic surgery.

The 140 years' journey of gastric cancer surgery: From the two hands of Billroth to the multiple hands of the robot

After the initial achievement by Billroth in 1881, surgery for gastric cancer has become increasingly extended. However, it turned out to be limited in Western countries after the publication that denied the role of extended surgery in the 1960s. While surgeons in Japan were still enthusiastic about extended surgery, the Japan Clinical Oncology Group (JCOG) conducted clinical trials to validate the role of extended surgery. Contrary to expectations, the efficacy of extended surgery was not demonstrated. In gastric cancer surgery, postoperative complications were reported to be associated with poor survival. A survival benefit could not be obtained by extended surgery, with high morbidity. Therefore, the paradigm had been changed from extended surgery to minimally invasive surgery (MIS). As an MIS for gastric cancer, laparoscopic surgery has been considered a practical method. Initial laparoscopic gastrectomy (LG) was first performed by Kitano in 1991. Thereafter, LG became increasingly common. Several clinical trials demonstrated the noninferiority of LG to open gastrectomy. LG is now regarded as the standard for cStage I gastric cancer, and the indication is expanding to advanced cancer. However, LG has some drawbacks owing to the restriction of movement caused by straight-shaped forceps. Robotic gastrectomy (RG) is considered a major breakthrough to circumvent the drawbacks in LG using articulated devices. However, the solid evidence demonstrating the advantage of RG has not been proved yet. The JCOG is now conducting a randomized controlled trial to evaluate the superiority of RG to LG in terms of reducing morbidity.

Robotic Gastrectomy Compared with Laparoscopic Gastrectomy for Clinical Stage I/II Gastric Cancer Patients: A Propensity Score-Matched Analysis

BACKGROUND

Robotic gastrectomy (RG) has been developed to address the drawbacks of laparoscopic gastrectomy (LG); however, whether or not RG is superior to conventional LG remains to be seen. The present study aimed to clarify the impact of RG on clinical stage I/II gastric cancer patients.

METHODS

The present study included 1208 patients with clinical stage I/II gastric cancer who had minimally invasive gastrectomy from January 2012 to March 2020 at the Shizuoka Cancer Center. The short- and long-term outcomes of RG and LG were compared after propensity score matching.

RESULTS

This study involved 835 LG and 345 RG patients. After propensity score matching, there were 342 patients each in the RG and LG groups, with an improved balance of confounding factors between the two groups. RG was associated with a significantly longer operative time and lower amylase concentration in the drainage fluid on the first postoperative day than LG. Furthermore, the incidence of intra-abdominal infectious complications in the RG was lower than that in the LG (4.4% vs. 9.4%; P = 0.015). The survival of the RG and LG groups was equivalent.

CONCLUSIONS

RG reduced the risk of intra-abdominal infectious complications in comparison with LG in the propensity score-matched analysis. Patients treated by the two approaches showed equivalent survival.

Robotic Surgery in Gastrointestinal Surgery

Robotic surgery is expanding in the minimally invasive treatment of gastrointestinal cancer. In the field of gastrointestinal cancer, robotic surgery is performed using a robot-assisted surgery system. In this system, the robot does not operate automatically but is controlled by the surgeon. The surgery assistant robot currently used in clinical practice worldwide is the leader-follower type, including the da Vinci® Surgical System (Intuitive Surgical). This review describes the current state of robotic surgery in the treatment of gastrointestinal cancer and discusses the future development of robotic systems in gastrointestinal surgery.

Robotic versus laparoscopic gastrectomy for gastric cancer: The largest meta-analysis

BACKGROUND

Minimally invasive surgery (MIS) has been increasingly used in the treatment of gastric cancer (GC). Laparoscopic gastrectomy (LG) has shown several advantages over open surgery in dealing with GC, although it is still considered a demanding procedure. Robotic gastrectomy (RG) is now being employed with increased frequency worldwide and has been reported to overcome some limitations of conventional LG. The aim of this updated meta-analysis is to compare surgical and oncological outcomes of RG versus LG for gastric cancer.

MATERIALS AND METHODS

A systematic review and meta-analysis was conducted using the PubMed, MEDLINE and Cochrane library database of published studies comparing RG and LG up to March 2020. The evaluated end-points were intra-operative, post-operative and oncological outcomes. Dichotomous data were calculated by odds ratio (OR) and continuous data were calculated by mean difference (MD) with 95% confidence intervals (95% CI), and a random-effect model was always applied.

RESULTS

Forty retrospective studies describing 17,712 patients met the inclusion criteria. With respect to surgical outcomes, robotic compared with laparoscopic gastrectomy was associated with higher operating time [MD 44.73, (95%CI 36.01, 53.45) p < 0.00001] and less intraoperative blood loss [MD -18.24, (95%CI -25.21, -11.26) p < 0.00001] and lower rate of surgical complication in terms of Dindo-Clavien ≥ 3 classification [OR 0.66, (95%CI 0.49, 0.88) p = 0.005]. With respect to oncological outcomes, the RG group showed a significantly increased mean number of retrieved lymph nodes [MD 1.84, (95%CI 0.84, 2.84) p = 0.0003], but mean proximal and distal resection margin distance and the recurrence rate were not significantly different between the two approaches.

CONCLUSIONS

With respect to safety, technical feasibility and oncological adequacy, robotic and laparoscopic groups were comparable, although the robotic approach seems to achieve better short-term surgical outcomes. Moreover, a higher rate of retrieved lymph nodes was observed in the RG group.