Complete Mesocolic Excision Surgery Research Articles

Laparoscopic complete mesocolic excision in colon cancer: a prospective cohort study

Introduction: Compared to conventional colon cancer surgery, laparoscopic complete mesocolic excision (CME) increases the likelihood of lymph node dissection. However, this surgery is not yet considered a safe strategy. The authors study this topic to evaluate the safety and feasibility of this surgery. Methods: A prospective cohort study was performed on patients undergoing laparoscopic CME surgery at the Hue University of Medicine and Pharmacy Hospital and Hue Central Hospital. Results: Demographic data, surgical features, and postoperative complications. Evaluate different clinicopathological factors determining the number and distribution of lymph nodes; and the rate of lymph node metastasis by tumor location and lymph node groups. Three-year overall survival and disease-free survival follow-up after surgery. Conclusion: The results of laparoscopic CME colectomy surgery are safe, with a reliable maximum number of harvested nodes.

Technical assessment in minimally invasive complete mesocolic excision: Is the complete mesocolic excision competency assessment tool valid and reliable?

The complete mesocolic excision competency assessment tool (CMECAT) is a novel tool designed to assess technical skills in minimally invasive complete mesocolic excision (CME) surgery. The aim of this study was to assess construct validity and reliability of CMECAT in a clinical context. Colorectal surgeons were asked to submit video recorded laparoscopic CME resections for independent assessment of their technical abilities. The videos were grouped by surgeons' training level, and four established CME experts were recruited as CMECAT assessors. Extended reliability analysis (G-theory) was applied to describe assessor agreement. A total of 19 videos and 72 assessments were included in the analysis. Overall, technical skills assessed by CMECAT improved with increased training level: the experts scored significantly better than the untrained surgeons (3.3 vs. 2.5 points; p < 0.01). On right-sided resections, significantly higher scores were reported with increased training level for all categories and sections, while for left-sided resections, the variance across groups was smaller and significantly higher scores were only reported for oncological safety describing items. Overall, assessor agreement was high (G-coefficient: 0.81). This study confirms that CMECAT can be applied to video recorded CME cases for technical skill assessment. Further, it can reliably assess technical performance in right sided CME surgery, where construct validity has now been established. More videos are required to evaluate its validity on left colonic CME. In the future, we hope CMECAT can improve feedback during CME training, serve as a tool in certification processes and contribute to distinguishing CME from conventional surgery in future research.

Complete Mesocolic Excision (CME) versus Conventional RT Hemicolectomy (CRH) in Patients with Right Sided Colon Cancer: A Systematic Review and Meta-Analysis

Abstract Background We live in an era with improved worldwide average living standards and increased access to adequate healthcare that has considerably improved the diagnosis and treatment of diseases. These measures have had an impact on average life expectancy in most regions of the world. Aim of the Work The aim of this study is to perform a systematic review and meta-analysis to investigate safety and long-term out- comes of Complete Mesocolic Excision (CME) Versus Conventional RT Hemicolectomy (CRH) in patients with right sided colon cancer. Materials and Methods This study is a systematic review and meta-analysis. Literature search, study design, and data analysis were performed following PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. Five medical databases were used in this research: MEDLINE, Cochrane Database of Systematic Reviews, Scopus, Web of Science, and Embase. The keyword was as follows: ―complete mesocolic excision.‖ I select studies published up to December 2020. I select only articles written in English and we did not include abstracts or unpublished data. After literature search, 30 studies have been recorded. Screening by titles and abstracts led to the identification of 20 possibly relevant articles. Of these records, 8 studies were excluded because patients with distal transverse and/or left colon cancer were also evaluated. Moreover, in 3 studies, only the most recently record was selected. Lastly, 8 studies, published between 2010 and 2020, met inclusion criteria. All selected studies were observational; 4 of them were prospective. Overall, 1762 patients were enrolled in qualitative and quantitative analysis, 700 in the CME group and 1062 in the CRH group. Results Postoperative complications were reported in 9 studies showing that no difference was observed between techniques. Six studies separately analyzed surgical and non-surgical postoperative complications. No significant variation was reported between the 2 groups in the 2 different types of complications (surgical complications OR 1.09, 95% CI 0.72–1.63, p = 0.69, no surgical complications OR 1.37, 95% CI 0.79–2.36, p = 0.26, respectively). No significant difference was al- so observed between the two groups in terms of anastomotic leakage, while a significant negative median was reported for intraoperative bleeding in favor of CME group. 4 studies evaluated the procedure time which was significantly shorter for CRH, although heterogeneity levels among studies was high. The analysis of postoperative length of stay showed no difference between the two groups of patients. Number of lymph node yield was reported in 8 studies. The pooled analysis of 1762 patients found a positive median retrieval of 9.17 in CME group. High heterogeneity among the included studies was detected. Seven studies reported data of 3-year OS with a significant OS benefit in CME group. This data was characterized by moderate between-study heterogeneity. Furthermore, 76.4% of patients undergoing CME surgery were alive at 5 years, compared with 68.2% of CRH. Meta-analysis of 3 studies reporting 5-year DFS con- firmed the significant DFS benefit for patients undergoing CME. No significant heterogeneity was observed between the 3 studies. Conclusion My study confirm that CME with CVL associated with D3 lymphadectomy in right-side colon cancer improved not only staging but also prognosis, particularly in II and III stage; CME was a significant independent predictive factor for disease-specific survival at 3 years and 5 years compared with CRH associated with D2 lymphadectomy. CME is a safe and reproducible procedure with acceptable morbi-mortality.

Results of Laparoscopic Surgery and D3 Lymph Node Dissection Combined With Chemotherapy for the Radical Treatment of Advanced-Stage Right Colon Cancer: A Single-Center Observational Study in Vietnam.

To describe the results of laparoscopic surgery and D3 lymph node dissection combined with adjuvant chemotherapy (ACT) for the treatment of advanced-stage right colon cancer (stages II and III). A total of 172 right colon cancer patients (with tumour, node, and metastasis (TNM) stage II and III; mean age of 59.30±14.27 years; 58.1% male, 41.9% female)who had undergone complete mesocolic excision (CME) with D3 lymph node dissection at Nguyen Tri Phuong Hospital,Ho Chi Minh City, Vietnam, were included in this study. They were divided into two groups: group 1 (n=34) without ACT and group 2 (n=138) with ACT. We collected clinical and laboratory data twice (before and after one year of performing laparoscopic surgery). Rates of recurrence and mortality were obtained during a five-year follow-up. After one year of surgery, the rate of anemia and the increase in serum carcinoembryonic antigen (CEA) levels in group 1 were significantly higher than those in group 2 (p<0.001). After five years of follow-up, the recurrence rate was 11.6% (that of group 1 was 41.2%, which is higher than that of group 2, i.e., 4.3%; p<0.001), and the mortality rate was 8.7% (that of group 1 was 32.4%, which is higher than that of group 2, i.e., 2.9%; p<0.001). Preoperative serum CEA levels were predictive of recurrence and mortality, with an area under the curve (AUC) of 0.729 and 0.805, respectively (p<0.001). Laparoscopic CME surgery and D3 lymph node dissection combined with ACT reduced the five-year recurrence and mortality rates for advanced-stage right colon cancer patients.

Splenic flexure cancer survival: a 25-year experience and implications for complete mesocolic excision (CME) and central vascular ligation (CVL).

The management of splenic flexure cancers (SFCs) in the era of complete mesocolic excision (CME) and central vascular ligation (CVL) is challenging because of its variable lymphatic drainage. This study aimed to compare survival outcomes for SFCs and non-SFCs, and better understand the clinicopathological characteristics which may define a distinct SFC phenotype. An observational cohort study at Concord Hospital, Sydney was conducted with patients who underwent resection for colon adenocarcinoma (1995-2019). Clinicopathological data were extracted from a prospective database. Overall survival (OS) and disease-free survival (DFS) estimates and their associations to clinicopathological variables were investigated with Kaplan-Meier and Cox regression analyses. Of 2149 patients with colon cancer, 129 (6%) had an SFC. The overall 5-year OS and DFS rates were 63.6% (95% CI 62.5-64.7) and 59.4% (95% CI 58.3-60.5), respectively. SFCs were not associated with OS (P = 0.6) or DFS (P = 0.5). SFCs were more likely to present urgently (P < 0.001) with obstruction (P < 0.001) or perforation (P = 0.03), and more likely to require an open operation (P < 0.001). These characteristics were associated with poorer survival outcomes. No differences were noted between SFCs and non-SFCs with respect to tumour stage (P = 0.3). SFCs have a distinct phenotype, the individual characteristics of which are associated with poorer survival. However, the survivals of SFCs and non-SFCs are similar, possibly because the most important determinant of outcome, tumour stage, is no different between the groups. This may have implications for the surgical approach to SFCs with respect to standardization of CME and CVL surgery for these cancers.

Laparoscopic Complete Mesocolic Excision Without Routine Gastro-Pancreatico-Colic Trunk Dissection: Survival Outcomes and Morbidity for 567 Cases.

Purpose: It is unclear whether the principles of open complete mesocolic excision (CME) can be safely applied to laparoscopic surgery. Furthermore, definitions vary over how radical optimal CME surgery should be. We report morbidity and oncological outcomes for laparoscopic CME without routine gastro-pancreatico-colic trunk (GPCT) dissection. Materials and Methods: An observational study with consecutive data for patients with Union for International Cancer Control (UICC) stage I-III colon adenocarcinoma who underwent elective laparoscopic resection between 2006 and 2015. Data were retrieved for demographics, tumor characteristics, treatment, and histology from prospectively maintained databases. Standardized, routinely video recorded, laparoscopic resections were performed in two United Kingdom centers from The National Training Programme for Laparoscopic Colorectal Surgery. Overall survival and disease-free survival (DFS) were reported using Kaplan-Meier curves and Cox regression. Results: Laparoscopic CME was performed in 567 patients, 52.7% (288/546) women, median (interquartile range [IQR]) age 73 (65-80) years. Median (IQR) length of stay was 4 (3-5) days with 4.0 (2.2-5.7)-year follow-up. Significant DFS predictors (hazard ratio [HR]) by multivariable Cox regression were age >80 years (1.9), American Society of Anesthesiologists (ASA) 3 and 4 (HR = 1.1), right colon cancer (1.7), UICC stage III (3.4), and intramesocolic grade (2.2). Overall 4-year DFS (95% confidence interval) was 81.3% (77-85). Four-year DFS by UICC grades I, II, and III was 94.6% (89-99), 83.4% (77-88), and 72.2% (66-78), respectively (log-rank P = .001). Morbidity by Clavien-Dindo grade was III 18 (3.2%), IV 4 (0.7%) and V 7 (1.2%). Conclusion: This large series suggests standardized laparoscopic CME without routine GPCT dissection has a low morbidity and achieves equivalent outcomes to the most radical open CME techniques.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study.

Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO). Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants. Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n=65; median score 8/14] vs. AMIGO [n=65; median score 6/14; p<0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging. 3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

Clinical analysis of metastatic characteristics of infrapyloric lymph nodes (No.206) and terminal ileum lymph nodes in patients with right colon cancer

BackgroundD3 or complete mesocolic excision (CME) surgery has become a common surgical procedure for the treatment of colon cancer metastasis. Clinical misuse and overuse of lymph node dissection bring unnecessary burdens to patients. A detailed guidance for lymph node dissection in patients with T3 and T4 stage right colon cancer at different locations is urgently needed.MethodsA retrospective study was performed. Patients received D3 or CME surgery were divided into ileocecal group, ascending colon group, and hepatic flexure group according to the 9th edition of the Japanese Society for Cancer of the Colon and Rectum guidelines. The distributions of lymph node metastases were analyzed according to tumor infiltration depth (T stage) and tumor location.ResultsThe incidence of metastases in the paracolic area (or station), intermediate area, and main (or central) area was 38.4% (139/362), 12.7% (46/362), and 9.7% (35/362), respectively. The proportion of patients having No.206 and terminal ileum lymph nodes metastases was 7.7% (14/181) and 3.7% (9/244), respectively. No.206 lymph node metastasis is related to tumor location (χ2 = 7.955, p = 0.019) and degree of differentiation (χ2 = 18.99, p = 0.000), and terminal ileum lymph node metastasis is related to tumor location (χ2 = 6.273, p = 0.043). Patients with T3/T4 hepatic flexure cancer received radical right hemicolectomy in addition to No.206 lymph node dissection.ConclusionRadical right hemicolectomy and No.206 group lymph node dissection are necessary for T3 and T4 stage colon cancer therapy.

Routine CT evaluation of central vascular ligation in patients undergoing complete mesocolic excision for sigmoid colon cancer.

Objective and reproducible quality measures of complete mesocolic excision (CME) for colon cancer are not currently available. This study aimed to measure the inferior mesenteric stump length following CME for sigmoid colon cancer and explore surgical, pathological and oncological outcomes in patients with a stump length of <10mm vs. ≥10mm. This was a single-centre, retrospective cohort study including patients undergoing minimally invasive surgery for sigmoid colon cancer between May 2013 and May 2015. Follow-up CT scans were reviewed, and a vascular stump cut-off of <10mm for adequate central ligation of the inferior mesenteric artery was applied. Differences in perioperative, histopathological and oncological outcome parameters (overall, disease-free and recurrence-free survival) were explored between <10mm vs. ≥10mm groups. A total of 127 patients (43% female) with a median age of 68years were included. The median follow-up time was 68months. CT measurements showed good interrater agreement (90% absolute agreement) and reliability among raters (kappa=0.77, 95% CI 0.53-1.00, p<0.001). A stump length ≥10mm was associated with longer operating time (150 vs. 180min, p=0.021), intramesocolic resection (p=0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102mm, p=0.005). An arterial stump length ≥10mm in sigmoid resection for colon cancer was associated with key clinical quality measures. Measurement of arterial stump length using routine follow-up CT may serve as a quality indicator of vascular ligation in CME surgery.

Complete mesocolic excision and D3 lymphadenectomy with central vascular ligation in right-sided colon cancer: a systematic review of postoperative outcomes, tumor recurrence and overall survival.

In right-sided colon cancer surgery, currently there is a great deal of discussion and debate regarding complete mesocolic excision (CME) versus conventional right hemicolectomy (CRH) on postoperative outcomes and oncological results. Our aim was to perform a systematic review of the short- and long-term outcomes of CME to standardize surgical approach in patients with right-sided colon cancer. A systematic review was performed examining available data on randomized and non-randomized studies evaluating the role of CME and D3 lymphadenectomy in the treatment of right-sided colon cancer, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards. After literature search, 919 studies have been recorded, 110 studies underwent full-text reviews and 30 studies met inclusion criteria. The total number of CME procedures was 5931. Postoperative complications was reported in 28 studies with pooled overall complications of 1.88% for CME surgery. Six studies reported 0% of overall postoperative complications and they demonstrated a low incidence of complications following CME procedure. Anastomotic leak was reported in 27 studies with pooled proportion of 0.92% after CME resections. There were 16 papers reporting overall survival following CME procedure, with a mean of 85% of patients survived at 5 years. Mean 5-year overall survival was 93.05% in stage I patients, 89.76% in stage II patients and 79.65% in stage III patients. Local and distant recurrence were included in 21 studies, reporting tumor recurrence rate of 12.25% following CME. 5-year tumor recurrence was 5.8% in stage I patients, 7.68% in stage II patients and 15.69% in stage III patients. CME does not increase the risk of postoperative complications and significantly improves the long-term oncological impact. Prospective multicentre studies results are needed to verify if CME could be considered standard surgery for right colon cancer.

Oncological outcomes after complete mesocolic excision in right-sided colon cancer: a population-based study.

Complete mesocolic excision (CME) has been proposed as the preferred surgical technique for resection of colon cancer. This prospective cohort study evaluates the effect of CME surgery on colon cancer mortality after right-sided hemicolectomy on a population level. Data from the Swedish Colorectal Cancer Registry and the Cause of Death Registry on all patients treated with elective right-sided hemicolectomy for colon cancer Stages I-III in the Stockholm County 2008-2012 were analysed. Adherence to principles of CME surgery was determined by structured analysis of anonymized surgical reports regarding the presence of five essential features. The exposure to CME was graded as group 0 (not exposed to CME), group 1 (intermediate) and group 2 (exposed to CME). In total, 1171 patients were analysed with 234 (20.0%) patients in CME group 0, 453 (38.7%) patients in CME group 1 and 484 (41.3%) in CME group 2. The 5-year colon cancer mortality was 20.2% in CME group 0, 13.9% in CME group 1 and 13.1% in CME group 2 (P=0.026). The adjusted hazard ratio for colon cancer mortality was 0.61 (95% CI 0.42-0.91; P=0.014) for CME group 1 and 0.52 (95% CI 0.35-0.77; P=0.001) for CME group 2. The presence of predefined CME features in surgical reports was related to a graded benefit on cancer-specific mortality after right-sided hemicolectomy for colon cancer Stages I-III.

Robotic Complete Mesocolic Excision (CME) is a safe and feasible option for right colonic cancers: short and midterm results from a single-centre experience

BackgroundComplete mesocolic excision (CME) for right colon cancers has traditionally been an open procedure. Surgical adoption of minimal access CME remains limited due to the technical challenges, training gaps and lack of level-1 data for proven benefits. Currently there is limited published data regarding the clinical results with the use of robotic CME surgery. Aim To report our experience, results and techniques, highlighting a clinical and oncological results and midterm oncological outcomes for robotic CME.AimTo report our experience, results and techniques, highlighting a clinical and oncological results and midterm oncological outcomes for robotic CME.MethodsAll patients undergoing standardised robotic CME technique with SMV first approach between January 2015 and September 2019 were included in this retrospective review of a prospectively collected database. Patient demographics, operative data and clinical and oncological outcomes were recorded.ResultsSeventy-seven robotic CME resections for right colonic cancers were performed over a 4-year period. Median operative time was 180 (128–454) min and perioperative blood loss was 10 (10–50) ml. There were 25 patients who had previous abdominal surgery. Median postoperative hospital stay was 5 (3–18) days. There was no conversion to open surgery in this series. Median lymph node count was 30 (10–60). Three (4%) patients had R1 resection. There was one (1%) local recurrence in stage III disease and 4(5%) distal recurrence in stage II and stage III. There was no 30- or 90-day mortality. Three-year disease-free survival was 100%, 91.7% and 92% for stages I, II and III, respectively. Overall survival was 94%.ConclusionsRobotic CME is feasible, effective and safe. Good oncological results and improved survival are seen in this cohort of patients with a standardised approach to robotic CME.

Oncological reasons for performing a complete mesocolic excision: a systematic review and meta-analysis.

While complete mesocolic excision (CME) has been shown to have an oncological benefit as compared to conventional colonic surgery for colon surgery, this benefit must be weighed up against the risk of major intra-abdominal complications. This paper aimed to assess the comparative oncological benefits of CME. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature until May 2020 was performed. Comparative studies assessing CME versus conventional colonic surgery for colon cancer were compared, and outcomes were pooled. A total of 700 publications were identified, of which 19 were found to meet the inclusion criteria. A total of 25 886 patients were compared, with 14 431 patients in the CME arm. CME was associated with a significantly higher rate of vascular injury (odds ratio 3, P < 0.001). Rates of local and distant recurrence were lower in the CME group (odds ratio 0.66 and 0.73, respectively, both P < 0.001). CME patients had a significantly higher lymph node yield (P < 0.001). While no significant differences were noted between the two groups in terms of pooled 3- or 5-year disease-free survival, pooled 5-year overall survival was significantly higher in the CME group (relative risk 0.82, P < 0.001). Based on the available evidence, CME is associated with improved oncologic outcomes at the expense of higher complication rates, including vascular injury. The oncological benefits need to weighed up against a multitude of factors including the level of hospital support, surgeon experience, patient age, and associated comorbidities.

Clavien-Dindo classification of complications after complete mesocolic excision in laparoscopic radical resection of right hemicolon cancer and analysis on its influencing factors

Objective: To investigate the Clavien-Dindo (CD) classification of complications after complete mesocolic excision (CME) in laparoscopic radical resection of right-sided hemicolon cancer and its influencing factors. Methods: A retrospective case-control study was performed. Inclusion criteria: (1) the adenocarcinoma located at colon from cecum to hepatic flexure; (2) laparoscopic right hemicolectomy with CME was completed. Exclusion criteria: (1) patients had severe organ dysfunction before operation; (2) tumor invaded adjacent organs or developed distant organ metastasis; (3) emergency surgery; (4) failure of laparoscopic surgery, and conversion to laparotomy; (5) without complete clinical data. Finally, clinical data of 141 patients in our hospital form March 2015 to February 2019 were retrospectively analyzed. CD grading standard was used to evaluate postoperative complications. Univariate and multivariate logistic regression analyse were used to analyze the factors that might affect the complications. Survival analysis was conducted by grouping the indicators with statistically significant difference in multivariate analysis. Kaplan-Meier method was used to draw the survival curve and log-rank test was used to analyze the difference. Results: Of the 141 patients, 89 were male and 52 were female with mean age of (61.8±11.0) years. All the operations completed successfully. A total of 37 postoperative complications were developed in 26 (18.4%) patients had postoperative 37 cases of complications, mainly including 7 delayed incision healing, 6 diarrhea, and 5 respiratory dysfunction. According to CD classification standard, grade I, II, and IV a complication rates were 40.5% (15/37), 56.8% (21/37), and 2.7% (1/37) respectively. Univariate analysis showed that age ≥ 65 years (χ(2)=4.338, P=0.037), BMI ≥ 28 kg/m(2) (χ(2)=5.971, P=0.015), and preoperative hemoglobin < 100 g/L (χ(2)=3.985, P=0.046) were risk factors of postoperative complications. Multivariate analysis testified that age ≥ 65 years (OR=7.991, 95%CI: 2.203 to 28.983, P=0.002) and body mass index (BMI) ≥ 28 kg/m(2) (OR=4.231, 95%CI: 1.034 to 17.322, P=0.045) were independent risk factors for complications after laparoscopic CME surgery for right-sided hemicolon cancer. All the patients were followed up for median time of 24 (1-48) months. The log-rank test showed that there were no significant differences in the cumulative survival rate between patients of age < 65 years and age ≥ 65 years (χ(2)=0.986, P=0.321), and between those with BMI < 28 kg/m(2) and BMI ≥ 28 kg/m(2) (χ(2)=0.370, P=0.543). Conclusions: The main complications after CME in laparoscopic radical resection of right hemicolon cancer are CD grade I and II. Elderly and obesity are independent risk factor for postoperative complications. Before the operation, reasonable preventive measures should be taken for the elderly and the obese in order to reduce postoperative complications.

Laparoscopic Right Hemicolectomy with Complete Mesocolic Excision (CME)

Complete mesocolic excision (CME) is considered as good clinical practice according to the German S3 Guideline for colorectal cancer. This recommendation is based on evidence showing improved histopathological quality criteria of specimens taken and better oncological outcomes following CME surgery compared to conventional colon resections. However, CME surgery, especially of the right colon, is more complex - due to the high variability of the vascular structures (e.g. Truncus Henle) and the anatomical proximity to the stomach, duodenum and pancreas. To increase safety of laparoscopic right hemicolectomy with CME and to improve surgical education of this procedure, a German expert group has developed a standardised procedure with critical safety assessment. This video shows the technique of laparoscopic right hemicolectomy with complete mesocolic excision (CME), according to the concept first described by the German expert group on Lap-CME. Carcinoma of the ascending colon. Laparoscopic right hemicolectomy with complete mesocolic excision (CME). The proposed standardisation of laparoscopic right hemicolectomy with complete mesocolic excision accommodates the increased complexity of the right colon and structures it into well-defined steps with critical safety assessments, which may result in minimised intraoperative complications and increased patient safety and should improve training.

Recognition of the interstitial plane of the surgical membrane in radical resection of right semicolon cancer

According to multicenter randomized controlled trials, laparoscopic radical resection of colon cancer has the same short and long term clinical efficacy as traditional open surgery. In laparoscopic radical resection of right semicolon cancer, it is important to separate the embryonic plane of the root, and to ligate and cut off the central vascular roots. Only by separation along the membrane space can one achieve minimally invasive operation with no bleeding, and ensure the integrity of the excision of the mesangium and avoid damage of internal fascia and other organs. The mesangial distribution of the right semicolon is adjacent to the mesangium of the stomach and is connected to the mesentery of the small intestine. The pancreaticoduodenum locates between the right semicolon mesentery and the retroperitoneal subperitoneal fascia. In particular, the relationship between the anterior and posterior Treitz fascia of the pancreaticoduodenum and the Toldt space is complex, which is closely related to the feasibility of complete mesocolic excision(CME). This article introduces the distribution of intermembranous space and mesangial bed in the right semicolon, presenting the problem in CME surgery. In addition, there are key points in identifying the gap between the membranes based on the author's experience and we propose a new evaluation criteria for membrane surgical specimens, which has certain guiding significance for radical CME surgery for right semicolon cancer.

Oncological outcomes of complete versus conventional mesocolic excision in laparoscopic right hemicolectomy.

Complete mesocolic excision (CME) has been proposed for colon cancer to improve oncological outcomes. The risks and benefits of laparoscopic CME have not been examined fully. We compared short- and long-term outcomes of CME with a conventional mesocolic excision (non-CME) in laparoscopic right hemicolectomy (RHC) for right-sided colon cancer. In total, 115 patients who underwent laparoscopic RHC with stage I-III right-sided colon cancer at Busan Paik Hospital from August 2007 to October 2011 were enrolled in this case-control study. Three trained colorectal surgeons reviewed videos of the surgeries; patients were divided into two groups: those who underwent a CME (CME group, n = 34) and those who underwent a conventional mesocolic excision (non-CME group, n = 81). There was no significant difference between the CME and non-CME groups in operative time, post-operative complications, or hospital stay. However, the CME group had more lymph nodes harvested (P < 0.001) and lower blood loss (P = 0.016) versus the non-CME group. There was no difference in 5-year disease-free survival rate between the groups, but 5-year overall survival rate was 100% in the CME group and 89.49% in the non-CME group (P < 0.05). Laparoscopic RHC with CME is safe and associated with better 5-year overall survival rate than non-CME for patients with stage I-III right-sided colon cancer. Implementation of CME surgery might improve oncological outcomes for patients with right-sided colon cancer.

Complete mesocolic excision in right-sided colon cancer does not increase severe short-term postoperative adverse events.

The aim was to assess whether complete mesocolic excision (CME) in patients with right-sided colon cancer is related to short-term mortality or postoperative adverse events requiring reoperation. The complete mobilization of an integral mesocolon and central ligation of blood vessels are essential steps in CME surgery. The resultant specimen, with an intact mesocolic fascia and a high number of harvested lymph nodes, is believed to be oncologically favourable. However, it has been suggested that CME surgery may increase the risk of intra-operative severe adverse events, due to exposure of vital retroperitoneal organs and large blood vessels. In a population-based, nested case-control study, all residents in the Stockholm County operated for right-sided colon cancer from 2004 until 2012 were identified from the Swedish Colorectal Cancer Registry. Patients who died within 90days after surgery or were reoperated within 30days after surgery, or during the index hospital stay, were defined as cases. Two controls per case were randomly sampled and individually matched for age, sex, TNM stage and emergency vs elective surgery. Exposure status (CME surgery) was assessed from original surgical reports. The estimated proportion of CME surgery was 14.8% (35 of 236) for cases and 19.5% (92 of 473) for controls. The unadjusted OR for short-term mortality or reoperation after CME surgery was 0.72 (95% CI: 0.47-1.10; P=0.15). The ORs were lower in the late part of the study (0.51; 95% CI: 0.26-1.01) and in high volume hospitals (0.61, 95% CI: 0.35-1.06). The present study does not indicate that CME surgery is associated with an increased risk of severe adverse events such as 90-day mortality or reoperation.

CME or traditional surgery for right-sided colon cancer?

One of the big controversies in colorectal cancer research is whether complete mesocolic excision (CME) offers a benefit for patients with carcinoma of the right colon or whether it might even harm these patients. A randomized trial to clarify this question has often been advocated. However, setting up such a trial is hampered by a major problem, which is mainly related to the difficulty of defining a standardized control group. First, there is no consensus of a standard non-CME hemicolectomy. Second, a surgeon who has been trained for CME will perform a “standard” right hemicolectomy differently than before. It won’t be the traditional hemicolectomy but a 5/6 CME-hemicolectomy, thus making it very difficult to detect a difference. Our approach to answering the question was a multicenter, non-randomized, registry-based trial with centralized assessment of the entire specimen. This trial has just closed recruitment after enrolling more than 1000 patients, so that long-term results can be expected in a few years.

Is complete mesocolic excision oncologically superior to conventional surgery for colon cancer? A retrospective comparative study.

Background:During the last decade, many efforts have been made in order to improve the oncologic outcomes following colonic resection. Complete mesocolic excision (CME) has proved to provide high rates of disease-free and overall survival rates in patients undergoing resection for colonic malignancies. The aim of our study was to further investigate the role of CME in colonic surgery through comparison with a series of conventional resections.Methods:All data regarding resections for colonic cancer since 2006 were obtained prospectively from two surgical departments. Retrieved data from 290 patients were analyzed and compared between those who underwent CME and those who had conventional surgery.Results:The CME group presented a higher rate of postoperative morbidity and readmissions. Histopathological features were in favor of CME surgery compared with the conventional group, in terms of both resected bowel length (33 vs. 20 cm) and lymph node harvest (27 vs. 18). Although CME was associated with better disease-free and overall survival times, only tumor differentiation, adjuvant chemotherapy and age had a statistically significant affect on those outcome values (P<0.05).Conclusion:CME improves histopathologic features, but without presenting oncologic superiority. Larger prospective studies following adequate surgical training are needed to prove the technique’s advantages in oncologic outcomes.