Feasibility and Safety of Laparoscopic Complete Mesocolic Excision (CME) for Right-sided Colon Cancer: Short-term Outcomes. A Randomized Clinical Study

Factor analysis of postsurgical gastroparesis syndrome after right hemicolectomy for colon cancer

The present study aimed to investigate factors influencing postsurgical gastroparesis syndrome (PGS) in patients with right-sided colon cancer. In total, 260 patients who underwent complete mesocolic excision for right-sided colon cancer were included in the present analysis. Among the included patients, 69 underwent open radical right-sided colon resection, 175 underwent laparoscopic radical right-sided colon resection and 16 underwent robot-assisted radical right-sided colon resection. The occurrence of PGS was observed, and both the χ2 test and multivariate regression analysis were conducted to identify influencing factors. Among the 260 patients, 32 experienced PGS, with an incidence rate of 12.3%. Univariate analysis demonstrated that age, perioperative blood glucose levels, self-rated anxiety scale scores and surgical approach were significantly associated with PGS (P<0.05), whereas sex, surgical duration, diabetes and perioperative albumin levels were not significant factors (P>0.05). Multivariate logistic regression analysis showed that age >70 years, perioperative blood glucose ≥11.1 mmol/l, a self-rating anxiety scale score ≥50 and radical extended right-sided colon resection were risk factors for PGS occurrence. In conclusion, the occurrence of PGS in patients with right-sided colon cancer was revealed to be associated with age, perioperative blood glucose levels, self-rated anxiety scale scores and surgical approach.

Artificial intelligence-enhanced navigation for nerve recognition and surgical education in laparoscopic colorectal surgery

BACKGROUND

Devices that help educate young doctors and enable safe, minimally invasive surgery are needed. Eureka is a surgical artificial intelligence (AI) system that can intraoperatively highlight loose connective tissues (LCTs) in the dissected layers and nerves in the surgical field displayed on a monitor. In this study, we examined whether AI navigation (AIN) with Eureka can assist trainees in recognizing nerves during colorectal surgery.

METHODS

In left-sided colorectal surgery (n = 51, between July 2023 and February 2024), Eureka was connected to the laparoscopic system side by side, and the nerve was highlighted on the monitor during the surgery. We examined the rate of failure to recognize nerves by trainee surgeons over a total of 101 scenarios after it was recognized intraoperatively by the supervising surgeon (certified by the Japanese Society of Endoscopic Surgery). We also examined the frequency of nerve recognition by the trainee physicians viewing the Eureka monitor when recognition was not possible (recognition assistance rate).

RESULTS

The nerve recognition failure rate and recognition assistance rate with AIN were as follows: right hypogastric nerve during sigmoid colon mobilization, 44/101 (43.6%) and 19/44 (43.2%); left hypogastric nerves during dissection of the dorsal rectum, 27/101 (26.7%) and 13/27 (48.1%); right lumbar splanchnic nerves, 32/101 (31.7%) and 29/32 (90.6%); left lumbar splanchnic nerves, 44/101 (43.6%) and 39/44 (88.6%); and pelvic visceral nerves during dissection of the dorsal rectum, 29/45 (64.4%) and 6/29 (20.7%), respectively.

CONCLUSION

Although the rate of recognition with assistance from AIN differed for the different nerves, this system can potentially assist in anatomic recognition, enhance surgical education, and contribute to nerve preservation.

TRIAL REGISTRATION

Improvement of AI navigation in minimally invasive surgery and examination of its intraoperative support and educational effectiveness. Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2022-27.

Complete mesocolic excision versus D2 lymphadenectomy in right hemicolectomy: a meta-analysis of propensity score matched studies and randomized controlled trials

Introduction

The complete mesocolic excision (CME) in right-sided hemicolectomy could result in higher lymph node yield and decreased local recurrence. However, this approach could increase intraoperative and postoperative complications. Therefore, our meta-analysis aims to demonstrate the outcomes of CME versus D2 conventional lymphadenectomy in right-side colon cancer.

Methods

We searched MEDLINE, Cochrane Central Register of Clinical Trials, and Scopus for studies published until April 2024. Odds ratios (OR) with 95% confidence intervals (CIs) were pooled using a random-effects model. Heterogeneity was assessed using the Cochran Q test and I 2 statistics, with P values <0.10 and I 2 >25% considered significant. Statistical analysis was performed using R Software, version 4.1.2.

Results

Three randomized controlled trials and four observational studies comprising 2296 patients were included, of whom 1138 (49.6%) were submitted to the CME and 1158 (50.4%) to the conventional D2 lymphadenectomy. CME was associated with decreased local recurrence rates (OR 0.07; 95% CI 0.001 to 0.36; P = 0.002). There were no significant differences between groups in overall complications, severe complications, intraoperative complications, blood loss, and 30-day mortality. No difference between groups was observed in distance metastasis and 3-year disease-free survival.

Conclusion

In this meta-analysis, CME significantly decreases local recurrence rates compared with D2 conventional lymphadenectomy in patients with right-side colon cancer. No significant difference was observed between groups in rates of overall complications, severe complications, intraoperative complications, blood loss, and 30-day mortality.

AI-based visualization of loose connective tissue as a dissectable layer in gastrointestinal surgery

We aimed to develop an AI model that recognizes and displays loose connective tissue as a dissectable layer in real-time during gastrointestinal surgery and to evaluate its performance, including feasibility for clinical application. Training data were created under the supervision of gastrointestinal surgeons. Test images and videos were randomly sampled and model performance was evaluated visually by 10 external gastrointestinal surgeons. The mean Dice coefficient of the 50 images was 0.46. The AI model could detect at least 75% of the loose connective tissue in 91.8% of the images (459/500 responses). False positives were found for 52.6% of the images, but most were not judged significant enough to affect surgical judgment. When comparing the surgeon's annotation with the AI prediction image, 5 surgeons judged the AI image was closer to their own recognition. When viewing the AI video and raw video side-by-side, surgeons judged that in 99% of the AI videos, visualization was improved and stress levels were acceptable when viewing the AI prediction display. The AI model developed demonstrated performance at a level approaching that of a gastrointestinal surgeon. Such visualization of a safe dissectable layer may help to reduce intraoperative recognition errors and surgical complications.

European multicentre analysis of the implementation of robotic complete mesocolic excision for right-sided colon tumours

AIM

Complete mesocolic excision (CME) is an oncologically driven technique for treating right colon cancer. While laparoscopic CME is technically demanding and has been associated with more complications, the robotic approach might reduce morbidity. The aim of this study was to assess the safety of stepwise implementation of robotic CME.

METHOD

A multicentre retrospective analysis of prospectively collected data on robotic right colectomy was performed at five European tertiary centres. Patients were classified for type of surgery: R-RHC (standard right colectomy), R-impCME (learning cases towards robotic CME defined as R-RHC with one but not all the hallmarks of CME) or R-CME (robotic CME). Primary outcomes were overall and severe 30-day complication rates before and after propensity score matching (PSM) analysis.

RESULTS

Five hundred and fifty-one consecutive patients undergoing robotic surgery for (pre)malignant lesions of the right colon between 2010 and 2020 were included: R-RHC (n = 101), R-impCME (n = 135) and R-CME (n = 315). Baseline characteristics differed for American Society of Anesthesiologists score (p = 0.0012) and preoperative diagnosis of adenocarcinoma (p < 0.001). Procedure time increased by surgical complexity (p < 0.001). Vascular event rates did not differ, with no superior mesenteric vein injuries. Conversion, complication and anastomotic leak rates, time to flatus/soft diet and length of stay (LOS) did not differ. While R-RHC was performed for a lower rate of malignancies (p < 0.001), lymph node yield was significantly higher in R-CME (p < 0.001). After PSM, analyses on 186 patients documented no differences in overall and severe 30-day complication rate, conversion rate, LOS or 30-day mortality.

CONCLUSION

R-CME can be implemented without increasing the overall or 30-day severe complication rate.

Complete mesocolic excision (CME) impacts survival only for Stage III right-sided colon cancer: a systematic review and meta-analysis

INTRODUCTION

Complete mesocolic excision (CME) is widely adopted for its assumed superior oncological outcome. However, it's unclear if all right-sided colon cancer patients benefit from CME. The aim of this systematic review is to investigate whether CME contributes to postoperative outcomes and to determine the surgical indications for CME.

MATERIAL AND METHODS

We searched eligible articles about CME versus non-CME procedures for right-sided colon cancer in the OVID Medline, Embase, and Cochrane CENTRAL databases, and a meta-analysis was conducted.

RESULTS

Twenty-two articles and seven abstracts involving 8088 patients were included in this study. Among them, 3803 underwent CME and 4285 non-CME procedures. The analysis showed that CME was favoured for three-year disease-free survival (DFS) and overall survival (OS), for local, systemic, and total recurrence, and for hospital stay durations. However, increased vascular injury and longer surgery time were observed in CME. Regarding the three-year OS, the superiority of CME was observed only in Stage III. Additionally, no significant differences were observed between CME and non-CME groups regarding overall complications, 30-day readmission rates, reoperation, or postoperative mortality rates.

CONCLUSIONS

CME for right-sided colon cancer should be considered, particularly in Stage III patients, to contribute to improved oncological outcomes. However, careful attention must be paid to the increased risk of vascular injury.

Short- and long-term outcomes of laparoscopic right hemicolectomy with D3 resection for right colon cancer in elderly patients

BACKGROUND

Laparoscopic right hemicolectomy (RHC) with D3 resection, similar to complete mesocolic excision, is an oncologically satisfying procedure; however, it remains controversial in elderly patients. There are no reports of the procedure for tumors fed by middle colic vessels because it is a difficult procedure. We evaluated the feasibility and oncological outcomes of the procedure in elderly patients.

METHODS

We retrospectively evaluated 336 consecutive patients undergoing laparoscopic right hemicolectomy with D3 resection for Stage I-III ascending and transverse colon cancer between 2010 and 2021. Patients were divided into the EP (age ≥ 75 years) and nEP (age < 75 years) groups, and short- and long-term outcomes were analyzed using propensity score matching.

RESULTS

The median follow-up period was 60.7 months. After matching, we enrolled 129 patients. The surgery time, estimated blood loss, postoperative complication rate, number of harvested lymph nodes, and recurrence rate did not differ significantly between the groups; however, the adjuvant chemotherapy rate was significantly lower in the EP group. The EP group had significantly shorter overall survival (OS) (p < 0.01) than the nEP group; however, the cancer-specific (p = 0.15) and recurrence-free (p = 0.36) survivals did not differ significantly from those in the nEP group. In multivariate analyses, age ≥ 75 years, ASA ≥ 3, and pT4 were independent prognostic factors for OS (p = 0.02, < 0.01, < 0.01, respectively); however, only pT4 was an independent prognostic factor for CSS and RFS (p < 0.01 for both).

CONCLUSIONS

This procedure offers safe, feasible, and satisfactory oncological outcomes for elderly patients.

Learning curve and safety of the implementation of laparoscopic complete mesocolic excision with intracorporeal anastomosis for right-sided colon cancer: results from a propensity score-matched study

BACKGROUND

Retrospective studies and randomized controlled trials support the safety of laparoscopic complete mesocolic excision (CME) for the treatment of right-sided colon cancer (RSCC). Few studies, however, examine the learning curve of this operation and its impact on safety during an implementation period. We aim to evaluate the learning curve and safety of the implementation of laparoscopic CME with intracorporeal anastomosis for RSCC.

METHODS

Consecutive patients undergoing a laparoscopic right colectomy with intracorporeal anastomosis for RSCC between January 2016 and June 2023 were included. Clinical, perioperative, and histopathological variables were collected. Correlation and cumulative sum (CUSUM) analyses between the operating time and case number were performed. Breakpoints of the learning curve were estimated using the broken-line model. CME and conventional laparoscopic right colectomy outcomes were compared after propensity score matching (PSM).

RESULTS

Two hundred and ninety patients underwent laparoscopic right colectomy during study period. One hundred and eight met inclusion criteria. After PSM, 56 non-CME and 28 CME patients were compared. CME group had a non-statistically significant tendency to a longer operating time (201 versus 195 min; p = 0.657) and a shorter hospital stay (3 versus 4 days; p = 0.279). No significant differences were found in total complication rates or their profile. Correlation analysis identified a significant trend toward operating time reduction with increasing case numbers (Pearson correlation coefficient =  - 0.624; p = 0.001). According to the CUSUM analysis, an institutional learning curve was deemed completed after 13 cases and the broken-line model identified three phases: learning (1-6 cases), consolidation (7-13 cases), and mastery (after 13 cases).

CONCLUSION

The learning curve of laparoscopic CME for RSCC can be achieved after 13 cases in centers with experience in advanced laparoscopic surgery and surgeons with familiarity with this technique. Its implementation within this setting seems to be as safe as performing a conventional right colectomy.

Surgical treatment of right colon cancer

The study aimed to perform a systematic review of the literature on surgical treatment for right colon cancer (RCC) with complete mesocolic excision (CME) and D2/D3 lymph node dissection (LND). Material and Methods. A literature review was performed for studies published between 2013 and 2023 by the online resources from the official Web sites of the societies/panels and PubMed database. Sources included guidelines, meta-analyses, randomized and nonrandomized clinical studies, guidelines by European Society of Medical Oncology, the Japanese Society for Cancer of the Colon and Rectum, and the National Comprehensive Cancer Network, Russian clinical guidelines. Results. CME significantly improved both immediate and long-term treatment results, which was confirmed by numerous meta-analyses. The extent of LND remains one of the most controversial issues in RCC. For many Asian surgeons, D3 LND is the standard procedure for the treatment of RCC, whereas the European approach is more conservative and apical lymph node dissection is not mandatory. There are also large differences in understanding the extent of D3 LND in RCC. Most surgeons understand this term as dissection of adipose tissue along the anterior and lateral surface of the superior mesenteric vein, however, there are authors who perform circular dissection along the superior mesenteric vessels, considering this extent of surgery to be the most radical. Conclusion. It is necessary to standardize methods and effective criteria for quality control of CME for RCC and LND. In this case, external independent assessment of the quality of surgical intervention is important. There is also currently a growing number of studies in which intraoperative fluorescence imaging makes it possible to better visualize the location of the apical lymph nodes and individualize LND.

Innovative perfused cadaveric model for complete mesocolic excision

A high-fidelity cadaver-based training scenario for right colectomy with complete mesocolic excision is presented (Video 1). A feasible perfusion strategy that allows a near-to-reality experience is demonstrated.

The safety and short-term effect of mixed approach in laparoscopic right hemicolectomy for right colon cancer compared with middle approach: a retrospective study

PURPOSE

To investigate whether the mixed approach is a safe and advantageous way to operate laparoscopic right hemicolectomy.

METHODS

A retrospective study was performed on 316 patients who underwent laparoscopic right hemicolectomy in our center. They were assigned to the middle approach group (n = 158) and the mixed approach group (n = 158) according to the surgical approaches. The baseline data like gender、age and body mass index as well as the intraoperative and postoperative conditions including operation time, blood loss, postoperative hospital stay and complications were analyzed.

RESULTS

There were no significant differences in age, sex, BMI, ASA grade and tumor characteristics between the two groups. Compared with the middle approach group, the mixed approach group was significantly lower in terms of operation time (217.61 min vs 154.31 min, p < 0.001), intraoperative blood loss (73.8 ml vs 37.97 ml, p < 0.001) and postoperative drainage volume. There was no significant difference in the postoperative complications like postoperative anastomotic leakage, postoperative infection and postoperative intestinal obstruction.

CONCLUSIONS

Compared with the middle approach, the mixed approach is a safe and advantageous way that can significantly shorten the operation time, reduce intraoperative bleeding and postoperative drainage volume, and does not prolong the length of hospital stay or increase the morbidity postoperative complications.

Effect of complete mesocolic excision (cme) on long-term survival after right colectomy for cancer: multivariate meta-analysis and restricted mean survival time estimation

INTRODUCTION

Debate exists concerning the impact of complete mesocolic excision (CME) on long-term oncological outcomes. The aim of this review was to condense the updated literature and assess the effect of CME on long-term survival after right colectomy for cancer.

METHODS

PubMed, MEDLINE, Scopus, and Web of Science were searched through July 2023. The included studies evaluated the effect of CME on survival. The primary outcome was long-term overall survival. Restricted mean survival time difference (RMSTD), hazard ratio (HR), and 95% confidence intervals (CI) were used as pooled effect size measures. GRADE methodology was used to summarize the certainty of evidence.

RESULTS

Ten studies (3665 patients) were included. Overall, 1443 (39.4%) underwent CME. The RMSTD analysis shows that at 60-month follow-up, stage I-III CME patients lived 2.5 months (95% CI 1.1-4.1) more on average compared with noCME patients. Similarly, stage III patients that underwent CME lived longer compared to noCME patients at 55-month follow-up (6.1 months; 95% CI 3.4-8.5). The time-dependent HRs analysis for CME vs. noCME (stage I-III disease) shows a higher mortality hazard in patients with noCME at 6 months (HR 0.46, 95% CI 0.29-0.71), 12 months (HR 0.57, 95% CI 0.43-0.73), and 24 months (HR 0.73, 95% CI 0.57-0.92) up to 27 months.

CONCLUSIONS

This study suggests that CME is associated with unclear OS benefit in stage I-III disease. Caution is recommended to avoid overestimation of the effect of CME in stage III disease since the marginal benefit of a more extended resection may have been influenced by tumor biology/molecular profile and multimodal adjuvant treatments.

A Randomized Phase III Trial of Complete Mesocolic Excision Compared with Conventional Surgery for Right Colon Cancer: Interim Analysis of a Nationwide Multicenter Study of the Italian Society of Surgical Oncology Colorectal Cancer Network (CoME-in trial)

BACKGROUND

Although complete mesocolic excision (CME) is supposed to be associated with a higher lymph node (LN) yield, decreased local recurrence, and survival improvement, its implementation currently is debated because the evidence level of these data is rather low and still not supported by randomized controlled trials.

METHOD

This is a multicenter, randomized, superiority trial (NCT04871399). The 3-year disease-free survival (DFS) was the primary end point of the study. The secondary end points were safety (duration of operation, perioperative complications, hospital length of stay), oncologic outcomes (number of LNs retrieved, 3- and 5-year overall survival, 5-year DFS), and surgery quality (specimen length, area and integrity rate of mesentery, length of ileocolic and middle-colic vessels). The trial design required the LN yield to be higher in the CME group at interim analysis.

RESULTS

Interim data analysis is presented in this report. The study enrolled 258 patients in nine referral centers. The number of LNs retrieved was significantly higher after CME (25 vs. 20; p = 0.012). No differences were observed with respect to intra- or post-operative complications, postoperative mortality, or duration of surgery. The hospital stay was even shorter after CME (p = 0.039). Quality of surgery indicators were higher in the CME arm of the study. Survival data still were not available.

CONCLUSIONS

Interim data show that CME for right colon cancer in referral centers is safe and feasible and does not increase perioperative complications. The study documented with evidence that quality of surgery and LN yield are higher after CME, and this is essential for continuation of patient recruitment and implementation of an optimal comparison. Trial registration The trial was registered at ClinicalTrials.gov with the code NCT04871399 and with the acronym CoME-In trial.

Surgical quality assessment for the prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for nonmetastatic right colon cancer (PIONEER study)

BACKGROUND

The modified complete mesocolic excision (mCME) procedure for right-sided colon cancer is a tailored approach based on the original complete mesocolic excision (CME) methodology. Limited studies evaluated the safety and feasibility of laparoscopic mCME using objective surgical quality assessments in patients with right colon cancer. The objectives of the PIONEER study were to evaluate oncologic outcomes after laparoscopic mCME and to identify optimal clinically relevant endpoints and values for standardizing laparoscopic right colon cancer surgery based on short-term outcomes of procedures performed by expert laparoscopic surgeons.

MATERIALS AND METHODS

This is an ongoing prospective, multi-institutional, single-arm study conducted at five tertiary colorectal cancer centers in South Korea. Study registrants included 250 patients scheduled for laparoscopic mCME with right-sided colon adenocarcinoma (from the appendix to the proximal half of the transverse colon). The primary endpoint was 3-year disease-free survival. Secondary outcomes included 3-year overall survival, incidence of morbidity in the first 4 weeks postoperatively, completeness of mCME, central radicality, and distribution of metastatic lymph nodes. Survival data will be available after the final follow-up date (June 2024).

RESULTS

The postoperative complication rate was 12.9%, with a major complication rate of 2.7%. In 87% of patients, central radicality was achieved with dissection at or beyond the level of complete exposure of the superior mesenteric vein. Mesocolic plane resection with an intact mesocolon was achieved in 75.9% of patients, as assessed through photographs. Metastatic lymph node distribution varied by tumor location and extent. Seven optimal clinically relevant endpoints and values were identified based on the analysis of complications in low-risk patients.

CONCLUSIONS

Laparoscopic mCME for right-sided colon cancer produced favorable short-term postoperative outcomes. The identified optimal clinically relevant endpoints and values can serve as a reference for evaluating surgical performance of this procedure.

Complete mesocolic excision for colon cancer: current status and controversies

According to Hohenberger's original description, complete mesocolic excision for colon cancer involves precise dissection of the avascular embryonic plane between the parietal retroperitoneum and visceral peritoneum of the mesocolon. This ensures mesocolic integrity, access to high ligation of the supplying vessels at their origin and an associated extended lymphadenectomy. Results from centres which have adopted this approach routinely have demonstrated that oncological outcomes can be improved by the rigorous implementation of established principles of cancer surgery. Meticulous anatomical dissection along embryonic planes is a well-established principle of precision cancer surgery used routinely by the specialist colorectal surgeon. Therefore, the real question concerns the need for true central vascular ligation and associated extended (D3) lymphadenectomy or otherwise, particularly along the superior mesenteric vessels when performing a right colectomy. Whether this approach results in improved overall or disease-free survival remains unclear and its role remains controversial particularly given the potential for significant morbidity associated with a more extensive central vascular dissection. Current literature is limited by considerable bias, as well as inconsistent and variable terminology, and the results of established randomized trials are awaited. As a result of the current state of equipoise, various national guidelines have disparate recommendations as to when complete mesocolic excision should be performed if at all. This article aims to review the rationale for and technical aspects of complete mesocolic excision, summarize available short and long term outcome data and address current controversies.

Laparoscopic Colorectal Surgery with Anatomical Recognition with Artificial Intelligence Assistance for Nerves and Dissection Layers

BACKGROUND

In digestive tract surgery, dissection of an avascular space consisting of loose connective tissue (LCT) appearing by countertraction improves oncological outcomes and reduces complications.1-3 Kumazu et al.4 described a deep learning approach that automatically segments LCT to help surgeons.4 During left colorectal surgery, lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries cause sexual dysfunction and/or urinary issues.5 As nerve preservation is critical for functional preservation, the AI model Kumazu reported is named Eureka (Anaut Inc., Tokyo, Japan) and was developed to separate nerves automatically. The educative efficacy of intraoperative nerve visualization has been described.6 Artificial intelligence (AI) assisted navigation is expected to aid in the anatomical recognition of nerves and the safe dissection layers surrounding nerves in the future.

METHODS

We used Eureka as an educational tool for surgeons' training during laparoscopic colorectal surgery. The laparoscopic system used was Olympus VISERA ELITE3 (Tokyo, Japan).

RESULTS

Total mesorectal excision (TME) was safely performed with nerve preservation. No postoperative complications occurred. Automatic segmentation and highlighting of LCT in the dissected layers, lumbar splanchnic, hypogastric, and pelvic visceral nerves (S3, S4), were performed in real time.

CONCLUSIONS

In colorectal cancer surgery, the nerves are vital anatomical structures serving as landmarks for dissection. Lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries (S3, S4) cause sexual dysfunction or urinary disorders.5 Nerve preservation is important for functional preservation. AI-assisted navigation methods are noninvasive, user-friendly, and expected to improve in accuracy in the future. They have the potential to develop nerve-guided TME.

Construction and validation of a prognostic signature for mucinous colonic adenocarcinoma based on N7-methylguanosine-related long non-coding RNAs

BACKGROUND

Mucinous colonic adenocarcinoma remains a challenging disease due to its high propensity for metastasis and recurrence. N7-methylguanosine (m7G) and long non-coding RNA (lncRNA) are closely associated with the occurrence and progression of tumors. However, research on m7G-related lncRNA in mucinous colonic adenocarcinoma is lacking. Therefore, we sought to explore the prognostic impact of m7G-related lncRNAs in mucinous adenocarcinoma (MC) patients.

METHODS

In this study, Pearson analysis was used to identify m7G-related lncRNAs from transcriptome data in The Cancer Genome Atlas (TCGA). Univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) regression were used to further screen m7G-related lncRNAs and incorporate them into a prognostic signature. Based on the risk model, patients were divided into low- and high-risk groups and randomly assigned to the training set and test sets in a 6:4 ratio. Kaplan-Meier, receiver operating characteristic (ROC) curve, multivariate regression, and nomogram analyses were used to confirm the accuracy of the signature. The CIBERSORT algorithm was used to calculate the degree of immune cell infiltration (ICI). Finally, the correlation of the prognostic signature with tumor mutational burden (TMB) and immunophenotype score (IPS) was evaluated.

RESULTS

A total of 432 m7G-related lncRNAs were identified by Pearson analysis. Univariate Cox regression, LASSO regression and survival analysis were performed to further select six m7G-related lncRNAs (P<0.05): AC254629.1, LINC01133, LINC01134, MHENCR, SMIM2-AS1, and XACT. Based on the risk model, heat maps, Kaplan-Meier curves, and ROC curves were constructed, and the results showed that there were significant differences in expression levels and survival status between the two risk groups. The area under the ROC curve (AUC) values for 3-, 5-, and 10-year survival in the training set were 0.944, 0.957, and 1.000, respectively. And in the test set were 0.964, 1.000, and 1.000, respectively. Subsequently, univariate and multivariate regression analyses of clinical characteristics and risk score were performed. The results of risk score were [hazard ratio (HR): 6.458, 95% confidence interval (CI): 2.708-15.403, P<0.001; HR: 7.280, 95% CI: 2.500-21.203, P<0.001], respectively. Using the risk score as an independent prognostic factor, the AUC of it over 3, 5, and 10 years was 0.911, 0.955, and 0.961, respectively. Calibration plots for the nomogram show that the model calibration line is very close to the ideal calibration line, indicating good calibration. The level of ICI was significantly different in the different risk groups. Survival analysis showed that, regardless of TMB risk, patients with MC and a high-risk score consistently had a poor overall survival (OS).

CONCLUSIONS

The m7G-related lncRNA prognostic signature has potential value for the prognosis of mucinous colonic adenocarcinoma.

Surgical outcomes of a prospective, phase 2 trial of robotic surgery for resectable right-sided colon cancer (the ROBOCOLO trial)

Aim

We evaluated the safety of robotic surgery for right-sided colon cancer in Japan.

Methods

This was a prospective, open-label, single-arm phase II trial conducted at two institutions. Patients ≥20 years old with stage I-III right-sided colon cancer and scheduled for radical resection with ≥D2 lymph node dissection were eligible. The criterion for surgeons was experience performing robot-assisted rectal resection in ≥40 cases. The primary endpoint was the postoperative complication rate ≤30 days after surgery.

Results

From August 2021 to February 2023, 42 patients were enrolled; three were excluded, with 39 analyzed as the full analysis set. The median age was 72 years, and the median body mass index was 23.2. The tumor was located in the cecum in 13 cases (33.3%), ascending colon in 20 cases (51.3%), and transverse colon in six cases (15.4%). Ileocolic resection was performed in 17 cases (43.5%) and right hemicolectomy in 22 cases (56.5%), both with D3 lymph node dissection. The median console time was 109 min, and the operative time was 170 min. The mean blood loss was 7.7 mL. Intracorporeal anastomosis was performed in 28 patients (71.8%). There were no conversions and no intraoperative adverse events. The median postoperative stay was 5 days. Postoperative complications occurred in four patients (10.2%; paralytic ileus [n = 3] and pneumonia [n = 1]). All postoperative complications were grade 1 or 2, with no mortalities noted. R0 resection was achieved in all patients.

Conclusions

This study demonstrated the safety and feasibility of robotic surgery for right-sided colon cancer.

[D2 and D3 lymph node dissection for colon cancer]

OBJECTIVE

To evaluate surgical and oncological results of standard and extended lymph node dissection (D2 and D3) in patients with colon cancer.

MATERIAL AND METHODS

We analyzed treatment outcomes in 74 patients with colon cancer stage T1-4aN0-2M0 who underwent right- and left-sided hemicolectomy, resection of sigmoid colon with standard and extended lymph node dissection (D2 and D3).

RESULTS

Surgical approach and level of D3 lymph node dissection did not increase intra- and postoperative morbidity. Laparoscopic interventions were followed by significantly lower intraoperative blood loss and earlier gas discharge. Metastatic lesion of apical lymph nodes was observed in 5 out of 36 patients who underwent D3 lymph node dissection (13.8%), and metastases in regional lymph nodes rN1-2 were found in all these patients. Overall 5-year survival was 86%. Disease-free and overall 5-year survival were similar after D2 and D3 lymph node dissection.

CONCLUSION

D3 lymph node dissection is safe for colon cancer. Metastatic lesions of apical lymph nodes during D3 lymph node dissection were detected only in patients with lesions of regional lymph nodes (rN1-2). Disease-free and overall 5-year survival were similar after D2 and D3 lymph node dissection.

Early recurrence after complete mesocolic excision for right-sided colon cancer with D3 lymphadenectomy: pattern, risk factors, prognostic impact, and individualized follow-up

The definition of early recurrence (ER) for right-sided colon cancer patients after complete mesocolic excision (CME) with D3 lymphadenectomy remains unclear. This study aimed to define the optimal time for ER and clarify risk factors for ER and post-recurrence survival (PRS). A total of 578 right-sided colon cancer patients who underwent CME with D3 lymphadenectomy were included. The minimum p value method was used to evaluate theme optimal time of recurrence-free survival to discriminate between ER and late recurrence (LR). Risk factors for ER were determined by a logistics regression model. The PRS was compared between ER and LR. The optimal time to define ER was 15 months (P = 1.8697E-7). 93 patients developed tumor recurrence, 46 patients had ER (≤15 months) and 47 patients had LR (>15 months). Preoperative serum CA19-9 > 37 U/mL (OR = 3.185, P = 0.001), pathological N+ stage (OR = 3.042, P = 0.027), and lymphovascular invasion (OR = 2.182, P = 0.027) were identified as independent risk factors associated with ER. Age > 75 years (HR = 1.828, P = 0.040), pathological N2 stage (HR = 1.850, P = 0.009), multiple sites of recurrence (HR = 1.680, P = 0.024), and time to recurrence ≤15 months (HR = 2.018, P = 0.043) were significantly associated with worse PRS in patients with recurrence. 15 months was the optimal time to distinguish ER and LR. ER was associated with a poor PRS. Elevated preoperative serum CA19-9 level, pathological N+ stage, and lymphovascular invasion were significantly predictive of ER.

Tata Memorial Centre Evidence Based Management of Colorectal cancer

This review article examines the evidence-based management of colorectal cancers, focusing on topics characterized by ongoing debates and evolving evidence. To contribute to the scientific discourse, we intentionally exclude subjects with established guidelines, concentrating instead on areas where the current understanding is dynamic. Our analysis encompasses a thorough exploration of critical themes, including the evidence surrounding complete mesocolic excision and D3 lymphadenectomy in colon cancers. Additionally, we delve into the evolving landscape of perioperative chemotherapy in both colon and rectal cancers, considering its nuanced role in the context of contemporary treatment strategies. Advancements in surgical techniques are a pivotal aspect of our discussion, with an emphasis on the utilization of minimally invasive approaches such as laparoscopy and robotic surgery in both colon and rectal cancers, including advanced rectal cases. Moving beyond conventional radical procedures, we scrutinize the feasibility and implications of endoscopic resections for small tumors, explore the paradigm of organ preservation in locally advanced rectal cancers, and assess the utility of total neoadjuvant therapy in the current treatment landscape. Our final segment reviews pivotal trials that have significantly influenced the management of colorectal liver and peritoneal metastasis.

Complete mesocolic excision for right colon cancer: Is D3 lymphadenectomy necessary?

AIM

Although complete mesocolic excision (CME) for colon cancer is oncologically sound, to date, there has been no consensus on the extent of lymphadenectomy in radical right colectomy. This study essentially compared the perioperative and survival outcomes of CME with two templates of lymphadenectomy for right colon cancer.

METHOD

This was a propensity matched, retrospective analysis of a single centre, prospectively maintained database of all patients undergoing elective right colectomy for nonmetastatic, biopsy-proven adenocarcinoma from November 2013 to October 2018. CME + D3 was adopted selectively, documented prospectively, and compared with patients undergoing CME + central vascular ligation (CVL). The only technical difference between the groups was the excision of the surgical trunk of Gillot in the CME + D3 group. Postoperative, long-term outcomes and patterns of recurrence were compared between the groups.

RESULTS

Of the 244 eligible patients, 88 (36.1%) and 156 (63.9%) underwent CME + D3 and CME + CVL, respectively. Matched groups (72 [CME + D3] vs. 108 [CME + CVL]) showed no difference in histology, tumour grade, postoperative complications, mortality, and hospital stay. CME + D3 was preferentially performed laparoscopically (35.2% vs. 9%), was associated with lower blood loss (215 mL vs. 297 mL, p = 0.001), higher nodal yield (31 vs. 25 nodes, p = 0.003) and a higher incidence of chyle leak (4 vs. 0, p = 0.013). At a median follow-up of more than 57 months, there was no significant difference in local recurrence, disease-free or overall survival.

CONCLUSION

In this retrospective study, lymphadenectomy along the superior mesenteric vein, as a component of CME for right colon cancer, offered a higher nodal yield with no improvement in oncological outcome. Dissection of the SMV, over and above a D2 dissection, could therefore be restricted to specialized colorectal units until further studies establish the incremental oncological benefit of this extended lymphadenectomy or define a patient group in whom it is beneficial.

A multicenter prospective observational study of lymph node metastasis patterns and short-term outcomes of extended lymphadenectomy in right-sided colon cancer

Background

The lymph node metastasis rate in right-sided colon cancer is unknown, and the optimal central vascular ligation level remains controversial. We aimed to determine the lymph node metastasis rate and short-term results of radical surgery with extended lymph node dissection in right-sided colon cancer.

Methods

This prospective multicenter observational study included patients with stage II/III right-sided colon cancer from five cancer hospitals. The metastasis rate of each node station was analyzed according to tumor location and main feeding artery.

Results

Between April 2018 and August 2021, 208 patients underwent dissection around the superior mesenteric artery (SMA) and vein (SMV). In transverse colon cancer, 7.5% and 2.5% of metastases occurred around the SMV and SMA at the root of the middle colic artery (MCA), respectively; 6.7% and 6.7% at the root of the right colic artery. In caecal cancer, 1.9% of metastases occurred around the SMV and 1.9% around the SMA. In ascending colon cancer, the rate was 1.1% around the SMV. Of the tumors, 17% fed mainly by the ileocolic artery had node metastases along the middle or right colic artery, as did 66.7% fed mainly by the right colic artery and 41.2% fed by the MCA (p = 0.01). Postoperative complications occurred in 42 patients (20.2%).

Conclusion

Routine prophylactic extended lymphadenectomy around the SMA might not be necessary in caecum and ascending colon cancer. Dissection around the SMA may be necessary in cases of transverse colon cancer or when the feeding artery is the MCA.

Complete mesocolic excision versus standard resection for colon cancer: a systematic review and meta-analysis of perioperative safety and an evaluation of the use of a robotic approach

PURPOSE

Complete mesocolic excision (CME) has been associated with improved oncological outcomes in treatment of colon cancer. However, widespread adoption is limited partly because of the technical complexity and perceived risks of the approach. The aim of out study was to evaluate the safety of CME compared to standard resection and to compare robotic versus laparoscopic approaches.

METHODS

Two parallel searches were undertaken in MEDLINE, Embase and Web of Science databases 12 December 2021. The first was to evaluate IDEAL stage 3 evidence to compare complication rates as a surrogate marker of perioperative safety between CME and standard resection. The second independent search compared lymph node yield and survival outcomes between minimally invasive approaches.

RESULTS

There were four randomized control trials (n = 1422) comparing CME to standard resection, and three studies comparing laparoscopic (n = 164) to robotic (n = 161) approaches. Compared to standard resection, CME was associated with a reduction in Clavien-Dindo grade 3 or higher complication rates (3.56% vs. 7.24%, p = 0.002), reduced blood loss (113.1 ml vs. 137.6 ml, p < 0.0001) and greater mean lymph node harvest (25.6 vs. 20.9 nodes, p = 0.001). Between the robotic and laparoscopic groups, there were no significant differences in complication rates, blood loss, lymph node yield, 5-year disease-free survival (OR 1.05, p = 0.87) and overall survival (OR 0.83, p = 0.54).

CONCLUSIONS

Our study demonstrated improved safety with CME. There was no difference in safety or survival outcomes between robotic and laparoscopic CME. The advantage of a robotic approach may lie in the reduced learning curve and an increased penetration of minimally invasive approach to CME. Further studies are required to explore this.

PROSPERO ID

CRD42021287065.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

BACKGROUND

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at 5 hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 males; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinical-pathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 minutes, p=0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p< 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSIONS

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Robotic versus laparoscopic right hemicolectomy with complete mesocolic excision: a retrospective multicenter study with propensity score matching

OBJECTIVE

During the past decade, the concept of complete mesocolic excision (CME) has been developed in an attempt to minimize recurrence for right-sided colon cancer. This study aims to compare outcomes of robotic versus laparoscopic right hemicolectomy with CME for right-sided colon cancer.

METHODS

We performed a retrospective multicenter propensity score matching study. From July 2016 to July 2021, 382 consecutive patients from different Chinese surgical departments were available for inclusion out of an initial cohort of 412, who underwent robotic or laparoscopic right hemicolectomy with CME. Data of all patients were retrospectively collected and reviewed. Of these, 149 cases were performed by a robotic approach, while the other 233 cases were done by laparoscopy. Propensity score matching was applied at a ratio of 1:1 to compare perioperative, pathologic, and oncologic outcomes between the robotic and the laparoscopic groups (n = 142).

RESULTS

Before propensity score matching, there were no statistical differences regarding the sex, history of abdominal surgery, body mass index (BMI), American Joint Committee on Cancer (AJCC) staging system, tumor location, and center between groups (p > 0.05), while a significant difference was observed regarding age (p = 0.029). After matching, two comparable groups of 142 cases were obtained with equivalent patient characteristics (p > 0.05). Blood loss, time to oral intake, return of bowel function, length of stay, and complications were not different between groups (p > 0.05). The robotic group showed a significantly lower conversion rate (0% vs. 4.2%, p = 0.03), but a longer operative time (200.9 min vs. 182.3 min, p < 0.001) and a higher total hospital cost (85,016 RMB vs. 58,266 RMB, p < 0.001) compared with the laparoscopic group. The number of harvested lymph nodes was comparable (20.4 vs. 20.5, p = 0.861). Incidence of complications, mortality, and pathologic outcomes were similar between groups (p > 0.05). The 2-year disease-free survival rates were 84.9% and 87.1% (p = 0.679), and the overall survival rates between groups were 83.8% and 80.7% (p = 0.943).

CONCLUSION

Despite the limitations of a retrospective analysis, the outcomes of robotic right hemicolectomy with CME were comparable to the laparoscopic procedures with fewer conversions to open surgery. More clinical advantages of the robotic surgery system need to be further confirmed by well-conducted randomized clinical trials with large cohorts of patients.

Prognostic immunogenic characteristics of iron pendant disease modifiers in colon cancer

Background

We explored the prognostic and immunogenic characteristics of iron pendant disease regulators in colon cancer to provide a scientific basis for the prediction of tumor prognosis-related markers and potential immunotherapeutic drug targets.

Methods

RNA sequencing and matched complete clinical information of colon cancer (COAD) were retrieved from the UCSC Xena database, and genomic and transcriptomic data of colon cancer from the TCGA database were downloaded. Then univariate and multifactorial Cox regression were used to process these data. The prognostic factors were analyzed by single-factor and multi-factor Cox regression, followed by Kaplan-Meier survival curves with the aid of R software "survival" package. Then we use FireBrowse online analysis tool to analyze the expression variation of all cancer genes, and draw a histogram according to the influencing factors to predict the 1, 3, and 5 year survival rates of patients.

Results

The results show that age, tumor stage and iron death score were significantly correlated with prognosis (p<0.05). Further multivariate cox regression analysis confirmed that age, tumor stage and iron death score were still significantly correlated with prognosis (p<0.05); The calibration curve results show that the deviation between the predicted values of 1 year, 3 years and 5 years and the diagonal of the figure is very small; the ROC curve results show that the AUC values of the 1-year and 5-year ROC curves of the bar graph are high; the DCA curve results show that the net yield of the bar graph is the largest; The scores of T cells and B cells in the high iron death score group were significantly lower than those in the low iron death score group, and the activities of immune related pathways were significantly reduced. There was a significant difference in the iron death score between the iron death molecular subtype and the gene cluster subtype.

Conclusions

The model showed a superior response to immunotherapy in the high-risk group, revealing a potential relationship between iron death and tumor immunotherapy, which will provide new ideas for the treatment and prognostic assessment of colon cancer patients.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

PURPOSE

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at five hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 male; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinicopathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 min, p = 0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p < 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSION

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Surgical efficacy and learning curves of laparoscopic complete mesocolic excision with intracorporeal anastomosis for right-sided colon cancer: A retrospective two-center cohort study

BACKGROUND

There is a potential benefit on long-term outcomes following complete mesocolic excision (CME) for right-sided colon cancer when compared to conventional colectomy. This study aims to analyze the learning curve and short-term outcomes of laparoscopic CME with intracorporeal anastomosis (ICA) for right-sided colon cancer in the hands of experienced colorectal surgeons.

METHODS

A two-center cohort study of consecutive patients undergoing right-sided colectomy from September 2021 to May 2022 at two tertiary colorectal centers in Denmark. Learning curves of surgical time were estimated using a cumulative sum analysis (CUSUM).

RESULTS

A total of 61 patients were included. According to the CUSUM analysis, 32 cases were needed to obtain a peak in operative time, resulting in a decrease in time consumption (group 1/learning phase: 217.2 min [SD 53.6] and group 2/plateau phase 191.6 min [SD 45.1], p = 0.05). There was a nonsignificant reduction in the rates of severe surgical complications (Clavien-Dindo > 3) (13% vs. 7%, p = 0.67) between the two groups, while the length of hospital stay remained constant (median 3.0 days, interquartile range, IQR [2.0; 4.0]).

CONCLUSION

The learning curve of laparoscopic CME with ICA for right-sided colon cancer demonstrated that 32 cases were needed to obtain a plateau phase expressed by operative time.

Robot-assisted versus laparoscopic short- and long-term outcomes in complete mesocolic excision for right-sided colonic cancer: a systematic review and meta-analysis

BACKGROUND

Complete mesocolic excision (CME) surgery is increasingly implemented for the resection of right-sided colonic cancer, possibly resulting in improved 5-year overall and disease-free survival compared to non-CME surgery. However, it is not clear what surgical platform should be used. The aim of this study was to compare the following outcomes between robot-assisted and laparoscopic CME-surgery for right-sided colonic cancer: (i) short-term clinical outcomes, (ii) pathological specimen quality, and (iii) long-term oncological outcomes.

METHODS

Medline, Embase, and Cochrane Database of Systematic Reviews were searched from inception until August 2021. Pooled proportions were calculated by applying the inverse variance method. Heterogeneity was explored by I-square and supplemented by sensitivity- and meta-regression analyses. The risk of bias was evaluated by either MINORS or Cochrane's risk-of-bias tool (RoB 2).

RESULTS

Fifty-five studies with 5.357 patients (740 robot-assisted and 4617 laparoscopic) were included in the meta-analysis. Overall postoperative morbidity was 17% [95% CI (14-20%)] in the robot-assisted group and 13% [95%CI (12-13%)] in the laparoscopic group. Robot-assisted CME was associated with a shorter hospital stay, lower intraoperative blood loss, a higher amount of harvested lymph nodes, and better 3-year oerall and disease-free survival. MINORS and RoB2 indicated a serious risk of bias across studies included.

CONCLUSIONS

This review which includes predominantly non-randomized studies suggests a possible advantage of the robot-assisted CME compared with a laparoscopic technique for several short-term outcomes.

Infrapyloric (No. 206) and greater curvature (No. 204) lymph node metastasis in adenocarcinoma located in the right half of the transverse colon (InCLART Study): protocol for a multicentre prospective observational study

INTRODUCTION

In the case of right-sided transverse colon cancer (RTCC) and hepatic flexure colon cancer (HFCC), there is a potential connection of lymph drainage between mesentery and greater omentum. However, most previous reports have been limited case series with No. 206 and No. 204 lymph node (LN) dissection for RTCC and HFCC.

METHODS AND ANALYSIS

The InCLART Study is a prospective observational study aiming to enrol 427 patients with RTCC and HFCC treated at 21 high-volume institutions in China. The prevalence of infrapyloric (No. 206) and greater curvature (No. 204) LN metastasis and short-term outcomes will be investigated in a consecutive series of patients with T2 or deeper invasion RTCC or HFCC, following the principle of complete mesocolic excision with central vascular ligation. Primary endpoints were performed to identify the prevalence of No. 206 and No. 204 LN metastasis. Secondary analyses will be used to estimate prognostic outcomes, intraoperative and postoperative complications, the consistency of preoperative evaluation and postoperative pathological results of LN metastasis.

ETHICS AND DISSEMINATION

Ethical approval for the study has been granted by the Ruijin Hospital Ethics Committee (approval number: 2019-081) and has been or will be approved successively by each participating centre's Research Ethics Board. The findings will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03936530; https://clinicaltrials.gov/ct2/show/NCT03936530).

Robotic colectomy with CME versus laparoscopic colon resection with or without CME for colon cancer: a systematic review and meta-analysis

INTRODUCTION

This systematic review with meta-analysis aimed to compare the robotic complete mesocolon excision (RCME) to laparoscopic colectomy (LC) with (LCME) or without CME (LC non-CME) in postoperative outcomes, harvested lymph nodes and disease-free survival.

METHODS

We performed a systematic review with meta-analysis according to PRISMA 2020 and AMSTAR 2 guidelines.

RESULTS

The literature search yielded seven comparative studies including 677 patients: 269 patients in the RCME group and 408 in the LC group. The pooled analysis concluded to a lower conversion rate in the RCME group (OR=0.17; 95% CI [0.04, 0.74], p=0.02). There was no difference between the two groups in terms of morbidity (OR=1.03; 95% CI [0.70, 1.53], p=0.87), anastomosis leakage (OR=0.83; 95% CI [0.18, 3.72], p=0.81), bleeding (OR=1.90; 95% CI [0.64, 5.58], p=0.25), wound infection (OR=1.37; 95% CI [0.51, 3.68], p=0.53), operative time (mean difference (MD)=36.32; 95% CI [-24.30, 96.93], p=0.24), hospital stay (MD=-0.94; 95% CI [-2.03, 0.15], p=0.09) and disease-free survival (OR=1.29; 95% CI [0.71, 2.35], p=0.41). In the subgroup analysis, the operative time was significantly shorter in the LCME group than RCME group (MD=50.93; 95% CI [40.05, 61.81], p<0.01) and we noticed a greater number of harvested lymph nodes in the RCME group compared with LC non-CME group (MD=8.96; 95% CI [5.98, 11.93], p<0.01).

CONCLUSIONS

The robotic approach for CME ensures a lower conversion rate than the LC. RCME had a longer operative time than the LCME subgroup and a higher number of harvested lymph nodes than the LC non-CME group.

Satisfactory short-term outcomes of totally laparoscopic ileostomy reversal compared to open surgery in colorectal cancer patients

Background

Recently, totally laparoscopic (TLAP) surgery has suggested its potential on ileostomy reversal. This study aimed to compare the short-term outcomes between TLAP and traditional open ileostomy reversal.

Patients and methods

From September 2016 to September 2021, 107 eligible patients underwent TLAP (n = 48) or open (n = 59) loop ileostomy reversal were retrospectively enrolled. Surgical parameters, postoperative recovery and complications were identified and compared between TLAP technique vs. open surgery.

Results

The operation time and estimated blood loss showed no obvious difference between TLAP and open group. However, TLAP reversal significantly decreased the incision length (4.5cm vs. 6cm, P < 0.001). Furthermore, patients underwent TLAP surgery showed quicker first ground activities (1 day vs. 2 days, P < 0.001), faster first flatus passage (2 days vs. 3 days, P = 0.004) and shorter postoperative stay (5 days vs. 7 days, P = 0.007). More importantly, postoperative complications were significantly reduced after TLAP reversal (3 cases vs. 10 cases, P = 0.026). Further logistic regression analyses also indicated the TLAP technique was associated with lower incidence of complications (OR=3.316, CI, 1.118-9.835; P = 0.031).

Conclusions

TLAP surgery is competitive in promoting postoperative recovery as well as reducing complications compared to the traditional open ileostomy reversal.

Colorectal infiltrating deep endometriosis: Laparoscopic treatment. A case report

Endometriosis is a disease affecting approximately 10% of women of fertile age. A particular presentation is deep infiltrating endometriosis of the rectosigmoid colon with symptoms that can mimic an intestinal obstruction or neoplasm. We report the case of a 39-year-old woman with pelvic pain during the menstrual cycle and significant anemia who presented an ectopic endometrial tissue in correspondence of the rectum. Because of the thickness of the lesion the patient underwent a segmental laparoscopic colorectal resection with end-to-end anastomosis.

Retroperitoneal mass, a rare manifestation of mucinous adenocarcinoma of appendix: A case report

The retroperitoneum (RP) might be affected by a variety of infections, inflammations, and tumors, including benign and malignant ones. Although primary malignant tumors are the most prevalent ones in this anatomic area, metastatic and invasive tumors rarely involve the retroperitoneum. Gastrointestinal stromal tumors (GISTs) are considered as the most common tumors that invade the retroperitoneum, but, to the best of our knowledge, it is the first time a surgery team has encountered the appendiceal tumor as a huge retroperitoneal mass. A 68-year-old man was referred to the emergency department with abdominal distension and weight loss. In his course of hospitalization, a huge right retroperitoneal mass was detected by a computed tomography (CT) scan; after that, the patient underwent laparotomy, evacuation of massive mucinous tissue located in the right retroperitoneum, and right hemicolectomy due to appendiceal tumor. The histopathological examination showed "mucinous appendiceal neoplasm." This is the first case study showing the invasion of an appendiceal tumor through the visceral peritoneum into the retroperitoneum, so an invasion of the peritoneal tumor to the retroperitoneum should be considered when a urologist approaches retroperitoneal masses.

Totally laparoscopic treatment of intestinal tuberculosis complicated with bowel perforation: The first case report in worldwide literature with a brief review

INTRODUCTION

Bowel perforation is a relatively rare presentation of abdominal tuberculosis, whose diagnosis is challenging but fundamental to minimize morbidity and mortality. Laparoscopy is considered an effective modality for diagnosis, but its role in surgical treatment is still not established. We reported the first worldwide case of totally laparoscopic treatment of intestinal tuberculosis complicated with bowel perforation.

CASE PRESENTATION

A 30-year-old man with a history of weight loss, preceded by 2 years of nonproductive cough, was admitted to the Infectious Disease Department with a presumed diagnosis of tuberculosis. A microbiological culture test confirmed the diagnosis, and the patient undertook quadruple antituberculous therapy. During hospitalization, he presented sudden abdominal pain, fever, and vomit. An abdominal CT scan showed small bowel perforation with granulomatous reaction. Laparoscopy was performed and revealed a 2 cm perforation on the medium ileum. Small bowel resection and totally intracorporeal side-to-side anastomosis were performed. No complication occurred until a clinical follow-up of 2 months.

CONCLUSION

In consideration of the increasing incidence of intestinal TB in both underdeveloped and Western countries, the diagnosis of this pathology should be taken into account in high-risk patients. Probably, the diagnostic challenges and emergency settings of intestinal TB with perforation and peritonitis, together with the lack of standardized guidelines regarding surgical management, make the use of laparoscopy apparently arduous, but the known advantages of laparoscopy and its technical feasibility should make it a conceivable option for the treatment of complicated cases.

Clinical implication of the advanced lung cancer inflammation index in patients with right-sided colon cancer after complete mesocolic excision: a propensity score-matched analysis

Background

This study aimed to assess the clinical implications of the advanced lung cancer inflammation index (ALI) in patients with right-sided colon cancer (RCC) after complete mesocolic excision (CME).

Methods

A total of 441 patients with RCC who underwent CME were included. The optimal cut-off value for the ALI was determined using the X-tile software. Logistic and Cox regression analyses were used to identify risk factors for postoperative complications and long-term outcomes. Predictive nomograms for overall survival (OS) and disease-free survival (DFS) were constructed after propensity score matching (PSM), and their performance was assessed using the net reclassification improvement index (NRI), integrated discrimination improvement index (IDI), and time-dependent receiver operating characteristic (time-ROC) curve analysis.

Results

The optimal preoperative ALI cut-off value was 36.3. After PSM, ASA classification 3/4, operative duration, and a low ALI were independently associated with postoperative complications in the multivariate analysis (all P<0.05). Cox regression analysis revealed that an age >60 years, a carbohydrate antigen 19-9 (CA19-9) level >37 U/mL, pathological N+ stage, and a low ALI were independently correlated with OS (all P<0.05). A CA19-9 level >37 U/mL, pathological N+ stage, lymphovascular invasion, and a low ALI were independent predictors of DFS (all P<0.05). Predictive nomograms for OS and DFS were constructed using PSM. Furthermore, a nomogram combined with the ALI was consistently superior to a non-ALI nomogram or the pathological tumor-node-metastasis classification based on the NRI, IDI, and time-ROC curve analysis after PSM (all P<0.05).

Conclusion

The ALI was an effective indicator for predicting short- and long-term outcomes in patients with RCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02712-0.

Complete mesocolic excision in comparison with conventional surgery for right colon cancer: a nationwide multicenter study of the Italian Society of Surgical Oncology colorectal cancer network (CoME-in trial). Study protocol for a randomized controlled trial

Complete mesocolic excision with central vascular ligation, or simply CME, includes the sharp dissection along the mesocolic visceral and parietal layers, with the ligation of the main vessels at their origins. To date, there is low evidence on its safety and efficacy. This is a study-protocol of a multicenter, randomized, superiority trial in patients with right-sided colon cancer. It aims to investigate whether the complete mesocolic excision improves the oncological outcomes as compared with conventional right hemicolectomy, without worsening early outcomes. Data on efficacy and safety of complete mesocolic excision are available only from a large trial recruiting eastern patients and from a low-volume single-center western study. No results on survival are still available. For this reason, complete mesocolic excision continues to be a controversial topic in daily practice, particularly in western world. This new nationwide multicenter large-volume trial aims to provide further data on western patients, concerning both postoperative and survival outcomes.

The SAGES MASTERS program presents: the 10 seminal articles for the Laparoscopic Right Colectomy Pathway

BACKGROUND

As one of the 12 clinical pathways of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Masters Program, the Colorectal Pathway intends to deliver didactic content organized along 3 levels of performance (competency, proficiency and mastery) each represented by an anchoring procedure (laparoscopic right colectomy, laparoscopic left/sigmoid colectomy, and intracorporeal anastomosis during minimally invasive (MIS) ileocecal or right colon resection). In this article, the SAGES Colorectal Task Force presents focused summaries of the top 10 seminal articles selected for laparoscopic right colectomy which surgeons should be familiar with.

METHODS

Using a systematic literature search of Web of Science, the most cited articles on laparoscopic right colectomy were identified, reviewed, and ranked by the SAGES Colorectal Task Force and invited subject experts. Additional articles not identified in the literature search were included if deemed impactful by expert consensus. The top 10 ranked articles were then summarized, with emphasis on relevance and impact in the field, findings, strengths and limitations, and conclusions.

RESULTS

The top 10 seminal articles selected for the laparoscopic right colectomy anchoring procedure include articles on surgical techniques for benign and malignant disease, with anatomical and video illustrations, comparative outcomes of laparoscopic vs open colectomy, variations in technique with impact on clinical outcomes, and assessment of the learning curve.

CONCLUSIONS

The top 10 seminal articles selected for laparoscopic right colectomy illustrate the diversity both in content and format of the educational curriculum of the SAGES Masters Program to support practicing surgeon progression to mastery within the Colorectal Pathway.

Lymph node recurrence after right colon resection for cancer: evidence for the utilisation of complete mesocolic excision

Complete mesocolic excision (CME) of colon cancer is a resection performed along embryological planes to include the completely intact mesentery surrounding the tumour with a high central vascular ligation. The aim is to remove all lymph nodes draining the cancer. Proponents of the technique cite the significantly decreased local recurrence and improved 5-year survival rates associated with CME versus conventional colectomy. Although increasingly performed in many centres, it has not yet gained widespread acceptance as it is technically more challenging and can incur an increased bleeding risk. A man in his 80s underwent a conventional right hemicolectomy for a pT4aN2aM0 ascending colon cancer at another institution. This was followed by chemotherapy. He presented to our institution 2 years later with an isolated 3.7×3.2 cm mesenteric tumour adjacent to his anastomosis. There was no intraluminal recurrence. He then underwent a repeat extended right colectomy with CME. Pathology confirmed lymph node recurrence. His case demonstrates the importance of CME in reducing carcinoma recurrence risk.

Analysis of 20 patients with laparoscopic extended right colectomy

BACKGROUND

Currently, the standard surgical procedure for right colon cancer is complete mesocolic excision. Whether preventive extended lymph node dissection for colon cancer located in the hepatic flexure or right transverse colon should be performed remains controversial because the safety and effectiveness of the operation have not been proven, and infrapyloric lymph nodes (No. 206) and lymph nodes in the greater curvature of the stomach (No. 204) have not been strictly defined and distinguished as surgical indicators in previous studies.

AIM

To analyze the metastatic status of infrapyloric lymph nodes and lymph nodes of the greater curvature of the stomach and perioperative complications and systematically evaluate the feasibility and safety of laparoscopic extended right colectomy using prospective data collected retrospectively.

METHODS

The study was a clinical study. Twenty patients with colon cancer who underwent laparoscopic extended right colon resection in our hospital from June 2020 to May 2021 were included.

RESULTS

Among the patients who underwent extended right colon resection, there were no intraoperative complications or conversion to laparotomy; 2 patients had gastrocolic ligament lymph node metastasis, and 5 patients had postoperative complications. The patients with postoperative complications received conservative treatment.

CONCLUSION

Laparoscopic extended right colon resection is safe. However, malignant tumors located in the liver flexure or the right-side transverse colon are more likely to metastasize to the gastrocolic ligament lymph nodes, and notably, the incidence of gastroparesis was high. The number of patients was small, and the follow-up time was short. It is necessary to further increase the sample size to evaluate the No. 204 and No. 206 lymph node metastasis rates and the long-term survival impact.

Prediction of prolonged resolution of chylous ascites after radical D3 resection for colorectal cancer: A population-based experience from a high-volume center

AIM

This study was aimed to analyze the incidence, risk factors, and management of chylous ascites (CA) after radical D3 resection for colorectal cancer, and to construct a predicting nomogram for prolonged resolution of CA.

METHOD

Consecutive colorectal cancer patients who underwent radical D3 resection were included. Logistic analysis was used to identify risk factors of postoperative CA, as well as prolonged CA resolution. A predictive nomogram for prolonged resolution of CA was developed and validated internally.

RESULTS

Among 7167 patients included, 277 (3.8%) patients developed CA. Logistic regression analysis demonstrated that laparoscopic operation (OR 1.507; P = 0.017) and tumors fed by the superior mesenteric artery (SMA, OR 2.456; P < 0.001) were independent risk factors of postoperative CA following radical D3 surgery for colorectal cancer. Open operation (OR 0.422; P = 0.027), drainage output on the first day of treatment (OR 1.004; P = 0.016), time to oral intake (OR 1.273; P = 0.042), and time to onset (OR 1.231; P = 0.024) were independently associated with prolonged resolution of postoperative CA (≥7 days). A predictive nomogram for prolonged CA resolution was developed with a C-index of 0.725.

CONCLUSION

The incidence of CA after radical D3 surgery of colorectal cancer was 3.8%. Open operation, drainage output on the first day of treatment, time to oral intake, and time to onset were independently associated with prolonged resolution of postoperative CA. A nomogram may assist in tailored treatment decision-making and counseling patient with treatment strategies.

Automated segmentation by deep learning of loose connective tissue fibers to define safe dissection planes in robot-assisted gastrectomy

The prediction of anatomical structures within the surgical field by artificial intelligence (AI) is expected to support surgeons’ experience and cognitive skills. We aimed to develop a deep-learning model to automatically segment loose connective tissue fibers (LCTFs) that define a safe dissection plane. The annotation was performed on video frames capturing a robot-assisted gastrectomy performed by trained surgeons. A deep-learning model based on U-net was developed to output segmentation results. Twenty randomly sampled frames were provided to evaluate model performance by comparing Recall and F1/Dice scores with a ground truth and with a two-item questionnaire on sensitivity and misrecognition that was completed by 20 surgeons. The model produced high Recall scores (mean 0.606, maximum 0.861). Mean F1/Dice scores reached 0.549 (range 0.335–0.691), showing acceptable spatial overlap of the objects. Surgeon evaluators gave a mean sensitivity score of 3.52 (with 88.0% assigning the highest score of 4; range 2.45–3.95). The mean misrecognition score was a low 0.14 (range 0–0.7), indicating very few acknowledged over-detection failures. Thus, AI can be trained to predict fine, difficult-to-discern anatomical structures at a level convincing to expert surgeons. This technology may help reduce adverse events by determining safe dissection planes.