Late phase II study of robot-assisted gastrectomy with nodal dissection for clinical stage I gastric cancer

The accumulation of myeloid-derived suppressor cells participates in abdominal infection-induced tumor progression through the PD-L1/PD-1 axis

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide, with gastrectomy being the primary treatment option. Sepsis, a systemic inflammatory response to infection, may influence tumor growth by creating an immunosuppressive environment conducive to cancer cell proliferation and metastasis. Here, the effect of abdominal infection on tumor growth and metastasis was investigated through the implementation of a peritoneal metastasis model and a subcutaneous tumor model. In a murine model induced by cecal ligation and puncture (CLP) to simulate the effects of sepsis, we observed significant immune dysregulation, including T-cell exhaustion and the release of myeloid-derived suppressor cells (MDSCs). This immune alteration was associated with increased programmed cell death protein 1 (PD-1) expression on T cells and programmed cell death 1 ligand 1 (PD-L1) expression on MDSCs within the tumor microenvironment, fostering an immune-suppressive environment. Polymorphonuclear MDSCs (PMN-MDSCs) expressing elevated PD-L1 after sepsis demonstrated more substantial suppressive effects on T-cell proliferation than controls. Treatment with anti-PD-1 monoclonal antibodies successfully restored T-cell function, reduced mortality, and decreased metastasis in CLP mice. These findings emphasize the impact of sepsis on tumor progression and suggest targeting the PD-1/PD-L1 axis as a potential therapeutic strategy for managing immune dysfunction in patients with cancer.

Short- and long-term outcomes of robotic- versus laparoscopic-assisted early-onset gastric cancer: a propensity score-matched retrospective cohort study

BACKGROUND

Early-onset gastric cancer (EOGC) is a distinct subtype of gastric cancer with increasing incidence, characterized by unique clinical and pathological features. This propensity score-matched retrospective cohort study aims to compare the perioperative safety and outcomes of EOGC patients who underwent laparoscopic versus robotic radical gastrectomy, providing a scientific basis for surgical treatment of EOGC.

MATERIALS AND METHODS

We included 252 patients diagnosed with EOGC at or before the age of 45, who underwent robotic or laparoscopic radical gastrectomy between January 2015 and April 2021. After propensity score matching, 47 patients in the robotic surgery group and 94 in the laparoscopic surgery group were compared. The study evaluated intraoperative and postoperative outcomes, pathological results, and long-term survival.

RESULTS

The robotic surgery group showed less intraoperative bleeding (50 ml vs. 100 ml, p = 0.042) and shorter postoperative hospital stays (6 days vs. 7 days, p = 0.008) compared to the laparoscopic group. The number of positive lymph nodes was higher in the robotic group (median 2 vs. 1, p = 0.016), but the number of lymph nodes harvested did not significantly differ. No significant differences were found in overall survival (3-year OS: 65.9% vs. 62.5%, p = 0.596) and disease-free survival (3-year DFS: 61.4% vs. 61.7%, p = 0.765) between the two groups.

CONCLUSIONS

Robotic resection for EOGC is non-inferior to laparoscopic surgery in terms of perioperative outcomes and long-term prognosis. This study suggests that robotic surgery may be a viable option for the treatment of EOGC.

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.

Initial 12 Cases of Robot-Assisted Gastrectomy for Gastric Cancer Using the Hinotori Surgical Robot System: Tips for the Efficient Introduction of a New Surgical Robot

Introduction: The use of robotic platform for gastrectomy for gastric cancer is rapidly increasing. This study aimed to describe the perioperative outcomes of 12 patients who underwent robotic gastrectomy for gastric cancer using the hinotori™ surgical robot system (hinotori), a novel robot-assisted surgical platform, and compare the outcomes with the existing system, the da Vinci® Surgical System (DVSS). Methods: This study included 12 consecutive patients with gastric cancer who underwent robotic gastrectomy for gastric cancer using the hinotori between March 2023 and September 2023 at our institution. The comprehensive perioperative outcomes of these patients were retrospectively analyzed and compared to 11 patients who underwent robotic gastrectomy using the DVSS during the same period. Results: The median age and body mass index were 71 years (range: 56-86) and 22.7 kg/m2 (range: 16.1-26.7). Distal and total gastrectomy were performed in 8 and 4 patients, respectively. The median console time and operation times were 187 (range: 112-270) and 252 minutes (range: 173-339), respectively. The median blood loss was 3 mL (range: 2-5). No intra- or postoperative complications were observed. There were no significant differences in perioperative outcomes between the hinotori and the DVSS. Conclusions: Robotic gastrectomy for gastric cancer using the hinotori is a feasible procedure and achieved perioperative outcomes similar to that using the DVSS. Clinical Trial Registration number: 114167-1.

Surgical invasiveness and lymphadenectomy in robotic and laparoscopic gastrectomy: A retrospective study with propensity-score matching

BACKGROUND

There is no consensus amongst comparative studies about the advantages of robotic over laparoscopic surgeries for gastric cancer (GC). We compared invasiveness and lymph node dissection between robotic and laparoscopic gastrectomies (RG and LG).

METHODS

We retrospectively reviewed the medical records of 215 consecutive patients with GC who underwent RG or LG with lymphadenectomy from January 2011-December 2020. Propensity score matching analysis was performed to control selection bias.

RESULTS

The RG group had less operative blood loss (P = 0.0005) and higher C-reactive protein levels on postoperative day 1 (P = 0.0006) than the LG group. When analyzing the specific sites of dissected lymph nodes, station groups of supra-pancreatic and lesser curvature areas accounted for this difference (P = 0.0073 and 0.0362, respectively).

CONCLUSIONS

RG demonstrated lesser intraoperative bleeding, less of a postoperative inflammatory response, and a higher proportion of lymph node removal than LG, suggesting that it is a better surgical and oncological procedure.

How to Decide Approaches and Procedures for Early and Advanced Gastric Cancer?

In the 6th edition of the Japanese Gastric Cancer Treatment Guidelines, laparoscopic surgery is recommended as one of the standard treatments for cStage I. On the other hand, the recommendation of robot-assisted surgery for gastric cancer was also added, albeit not conclusively, to perform it for cStage I gastric cancer. Conversely, laparoscopic surgery for cStage II/III is not recommended, and several randomized controlled trials (RCTs) are being conducted in East Asia to expand the indication for advanced gastric cancer. Although laparoscopic surgery and robot-assisted surgery are now recommended in the Guidelines for Early-Stage Gastric Cancer, each institution should set its own criteria for indications according to its level of proficiency and try to provide high-quality treatment. For advanced gastric cancer, although there is no solid evidence for laparoscopic or robot-assisted surgery, the reality is that it is already being performed in facilities with ample experience. New evidence is expected to be reported in the future, based on which the recommendations may change.

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.

Comparisons of surgical outcomes between robotic and laparoscopic total gastrectomy in patients with clinical stage I/IIA gastric cancer

BACKGROUND

The robotic approach is especially promising for challenging surgeries, such as total gastrectomy. However, it remains unclear whether robotic total gastrectomy (RTG) is superior to conventional laparoscopic total gastrectomy (LTG). The present study aimed to clarify the impact of RTG on short- and long-term outcomes for patients with clinical stage I/IIA gastric cancer.

METHODS

This study included 98 patients with clinical stage I/IIA gastric cancer who underwent minimally invasive total gastrectomy from October 2013 to December 2020 at the Shizuoka Cancer Center. The short- and long-term outcomes of RTG were compared with those of LTG.

RESULTS

This study included 36 RTG and 58 LTG patients. RTG was associated with a significantly longer operative time than LTG (p = 0.023). All complications tended to be lower in the RTG group than in the LTG group (2.8% and 15.5%, respectively; p = 0.083). There were no patients with anastomotic leakage in the RTG group. The multivariate analysis identified LTG as the only independent risk factor for postoperative complications (odds ratio, 6.620; 95% confidence interval, 1.132-126.4; p = 0.034). The survival of the RTG and LTG groups was equivalent.

CONCLUSIONS

RTG reduced the risk of complications compared to LTG. Patients treated using the two approaches showed equivalent survival.

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.

The impact of pancreas compression time during minimally invasive gastrectomy on the postoperative complications in gastric cancer

AIM

Pancreas compression during minimally invasive gastrectomy causes blunt injury to the pancreas and leads to postoperative complications. However, the extent of practical compression associated with the incidence of postoperative complications remains unknown. This study aimed to evaluate the impact of pancreas compression, particularly the duration of compression, on short-term outcomes in minimally invasive gastrectomy for gastric cancer.

METHODS

This study included 178 patients who underwent laparoscopic or robotic gastrectomy at the Shizuoka Cancer Center in 2018. The total time of pancreas compression during gastrectomy was measured using video-reviews, and the correlation between the time and surgical outcomes was evaluated.

RESULTS

A duration of 3 min was selected as the cutoff value of pancreas compression time to predict high drain amylase concentration on postoperative day 1 (≥1000 U/L). The incidence of clinically relevant pancreatic fistula (1.5% vs 12.4%, P = .011) and all postoperative complications (12.3% vs 30.1%, P = .010) were significantly higher in the longer-compression group than in the shorter-compression group. The multivariable analysis identified longer compression as the only independent risk factor for postoperative complications.

CONCLUSION

More than a few minutes of pancreas compression during minimally invasive gastrectomy was associated with a higher incidence of postoperative complications.

Application of robots in general surgery

Background: Application of robotic surgery in the field of general surgery has been increasing. This paper is an overview of the current uses and future perspectives of robotic surgery in four major divisions—endocrine, upper gastrointestinal, hepato-biliary-pancreatic (HBP), and colorectal surgery.Current Concepts: In endocrine surgery, cosmetic advantage is the highest priority when selecting a surgical approach for thyroidectomy. Currently, the transaxillary route is the most common approach. The introduction of the single-port system could maximize the advantages of this technique. In upper gastrointestinal surgery, the use of robots has the advantage of better retrieval of lymph nodes, less bleeding, earlier discharge, and less complications than the laparoscopic approach. However, a more prospective comparative trial is required to confirm those findings. In the HBP field, the indications of robotic surgery have expanded, starting with cholecystectomy to more challenging procedures, such as donor hepatectomy and pancreaticoduodenectomy. Meticulous dissection using robots could provide benefits to patients. In colorectal surgery, robotic surgery is an excellent technical tool for minimally invasive surgeries for rectal cancers, especially in male patients with narrow, deep pelvises. However, further studies are required to confirm the impact of robotic surgery on rectal cancers.Discussion and Conclusion: Robots are used to provide optimal surgical outcomes. Investigating new technologies and innovative surgical procedures is the highly important for a surgeon in the era of minimally invasive surgery.

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.

Efficacy of minimally invasive distal gastrectomy for elderly patients with clinical stage I/IIA gastric cancer: a propensity-score matched analysis

BACKGROUND

Phase III trials have shown the non-inferiority of minimally invasive distal gastrectomy (MIDG) comparison with open distal gastrectomy (ODG) in patients with gastric cancer; however, it remains unclear whether MIDG is also effective in the elderly. This study aimed to clarify the efficacy of MIDG in elderly gastric cancer patients.

PATIENTS AND METHODS

This study included 316 patients older than 75 years with clinical stage I/IIA gastric cancer who underwent distal gastrectomy from August 2008 to December 2016 at the Shizuoka Cancer Centre. The long-term outcomes between MIDG and ODG were compared after propensity score matching.

RESULTS

After propensity score matching, there were 97 patients each in the MIDG and ODG groups, with an improved balance of confounding factors between the two groups. MIDG was associated with significantly longer operative time and a lower level of blood loss than ODG. The incidence of complications was comparable between the two groups. Survival outcomes were better in the MIDG group than in the ODG group (overall survival; P = 0.034, relapse-free survival; P = 0.027). In the multivariable analysis, ODG [hazard ratio (HR) 1.971, P = 0.046], being 80 years or older (HR 2.285, P = 0.018), male sex (HR 2.428, 95% P = 0.024), and poor physical status (HR 2.324, P = 0.022) were identified as independent prognostic factors for overall survival.

CONCLUSIONS

We found that MIDG showed better efficacy than ODG in elderly gastric cancer patients. MIDG is an acceptable option for elderly patients.

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.

Pooled analysis of the oncological outcomes in robotic gastrectomy versus laparoscopic gastrectomy for gastric cancer

Aim:

Robotic gastrectomy (RG) is more and more widely used in the treatment of gastric cancer. However, the long-term oncological outcomes of RG have not been well evaluated. The aim of this study was to evaluate the long-term oncological outcomes of RG and laparoscopic gastrectomy (LG) in the treatment of gastric cancer.

Materials and Methods:

PubMed, China National Knowledge Infrastructure, Cochrane Library and EMBASE electronic databases were searched until August 2019. Eligible studies were analysed for comparison of oncological outcomes between RG and LG in patients with gastric cancer.

Results:

Eleven retrospective comparative studies, which included 1347 (32.52%) patients in the RG group and 2795 (67.48%) patients in the LG group, were selected for the analysis. Meta-analysis of the 11 included studies showed that there was no statistically significant difference in the OS between the RG and LG groups (hazard ratios [HRs] = 0.97, 95% confidence intervals [CIs] = 0.80–1.19, P = 0.80). Six studies evaluated disease-free survival (DFS), and pooled analysis showed that there was no statistically significant difference in DFS between RG group and LG group (HR = 0.94, 95% CIs = 0.72–1.23, P = 0.65). According to the odds ratio (OR) analysis, there was no significant difference in 3-year OS, 5-year OS, 3-year DFS and 5-year DFS between the RG and LG groups. Nine articles reported the recurrence rate, and the meta-analysis showed that there was no statistically significant difference between the RG and LG groups (OR = 0.88, 95% CIs = 0.69–1.12, P = 0.31).

Conclusions:

This meta-analysis indicated that the long-term oncological outcomes in the RG group were similar to that in the LG group.

Preoperative risk factors for postoperative intra-abdominal infectious complication after gastrectomy for gastric cancer using a Japanese web-based nationwide database

BACKGROUND

Postoperative intra-abdominal infectious complication (PIIC) after gastrectomy for gastric cancer worsens in-hospital death or long-term survival. However, the methodology for PIIC preoperative risk assessment remains unestablished. We aimed to develop a preoperative risk model for postgastrectomy PIIC.

METHODS

We collected 183,936 patients' data on distal or total gastrectomy performed in 2013-2016 for gastric cancer from the Japanese National Clinical Database and divided into development (2013-2015; n = 140,558) and validation (2016; n = 43,378) cohort. The primary outcome was the incidence of PIIC. The risk model for PIIC was developed using 18 preoperative factors: age, sex, body mass index, activities of daily living, 12 comorbidity types, gastric cancer stage, and surgical procedure in the development cohort. Secondarily, we developed another model based on the new scoring system for clinical use using selected factors.

RESULTS

The overall incidence of PIIC was 4.7%, including 2.6%, 1.7%, and 1.3% in anastomotic leakage, pancreatic fistula, and intra-abdominal abscess, respectively. Among the 18 preoperative factors, male [odds ratio, (OR) 1.92], obesity (OR, 1.52-1.96), peripheral vascular disease (OR, 1.55), steroid use (OR, 1.83), and total gastrectomy (OR, 1.89) strongly correlated with PIIC incidence. The entire model using the 18 factors had good discrimination and calibration in the validation cohort. We selected eight relevant factors to create a simple scoring system, using which we categorized the patients into three risk groups, which showed good calibration.

CONCLUSION

Using nationwide clinical practice data, we created a preoperative risk model for postgastrectomy PIIC for gastric cancer.

Does three-dimensional surgery affect recurrence patterns in patients with gastric cancer after laparoscopic R0 gastrectomy? Results from a 3-year follow-up phase III trial

BACKGROUND

Numerous studies have shown that the short-term efficacy of three-dimensional (3D) laparoscopic radical gastrectomy (LG) is comparable to that of two-dimensional (2D)-LG. Whether 3D-LG affects the recurrence patterns of gastric cancer (GC) patients has not been investigated.

METHODS

From January 2015 to April 2016, a total of 419 patients were recruited for a phase III clinical trial (NCT02327481), which compared the short-term outcomes between the 2D and 3D groups. The long-term efficacy including recurrence patterns was compared between the 2D and 3D groups in this retrospective study. Multivariate analyses were performed to determine whether 3D-LG affects the recurrence patterns.

RESULTS

Ultimately, 401 patients were analyzed (197 in the 2D-LG group and 204 in the 3D-LG group), and no differences were observed in the clinicopathological data between the two groups. There were no significant differences between the two groups in the recurrence types, first recurrence time or recurrence-free survival (RFS) (all p > 0.05). According to the 7th American Joint Committee on Cancer tumor-node-metastasis (TNM) staging system, both groups were stratified into pathological stages I, II, and III. The stratified analysis showed no significant differences in RFS or overall survival (OS) among patients in each subgroup (all p > 0.05). The multivariate analysis of RFS showed that tumor diameter, pTNM stage, lymphovascular invasion, and adjuvant chemotherapy were independent factors (all p < 0.05). The multivariate analysis of post-recurrence survival (PRS) showed that adjuvant chemotherapy was an independent protective factor (p = 0.043).

CONCLUSIONS

3D-LG for GC did not differ significantly from 2D-LG in the effects on 3-year recurrence patterns, RFS and OS, which provides more tumor-related evidence for 3D technology. And due to the technological similarity, it may have certain reference value for robotic-assisted gastrectomy. Further multicenter, large-scale clinical trials are warranted.

Should robotic gastrectomy become a standard surgical treatment option for gastric cancer?

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 has been used increasingly since. We reviewed the current evidence on RG, open gastrectomy (OG), and conventional laparoscopic gastrectomy (LG) to identify differences in surgical outcomes between Japan and other countries. Briefly, three independent reviewers systematically reviewed the data collected from a comprehensive literature search by an independent organization and focused on the following nine endpoints: mortality, morbidity, operative time, estimated volume of blood loss, length of postoperative hospital stay, long-term oncologic outcome, quality of life, learning curve, and cost. Overall, the mortality rate of the three approaches did not differ, but RG and LG had less intraoperative blood loss and resulted in a shorter postoperative hospital stay than OG. RG had longer operative times and incurred higher costs than LG and OG. However, in Japan, RG may be more effective than LG and OG for decreasing morbidity. Further studies are needed to establish the specific indications for RG, optimal robotic setup, and dissection methods to best utilize the surgical robot.

Long-term outcomes of robotic gastrectomy for clinical stage I gastric cancer: a single-center prospective phase II study

INTRODUCTION

The outcomes of robotic gastrectomy (RG) for gastric cancer remain unclear due to a lack of prospective studies. We had previously designed and conducted a prospective phase II study of RG that showed favorable short-term outcomes. Herein, we aimed to determine the long-term outcomes of RG for clinical stage I gastric cancer.

PATIENTS AND METHODS

This single-center, prospective phase II study enrolled patients with clinical stage I gastric cancer undergoing RG. The survival outcomes, which were the secondary endpoints of the study, were evaluated.

RESULTS

Between December 2012 and April 2015, 120 patients were enrolled in this study. The 5-year overall survival (OS) was 96.7% (95% confidence interval [CI] 91.5-98.7%). The 5-year recurrence-free (RFS) and disease-specific survival (DSS) rates were 96.7% (95% CI 91.5-98.7%) and 99.2% (95% CI 94.3-99.9%), respectively. When confining the analysis to distal and pylorus-preserving gastrectomy, the 5-year OS, RFS, and DSS were 98.1% (95% CI 92.7-99.5%), 98.1% (95% CI 92.7-99.5%), and 100%, respectively. Only one patient died due to relapse of gastric cancer, while three died from other causes.

CONCLUSIONS

Long-term outcomes of RG was comparable to those of open and laparoscopic gastrectomy when the surgeries were performed by experienced surgeons in a high-volume center.

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

BACKGROUND

Minimally invasive surgery for gastric cancer (GC) has gained widespread use as a safe curative procedure especially for early GC.

AIM

To determine risk factors for postoperative complications after minimally invasive gastrectomy for GC.

METHODS

Between January 2009 and June 2019, 1716 consecutive patients were referred to our division for primary GC. Among them, 1401 patients who were diagnosed with both clinical and pathological Stage III or lower GC and underwent robotic gastrectomy (RG) or laparoscopic gastrectomy (LG) were enrolled. Retrospective chart review and multivariate analysis were performed for identifying risk factors for postoperative morbidity.

RESULTS

Morbidity following minimally invasive gastrectomy was observed in 7.5% of the patients. Multivariate analyses demonstrated that non-robotic minimally invasive surgery, male gender, and an operative time of ≥ 360 min were significant independent risk factors for morbidity. Therefore, morbidity was compared between RG and LG. Accordingly, propensity-matched cohort analysis revealed that the RG group had significantly fewer intra-abdominal infectious complications than the LG group (2.5% vs 5.9%, respectively; P = 0.038), while no significant differences were noted for other local or systemic complications. Multivariate analyses of the propensity-matched cohort revealed that non-robotic minimally invasive surgery [odds ratio = 2.463 (1.070-5.682); P = 0.034] was a significant independent risk factor for intra-abdominal infectious complications.

CONCLUSION

The findings showed that robotic surgery might improve short-term outcomes following minimally invasive radical gastrectomy by reducing intra-abdominal infectious complications.

Comparison of Surgical Outcomes Between Robotic and Laparoscopic Distal Gastrectomy for cT1 Gastric Cancer

BACKGROUND

Increasing numbers of patients are treated by robotic distal gastrectomy (RDG); however, it remains unclear whether RDG is clinically comparable with conventional laparoscopic distal gastrectomy (LDG). This study aimed to clarify the feasibility of RDG from safety aspects.

METHODS

The study included 109 cT1 gastric cancer patients who underwent RDG at Shizuoka Cancer Center from January 2012 to April 2015. Short-term outcomes were compared with 160 cT1 gastric cancer patients who underwent LDG during the same period.

RESULTS

Patient characteristics were well matched. The RDG patients experienced longer operative times (323 min) than LDG patients (285 min; P < 0.001), although all other surgical outcomes were comparable between the groups. Drain amylase levels on POD 1 were significantly lower in the RDG group compared to LDG cases (median 452 U/L and 892 U/L; P < 0.001). The incidence of all complications was similar across the study patients, although intra-abdominal infectious complications tended to be lower in the RDG group than in the LDG group (2.8 and 8.1%; P = 0.112).

CONCLUSIONS

RDG was comparable to LDG in terms of feasibility for cT1 gastric cancer. RDG has the potential to reduce pancreas damage and thus to decrease intra-abdominal infectious complications.

Update on the Treatment of Gastric Cancer

Gastric cancer remains a major health concern worldwide, particularly in Asia. Surgery is the only curative treatment, and D2 gastrectomy is the standard therapy for resectable cases. Several clinical trials have been conducted in Japan to achieve higher cure rates via extended surgery; however, despite higher morbidity, none demonstrated prolonged survival. Against this background, minimally invasive surgical approaches that preserve gastric function and improve postoperative quality of life have been developed in recent years. For early gastric cancer, endoscopic resection and laparoscopic gastrectomy have achieved remarkable success even for later-stage cases. Long-term outcomes have been investigated in large-scale, randomized controlled trials. In addition, robot-assisted gastrectomy is now more common in clinical practice. S-1, an anti-tumor drug, is a key agent for treating gastric cancer and has resulted in dramatic improvements in survival. For locally advanced gastric cancer, patients are usually treated with surgery and adjuvant or neoadjuvant chemotherapy, and the efficacies of various regimens have been examined in many clinical trials. For unresectable or recurrent gastric cancer, new agents such as molecular-targeted agents and immune checkpoint inhibitors have emerged as notable treatments and are now being tested in numerous clinical trials. This review provides an update on gastric cancer treatment, highlighting current individualized strategies and future perspectives.

Impact of an Ultrasonically Activated Device in Robot-Assisted Distal Gastrectomy

Objective

Robot-assisted gastrectomy is increasingly used for the treatment of gastric cancer, although it remains a time-consuming procedure. An ultrasonically activated device might be useful to shorten operation times. This study therefore assessed the effect of ultrasonically activated device use on procedural times and on other early surgical outcomes.

Methods

Consecutive patients (N = 42) who underwent robot-assisted distal gastrectomy for gastric cancer were included. Clinicopathological characteristics and early surgical outcomes were compared between robotic-assisted gastrectomy procedures using an ultrasonically activated device (U group, n = 21) and those without it (NU group, n = 21).

Results

There were no significant differences in patient characteristics between the groups; however, the median operation time was significantly less in the U group than in the NU group (291 vs 351 minutes, P = 0.006). In detail, the median duration of console time until dividing the duodenum was less in the U group (70 vs 102 minutes, P < 0.001). Estimated blood loss, incidence of postoperative morbidity, and duration of postoperative hospital stay were not different between the groups.

Conclusions

An ultrasonically activated device reduced the operation time of robot-assisted gastrectomy without increasing blood loss and morbidity.

Robotic versus laparoscopic Gastrectomy for gastric cancer: a systematic review and updated meta-analysis

Background

Advanced minimally invasive techniques including robotic surgery are being employed with increasing frequency around the world, primarily in order to improve the surgical outcomes of laparoscopic gastrectomy (LG). We conducted a systematic review and meta-analysis to evaluate the feasibility, safety and efficacy of robotic gastrectomy (RG).

Methods

Studies, which compared surgical outcomes between LG and RG, were retrieved from medical databases before May 2017. Outcomes of interest were estimated as weighted mean difference (WMD) or risk ratio (RR) using the random-effects model. The software Review Manage version 5.1 was used for all calculations.

Results

Nineteen comparative studies with 5953 patients were included in this analysis. Compared with LG, RG was associated with longer operation time (WMD = −49.05 min; 95% CI: -58.18 ~ −39.91, P < 0.01), less intraoperative blood loss (WMD = 24.38 ml; 95% CI: 12.32 ~ 36.43, P < 0.01), earlier time to oral intake (WMD = 0.23 days; 95% CI: 0.13 ~ 0.34, P < 0.01), and a higher expense (WMD = −3944.8 USD; 95% CI: -4943.5 ~ −2946.2, P < 0.01). There was no significant difference between RG and LG regarding time to flatus, hospitalization, morbidity, mortality, harvested lymph nodes, and cancer recurrence.

Conclusions

RG can be performed as safely as LG. However, it will take more effort to decrease operation time and expense.

Robot-assisted laparoscopic vs open gastrectomy for gastric cancer: Systematic review and meta-analysis

AIM

To evaluate the potential effectiveness of robot-assisted gastrectomy (RAG) in comparison to open gastrectomy (OG) for gastric cancer patients.

METHODS

A comprehensive systematic literature search using PubMed, EMBASE, and the Cochrane Library was carried out to identify studies comparing RAG and OG in gastric cancer. Participants of any age and sex were considered for inclusion in comparative studies of the two techniques independently from type of gastrectomy. A meta-analysis of short-term perioperative outcomes was performed to evaluate whether RAG is equivalent to OG. The primary outcome measures were set for estimated blood loss, operative time, conversion rate, morbidity, and hospital stay. Secondary among postoperative complications, wound infection, bleeding and anastomotic leakage were also analysed.

RESULTS

A total of 6 articles, 5 retrospective and 1 randomized controlled study, involving 6123 patients overall, with 689 (11.3%) cases submitted to RAG and 5434 (88.7%) to OG, satisfied the eligibility criteria and were included in the meta-analysis. RAG was associated with longer operation time than OG (weighted mean difference 72.20 min; P < 0.001), but with reduction in blood loss and shorter hospital stay (weighted mean difference -166.83 mL and -1.97 d respectively; P < 0.001). No differences were found with respect to overall postoperative complications (P = 0.65), wound infection (P = 0.35), bleeding (P = 0.65), and anastomotic leakage (P = 0.06). The postoperative mortality rates were similar between the two groups. With respect to oncological outcomes, no statistical differences among the number of harvested lymph nodes were found (weighted mean difference -1.12; P = 0.10).

CONCLUSION

RAG seems to be a technically valid alternative to OG for performing radical gastrectomy in gastric cancer resulting in safe complications.

Robotic gastrectomy for gastric cancer

The number of robotic gastrectomy (RG) performed per year has been increasing, particularly in East Asia where the incidence of gastric cancer is high and approximately half of the cases are diagnosed as early gastric cancer. With articulated devices of RG, surgeons are able to perform every procedure more meticulously, which can result in less bleeding and damage to organs. There are many single arm and comparative studies, and these study showed similar trends, which included relatively less estimated blood loss and longer operation time following RG than laparoscopic gastrectomy (LG), equivalent number of harvested lymph nodes and similar length of postoperative hospital stay between RG and LG. Considering the results of these retrospective comparative studies, RG seems to be as feasible as LG in terms of early surgical outcomes. However, medical expense of RG is approximately twice as much as that of LG. Lack of solid evidence in terms of long-term outcomes is another problem. Considering the higher medical expenses associated with RG, its superiority in terms of long-term survival outcomes needs to be confirmed in the future for it to be accepted more widely.

Robot-assisted laparoscopic gastrectomy for gastric cancer

Phase III evidence in the shape of a series of randomized controlled trials and meta-analyses has shown that laparoscopic gastrectomy is safe and gives better short-term results with respect to the traditional open technique for early-stage gastric cancer. In fact, in the East laparoscopic gastrectomy has become routine for early-stage gastric cancer. In contrast, the treatment of advanced gastric cancer through a minimally invasive way is still a debated issue, mostly due to worries about its oncological efficacy and the difficulty of carrying out an extended lymphadenectomy and intestinal reconstruction after total gastrectomy laparoscopically. Over the last ten years the introduction of robotic surgery has implied overcoming some intrinsic drawbacks found to be present in the conventional laparoscopic procedure. Robot-assisted gastrectomy with D2 lymphadenectomy has been shown to be safe and feasible for the treatment of gastric cancer patients. But unfortunately, most available studies investigating the robotic gastrectomy for gastric cancer compared to laparoscopic and open technique are so far retrospective and there have not been phase III trials. In the present review we looked at scientific evidence available today regarding the new high-tech surgical robotic approach, and we attempted to bring to light the real advantages of robot-assisted gastrectomy compared to the traditional laparoscopic and open technique for the treatment of gastric cancer.