Current controversies in colorectal surgery: the way to resolve uncertainty and move forward

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Extended Versus Standard Complete Mesocolon Excision in Sigmoid Colon Cancer: A Multicenter Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate whether extended complete mesocolic excision (e-CME) for sigmoid colon cancer improves oncological outcomes without compromising morbidity or functional results.

BACKGROUND

In surgery for cancer of the sigmoid colon and upper rectum, s-CME removes the lymphofatty tissue surrounding the inferior mesenteric artery (IMA), but not the lymphofatty tissue surrounding the portion of the inferior mesenteric vein that does not run parallel to the IMA. Evidence about the safety and efficacy of extending CME to include this tissue is lacking.

METHODS

This single-blind study randomized sigmoid cancer patients at 4 centers to undergo e-CME or s-CME. The primary outcome was the total number of lymph nodes harvested. Secondary outcomes included disease-free and overall survival at 2 years, morbidity, and bowel and genitourinary function. Clinicaltrials.gov: NCT03107650.

RESULTS

We analyzed 93 patients (46 e-CME and 47 s-CME). Perioperative outcomes were similar between groups. No differences between groups were found in the total number of lymph nodes harvested [21 (interquartile range, IQR, 14-29) in e-CME vs 20 (IQR, 15-27) in s-CME, P = 0.873], morbidity (P = 0.829), disease-free survival (P = 0.926), or overall survival (P = 0.564). The extended specimen yielded a median of 1 lymph node (range, 0-6), none of which were positive.Bowel function recovery was similar between arms at all timepoints. Males undergoing e-CME had worse recovery of urinary function (P = 0.026).

CONCLUSION

Extending lymphadenectomy to include the IMV territory did not increase the number of lymph nodes or improve local recurrence or survival rates.

Infrapyloric and gastroepiploic node dissection for hepatic flexure and transverse colon cancer: A systematic review

INTRODUCTION

The hepatic flexure and transverse colon have a complex intermingled lymphovascular anatomy crossing between mesocolon and mesogastrium. Few studies have investigated the oncological relevance of metastatic infrapyloric and gastroepiploic lymph nodes (IGLN) from hepatic flexure and transverse colon tumors. This study aimed to evaluate the incidence and risk factors for IGLN metastases, and the indications, surgical morbidities, and oncological outcome following extended lymphadenectomy.

MATERIALS AND METHODS

According to the PRISMA statement, a systematic review on IGLN lymphadenectomy for colon cancer was conducted into PubMed, Embase, and Cochrane databases. A critical appraisal of study was performed according to the Joanna Briggs Institute Tools.

RESULTS

Nine studies were included. IGLN metastases incidence ranged 0.7-22%. IGLN positivity for patients with metastatic mesocolic lymph nodes ranged 1.7-33.3%. Postoperative complication rate ranged 8.5-36.9%, mostly low grade according to Clavien-Dindo's classification. Postoperative mortality rate ranged 0-5.4% at 30-days. IGLN metastases were associated with advanced disease with a 5-year progression-free survival rate up to 33.9%. Two authors reported perineural invasion and N stage as risk factors, while another reported endoscopic obstruction, signet ring adenocarcinoma, CEA level ≥17 ng/ml, and M1 stage to be risk factors for IGLN involvement. Apart from one study, all other studies were of moderate/high quality.

CONCLUSIONS

Metastatic IGLNs are not uncommon and should be highly considered. IGLN metastases could be potentially associated with an aggressive disease. IGLN dissection is not associated with higher morbidity and mortality than standard CME. Preoperative risk factors of IGLN involvement could guide surgical indication for extended lymphadenectomy.

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

AIM

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 <10 mm vs. ≥10 mm.

METHOD

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 <10 mm 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 <10 mm vs. ≥10 mm groups.

RESULTS

A total of 127 patients (43% female) with a median age of 68 years were included. The median follow-up time was 68 months. 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 ≥10 mm was associated with longer operating time (150 vs. 180 min, p = 0.021), intramesocolic resection (p = 0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102 mm, p = 0.005).

CONCLUSION

An arterial stump length ≥10 mm 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.

Prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for non-metastatic right colon cancer (PIONEER study): study protocol of a multicentre single-arm trial

Background

The introduction of complete mesocolic excision (CME) with central vascular ligation (CVL) for right-sided colon cancer has improved the oncologic outcomes. Recently, we have introduced a modified CME (mCME) procedure that keeps the same principles as the originally described CME but with a more tailored approach. Some retrospective studies have reported the favourable oncologic outcomes of laparoscopic mCME for right-sided colon cancer; however, no prospective multicentre study has yet been conducted.

Methods

This study is a multi-institutional, prospective, single-arm study evaluating the oncologic outcomes of laparoscopic mCME for adenocarcinoma arising from the right side of the colon. A total of 250 patients will be recruited from five tertiary referral centres in South Korea. The primary outcome of this study is 3-year disease-free survival. Secondary outcome measures include 3-year overall survival, incidence of surgical complications, completeness of mCME, and distribution of metastatic lymph nodes. The quality of laparoscopic mCME will be assessed on the basis of photographs of the surgical specimen and the operation field after the completion of lymph node dissection.

Discussion

This is a prospective multicentre study to evaluate the oncologic outcomes of laparoscopic mCME for right-sided colon cancer. To the best of our knowledge, this will be the first study to prospectively and objectively assess the quality of laparoscopic mCME. The results will provide more evidence about oncologic outcomes with respect to the quality of laparoscopic mCME in right-sided colon cancer.

Trial registration

ClinicalTrials.gov ID: NCT03992599 (June 20, 2019). The posted information will be updated as needed to reflect protocol amendments and study progress.

Protocol for a multicentre randomized clinical trial comparing oncological outcomes of D2 versus D3 lymph node dissection in colonic cancer (COLD trial)

Background

The extent of lymph node dissection in colonic cancer surgery remains arguable, and evidence from RCTs regarding extended lymph node dissection outcomes is lacking. This study aimed to compare the long‐term results of D3 lymph node dissection with those of D2 dissection.

Methods

This is a multicentre RCT. The aim is to enrol 768 patients with primary colonic cancer assigned randomly to D2 or D3 lymph node dissection. The trial is assessing the superiority of 5‐year overall survival as the primary endpoint in patients undergoing D3 lymph node dissection versus D2 dissection. Secondary endpoints include disease‐free survival, short‐term outcomes (30‐day morbidity and mortality), quality of complete mesocolic excision and lymph node dissection, pattern of lymph node metastasis and quality of life in patients following D2 and D3 lymph node dissection. Experience of 20 D3 and 20 D2 lymph node dissections is required for surgeons to participate in the trial. For surgical accreditation four non‐edited videos of procedures will be assessed. Patients will be followed up for 5 years after last patient enrolment. Intention‐to‐treat analysis will be performed.

Discussion

The results of this study will demonstrate whether extended lymph node dissection is superior to standard dissection in terms of oncological outcomes, and will also assess the impact of more extensive surgery on short‐term outcomes and quality of life.

Risk Factors for Complications following Introduction of Radical Surgery for Colon Cancer: A Consecutive Patient Series

BACKGROUND

Rectal cancer surgery is standardized, resulting in improved survival. Colon cancer has fallen behind and therefore more radical surgical techniques have been introduced. One technique is complete mesocolic excision. The aim of this article was to study the complications after the introduction of standardized complete mesocolic excision in a single center.

METHODS

Complete mesocolic excision was introduced in 2007, and data were collected from 286 patients prior to surgery (2007-2010). The surgeon decided on open or laparoscopic surgery. Follow-up information was recorded until 31 December 2015. Complications were classified according to a modified Clavien-Dindo classification.

RESULTS

Complications occurred in 47%, severe complications (grade III and IV) in 15%. In-hospital mortality was 3.5%. A total of 142 patients (49.7%) were operated by open surgery. Logistic regression revealed anemia (p = 0.001), open surgery (p < 0.001), and long operating time (p < 0.001) as significant factors for complications in general. Multinomial logistic regression revealed that severe complications occurred more often in males (odds ratio: 2.56; 95% confidence interval: 0.98-6.68), patients with anemia (odds ratio: 3.49; 95% confidence interval: 1.27-9.60), elevated body mass index (odds ratio: 1.14; 95% confidence interval: 1.02-1.28), and in open surgery (odds ratio: 9.95; 95% confidence interval: 2.58-38.35). Age was not associated with severe complications. Survival was not significantly influenced by complications. Overall survival (5 years) was 90% among patients with complications and 92% among those without complications.

CONCLUSION

Severe complications following the introduction of complete mesocolic excision are patient dependent and related to open surgery. Patients selected for laparoscopy had less number of complications; therefore, introducing complete mesocolic excision by laparoscopy is justified. Identification of these factors can improve selection of appropriate surgical approach and postoperative patient safety.

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.

"Top down no-touch" technique in robotic complete mesocolic excision for extended right hemicolectomy with intracorporeal anastomosis

BACKGROUND

Proper identification of the mesocolic vessels is essential for achieving complete mesocolic excision (CME) in cases of colon cancer requiring an extended right hemicolectomy. In robotic procedures, we employed a "top down technique" to allow early identification of the gastrocolic trunk and middle colic vessels. The aim of our study was to illustrate the details of this technique in a series of 12 patients.

METHODS

The top down technique consists of two steps. First, the omental bursa was entered to identify the right gastroepiploic vein. Tracing down this vein as a landmark, the gastrocolic trunk was exposed, branches of this trunk and the middle colic vessels were divided. Second, dissection was directed to the ileocolic region and proceeded in an inferior-to-superior direction along the superior mesenteric vein to divide the ileocolic and right colic vessels consecutively. The ileotranverse anastomosis was created intracorporeally.

RESULTS

There were 8 males and 4 females with a mean age of 64.8 ± 16.9 years and a mean body mass index of 25.6 ± 3.7 kg/m². All the procedures were completed successfully. No conversions occurred. The mean operative time and blood loss were 312.1 ± 93.9 min and 110.0 ± 89.9 ml, respectively. The mean number of harvested lymph nodes was 45.2 ± 11.1. The mean length of hospital stay was 7.6 ± 4.7 days. Two patients had intraoperative complications and two had postoperative complications. There was no disease recurrence at a mean follow-up period of 10.4 ± 7.1 months.

CONCLUSIONS

The top down technique appears to be useful in robotic CME for an extended right hemicolectomy. Early identification of the gastrocolic trunk and middle colic vessels via this technique may prevent inadvertent vascular injury at the mesenteric root of the transverse colon.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

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.

Laparoscopic abdominoperineal excision with trans-abdominal individualized levator transection: interim analysis of a randomized controlled trial

AIM

Extralevator abdominoperineal excision (ELAPR) is challenging 'conventional' abdominoperineal excision (APR), yet the safety and efficacy of ELAPR is still under debate. We therefore developed a laparoscopic APR with trans-abdominal individualized levator transection (LAPR-TILT) approach and compared the outcome with a conventional laparoscopic APR (CLAPR).

METHOD

All eligible patients were entered a single-centre randomized controlled trial to compare CLAPR and LAPR-TILT. We assessed the first 185 patients, including operative findings, complications, histopathology and urogenital function.

RESULTS

Ninety-three patients in the CLAPR group and 92 patients in the APR-TILT group were included for analysis. The APR-TILT procedure took less time [137 (101-175) min vs 146 (102-187) min; P = 0.03], mainly owing to faster perineal dissection. APR-TILT resulted in a reduced rate of bowel perforation (1.1% vs 8.6%; P = 0.04), circumferential resection margin positivity (1.1% vs 10.8%; P = 0.01) and postoperative wound complications (5.4% vs 16.2%; P = 0.02) compared with the CLAPR procedure. At a median follow-up of 19 months after surgery, three patients (3.2%) in the CLAPR group had tumour recurrence while no tumour recurrence occurred in the LAPR-TILT group. Patients who underwent LAPR-TILT reported fewer urinary or sexual problems (LAPR-TILT vs CLAPR, 10.9% vs 24.7% and 17.4% vs 38.7%, respectively).

CONCLUSION

Compared with CLAPR, LAPR-TILT achieved better pathological results for factors that are surrogate parameters for local recurrence. LAPR-TILT could also reduce the risk of urogenital dysfunction.

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.

Recent surgical advances in colorectal cancer excision: toward optimal outcomes

Colorectal cancer is the third most common cancer affecting both males and females in the western world. Despite all the developments in the current treatment of colorectal cancer, it is still continuing to be an important factor of patient morbidity and mortality worldwide. Surgery is the mainstay of treatment for colorectal cancer. Over the last decade, there have been major changes and developments in the surgical treatment. Understanding the importance of the anatomy, technological advances in minimally invasive surgery and effects of chemoradiotherapy have changed the approaches to colorectal cancer treatment. Today, novel treatment strategies must be targeted not only minimally invasive approaches, but also aiming to increase patients’ quality of life without compromising the oncological principles.

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.

Short-term outcomes after complete mesocolic excision compared with 'conventional' colonic cancer surgery

BACKGROUND

Complete mesocolic excision (CME) seems to be associated with improved oncological outcomes compared with 'conventional' surgery, but there is a potential for higher morbidity.

METHODS

Data for patients after elective resection at the four centres in the Capital Region of Denmark (June 2008 to December 2013) were retrieved from the Danish Colorectal Cancer Group database and medical charts. Approval from a Danish ethics committee was not required (retrospective study).

RESULTS

Some 529 patients who underwent CME surgery at one centre were compared with 1701 patients undergoing 'conventional' resection at the other three hospitals. Laparoscopic CME was performed in 258 (48·8 per cent) and laparoscopic 'conventional' resection in 1172 (68·9 per cent). More extended right colectomy procedures were done in the CME group (17·4 versus 3·6 per cent). The 90-day mortality rate in the CME group was 6·2 per cent versus 4·9 per cent in the 'conventional' group (P = 0·219), with a propensity score-adjusted logistic regression odds ratio (OR) of 1·22 (95 per cent c.i. 0·79 to 1·87). Laparoscopic surgery was associated with a lower risk of mortality at 90 days (OR 0·63, 0·42 to 0·95). Intraoperative injury to other organs was more common in CME operations (9·1 per cent versus 3·6 per cent for 'conventional' resection; P < 0·001), including more splenic (3·2 versus 1·2 per cent; P = 0·004) and superior mesenteric vein (1·7 versus 0·2 per cent; P < 0·001) injuries. Rates of sepsis with vasopressor requirement (6·6 versus 3·2 per cent; P = 0·001) and postoperative respiratory failure (8·1 versus 3·4 per cent; P < 0·001) were higher in the CME group.

CONCLUSION

CME is associated with more intraoperative organ injuries and severe non-surgical complications than 'conventional' resection for colonic cancer.

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.

Complete mesocolic excision in colorectal cancer: a systematic review

AIM

Several studies have suggested an increased lymph node yield, reduced locoregional recurrence and increased disease-free survival after complete mesocolic excision (CME) for colorectal cancer. This review was undertaken to assess the use of CME for colon cancer by evaluating the technique and its clinical outcome.

METHOD

A literature search of publications was performed using PubMed and Medline. Only studies published in English were included. Studies assessed for quality and data were extracted by two independent reviewers. End-points included number of lymph nodes per patient, quality of the plane of mesocolic excision, postoperative mortality and morbidity, 5-year locoregional recurrence and 5-year cancer-specific survival.

RESULTS

There were 34 articles comprising 12 retrospective studies, nine prospective studies and 13 original articles including case series, observational studies and editorials. Of the prospective studies, four reported an increased lymph node harvest and a survival benefit. The others reported an improvement in the quality of the specimen as assessed by histopathological examination. Laparoscopic CME has the same oncological outcome as open surgery but completeness of excision during laparoscopy may be compromised for tumours in the transverse colon.

CONCLUSION

Studies demonstrate that CME removes significantly more tissue around the tumour including maximal lymph node clearance. There is little information on serious adverse events after CME and a long-term survival benefit has not been proved.

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.

Complete mesocolic resection and extended lymphadenectomy for colon cancer: a systematic review

AIM

Complete mesocolic excision (CME) and extended lympha-denectomy (EL) have been proposed as safe procedures for improving colon cancer survival outcomes. The aim of this study was to evaluate the evidence regarding oncological outcomes, morbidity and mortality after such techniques for colon cancer.

METHOD

A systematic review of the literature was conducted to evaluate evidence regarding oncological outcomes, morbidity and mortality after CME or EL. Three major databases (PubMed, MEDLINE and the Cochrane Library) were searched. The review included original articles reporting outcomes after CME or EL from January 1950 to July 2012.

RESULTS

Twenty-one, predominately retrospective, studies involving 5246 patients (mean age 68.2 years, 56.5% men) were included. Reporting of outcomes was inconsistent. Median follow up was 60 months. The operative mortality rate was 3.2% and the cumulative morbidity rate was 21.5%. The weighted mean local recurrence rate and the 5-year overall and disease-free survival rates were 4.5%, 58.1% and 77.4%, respectively.

CONCLUSION

The available data for CME and EL have numerous fundamental limitations that prohibit adoption. Contemporary controlled studies are required before universal recommendation.

Number of published randomized controlled multi center trials testing pharmacological interventions or devices is increasing in both medical and surgical specialties

BACKGROUND

In general, there is a need for testing new interventions in large randomized controlled trials. Depending on the research question it may be advantageous to establish multicenter studies as a way of organizing clinical trials in order to increase study power.

MAIN OBJECTIVES

The object of this study was to investigate the development in the organization of multicenter studies, the distribution of studies within different clinical specialties, across continents, and investigate the differences related to testing various interventions.

METHODS AND MATERIALS

A literature search was done in MEDLINE for multicenter studies published in 1995, 2000, 2005, and 2010, respectively. Data extraction identified data related to clinical specialties, interventions, participating patients, departments, countries, and continents.

RESULTS

The number of multicenter studies increased from 112 in 1995 to 1,273 in 2010, with a larger share of multicenter studies being performed in Europe and North America. The pharmacological interventions were primarily being tested in medical studies followed by the device tests predominantly in surgical studies. The number of included patients as well as the number of participating departments increased during the time span, though the increase in studies was most evident in Europe and North America compared with the rest of the world.

Implementation of complete mesocolic excision at a university hospital in Denmark: An audit of consecutive, prospectively collected colon cancer specimens

AIM

Over recent years there has been a new focus on the quality of colon cancer surgery following the description and introduction of complete mesocolic excision (CME). In the same period, laparoscopic surgery has been widely applied to the treatment of colon cancer. We aimed to evaluate the introduction of both CME and laparoscopic-assisted surgery at Aarhus University Hospital, Denmark between 2008 and 2011. Secondly we aimed to evaluate the impact on the quality of surgery of post-operative team meetings where pathologists demonstrated the plane of surgery on the specimens.

METHOD

A series of 209 consecutive and prospectively collected colon cancer specimens were evaluated by assessing the plane of surgery and measuring the amount of tissue resected. Multivariate analyses were used to control for influencing factors.

RESULTS

The proportion of specimens resected in the mesocolic plane was high and increased significantly following the introduction of post-operative team meetings (52%-76%, p = 0.02). Laparoscopic surgery enhanced the distance between the tumour and the arterial tie by a mean of 27 mm (p < 0.0001) and the distance between the nearest bowel wall and the arterial tie by 26 mm (p < 0.0001) when compared to an open approach. Factors such as body mass index and age influenced the outcome for surgical quality.

CONCLUSION

Implementation of CME and laparoscopic-assisted surgery for colon cancer is a challenge and requires continuous training and feedback. Post-operative multidisciplinary team meetings may be a key element in this process.

Successful total shift from multiport to single-port laparoscopic surgery in low anterior resection of colorectal cancer

OBJECTIVE

To assess the possibility of using single-port low anterior resection (LAR) in place of conventional laparoscopic LAR.

BACKGROUND

Though single-port LS is gradually evolving, the application of single-port LS techniques in LAR have been viewed with skepticism due to technical difficulties.

METHODS

Data from patients who had undergone either conventional laparoscopic LAR (n = 49) or single-port LAR (n = 67) for colorectal cancers between March 2006 and March 2013 were analyzed retrospectively.

RESULTS

In single-port LAR group, oncologic outcomes were satisfactory with respect to attainment of lymph nodes (23.4 ± 15.3) and surgical margins (proximal cut margin: 7.1 ± 4.6 cm, distal cut margin: 7.7 ± 5.7 cm). Single-port LAR showed acceptable clinical outcomes manifested by comparable outcomes of post-operative analgesics requirement and length of hospital stay, and by low incidence of post-operative complications (conventional laparoscopic LAR group: 30.6% vs. single-port LAR group: 14.9%; P < 0.01). Operative time was comparable between groups (conventional laparoscopic LAR group: 309 ± 93 min vs. single-port LAR group: 277 ± 106 min; P = 0.097). Throughout a series of 67 consecutive single-port LARs, no conversion to multiport or open surgery was occurred.

CONCLUSION

This study shows that single-port LAR is both safe and feasible for use in resection of colorectal cancer when performed by surgeons who are trained in conventional laparoscopic technique. If further and more extensive studies support our results, then single-port LAR can be an acceptable alternative to conventional laparoscopic LAR for treatment of colorectal cancer.

Rectal cancer : when is the local recurrence risk low enough to refrain from the aim to prevent it?

Recently, preliminary results of the OCUM study (optimized surgery and MRI-based multimodal therapy of rectal cancer) were published and raised concern in the scientific community. In this observational study, the circumferential resection margin status assessed in preoperative MRI (mrCRM) was used to decide for either total mesorectal excision (TME) alone or neoadjuvant radiochemotherapy (nRCT). In contrast to current guidelines, neither T3 stage (with negative CRM) nor clinically positive lymph nodes were an indication for nRCT. Pathologically node-positive patients received chemotherapy (ChT). Overall, 230 patients were included, of whom 96 CRM-positive patients received nRCT. The CRM was accurately predicted in MRI, the rate of mesorectal plane resection was high. Recurrence rates have not yet been reported, but an impressive rate of down-staging for both T and N stage after nRCT was observed, while acute side effects were minimal. Nonetheless, the authors conclude that a substantial number of patients could be "spared severe radiation toxicity" and propagate their concept for prospectively replacing current guidelines. This is based on the hypothesis that CRM is a valid surrogate parameter for the risk of local recurrence and in case of a negative CRM, nRCT becomes dispensable. Moreover, it is assumed that lymph node status is no more relevant. Both assumptions are a contradiction to recent data from randomized studies as specified below. As 5-year locoregional recurrence rate (LRR) of only of 5-8% and < 5% in low risk rectal cancer can be achieved by the addition of RT, the noninferiority of surgery alone can not be presumed unless the expected 5-year LRR is ≤ 5-8%, whereas any excess of this range renders the study design inacceptable. Unless a publication explicitly specifies 5-year LRR, results are not exploitable for clinical decisions.