Robotic versus laparoscopic surgery for rectal cancer: an overview of systematic reviews with quality assessment of current evidence

Feasibility of robotic-assisted surgery in advanced rectal cancer: a multicentre prospective phase II study (VITRUVIANO trial)

BACKGROUND

The potential benefits of robotic-assisted compared with laparoscopic surgery for locally advanced cancer have not been sufficiently proven by prospective studies. One factor is speculated to be the lack of strict surgeon criteria. The aim of this study was to assess outcomes for robotic surgery in patients with locally advanced rectal cancer with strict surgeon experience criteria.

METHODS

A criterion was set requiring surgeons to have performed more than 40 robotically assisted operations for rectal cancer. Between March 2020 and May 2022, patients with rectal cancer (distance from the anal verge of 12 cm or less, cT2-T4a, cN0-N3, cM0, or cT1-T4a, cN1-N3, cM0) were registered. The primary endpoint was the rate positive circumferential resection margin (CRM) from the pathological specimen. Secondary endpoints were surgical outcomes, pathological results, postoperative complications, and longterm outcomes.

RESULTS

Of the 321 registered patients, 303 were analysed, excluding 18 that were ineligible. At diagnosis: stage I (n = 68), stage II (n = 84) and stage III (n = 151). Neoadjuvant therapy was used in 56 patients. There were no conversions to open surgery. The median console time to rectal resection was 170 min, and the median blood loss was 5 ml. Fourteen patients had a positive CRM (4.6%). Grade III-IV postoperative complications were observed in 13 patients (4.3%).

CONCLUSION

Robotic-assisted surgery is feasible for locally advanced rectal cancer when strict surgeon criteria are used.

Robot-assisted pelvic and renal surgery compared with laparoscopic or open surgery: Literature review of cost-effectiveness and clinical outcomes

BACKGROUND AND AIM

The purpose of this study was to evaluate clinical experiences and cost-effectiveness by comparing robot-assisted surgery with laparoscopic- or open surgery for pelvic and renal operations.

METHODS

A narrative review was carried out.

RESULTS

When using robotic-assisted surgery, oncological and functional results are similar to after laparoscopic or open surgery. One exception may be a shorter survival in cancer of the cervix uteri. In addition, postoperative complications after robotic-assisted surgery are similar, bleeding and transfusion needs are less, and the hospital stay is shorter but the preparation of the operating theater before and after surgery and the operation times are longer. Finally, robot-assisted surgery has, in several studies, been reported to be not cost-effective primarily due to high investment costs. However, more recent studies provide improved cost-effectiveness estimates due to more effective preparation of the operating theater before surgery, improved surgeon experience, and decreased investment costs.

CONCLUSIONS

Complications and functional and oncological outcomes after robot-assisted surgery are similar to open surgery and laparoscopic surgery. The cost-effectiveness of robot-assisted surgery is likely to equal or surpass the alternatives.

Comparative analysis of robotic and laparoscopic surgery for mid and low rectal cancer in patients with varied body mass indexes: evaluating of short-term outcomes

The main aim of this study was to evaluate and contrast the efficacy of robotic and laparoscopic surgical procedures in the treatment of low and mid rectal cancer in different BMI (body mass index) groups. The clinical records of patients who had laparoscopic or robotic proctectomy at a single center between December 2019 and August 2023 were analyzed. Then we utilized a classification framework to categorize individuals based on their BMI into three unique groups: non-obese, overweight, and obese. The short-term efficacy was evaluated. A consecutive sample of 1413 patients was included in this retrospective investigation. 1158 people out of the total sample chose laparoscopic surgery, whereas 255 people chose robotic surgery. In the group of obese people, robotic surgery showed a statistically significant decrease in blood loss compared to laparoscopic surgery (P = 0.026). People who were overweight or obese were in the hospital for a shorter amount of time after robotic surgery than after laparoscopic surgery (P = 0.033 and P = 0.031, respectively). People with different BMIs in the robotic surgery group took less time to have a flatus passage and oral intake those in the laparoscopic surgery group. Oncological outcomes and the frequency of complications were comparable between the two treatments with different BMIs. Surgical resection of patients undergoing low-anterior surgery may benefit from a robotic approach, particularly in overweight and obese patients.

Short-term and long-term efficacy in robot-assisted treatment for mid and low rectal cancer: a systematic review and meta-analysis

OBJECTIVE

This study aims to conduct a meta-analysis to evaluate the short-term and long-term therapeutic effects of robot-assisted laparoscopic treatment in patients with mid and low rectal cancer.

METHODS

A comprehensive search strategy was employed to retrieve relevant literature from PubMed, NCBI, Medline, and Springer databases, spanning the database inception until August 2023. The focus of this systematic review was on controlled studies that compared the treatment outcomes of robot-assisted (Rob) and conventional laparoscopy (Lap) in the context of mid and low rectal cancer. Data extraction and literature review were meticulously conducted by two independent researchers (HMW and RKG). The synthesized data underwent rigorous analysis utilizing RevMan 5.4 software, adhering to established methodological standards in systematic reviews. The primary outcomes encompass perioperative outcomes and oncological outcomes. Secondary outcomes include long-term outcomes.

RESULT

A total of 11 studies involving 2239 patients with mid and low rectal cancer were included (3 RCTs and 8 NRCTs); the Rob group consisted of 1111 cases, while the Lap group included 1128 cases. The Rob group exhibited less intraoperative bleeding (MD =  -40.01, 95% CI: -57.61 to -22.42, P < 0.00001), a lower conversion rate to open surgery (OR = 0.27, 95% CI: 0.09 to 0.82, P = 0.02), a higher number of harvested lymph nodes (MD = 1.97, 95% CI: 0.77 to 3.18, P = 0.001), and a lower CRM positive rate (OR = 0.46, 95% CI: 0.23 to 0.95, P = 0.04). Additionally, the Rob group had lower postoperative morbidity rate (OR = 0.66, 95% CI: 0.53 to 0.82, P < 0.0001) and a lower occurrence rate of complications with Clavien-Dindo grade ≥ 3 (OR = 0.60, 95% CI: 0.39 to 0.90, P = 0.02). Further subgroup analysis revealed a lower anastomotic leakage rate (OR = 0.66, 95% CI: 0.45 to 0.97, P = 0.04). No significant differences were observed between the two groups in the analysis of operation time (P = 0.42), occurrence rates of protective stoma (P = 0.81), PRM (P = 0.92), and DRM (P = 0.23), time to flatus (P = 0.18), time to liquid diet (P = 0.65), total hospital stay (P = 0.35), 3-year overall survival rate (P = 0.67), and 3-year disease-free survival rate (P = 0.42).

CONCLUSION

Robot-assisted laparoscopic treatment for mid and low rectal cancer yields favorable outcomes, demonstrating both efficacy and safety. In comparison to conventional laparoscopy, patients experience reduced intraoperative bleeding and a lower incidence of complications. Notably, the method achieves comparable short-term and long-term treatment results to those of conventional laparoscopic surgery, thus justifying its consideration for widespread clinical application.

Robotic versus laparoscopic surgery for middle and low rectal cancer (REAL): short-term outcomes of a multicentre randomised controlled trial

BACKGROUND

Robotic surgery for rectal cancer is gaining popularity, but evidence on long-term oncological outcomes is scarce. We aimed to compare surgical quality and long-term oncological outcomes of robotic and conventional laparoscopic surgery in patients with middle and low rectal cancer. Here we report the short-term outcomes of this trial.

METHODS

This multicentre, randomised, controlled, superiority trial was done at 11 hospitals in eight provinces of China. Eligible patients were aged 18-80 years with middle (>5 to 10 cm from the anal verge) or low (≤5 cm from the anal verge) rectal adenocarcinoma, cT1-T3 N0-N1 or ycT1-T3 Nx, and no evidence of distant metastasis. Central randomisation was done by use of an online system and was stratified according to participating centre, sex, BMI, tumour location, and preoperative chemoradiotherapy. Patients were randomly assigned at a 1:1 ratio to receive robotic or conventional laparoscopic surgery. All surgical procedures complied with the principles of total mesorectal excision or partial mesorectal excision (for tumours located higher in the rectum). Lymph nodes at the origin of the inferior mesenteric artery were dissected. In the robotic group, the excision procedures and dissection of lymph nodes were done by use of robotic techniques. Neither investigators nor patients were masked to the treatment allocation but the assessment of pathological outcomes was masked to the treatment allocation. The primary endpoint was 3-year locoregional recurrence rate, but the data for this endpoint are not yet mature. Secondary short-term endpoints are reported in this article, including two key secondary endpoints: circumferential resection margin positivity and 30-day postoperative complications (Clavien-Dindo classification grade II or higher). The outcomes were analysed according in a modified intention-to-treat population (according to the original assigned groups and excluding patients who did not undergo surgery or no longer met inclusion criteria after randomisation). This trial was registered with ClinicalTrials.gov, number NCT02817126. Study recruitment has completed, and the follow-up is ongoing.

FINDINGS

Between July 17, 2016, and Dec 21, 2020, 1742 patients were assessed for eligibility. 502 patients were excluded, and 1240 patients were enrolled and randomly assigned to receive either robotic surgery (620 patients) or laparoscopic surgery (620 patients). 69 patients were excluded (34 in the robotic surgery group and 35 in the laparoscopic surgery group). 1171 patients were included in the modified intention-to-treat analysis (586 in the robotic group and 585 in the laparoscopic group). Six patients in the robotic surgery group received laparoscopic surgery and seven patients in the laparoscopic surgery group received robotic surgery. 22 (4·0%) of 547 patients in the robotic group had a positive circumferential resection margin as did 39 (7·2%) of 543 patients in the laparoscopic group (difference -3·2 percentage points [95% CI -6·0 to -0·4]; p=0·023). 95 (16·2%) of patients in the robotic group had at least one postoperative complication (Clavien-Dindo grade II or higher) within 30 days after surgery, as did 135 (23·1%) of 585 patients in the laparoscopic group (difference -6·9 percentage points [-11·4 to -2·3]; p=0·003). More patients in the robotic group had a macroscopic complete resection than in the laparoscopic group (559 [95·4%] of 586 patients vs 537 [91·8%] of 585 patients, difference 3·6 percentage points [0·8 to 6·5]). Patients in the robotic group had better postoperative gastrointestinal recovery, shorter postoperative hospital stay (median 7·0 days [IQR 7·0 to 11·0] vs 8·0 days [7·0 to 12·0], difference -1·0 [95% CI -1·0 to 0·0]; p=0·0001), fewer abdominoperineal resections (99 [16·9%] of 586 patients vs 133 [22·7%] of 585 patients, difference -5·8 percentage points [-10·4 to -1·3]), fewer conversions to open surgery (10 [1·7%] of 586 patients vs 23 [3·9%] of 585 patients, difference -2·2 percentage points [-4·3 to -0·4]; p=0·021), less estimated blood loss (median 40·0 mL [IQR 30·0 to 100·0] vs 50·0 mL [40·0 to 100·0], difference -10·0 [-20·0 to -10·0]; p<0·0001), and fewer intraoperative complications (32 [5·5%] of 586 patients vs 51 [8·7%] of 585 patients; difference -3·3 percentage points [-6·3 to -0·3]; p=0·030) than patients in the laparoscopic group.

INTERPRETATION

Secondary short-term outcomes suggest that for middle and low rectal cancer, robotic surgery resulted in better oncological quality of resection than conventional laparoscopic surgery, with less surgical trauma, and better postoperative recovery.

FUNDING

Shenkang Hospital Development Center, Shanghai Municipal Health Commission (Shanghai, China), and Zhongshan Hospital Fudan University (Shanghai, China).

Options for Low Rectal Cancer: Robotic Total Mesorectal Excision

Low rectal cancers (LRCs) may offer a difficult technical challenge even to experienced colorectal surgeons. Although laparoscopic surgery offers a superior exposure of the pelvis when compared with open approach, its role in rectal cancer surgery has been controversial. Robotic platforms are well suited for difficult pelvic surgery due to its three-dimensional visualization, degree of articulation of instruments, precise movements, and better ergonomics. The robot may be suitable especially in the anatomically narrow pelvis such as in male and obese patients. Meticulous dissection in critical steps, such as splenic flexure takedown, nerve-sparing mesorectal excision, and distal margin clearance, are potential technical advantages. In addition, robotic rectal resections are associated with lower conversion rates to open surgery, less blood loss, and shorter learning curve with similar short-term quality of life outcomes, similar rates of postoperative complications, and equivalent short-term surrogate outcomes compared with conventional laparoscopy. Robotic surgery approach, if used correctly, can enhance the skills and the capabilities of the well-trained surgeon during minimally invasive procedures for LRC.

Postoperative complications observed with robotic versus laparoscopic surgery for the treatment of rectal cancer: An updated meta-analysis of recently published studies

BACKGROUND

This is an updated meta-analysis comparing the postoperative complications observed with robotic versus laparoscopic surgery (LS) for the treatment of rectal cancer.

METHODS

Cochrane central, MEDLNE (Medical Literature Analysis and Retrieval System Online), EMBASE (Excerpta Medica dataBASE), Google Scholar, Web of Science and http://www.ClinicalTrials.gov were searched for studies (published after the year 2015), comparing robotic versus LS for the treatment of rectal cancer. The postoperative outcomes were considered as the endpoints in this analysis. RevMan 5.4 was used to carry out the statistical analysis. Risk ratio (RR) with 95% confidence intervals (CI) were used to represent the results following data analysis.

RESULTS

A total number of 22,744 participants were included in this study whereby 9178 participants were assigned to the robotic surgery and 13,566 participants were assigned to the LS group. The time period of patients' enrollment varied from years 2007 to 2017. Our results showed that overall complications (RR: 0.91, 95% CI: 0.71-1.17; P = .45), wound complications (RR: 0.81, 95% CI: 0.64-1.04; P = .09), anastomotic leak (RR: 1.12, 95% CI: 0.88-1.42; P = .37), anastomotic bleeding (RR: 0.88, 95% CI: 0.29-2.64; P = .82), stoma-related complications (RR: 0.88, 95% CI: 0.24-3.21; P = .85), intra-abdominal abscess (RR: 0.53. 95% CI: 0.22-1.31; P = .17), urinary tract infection (RR: 0.94, 95% CI: 0.53-1.66; P = .83), enterocolitis (RR: 1.35, 95% CI: 0.38-4.71; P = .64), reoperation (RR: 0.85, 95% CI: 0.46-1.54; P = .58), and mortality (RR: 0.75, 95% CI: 0.34-1.62; P = .46) were not significantly different between robotic-assisted versus LS for rectal cancer. Postoperative ileus (RR: 1.21, 95% CI: 0.81-1.81; P = .34), readmission (RR: 1.17, 95% CI: 0.75-1.83; P = .48), and urinary retention (RR: 0.51, 95% CI: 0.21-1.23; P = .14) were also similarly manifested.

CONCLUSIONS

In this updated meta-analysis, both robotic and laparoscopic surgeries were equally effective for the treatment of rectal cancer. Similar postoperative complications were observed. However, our analysis was restricted only to postoperative outcomes, parameters such as duration of surgery were not taken into consideration.

Advantages of robotic abdominoperineal resection compared with laparoscopic surgery: a single-center retrospective study

PURPOSE

Although robotic surgery for rectal cancer can overcome the shortcomings of laparoscopic surgery, studies focusing on abdominoperineal resection are limited. The aim of this study was to compare the operative outcomes between robotic and laparoscopic abdominoperineal resection.

METHODS

This retrospective cohort study was conducted from April 2010 to March 2020. Patients with rectal cancer who underwent robotic or laparoscopic abdominoperineal resection without lateral lymph node dissection were enrolled. The perioperative and oncological outcomes were compared.

RESULTS

We evaluated 33 and 20 patients in the robotic and laparoscopic groups, respectively. The median operative time and blood loss were comparable between the two groups. No significant differences in the overall complication rates were noted, whereas the rates of urinary dysfunction (3% vs. 26%, p = 0.02) and perineal wound infection (9% vs. 35%, p = 0.03) in the robotic group were significantly lower in comparison to the laparoscopic group. The median postoperative hospital stay was significantly shorter in the robotic group (8 days vs. 11 days, p < 0.01). The positive resection margin rates were comparable between the two groups.

CONCLUSION

Robotic abdominoperineal resection demonstrated better short-term outcomes than laparoscopic surgery, suggesting that it could be a useful approach.

Robotic Surgery in Rectal Cancer

Rectal cancer is an important cause of morbidity and mortality worldwide. The most effective and curative treatment is surgery, and the standard procedure is total mesorectal excision, initially performed by open surgery and posteriorly by minimally invasive techniques. Robotic surgery is an emerging technology that is expected to overcome the limitations of the laparoscopic approach. It has several advantages, including a stable camera platform with high definition three-dimensional image, flexible instruments with seven degrees of freedom, a third arm for fixed retraction, fine motion scaling, excellent dexterity, ambidextrous capability, elimination of physiological tremors and better ergonomics, that facilitate a steady and precise tissue dissection. The main technical disadvantages are the loss of tactile sensation and tensile feedback and the complex installation process. The aim of the present study is to review the importance and benefits of robotic surgery in rectal cancer, particularly in comparison with the laparoscopic approach. Intraoperative estimated blood loss, short and long-term outcomes as well as pathological outcomes were similar between robotic and laparoscopic surgery. The operative time is usually longer in robotic surgery and the high costs are still its major drawback. Robotic surgery for rectal cancer demonstrated lower conversion rate to open surgery and benefits in urinary and sexual functions and has been established as a safe and feasible technique.

Short-term outcome in robotic vs laparoscopic and open rectal tumor surgery within an ERAS protocol: a retrospective cohort study from the Swedish ERAS database

BACKGROUND

Advantages of robotic technique over laparoscopic technique in rectal tumor surgery have yet to be proven. Large multicenter, register-based cohort studies within an optimized perioperative care protocol are lacking. The aim of this retrospective cohort study was to compare short-term outcomes in robotic, laparoscopic and open rectal tumor resections, while also determining compliance to the enhanced recovery after surgery (ERAS)®Society Guidelines.

METHODS

All patients scheduled for rectal tumor resection and consecutively recorded in the Swedish part of the international ERAS® Interactive Audit System between January 1, 2010 to February 27, 2020, were included (N = 3125). Primary outcomes were postoperative complications and length of stay (LOS) and secondary outcomes compliance to the ERAS protocol, conversion to open surgery, symptoms delaying discharge and reoperations. Uni- and multivariate comparisons were used.

RESULTS

Robotic surgery (N = 827) had a similar rate of postoperative complications (Clavien-Dindo grades 1-5), 35.9% compared to open surgery (N = 1429) 40.9% (OR 1.15, 95% CI (0.93, 1.41)) and laparoscopic surgery (N = 869) 31.2% (OR 0.88, 95% CI (0.71, 1.08)). LOS was longer in the open group, median 9 days (IRR 1.35, 95% CI (1.27, 1.44)) and laparoscopic group, 7 days (IRR 1.14, 95% CI (1.07, 1.21)) compared to the robotic group, 6 days. Pre- and intraoperative compliance to the ERAS protocol were similar between groups.

CONCLUSIONS

In this multicenter cohort study, robotic surgery was associated with shorter LOS compared to both laparoscopic and open surgery and had lower conversion rates vs laparoscopic surgery. The rate of complications was similar between groups.

Methodological quality was critically low in 9/10 systematic reviews in advanced cancer patients-A methodological study

OBJECTIVE

To assess the methodological quality and the consideration of heterogeneity in systematic reviews (SRs).

STUDY DESIGN AND SETTING

We conducted a methodological study (CRD42019134904) and searched three databases from January 2010 to July 2019. Interventional SRs with a statistically significant meta-analysis of at least four randomized controlled trials in advanced cancer patients were included. A MeaSurement Tool to Assess Systematic Reviews (AMSTAR) 2 was used to evaluate the SRs' methodological quality. The consideration of heterogeneity was categorized in clinical or/and methodological heterogeneity and not explored.

RESULTS

From 6234 identified references, 261 SRs were included. Most SRs had a critically low quality (230, 88.1%). The majority of them (209, 80.1%) was classified as critically low because of non-registration (222, 85.1%) combined with the non-reporting of excluded full-texts and missing justifications for exclusion (218, 83.5%). Heterogeneity in trial results was not explored at all in 51 (19.5%) SRs whereas clinical heterogeneity was considered in 117 (44.8%), methodological heterogeneity in 13 (5.0%), and both clinical and methodological heterogeneity in 80 (30.7%) SRs.

CONCLUSION

The consideration of these findings in trainings for review authors and peer reviewers could improve the awareness of quality criteria and the quality of future SRs.

TRIAL REGISTRATION

PROSPERO-ID: CRD42019134904.

Difference in surgical outcomes of rectal cancer by study design: meta-analyses of randomized clinical trials, case-matched studies, and cohort studies

Background

RCTs are considered the standard in surgical research, whereas case-matched studies and propensity score matching studies are conducted as an alternative option. Both study designs have been used to investigate the potential superiority of robotic surgery over laparoscopic surgery for rectal cancer. However, no conclusion has been reached regarding whether there are differences in findings according to study design. This study aimed to examine similarities and differences in findings relating to robotic surgery for rectal cancer by study design.

Methods

A comprehensive literature search was conducted using PubMed, Scopus, and Cochrane CENTRAL to identify RCTs, case-matched studies, and cohort studies that compared robotic versus laparoscopic surgery for rectal cancer. Primary outcomes were incidence of postoperative overall complications, incidence of anastomotic leakage, and postoperative mortality. Meta-analyses were performed for each study design using a random-effects model.

Results

Fifty-nine articles were identified and reviewed. No differences were observed in incidence of anastomotic leakage, mortality, rate of positive circumferential resection margins, conversion rate, and duration of operation by study design. With respect to the incidence of postoperative overall complications and duration of hospital stay, the superiority of robotic surgery was most evident in cohort studies (risk ratio (RR) 0.83, 95 per cent c.i. 0.74 to 0.92, P < 0.001; mean difference (MD) –1.11 (95 per cent c.i. –1.86 to –0.36) days, P = 0.004; respectively), and least evident in RCTs (RR 1.12, 0.91 to 1.38, P = 0.27; MD –0.28 (–1.44 to 0.88) days, P = 0.64; respectively).

Conclusion

Results of case-matched studies were often similar to those of RCTs in terms of outcomes of robotic surgery for rectal cancer. However, case-matched studies occasionally overestimated the effects of interventions compared with RCTs.

Current status of robotic gastrectomy for gastric cancer: comparison with laparoscopic gastrectomy

Robotic systems were developed to overcome limitations of laparoscopic surgery with its mechanical advantages. Along with the technical advances, robotic gastrectomy for gastric cancer is increasing. However, the evidence regarding safety and efficacy for robotic gastrectomy for gastric cancer is not mature yet. Although studies are limited, it is evident that robotic gastrectomy has a longer operation and less blood loss compared with laparoscopic gastrectomy. Studies revealed long-term oncological outcomes after robotic gastrectomy was comparable to those after laparoscopic gastrectomy. Taken together, robotic gastrectomy with systemic lymph node dissection is suggested as a safe procedure with equivalent short- and long-term oncologic outcomes to either laparoscopic or open gastrectomy for the surgical treatment of gastric cancer. However, high cost is the most significant barrier to justify robotic surgery as a routine and standard treatment for patients with gastric cancer. In the meanwhile, robotic surgery will be expansively used as long as technologic developments continue.

Comparison of the perioperative outcomes of laparoscopic surgery, robotic surgery, open surgery, and transanal total mesorectal excision for rectal cancer: An overview of systematic reviews

Regarding the surgical approaches for rectal cancer, many techniques have been reported in randomized controlled trials, meta-analyses, and reviews of comparisons between two techniques, e.g. open surgery vs laparoscopic surgery, laparoscopic surgery vs robotic surgery, or laparoscopic surgery vs transanal total mesorectal excision. Since robotic surgery and transanal total mesorectal excision were developed after laparoscopic surgery had become an established minimally invasive technique, they have each been compared with laparoscopic surgery. Therefore, a review was performed to compare the surgical outcomes of robotic surgery and transanal total mesorectal excision, and to perform such comparisons among ≥3 of the above mentioned approaches, in the expectation that this review will serve as a reference for aiding treatment selection in future. The results of the current review suggest that all of the examined procedures have advantages and disadvantages, but that there are no decisive factors that could be used to select one procedure over any other. At the present time it cannot be demonstrated that laparoscopic surgery, robotic surgery, transanal total mesorectal excision, or open surgery is superior to the other techniques, and it is important to select the best technique for each patient from among those that a surgeon can perform. It is also important to maintain a flexible attitude that allows new techniques to be adopted as needed in the future.

Robotic versus laparoscopic surgery for gastric cancer: an overview of systematic reviews with quality assessment of current evidence

Many systematic reviews have been published to evaluate the clinical benefits of robotic surgery for gastric cancer. However, these reviews have investigated various outcomes and differ considerably in quality. In this overview, we summarize the findings and quality of these reviews. A comprehensive literature search was conducted using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials to identify systematic reviews and meta-analyses that compared robotic surgery with laparoscopic surgery for gastric cancer. We summarized the results of the meta-analyses and evaluated the quality of the reviews using the AMSTAR-2 tool. The literature search identified 14 eligible reviews. The reviews showed that estimated blood loss was significantly less and time to resumption of oral intake was significantly shorter in patients who underwent robotic surgery than in those who underwent laparoscopic surgery. However, no significant differences in other outcomes were found between the two types of surgery. The quality of the included reviews was judged to be critically low. In conclusion, the available evidence, albeit of critically low quality, suggests that robotic surgery decreases estimated blood loss and shortens the time to resumption of oral intake in patients with gastric cancer. There is currently no high-quality evidence that robotic surgery has clinical benefits for gastric cancer patients.

The quality of systematic reviews/meta-analyses published in the field of bariatrics: A cross-sectional systematic survey using AMSTAR 2 and ROBIS

High-quality systematic reviews (SR) and meta-analyses (MA) are considered to be reliable sources of information. This study aims to assess the quality of studies published as SR or MA in the field of bariatrics in 2016 and 2017. We identified SR and MA in the field of bariatrics by searching electronic databases (MEDLINE, Embase, and Cochrane Database of Systematic Reviews). Eligible studies were those identified as SR/MA in the title/abstract, which aimed to assess any outcome in patients with morbid obesity undergoing or scheduled to undergo bariatric surgery. Two authors independently reviewed all titles and abstracts, assessed full texts of potentially eligible studies, and assessed the quality of included studies. Any discrepancies were resolved by the third reviewer. We evaluated the quality and risk of bias of each SR/MA using AMSTAR 2 checklist and ROBIS tool, respectively. Seventy-eight of 4236 references met inclusion criteria and were assessed for their quality/risk of bias. The methodological quality of 99% of all papers was classified as "critically low." A total of 6% of the studies were at low risk of bias, and 78% were assessed as being at high risk of bias. The methodological quality of studies published in 2016 and 2017 as SR/MA is highly unsatisfactory.

Robotic Colorectal Surgery

The role of robotics in colon and rectal surgery has been established as an important and effective tool for the surgeon. Its inherent technologies have provided for increased visualization and ease of dissection in the minimally invasive approach to surgery. The value of the robot is apparent in the more challenging aspects of colon and rectal procedures, including the intracorporeal anastomosis for right colectomies and the low pelvic dissection for benign and malignant diseases.

Robotic Surgery for Rectal Cancer: Operative Technique and Review of the Literature

The number of patients undergoing robotic surgery for rectal cancer has rapidly increased in Japan, since the government approved the procedure for national insurance coverage in April 2018. Robotic surgery has the potential to overcome some limitations of laparoscopic surgery, especially in the narrow pelvis, providing a three-dimensional view, articulated instruments, and a stable camera platform. Although meta-analyses and randomized controlled trials have failed to demonstrate the superiority of robotic surgery over laparoscopic surgery with respect to the short-term clinical outcomes, the published findings suggest that robotic surgery may be potentially beneficial for patients who are obese, male, or patients undergoing sphincter-preserving surgery for rectal cancer. The safety and feasibility of robotic surgery for lateral lymph node dissection, the standard procedure for locally advanced lower rectal cancer in Japan, have been demonstrated in some retrospective studies. However, additional prospective, randomized trials are required to determine the actual benefits of robotic surgery to ameliorate the urogenital and oncological outcomes. The cost of this approach is a long-standing principal concern. A literature search showed that the cost of robotic surgery for rectal cancer was 1.3-2.5 times higher per patient than that for the laparoscopic approach. We herein describe our surgical technique using a da Vinci Surgical System (S/Si/Xi) with 10 years of experience in performing robotic surgery. We also review current evidence regarding short-term clinical and long-term oncological outcomes, lateral lymph node dissection, and the cost of the procedure.