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.

Complete mesocolic excision for right hemicolectomy: an updated systematic review and meta-analysis.

PURPOSE: Complete mesocolic excision improves lymphadenectomy for right hemicolectomy and respects the embryological planes. However, its effect on cancer-free and overall survival is questioned. Therefore, we aimed to determine the potential benefits of the technique by performing a systematic review of the literature and meta-analysis of the available evidence. METHODS: Web of Science, PubMed/Medline, and Embase were searched on February 22, 2023. Original studies on short- and long-term oncological outcomes of adult patients undergoing right hemicolectomy with complete mesocolic excision as a treatment for primary colon cancer were considered for inclusion. Outcomes were extracted and pooled using a model with random effects. RESULTS: A total of 586 publications were identified through database searching, and 18 from citation searching. Exclusion of 552 articles left 24 articles for inclusion. Meta-analysis showed that complete mesocolic excision increased the lymph node harvest (5 studies, 1479 patients, MD 9.62, 95% CI 5.83-13.41, p > 0.0001, I2 84%), 5-year overall survival (5 studies, 2381 patients, OR 1.88, 95% CI 1.14-3.09, p = 0.01, I2 66%), 5-year disease-free survival (4 studies, 1376 patients, OR 2.21, 95% CI 1.51-3.23, p < 0.0001, I2 0%) and decreased the incidence of local recurrence (4 studies, 818 patients, OR 0.27, 95% CI 0.09-0.79, p = 0.02, I2 0%) when compared to standard right hemicolectomy. Perioperative morbidity was similar between the techniques (8 studies, 3899 patients, OR 1.04, 95% CI 0.89-1.22, p = 0.97, I2 0%). CONCLUSION: Meta-analysis of observational and randomised studies showed that right hemicolectomy with complete mesocolic excision for primary right colon cancer improves oncologic results without increasing morbidity/mortality. These results need to be confirmed by high-quality evidence and randomised trials in selected patients to assess who may benefit from the procedure.

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.

Bach Mai Procedure for complete mesocolic excision, central vascular ligation, and D3 lymphadenectomy in total laparoscopic right hemicolectomy: a prospective study.

PURPOSE: Total laparoscopic right hemicolectomy with complete mesocolic excision (CME), central vascular ligation (CVL), and D3 lymphadenectomy is still the most challenging colon procedures for gastrointestinal surgeons. We herein report the technical details and our preliminary experience of Bach Mai Procedure - a novel-combining (cranial, medial to lateral, and caudal) approach with early resection of the terminal ileum. METHODS: The dissection stage was central vascular isolation and ligation by a combined multiple approaches in the following four steps: cranial approach, dissecting along the inferior aspect of pancreatic isthmus to reveal the middle colic vessels and the anterior aspect of the superior mesentery vein and then exposed the right gastroepiploic vein and the trunk of Henle; medial-to-lateral approach, exposing the surgical axis - the superior mesenteric vascular axis and then early resection of the terminal ileum to open the dissection from the bottom up; and caudal approach, radical ligation of the ileocecal artery and right colic artery (central vascular ligation), lymph node dissection (D3 lymphadenectomy), and resecting the Toldt fascia of the colon to release the entire right colon from the abdominal wall. RESULTS: In 12 months, there were 32 cases of primary right-sided colon malignancies that have undergone tLRHD3, CME/CVL based on the Bach Mai Procedure. In 3 cases (9.4%), the tumor site was hepatic flexure. The median of lymph node number (LNN) was 38, with the maximum number which was 101. No serious postoperative complications (grade 3 or higher) neither inhospital mortality was detected. CONCLUSION: This Bach Mai procedure, a novel-combining approach with early resection of the terminal ileum, is technically feasible and safe for tLRHD3, CME/CVL. Further investigations and follow-up must be proceeded to evaluate the long-term outcomes of our technique.

Association between plane of mesocolic dissection and recurrence after complete mesocolic excision for right-sided colon cancer: a cohort study.

AIM: Dissection in the mesocolic plane is considered by some medical professionals to be crucial in complete mesocolic excision. We aimed to assess whether intramesocolic plane dissection is associated with a risk of recurrence after complete mesocolic excision for right-sided colon cancer. METHOD: This is a single-centre study based on prospectively registered data on patients undergoing resection for Union for International Cancer Control Stage I-III right-sided colon adenocarcinoma during the period 2010-2017. Patients were stratified in an intramesocolic plane group or a mesocolic plane group based on a prospective assessment of fresh specimens by a pathologist. Primary outcome was the 4.2 year risk of recurrence after inverse probability treatment weighting and competing risk analyses. RESULTS: Of 383 patients, 4 (1%) were excluded as the specimen was assessed as muscularis propria plane, 347 (91.6%) specimens were deemed as mesocolic and 32 (8.4%) as intramesocolic. The 4.2 year cumulative incidence of recurrence after inverse probability treatment weighting was 9.1% (95% CI 6.0%-12.1%) in the mesocolic group compared with 14.0% (3.6%-24.5%) in the intramesocolic group with an absolute risk difference in favour of mesocolic plane dissection of 4.9% (-5.7 to 15.6, p = 0.37). No difference was observed in the risk of local recurrence, death before recurrence or overall survival after 4.2 years between the two groups. CONCLUSION: Mesocolic plane dissection can be achieved in more than 90% of patients. The classification seems to be a guide for good surgical practice and not to be used for research purposes.

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.

Achieving a Textbook Outcome in Colon Cancer Surgery Is Associated with Improved Long-Term Survival.

BACKGROUND: Colon cancer surgery is a complex clinical pathway and traditional quality metrics may exhibit significant variability between hospitals and healthcare providers. The Textbook Outcome (TO) is a composite quality marker capturing the fraction of patients, in whom all desired short-term outcomes of care are realised. The aim of the present study was to assess the TO in a series of non-metastatic colon cancer patients treated with curative intent, with emphasis on long-term survival. METHODS: Stage I-III colon cancer patients, who underwent curative colectomy following the Complete Mesocolic Excision principles, were retrospectively identified from the institutional database. TO was defined as (i) hospital survival, (ii) radical resection, (iii) no major complications, (iv) no reintervention, (v) no unplanned stoma and (vi) no prolonged hospital stay or readmission. RESULTS: In total, 128 patients (male 61%, female 39%, mean age 70.7 ± 11.4 years) were included in the final analysis. Overall, 60.2% achieved a TO. The highest rates were observed for "hospital survival" and "no unplanned stoma" (96.9% and 97.7%), while the lowest rates were for "no major complications" and "no prolonged hospital stay" (69.5% and 75%). Older age, left-sided resections and pT4 tumours were factors limiting the chances of a TO. The 5-year overall and 5-year cancer-specific survival were significantly better in the TO versus non-TO subgroup (81% vs. 59%, p = 0.009, and 86% vs. 65%, p = 0.02, respectively). CONCLUSIONS: Outcomes in colon cancer surgery may be affected by patient-, doctor- and hospital-related factors. TO represents those patients who achieve the optimal perioperative results, and is furthermore associated with improved long-term cancer survival.

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.

Extragastrointestinal stromal tumour of the transverse mesocolon mimicking giant ovarian cystic neoplasm.

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours which are most commonly found along the gastrointestinal tract. They are more rarely found in an extragastrointestinal location and typically present late due to only vague symptoms from mass effect. There are very few case reports of GIST arising within the transverse mesocolon. We report a case of a large cystic transverse mesocolic GIST which preoperative imaging concluded was likely of ovarian origin. This resulted in an abrupt change in the surgical management intraoperatively, but fortunately, an R0 resection was still achieved. This serves as an important lesson to keep the differential diagnosis broad when dealing with large cystic abdominal masses. The tumour was found to be KIT wild type, with a platelet-derived growth factor receptor alpha D842V mutation identified, conferring intrinsic resistance to imatinib.

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.

The retrocolic fascial system revisited for right hemicolectomy with complete mesocolic excision based on anatomical terminology: do we need the eponyms Toldt, Gerota, Fredet and Treitz?

AIM: Right hemicolectomy with complete mesocolic excision (CME) requires the removal of an intact mesocolic envelope. The study aimed to determine, on the basis of macroscopic and microscopic anatomical studies, the optimal surgical dissection planes for CME to preserve fascial integrity. Unequivocal anatomical nomenclature was applied to describe the retrocolic fascial system and compared to frequently used eponyms (Toldt, Gerota, Fredet, Treitz). METHOD: Stepwise macroscopic dissections, cross-section studies and histological analysis were performed on body donors to identify the components of the retrocolic fascial system. Based on these anatomical findings, the optimal surgical dissection planes for CME were validated in laparoscopic training courses on body donors and in robot-assisted surgical procedures in patients. RESULTS: The mesocolic tissue and lymphovascular pedicles were enveloped by the ventral and dorsal mesocolic leaf (mesocolic fascia). The mesocolic fascia was attached to the parietal peritoneal fascia ('fascia of Toldt') along the parieto-mesocolic interface, and further cranially to the pre-duodenopancreatic fascia along the mesocolic-duodenopancreatic interface ('space of Fredet'). Dorsally, the parietal peritoneal fascia was separated from the anterior renal fascia ('fascia of Gerota') by the parieto-renal interface. Dissection along this interface in front of the anterior renal fascia followed by incision of the parietal peritoneal fascia at the duodenal border and opening the mesocolic-duodenopancreatic interface yielded the best macroscopic appearance of specimens and was considered optimal for CME. CONCLUSION: The retrocolic fascial system as well as the surgical dissection planes for CME can be described by clearly defined anatomical terms rather than potentially confusing eponyms.

Five-Year Prognosis of Complete Mesocolic Excision in Patients with Colon Cancer: A Prospective, Nonrandomized, Double-Blind Controlled Trial.

BACKGROUND: Previous studies on how complete mesocolic excision (CME) affects prognosis indicate fundamental limitations that prevent the procedure from being completely accepted in practice. This study evaluated 5-year survival in colon cancer patients who underwent CME in a strict quality-controlled trial. STUDY DESIGN: A prospective, nonrandomized, double-blind, controlled trial recruited patients who underwent open radical resection for colon cancer between November 2012 and November 2017. Third-party experts evaluated whether patients had undergone mesocolic dissection and/or central ligation by looking at photographs of both surgical field and specimen, and then divided patients into CME and non-CME (NCME) groups. The primary outcome was the 5-year local recurrence-free survival rate. Clinicopathological and follow-up data were recorded. RESULTS: There were 261 patients with a median follow-up time of 57 months assigned to the CME group, and 129 patients with a median follow-up time of 59 months were assigned to the NCME group. The 5-year local recurrence-free survival rate of patients with Union Internationale Contre le Cancer stage I to III cancer did not differ significantly between the groups. For stage I to III cancer and stage III cancer, the absolute risk reduction of 5-year cumulative death and disease progression after CME were 9.1% (95% CI 1% to 17%; p = 0.033) and 16.1% (95% CI 1% to 31%; p = 0.040), respectively. Meanwhile, CME also could reduce 14% 5-year cumulative incidence recurrence for Union Internationale Contre le Cancer stage III cancer compared with NCME (CME, 27.3% vs NCME, 41.3%; p = 0.042) after adjusting for the effect of non-cancer-related death. CONCLUSIONS: CME should be considered as a standard surgical procedure in affected patients.

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.

Assessment of adjuvant chemotherapy benefits after complete mesocolic excision in patients with colon cancer: Reanalysis of data from the ESCME trial.

AIM: The benefits of adjuvant chemotherapy (AC) in colon cancer after complete mesocolic excision (CME) have not been evaluated sufficiently. We reanalysed the ESCME trial data to investigate the survival benefits and establish AC stratified indications. METHODS: The data of Stage II and III colon cancer patients who received CME in the ESCME trial were reanalysed. Patients were divided into AC and non-AC (NAC) groups. The primary outcomes measured were differences in 5-year cancer-specific survival and disease-free survival (DFS) between the groups. RESULTS: Of the 206 patients enrolled in the study, 125 patients (AC, 49; NAC, 76) had Stage II cancer and 111 (AC, 86; NAC, 25) had Stage III cancer. There were no significant differences in the adjusted 5-year cancer-specific survival and DFS between the AC and NAC groups. Poor differentiation (hazard ratio [HR] 2.947; 95% CI 1.218-7.131) and RAS mutation (HR 3.140; 95% CI 1.363-7.234) affected the 5-year DFS significantly in multivariate Cox regression analysis for Stage II and III cancer, respectively. In subgroup analysis, AC significantly improved 5-year DFS (HR 0.369; 95% CI 0.140-0.978) for Stage III cancer with lymphovascular/perineural invasion compared to NAC. CONCLUSION: The current indication and benefits of AC for colon cancer patients after CME should be re-evaluated. AC is more appropriate for Stage III cancer with lymphovascular/perineural invasion.

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.