Short term results of complete (D3) vs. standard (D2) mesenteric excision in colon cancer shows improved outcome of complete mesenteric excision in patients with TNM stages I-II

Vascular anatomy of the transverse mesocolon and bidirectional laparoscopic D3 lymph node dissection for patients with advanced transverse colon cancer

Laparoscopic D3 lymph node dissection for transverse colon cancer is technically demanding because of complicated anatomy. Here, we reviewed the vascular structure of the transverse mesocolon, explored the extent of the base of the transverse mesocolon, and evaluated the feasibility and oncological safety of D3 lymph node dissection. We retrospectively reviewed the clinical records of 42 patients with advanced transverse colon cancer who underwent curative surgery and D3 dissection at Kyushu University Hospital between January 2008 and December 2015. We examined the venous and arterial anatomy of the transverse mesocolon of each resection and compared surgical outcomes between patients who underwent laparoscopic D3 (Lap D3) and open D3 (Open D3) dissection. Patients included two with Stage I, 18 with Stage II, 20 with Stage III, and two with Stage IVA. Thirty-six (85.7%) and six (14.3%) patients underwent Lap D3 or Open D3, respectively. The tumor sizes of the Open D3 and Lap D3 groups were 7.8 and 3.7 cm, respectively (P < 0.001). The Lap D3 group had significantly less blood loss (26 mL vs 272 mL, P = 0.002). The other outcomes of the two groups were not significantly different, including 3-year overall survival (87.7% vs 83.3%, P = 0.385). We observed four patterns of the middle colic artery (MCA) arising from the superior mesenteric artery (SMA), and the frequency of occurrence of a single MCA was 64.3%. The right-middle colic vein (MCV) was present in 92.9% of resections and served as a tributary of the gastrocolic trunk, and 90.5% of the left MCVs drained into the superior mesenteric vein (SMV). The root of the transverse mesocolon was broadly attached to the head of the pancreas and to the surfaces of the SMV and SMA. Laparoscopic D3 lymph node dissection may be tolerated by patients with advanced transverse colon cancer.

D2 VS D3 LYMPH NODE DISSECTION FOR RIGHT COLON CANCER (review)

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Long-term Functional Outcome After Right-Sided Complete Mesocolic Excision Compared With Conventional Colon Cancer Surgery: A Population-Based Questionnaire Study

BACKGROUND

Complete mesocolic excision improves the long-term outcome of colon cancer but might carry a risk of bowel dysfunction.

OBJECTIVE

This study aimed to investigate whether right-sided complete mesocolic excision is associated with an increased risk of long-term bowel dysfunction and reduced quality of life compared with conventional colon cancer resections.

DESIGN

Data were extracted from a population-based study comparing complete mesocolic excision and conventional colon cancer resections and from a national questionnaire survey regarding functional outcome.

SETTINGS

Elective right-sided colon resections for stage I to III colon adenocarcinoma were performed at 4 university colorectal centers between June 2008 and December 2014.

PATIENTS

Seven hundred sixty-two patients were eligible to receive the questionnaire in November 2015.

MAIN OUTCOME MEASURES

The primary outcomes measured were the risk of diarrhea (Bristol stool scale score of 6-7), 4 or more bowel movements daily, and the impact of bowel function on quality of life. Secondary outcomes were other bowel symptoms, chronic pain, and quality of life measured by the European Organisation for Research and Treatment of Cancer QLQ-C30.

RESULTS

One hundred forty-one (63.8%) and 324 (59.9%) patients undergoing complete mesocolic excision and conventional resections responded after a median of 3.99 (interquartile range, 2.11-5.32) and 4.11 (interquartile range, 3.01-5.53) years (p = 0.04). Complete mesocolic excision was not associated with increased risk of diarrhea (adjusted OR, 1.07; 95% CI, 0.57-1.95; p = 0.84), 4 or more bowel movements daily (adjusted OR, 1.16; 95% CI, 0.57-2.24; p = 0.68), or lower quality of life (adjusted OR, 0.84; 95% CI, 0.49-1.40; p = 0.50). Complete mesocolic excision was associated nonsignificantly with nocturnal bowel movements, but not associated with chronic pain or other secondary outcomes.

LIMITATIONS

This study was limited by the retrospective design with unknown baseline symptoms. Responding patients were younger but without obvious selection bias. The outcome "diarrhea" seemed somehow sensitive to information bias.

CONCLUSION

Right-sided complete mesocolic excision seems associated with neither bowel dysfunction nor impaired quality of life when compared with conventional surgery. See Video Abstract at http://links.lww.com/DCR/A665.

The risk of long-term bowel dysfunction after resection for sigmoid adenocarcinoma: a cross-sectional survey comparing complete mesocolic excision with conventional surgery

AIM

To investigate whether complete mesocolic excision (CME) might carry a higher risk of bowel dysfunction and subsequent reduction in quality of life compared with conventional resection.

METHOD

A cross-sectional questionnaire study based on data from a national survey regarding long-term bowel function and a population-based cohort study comparing CME (study group) with conventional resection (control group). A total of 622 patients undergoing elective resection for Stage I-III sigmoid adenocarcinoma at four university colorectal centres between June 2008 and December 2014 were eligible to receive the questionnaire in mid-November 2015. Primary outcomes were four or more bowel movements daily, nocturnal bowel movements, unproductive call to stool, obstructive sensation and impact of bowel function on quality of life (QOL).

RESULTS

One hundred and twenty-seven (69.0%) and 289 (66.0%) patients in the study and control groups, respectively, responded to the questionnaire after medians of 4.41 [interquartile range (IQR) 2.50, 5.83] and 4.57 (IQR 3.15, 5.82) years, respectively (P = 0.048). CME was not associated with: increased risk of four or more bowel movements daily [adjusted OR 1.14 (95% CI 0.59-2.14; P = 0.68)], nocturnal bowel movements [adjusted OR 1.31 (0.66-2.53; P = 0.43)], unproductive call to stool [adjusted OR 0.99 (0.54-1.77; P = 0.97)] or obstructive sensation [adjusted OR 1.01 (0.56-1.78; P = 0.96)]. While one in five patients in both groups had moderate to severe impact of bowel function on QOL, there was no association with CME.

CONCLUSION

For patients with sigmoid cancer, CME is associated with neither higher risk of bowel dysfunction nor impaired QOL.

Green indocyanine fluorescence in robotic abdominal surgery

Fluorescent imaging with indocyanine green (ICG) is an emerging technology that is gaining acceptance for being a valid tool in surgeons' decision making. ICG binds to plasma lipoproteins if injected intravenously and, when excited by near-infrared light, provides anatomic information about organs vascularization and tissues perfusion. If injected in tissues, it migrates in the lymphatic system, therefore enabling the identification of lymphatic draining pathways of different organs. In this paper we address specific applications of ICG fluorescence in robotic general surgery.

MicroRNA-21 promotes TGF-β1-induced epithelial-mesenchymal transition in gastric cancer through up-regulating PTEN expression

This study aimed to explore the effects of miR-21 and PTEN/Akt signaling pathway on TGF-β1-induced epithelial-mesenchymal transition (EMT) in gastric cancer (GC). GC tissues and adjacent tissues were collected from 83 patients. The qRT-PCR assay was performed to detect miR-21 expression. The expressions of PTEN, Akt and p-Akt were detected by immunohistochemistry. After 48 h of treatment with TGF-β1 (10 ng/mL), the SGC-7901 and KATO-III cells were divided into the blank, negative control (NC), miR-21 inhibitors, PTEN-siRNA and miR-21 inhibitors + PTEN-siRNA groups. EMT related factors and PTEN expressions were detected by qRT-PCR assay and Western blotting. The scratch test was conducted to observe cell migration. Xenograft tumor model in nude mice was used to evaluate the effects of miR-21 on EMT of GC cells in vivo. In GC tissues, the expressions of miR-21, Akt and p-Akt were up-regulated, while PTEN expression was down-regulated. Gene and protein expressions of E-cadherin and PTEN in the miR-21 inhibitors group were higher than the blank, NC, PTEN-siRNA and miR-21 inhibitors + PTEN-siRNA groups, while the expressions of N-cadherin, β-catenin, Vimentin and Slug in the miR-21 inhibitors group were lower than other groups. MiR-21 inhibitors significantly inhibit cell migration and invasion in GC cell lines. In vivo xenograft experiment revealed that miR-21 inhibitor inhibits the growth of transplanted tumor through up-regulating E-cadherin and PTEN expressions and down-regulating the expressions of N-cadherin, β-catenin, Vimentin and Slug. These results suggest that miR-21 could promote TGF-β1-induced EMT in GC cells through up-regulating PTEN expression.

Surgical and oncological outcomes after complete mesocolic excision in right-sided colon cancer compared with conventional surgery: a retrospective, single-institution study

PURPOSE

The aim of the study was whether complete mesocolic excision (CME) with central vascular ligation (CVL) is associated with a survival benefit compared with traditional procedure in right-sided colon cancer.

METHODS

Overall, 251 consecutive patients underwent surgery for right colon cancer between 2007 and 2012. After exclusion, 95 subjects received non-CME surgery before 2010, and 97 subjects received CME surgery after January 2010, when we started to perform CME systematically. The number of lymph nodes, morbidity, and mortality was analyzed. Overall survival (OS) and disease-specific survival (DSS) were investigated.

RESULTS

The median number of examined lymph nodes was 33.28 in the CME group and 26.92 in the non-CME group, p < 0.001. Postoperative complications were 21.6% in the CME group and 17.8% in the non-CME group, without significant difference. One out of 192 patients died. Three-year OS was 88% in the CME group and 71% in the non-CME group (p = 0.003). In stage II, 3-year DSS was 97% in the CME group and 86% in the non-CME group. In stage III, the 3-year DSSs in the CME and in the non-CME groups were 86 and 67%, respectively (p < 0.001). Cox's regression showed that CME (p = 0.0012), the number of lymph nodes (p = 0.029), and TNM stage (p < 0.001) were significant independent predictors of DSS at 3 years.

CONCLUSION

Surgical standardization of CME with CVL for right-sided colon cancer is associated with better staging and prognosis, particularly in UICC stage II and III. This study shows that CME is safe and reproducible with acceptable morbidity.

[Short-term outcomes of complete mesocolic excision for right colon cancer]

PURPOSE

Complete mesocolic excision (CME) appears to be a relatively new concept for colon cancer. The purpose is to evaluate the results of CME with high vascular ligation (D3 lymph node dissection) for right colon cancer. The presented study identifies possible risks and advantages of the proposed method, as well as the role of the laparoscopic approach.

MATERIAL AND METHODS

The article included data from 39 patients with right colon cancer, TNM stage I-III, operated on between November 2015 and December 2016 in the oncoproctology Department of the Blokhin Cancer Research Center. The analysis of main intraoperative parameters, morbidity and mortality was carried out.

RESULTS

There was no postoperative mortality. 17 (43.6%) of operations were performed by open and 22 - by laparoscopic approach. The conversion for laparoscopic approach was 1 (4.5%) in 22. The median duration of the operation was 180 (130-260) minutes for laparoscopic approach and 120 (90-280) minutes for open approach, р=0.0056. Median intraoperative blood loss was 30 (30-300) ml for laparoscopic approach, and 300 (30-500) ml for open approach (р=0.0001). The duration of lymphorrhoea, time to first bowel movement, time to start liquid and solid food intake were 5.1±2.4, 1.3±0.5, 1.26±0.4 and 3.2±0.7 days, respectively. The median number of removed lymph nodes was 35.7 (6-68), the median number of metastatic lymph nodes was 1.9 (0-16). The median number of removed apical lymph nodes was 10.3 (0-24). Metastases did not affect any of the lymph nodes of the apical group.

CONCLUSION

Right mesocolic excision with D3 lymphadenectomy for right colon cancer is technically safe, and the laparoscopic approach provides all the benefits of minimally invasive surgery and excellent early treatment outcomes. Preliminary data shows no metastasis in apical lymphnodes for right colon cancer. Nonetheless, it is necessary to study the long-term results for the evaluation of oncological outcomes.

Laparoscopic complete mesocolic excisions for colonic cancer in the last decade: Five-year survival in a single centre

AIM

To analyse clinical and long-term oncologic results after laparoscopic complete mesocolic excision (CME) for colonic cancer over a 10-year period.

METHODS

Consecutive patients who received laparoscopic CME at our hospital from 2007 to 2017 were prospectively registered and retrospectively analysed. In total, 341 patients were included with tumour-nodal-metastasis (TNM) stages 0-III.

RESULTS

The mean age of the patients was 71.9 years. The median length of stay was 5 d. The mean lymph node harvest was 17.8. The mortality rate was 1.2%. Fifteen patients were reoperated on for anastomotic leaks. The local recurrence rate was 2.3%. Five-year TTR and cancer-specific survival CSS were 83.1% and 90.3%. The location of the tumour was not a significant variable for survival in unadjusted and adjusted survival analysis. TNM stage and anastomotic leaks were significant variables with respect to survival.

CONCLUSION

Laparoscopic CME results in acceptable complication rates and long-term oncologic results. It is important to avoid anastomotic leaks because of their negative effect on survival.

Laparoscopic modified mesocolic excision with central vascular ligation in right-sided colon cancer shows better short- and long-term outcomes compared with the open approach in propensity score analysis

Background

The introduction of complete mesocolic excision (CME) with central vessel ligation (CVL) for right-sided colon cancer has improved oncologic outcomes. However, there is controversy over the oncologic safety of laparoscopic CME with CVL. This study compared short-term and long-term oncologic outcomes between laparoscopic and open modified CME (mCME) with CVL in patients with right-sided colon cancer.

Methods

We enrolled 1239 patients who underwent open mCME with CVL and 1010 patients treated by a laparoscopic approach for right-side colon cancer between 2000 and 2013 and used 1:1 propensity score matching to adjust for potential baseline confounders between two groups.

Results

After propensity score matching, 683 patients who underwent open mCME with CVL were compared with 683 patients treated with a laparoscopic approach. There were no significant differences between these groups in age, sex, ASA score, TNM stage, tumor size, lymphovascular invasion, and perineural invasion. Comparison of open and laparoscopic mCME groups showed no significant difference in postoperative morbidity (21.4 vs. 18.3%, p = 0.175) and mortality (0.1 vs. 0%, p = 1.000). The laparoscopic mCME group showed shorter length of hospital stay. The 5-year overall survival rate was 83.7% in the open group and 94.7% in the laparoscopic group (p < 0.001). The laparoscopic group also showed a significantly better 5-year disease-free survival rate (82.7 vs. 88.7%, p = 0.009) and 5-year disease-specific survival rate (83.7 vs. 94.7%, p < 0.001).

Conclusion

Laparoscopic modified mesocolic excision with central vascular ligation is a safe and feasible approach with better short-term recovery profiles and potential oncologic benefits than the open approach for right-sided colon cancer.

Safety, quality and effect of complete mesocolic excision vs non-complete mesocolic excision in patients with colon cancer: a systemic review and meta-analysis

AIM

The application of complete mesocolic excision (CME) in colon cancer is controversial. We performed a meta-analysis to compare the safety, quality and effect of CME with non-complete mesocolic excision (NCME) in patients with colon cancer.

METHOD

We searched PubMed, ScienceDirect, the Cochrane Library and Scopus to identify studies comparing CME with NCME in colon cancer. We focused on three study outcome areas: safety (operation time, blood loss, complications, mortality); quality (large bowel length, distance from the tumour to the high vascular tie, area of mesentery, total lymph nodes); and effect (long-term survival).

RESULTS

A total of 8586 patients from 12 studies were included in the meta-analysis. CME was associated with greater intra-operative blood loss [weighted mean difference (WMD) 79.87, 95% CI: 65.88-93.86], more postoperative surgical complications (relative risk 1.23, 95% CI: 1.08-1.40), longer large bowel resection (WMD 47.06, 95% CI: 10.49-83.62), greater distance from the tumour to the high vascular tie (WMD 17.51, 95% CI: 15.16-19.87), larger area of mesentery (WMD 36.09, 95% CI: 18.06-54.13) and more lymph nodes (WMD 6.13, 95% CI: 1.97-10.28) than NCME. CME also had positive effects on 5-year survival [hazard ratio (HR) 0.33, 95% CI: 0.13-0.81], 3-year survival (HR 0.58, 95% CI: 0.39-0.86) and 3-year survival for Stage III disease (HR 0.69, 95% CI: 0.60-0.80) compared with NCME.

CONCLUSION

Limited evidence suggests that CME is a more effective strategy for improving specimen quality and survival but with a higher complication rate.

Robotic right colectomy with intracorporeal anastomosis for malignancy

Techniques for robotic resection of the right colon have not been extensively published or adopted. We report our initial experience of robotic right colectomy with intracorporeal anastomosis and specimen extraction through a Pfannenstiel incision retrospectively. Twenty-one consecutive patients with a right colon cancer (n = 18) or polyp too large to remove endoscopically (n = 3) were treated at Mayo Clinic Rochester, Minnesota. Main outcomes measured were estimated blood loss, operative time, conversion rate, return of gastrointestinal function, length of stay, overall and severe complications, discharge status, and pathology. All 21 procedures were technically successful without the need for conversion. The mean total operative time was 250 ± 56 min, estimated blood loss was less than 100 mL in 19 (90%), only 1 (5%) ileus occurred, mean length of stay and return of gastrointestinal function was 4 ± 1.3 and 1 ± 0.6 days, respectively, only 1 (5%) patient experienced a Dindo grade ≥ 3 complication, and 20 (95%) were discharged to home. Mean number of nodes resected was 26 ± 12. Tumors were diagnosed as stage 0 in 3 (14%), stage I in 7 (33%), stage II in 4 (19%), stage III in 6 (28%), and stage IV in 1 (5%). Main limitations were nonrandomized nature, single institution experience, small patient sample size, and procedures only being performed by two surgeons. Finally, we conclude that robotic right colectomy with central mesocolic excision, intracorporeal anastomosis, and extraction through a Pfannenstiel incision is technically feasible, efficacious, oncologically acceptable, and safe to perform.

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.

A novel hand-assisted laparoscopic versus conventional laparoscopic right hemicolectomy for right colon cancer: study protocol for a randomized controlled trial

Background

Although conventional laparoscopic and hand-assisted laparoscopic surgery for colorectal cancer is widely used today, there remain many technical challenges especially for right colon cancer in obese patients. Herein, we develop a novel hand-assisted laparoscopic surgery (HALS) with complete mesocolic excision (CME), D3 lymphadenectomy, and a total “no-touch” isolation technique (HALS-CME) in right hemicolectomy to overcome these issues. According to previous clinic practice, this novel procedure is not only feasible and safe but has several technical merits. However, the feasibility, short-term minimally invasive virtues, long-term oncological superiority, and potential total “no-touch” isolation technique benefits of HALS-CME should be confirmed by a prospective randomized controlled trial.

Methods/design

This is a single-center, open-label, noninferiority, randomized controlled trial. Eligible participants will be randomly assigned to the HALS-CME group or to the laparoscopic surgery with CME, D3 lymphadenectomy, and total “no-touch” isolation technique (LAP-CME) group, or to conventional laparoscopic surgery with CME and D3 lymphadenectomy (cLAP) group at a 1:1:1 ratio using a centralized randomization list. Primary endpoints include safety, efficacy, and being oncologically clear, and 3-year disease-free, progression-free, and overall survival. Second endpoints include operative outcomes (operation time, blood loss, and incision length), pathologic evaluation (grading the plane of surgery, length of proximal and distal resection margins, distance between the tumor and the central arterial high tie, distance between the nearest bowel wall and the same high tie, area of mesentery resected, width of the chain of lymph-adipose tissue, length of the central lymph-adipose chain, number of harvested lymph nodes), and postoperative outcomes (pain intensity, postoperative inflammatory and immune responses, postoperative recovery).

Discussion

This trial will provide valuable clinical evidence for the feasibility, safety, and potential total “no-touch” isolation technique benefits of HALS-CME for right hemicolectomy. The hypothesis is that HALS-CME is feasible for the radical D3 resection of right colon cancer and offers short-term safety and long-term oncological superiority compared with conventional laparoscopic surgery.

Trial registration

ClinicalTrials.gov, NCT02625272. Registered on 8 December 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2084-3) contains supplementary material, which is available to authorized users.

Laparoscopic Colorectal Surgery for Cancer: What Is the Role of Complete Mesocolic Excision and Splenic Flexure Mobilization?

Laparoscopic colorectal surgery for cancer is nowadays routinely performed worldwide. After the introduction by Heald of total mesorectal excision for rectal cancer, also a complete mesocolic excision has been advocated as an essential surgical step to improve oncologic results in patients with colon cancer. The complete removal of mesocolon with high ligation of the main mesenteric arteries and veins and the mobilization of splenic flexure are well-known but still debated in western surgical society. The authors reviewed the literature and outlined the rationale and the results of splenic flexure mobilization and complete mesocolic excision in laparoscopic surgery for colorectal cancer.

Impact of Proximal Vascular Ligation on Survival of Patients with Colon Cancer

In an effort to optimize further the surgical management of colon cancer, many groups have advocated extended lymphadenectomy as a strategy to improve completeness of resection and lymph node harvest. This review evaluates lymphadenectomy according to the definitions for extent of lymph node dissection based on the guidelines provided by the Japanese Society of Cancer of the Colon and Rectum and the contemporary concepts of complete mesocolic excision and central vascular ligation. The proposed benefits of a D3 or central nodal dissection along root vessels in colon cancer is improving accuracy of lymph node evaluation and ensuring complete removal of lymph nodes that may harbor undetected tumor cells or other undefined immunologic processes important for metastases. Metastasis to central lymph nodes occurs in 1 to 8% of patients with colon cancer and is most commonly seen in T3 and T4 tumors. Although central lymph node metastasis is associated with decreased survival after resection, resection of the nodes, when present, may confer a survival benefit analogous to resection of metastasis at distant sites. Current data support a standardized anatomic approach to colonic resection with complete resection of the mesocolic envelope and ligation at least to the D2 level.

The Radical Extent of lymphadenectomy - D2 dissection versus complete mesocolic excision of LAparoscopic Right Colectomy for right-sided colon cancer (RELARC) trial: study protocol for a randomized controlled trial

Background

The extent of lymphadenectomy during laparoscopic right colectomy can affect the oncological outcome and the safety of surgery. The principle of complete mesocolic excision (CME) has been gradually accepted and increasingly applied by colorectal surgeons. The aim of this study is to investigate whether extended lymphadenectomy (CME) in laparoscopic colectomy could improve the oncological outcomes of patients with right-sided colon cancers, compared with D2 lymphadenectomy.

Methods/design

The Radical Extent of lympadenectomy: D2 dissection versus complete mesocolic excision of LAparoscopic Right Colectomy for right-sided colon cancer (RELARC) study is a prospective, multicenter, randomized controlled trial in which 1072 eligible patients with right-sided colon cancers will be randomly assigned to the CME group or the D2 dissection group during laparoscopic right colectomy. Inclusion criteria are locally advanced colon cancers situated from the cecum to the right third of the transverse colon and clinically staged as T2-4aN0M0 or TanyN + M0. The primary endpoint of this trial is 3-year disease-free survival. Secondary endpoints include 3-year overall survival, postoperative complication rates, perioperative mortality rates, and rates of positive central lymph nodes (the station 3 nodes).

Discussion

The RELARC trial is a prospective, multicenter, randomized controlled trial that will provide evidence on the optimal extent of lymphadenectomy during laparoscopic right colectomy in terms of better oncological outcome and operation safety.

Trial registration

ClinicalTrials.gov: NCT02619942. Registered on 29 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1710-9) contains supplementary material, which is available to authorized users.

Pattern of Colon Cancer Lymph Node Metastases in Patients Undergoing Central Mesocolic Lymph Node Excision: A Systematic Review

BACKGROUND

Extended mesocolic lymph node dissection in colon cancer surgery seems to improve oncological outcome. A possible reason might be related to metastases in the central mesocolic lymph nodes.

OBJECTIVE

The purpose of this study was to describe the pattern of mesocolic lymph node metastases, particularly in central lymph nodes, and the risk of skip, aberrant, and gastrocolic ligament metastases as the argument for performing extended lymph node dissection.

DATA SOURCES

EMBASE and PubMed were searched using the terms colon or colorectal with sentinel node, lymph node mapping, or skip node; lymph node resection colon; and complete or total and mesocolic excision.

STUDY SELECTION

Studies describing the risk of metastases in central, skip, aberrant, and gastrocolic ligament lymph node metastases from colon adenocarcinomas in 10 or more patients were included. No languages were excluded.

MAIN OUTCOME MEASURES

The risk of metastases in the central mesocolic lymph nodes was measured.

RESULTS

A total of 2052 articles were screened, of which 277 underwent full-text review. The 47 studies fulfilling the inclusion criteria were very heterogeneous, and meta-analyses were not considered appropriate. The risk of central mesocolic lymph node metastases for right-sided cancers varies between 1% and 22%. In sigmoid cancer, the risk is reported in ≤12% of the patients and is associated with advanced T stage.

LIMITATIONS

The retrospective design and heterogeneity, in terms of definitions of lymph node location, tumor sites, stage, morphology, pathology assessment, and inclusion criteria (selection bias), of the included studies were limitations. Also, anatomic definitions were not uniform.

CONCLUSIONS

The present literature cannot give a theoretical explanation of a better oncological outcome after extended lymph node dissection. Consensus for a standardization of anatomical definitions and surgical and pathological assessments is warranted for future mapping studies.

Surgery along the embryological planes for colon cancer: a systematic review of complete mesocolic excision

BACKGROUND

Complete mesocolic excision (CME) for colonic cancer offers a surgical specimen of higher quality, with higher number of lymph nodes compared to conventional colectomy. However, evidence on oncological outcomes is limited. The aim of the present study is to review recent literature and provide more information regarding the effect of CME colectomy on short- and long-term outcomes.

METHOD

PubMed and MEDLINE databases were searched, and articles in English reporting data on CME were reviewed. Intraoperative events; postoperative morbidity and mortality; histopathological characteristics, including macroscopic assessment, number, and status of retrieved lymph nodes; and oncological outcomes were the end-points.

RESULTS

Thirty-two studies were analyzed. As regards the macroscopic assessment, a larger specimen (p = 0.02) that contains a higher number of lymph nodes (p < 0.00001) is acquired after CME. Two studies report a higher disease-free survival, in stage I and II and particularly in stage III disease after CME. CME by laparoscopy offers comparable outcomes, as regards intraoperative blood loss and immediate postoperative morbidity and mortality rates. Specimen quality is similar after either approach, for cancers located at the right and left colon, but not at the transverse colon.

CONCLUSION

There is strong evidence that CME offers a longer central pedicle that contains more lymph nodes than conventional surgery for colon cancer. CME represents the surgical background for the maximum lymph node harvest, an important quality marker for the surgical outcome. However, and according to present data, there is limited evidence that colectomy in terms of CME leads to improved long-term oncological outcomes.

No benefit of extended mesenteric resection with central vascular ligation in right-sided colon cancer

AIM

The optimal extent of mesenteric resection in colon cancer surgery is not known. We have previously shown an increased mortality associated with wider mesenteric resection in right hemicolectomy. This study compares the short- and long-term outcome in three variations of right hemicolectomy based on the position of the vascular ligature in the mesentery.

METHOD

In all, 2084 cases of cancer in the caecum or ascending colon were identified in the Swedish Colorectal Cancer Registry and categorized according to the position of the vascular ligature: central ligation of ileocolic vessels (ICVs) ± right colic vessels (n = 390), central ligation of ICVs + right branch of middle colic vessels (MCVs) (n = 1360) and central ligation of ICVs + central ligation of MCVs (n = 334).

RESULTS

Neither 3-year overall survival, 3-year disease-free survival nor local recurrence rate differed between the groups (P = 0.604; P = 0.247; P = 0.237). There was still no difference after multivariate analysis adjusted for age, sex, American Society of Anesthesiologists classification, TNM stage and adjuvant therapy. An increased peri-operative mortality, however, was observed in extended mesenteric resections, increasing from 0.8% in non-extended to 3.6% in more extended resection, P = 0.025.

CONCLUSION

The study showed no survival benefit by more extended mesenteric resection, indicating that there is no need to extend the mesenteric resection to involve the MCVs in cancer of the caecum or ascending colon. On the contrary, increased peri-operative mortality by more extensive mesenteric resection was noted suggesting that a more conservative approach may be favourable.

Open compared with laparoscopic complete mesocolic excision with central lymphadenectomy for colon cancer: a systematic review and meta-analysis

AIM

Several studies report improved survival in colon cancer with use of extended lymphadenectomy techniques (ELTs), such as D3 lymphadenectomy or complete mesocolic excision. The noninferiority of laparoscopic versus open techniques has already been established in D2 resections. The aim of this study was to compare the safety and efficacy of open and laparoscopic approaches for ELTs in colon cancer.

METHOD

Major databases, including PubMed, Scopus and the Cochrane library, were searched using defined inclusion and exclusion criteria, and relevant data were extracted. The Cochrane and Newcastle-Ottawa tools were used for critical appraisal and quality assessment. Meta-analysis with various subgroup analyses were undertaken, and clinical and statistical heterogeneity, along with publication bias, were also assessed.

RESULTS

One randomized and seven case-control trials were included. All studies were found to be of low methodological quality with some external validity issues. There was no difference in short-term mortality [OR = 2.16 (95% CI: 0.73-6.41); P = 0.16], anastomotic leakage, ileus or deep-sited infection/abscess. There was a trend for longer operative time [weighted mean difference (WMD) = -30.88 (95% CI: -62.38 to 0.61); P = 0.05] and shorter length of hospital stay [WMD = 2.29 (95% CI: -0.39 to 4.98); P = 0.09] with the laparoscopic approach. Laparoscopic right hemicolectomy had a lower wound-infection rate [OR = 2.87 (95% CI: 1.38-5.98); P = 0.005] compared with the relevant open group. No statistically significant difference was found in overall survival [hazard ratio (HR) = 0.85 (95% CI: 0.69-1.06); P = 0.15], disease-free survival, local recurrence and distant metastases.

CONCLUSION

Based on the current evidence, the laparoscopic technique appears to be at least as safe as the open technique when used in performing ELTs for colonic cancer, with similar morbidity and oncological outcomes.

Surgery for Colorectal Cancer - Trends, Developments, and Future Perspectives

BACKGROUND

Although colorectal surgery is long established as the mainstay treatment for colon cancer, certain topics regarding technical fine-tuning to increase postsurgical recurrence-free survival have remained a matter of debate throughout the past years. These include complete mesocolic excision (CME), treatment strategies for metastatic disease, significance of hyperthermic intraperitoneal chemotherapy (HIPEC), and surgical techniques for the treatment of colorectal cancer recurrence. In addition, new surgical techniques have been introduced in oncologic colorectal surgery, and their potential to provide sufficiently radical resection has yet to be proven.

METHODS

A structured review of the literature was performed to identify the current state of the art with regard to the mentioned key issues in colorectal surgery.

RESULTS

This article provides a comprehensive review of the current literature addressing the above-mentioned current challenges in colorectal surgery. The focus lies on the impact of CME and, in relation to this, on lymph node dissection, as well as on treatment of metastatic disease including peritoneal spread, and finally on the treatment of recurrent disease.

CONCLUSION

Uniformly, the current literature reveals that surgery aiming at complete malignancy elimination within multimodal treatment approaches represents the fundamental quantum leap for the achievement of long-term tumor-free survival.

Complete mesocolic excision and extended (D3) lymphadenectomy for colonic cancer: is it worth that extra effort? A review of the literature

PURPOSE

Recent interest in complete mesocolic excision (CME) with central vascular ligation (CVL) or extended (D3) lymphadenectomy (EL) for curative resection of colon cancer has been driven by published series from experienced practitioners showing excellent survival outcomes and low recurrence rates. In this article, we attempt to clarify the role of CME or EL in modern colorectal surgery.

METHODS

A narrative review of the evidence for CME and EL in the curative treatment of colon cancer.

RESULTS

The principal of CME surgery, similar to total mesorectal excision (TME) for rectal cancer, is the removal of all lymphatic, vascular, and neural tissue in the drainage area of the tumour in a complete mesocolic envelope with intact mesentery, peritoneum and encasing fascia. Extended (D3) lymphadenectomy (EL) is based on similar principles. Sound anatomical and oncological arguments are made to support the principles of removing the tumor contained within an intact mesocolic facial envelope together with an extended lymph node harvest. Excellent oncological outcomes with minimal morbidity and mortality have been reported. This has led to calls for the standardisation of surgery for colon cancer using CME. However, there is conflicting evidence regarding the prognostic benefit of greater lymph node harvests and the evidence for an oncological benefit of CME is limited by methodology flaws and several potential confounding factors.

CONCLUSIONS

Although there is a reasonable anatomical and oncological basis for these techniques, there are no randomised controlled trials from which to draw confident conclusions and there is insufficient consistent high quality evidence to recommend widespread adoption of CME.

Laparoscopic Complete Mesocolic Excision versus Open Complete Mesocolic Excision for Transverse Colon Cancer: Long-Term Survival Results of a Prospective Single Centre Non-Randomized Study

BACKGROUND/AIM

Laparoscopic complete mesocolic excision (CME) used in the treatment of transverse colon cancer has been questioned on the basis of the technical challenges. The aim of this study was to evaluate the medium- and long-term clinical and survival outcomes after laparoscopic and open CME for transverse colon cancer and to compare the 2 approaches.

METHODS

This study was a retrospective non-randomized study of patients with prospectively registered data on open and laparoscopic CME for transverse colon cancer tumour-node-metastasis stages I-III operated on between 2007 and 2014. This was a single-centre study in a community teaching hospital. A total of 56 patients with transverse colon cancer were included, excluding those with tumours in the colonic flexures. The outcome aims were 4-year time to recurrence (TTR) and cancer-specific survival (CSS). Morbidity was also measured.

RESULTS

The 4-year TTR was 93.9% in the laparoscopic group and 91.3% in the open group (p = 0.71). The 4-year CSS was 97.0% in the laparoscopic group and 91.3% in the open group (p = 0.42).

LIMITATIONS

This was a prospective single-institution study with a small sample size.

CONCLUSION

Results of the study suggest that the laparoscopic CME approach might be the preferred approach for transverse colon cancer, especially regarding its benefits in terms of short-term morbidity, length of stay and oncological outcome.

Complete mesocolic excision: Techniques and outcomes

Complete mesocolic excision (CME) for the treatment of colon cancer was first introduced in the West in 2008. The first aim of this procedure is to remove the afflicted colon and its accessory lymphovascular supply by resecting the colon and mesocolon in an intact envelope of visceral peritoneum, which holds potentially involved lymph nodes. The second component of CME is a central vascular tie to remove completely all lymph nodes in the central (vertical) direction. In its original iteration, CME was performed via laparotomy, although many centers preferentially perform laparoscopic surgery, with its associated benefits and similar oncological outcomes, as the standard treatment for colonic cancer. Here, we present the surgical techniques for CME in open and laparoscopic surgery, as well as the surgical, pathological and oncological outcomes of the procedure that are available to date. Because there are no randomized control trials comparing CME to “standard” colon surgery, the principles underlying CME seem anatomical and logical, and the results published from the Far East, reporting an 80% 5-year survival rate for Stage III cancer, should guide us.

Extent of surgery in cancer of the colon: Is more better?

Since the introduction of total mesorectal excision as the standard approach in mid and low rectal cancer, the incidence of local recurrence has sharply declined. Similar attention to surgical technique in colon cancer (CC) has resulted in the concept of complete mesocolic excision (CME), which consists of complete removal of the intact mesentery and high ligation of the vascular supply at its origin. Although renewed attention to meticulous surgical technique certainly has its merits, routine implementation of CME is currently unfounded. Firstly, in contrast to rectal cancer, local recurrence originating from an incompletely removed mesentery is rare in CC and usually a manifestation of systemic disease. Secondly, although CME may increase nodal counts and therefore staging accuracy, this is unlikely to affect survival since the observed relationship between nodal counts and outcome in CC is most probably not causal but confounded by a range of clinical variables. Thirdly, several lines of evidence suggest that metastasis to locoregional nodes occurs early and is a stochastic rather than a stepwise phenomenon in CC, in essence reflecting the tumor-host-metastasis relationship. Unsurprisingly, therefore, comparative studies in CC as well as in other digestive cancers have failed to demonstrate any survival benefit associated with extensive, additional or extra-mesenteric lymphadenectomy. Finally, routine implementation of CME may cause patient harm by longer operating times, major vascular damage and autonomic nerve injury. Therefore, data from randomized trials reporting relevant endpoints are required before CME can be recommended as a standard approach in CC surgery.

Disease-free survival after complete mesocolic excision compared with conventional colon cancer surgery: a retrospective, population-based study

BACKGROUND

Application of the principles of total mesorectal excision to colon cancer by undertaking complete mesocolic excision (CME) has been proposed to improve oncological outcomes. We aimed to investigate whether implementation of CME improved disease-free survival compared with conventional colon resection.

METHODS

Data for all patients who underwent elective resection for Union for International Cancer Control (UICC) stage I-III colon adenocarcinomas in the Capital Region of Denmark between June 1, 2008, and Dec 31, 2011, were retrieved for this population-based study. The CME group consisted of patients who underwent CME surgery in a centre validated to perform such surgery; the control group consisted of patients undergoing conventional colon resection in three other hospitals. Data were collected from the Danish Colorectal Cancer Group (DCCG) database and medical charts. Patients were excluded if they had stage IV disease, metachronous colorectal cancer, rectal cancer (≤ 15 cm from anal verge) in the absence of synchronous colon adenocarcinoma, tumour of the appendix, or R2 resections. Survival data were collected on Nov 13, 2014, from the DCCG database, which is continuously updated by the National Central Office of Civil Registration.

FINDINGS

The CME group consisted of 364 patients and the non-CME group consisted of 1031 patients. For all patients, 4-year disease-free survival was 85.8% (95% CI 81.4-90.1) after CME and 75.9% (72.2-79.7) after non-CME surgery (log-rank p=0.0010). 4-year disease-free survival for patients with UICC stage I disease in the CME group was 100% compared with 89.8% (83.1-96.6) in the non-CME group (log-rank p=0.046). For patients with UICC stage II disease, 4-year disease-free survival was 91.9% (95% CI 87.2-96.6) in the CME group compared with 77.9% (71.6-84.1) in the non-CME group (log-rank p=0.0033), and for patients with UICC stage III disease, it was 73.5% (63.6-83.5) in the CME group compared with 67.5% (61.8-73.2) in the non-CME group (log-rank p=0.13). Multivariable Cox regression showed that CME surgery was a significant, independent predictive factor for higher disease-free survival for all patients (hazard ratio 0.59, 95% CI 0.42-0.83), and also for patients with UICC stage II (0.44, 0.23-0.86) and stage III disease (0.64, 0.42-1.00). After propensity score matching, disease-free survival was significantly higher after CME, irrespective of UICC stage, with 4-year disease-free survival of 85.8% (95% CI 81.4-90.1) after CME and 73.4% (66.2-80.6) after non-CME (log-rank p=0·0014).

INTERPRETATION

Our data indicate that CME surgery is associated with better disease-free survival than is conventional colon cancer resection for patients with stage I-III colon adenocarcinoma. Implementation of CME surgery might improve outcomes for patients with colon cancer.

FUNDING

Tvergaards Fund and Edgar and Hustru Gilberte Schnohrs Fund.

Historical development of mesenteric anatomy provides a universally applicable anatomic paradigm for complete/total mesocolic excision

Although total mesorectal excision has now become the ‘gold standard' for the surgical management of rectal cancer, this is not so for colon cancer. Recent data, provided by Hohenberger and West et al. and others, have demonstrated excellent oncological outcomes when mesenterectomy is extensive (as is implicit in the concept of a ‘high tie') and the mesenteric package not violated. Such studies highlight the importance of understanding the basics of the mesenteric organ (including the small intestinal mesentery, mesocolon, mesosigmoid and mesorectum) and of abiding to principles of planar surgery. In this review, we first offer classic descriptions of the mesocolon and then detail contemporary thinking. In so doing, we provide an anatomical basis for safe and effective complete mesocolic excision (CME) in the management of colon cancer. Finally we list opportunities associated with the new anatomical paradigm, demonstrating benefits across multiple disciplines. Perhaps most importantly, we feel that a crystallized view of mesenteric anatomy will overcome factors that have hindered the general uptake of CME.