The Mesentery-Past, Present, and Future.

This article summarizes the events that shaped our current understanding of the mesentery and the abdomen. The story of how this evolved is intriguing at several levels. It speaks to considerable personal commitment on the part of the pioneers involved. It explains how scientific and clinical fields went different directions with respect to anatomy and clinical practice. It demonstrates that it is no longer acceptable to adhere unquestioningly to models of abdominal anatomy and surgery. The article concludes with a brief description of the Mesenteric Model of abdominal anatomy, and of how this now presents an opportunity to unify scientific and clinical approaches to the latter.

European consensus on the standardization of robotic total mesorectal excision for rectal cancer.

AIM: Surgery for rectal cancer is challenging for both technical and anatomical reasons. The European Academy of Robotic Colorectal Surgery (EARCS) provides a competency-based training programme through a standardized approach. However, there is no consensus on technical standards for robotic surgery when used during surgery for rectal cancer. The aim of this consensus study was to establish operative standards for anterior resection incorporating total mesorectal excision (TME) using robotic techniques, based on recommendations of expert European colorectal surgeons. METHOD: A Delphi questionnaire with a 72-item statement was sent through an electronic survey tool to 24 EARCS faculty members from 10 different countries who were selected based on expertise in robotic colorectal surgery. The task was divided into theatre setup, colonic mobilization and rectal dissection, and each task area was further divided into several subtasks. The levels of agreement (A* > 95% agreement, A > 90%, B > 80% and C > 70%) were considered adequate while agreement of < 70% was considered inadequate. Once consensus was reached, a draft document was compiled and sent out for final approval. RESULTS: The average length of experience of robotic colorectal surgery for participants in this study was 6 years. Initial agreement was 87%; in nine items, it was < 70%. After suggested modifications, the average level of agreement for all items reached 94% in the second round (range 0.75-1). CONCLUSION: This is the first European consensus on the standardization of robotic TME. It provides a baseline for technical standards and structured training in robotic rectal surgery.

A personal perspective of the development of MRI for Total Mesorectal Excision surgery.

In this personal account Professor Heald discusses the international implementation of total mesorectal excision for rectal cancer and the development of a generation of "specimen-orientated" surgeons. He describes the importance of the surgeon, radiologist and pathologist working together to improve techniques in all three disciplines and the research challenges for the future.

A collaborative review of the current concepts and challenges of anastomotic leaks in colorectal surgery.

The reduction of the incidence, detection and treatment of anastomotic leakage (AL) continues to challenge the colorectal surgical community. AL is not consistently defined and reported in clinical studies, its occurrence is variably reported and its impact on longterm morbidity and health-care resources has received relatively little attention. Controversy continues regarding the best strategies to reduce the risk. Diagnostic tests lack sensitivity and specificity, resulting in delayed diagnosis and increased morbidity. Intra-operative fluorescence angiography has recently been introduced as a means of real-time assessment of anastomotic perfusion and preliminary evidence suggests that it may reduce the rate of AL. In addition, concepts are emerging about the role of the rectal mucosal microbiome in AL and the possible role of new prophylactic therapies. In January 2016 a meeting of expert colorectal surgeons and pathologists was held in London, UK, to identify the ongoing controversies surrounding AL in colorectal surgery. The outcome of the meeting is presented in the form of research challenges that need to be addressed.

Adjuvant chemotherapy may improve disease-free survival in patients with rectal cancer positive for MRI-detected extramural venous invasion following chemoradiation.

AIM: MRI-detected extramural venous invasion (mrEMVI) is a poor prognostic factor in rectal cancer. Preoperative chemoradiotherapy (CRT) can cause regression in the severity of EMVI and subsequently improve survival whereas mrEMVI persisting after CRT confers an increased risk of recurrence. The effect of adjuvant chemotherapy (AC) following CRT on survival in rectal cancer remains unclear. The aim of this study was to determine whether there is a survival advantage for AC given to patients with mrEMVI persisting after CRT. METHOD: A prospective analysis was conducted of consecutive patients with locally advanced rectal cancer between 2006 and 2013. All patients underwent CRT followed by surgery. AC was given to selected patients based on the presence of specific 'high-risk' features. Comparison was made between patients offered AC with observation alone. The primary outcome was 3-year disease-free survival (DFS). RESULTS: Of 631 patients, 227 (36.0%) demonstrated persistent mrEMVI following CRT. Patients were grouped on the basis of AC or observation and were matched for age, performance status and final histopathological staging. Three-year DFS in the AC group was 74.6% compared with 53.7% in the observation only group. AC had a survival benefit on multivariate analysis (hazard ratio 0.458; 95% CI: 0.271-0.775, P = 0.004). CONCLUSION: Patients with persistent mrEMVI following CRT who receive AC may have a decreased risk of recurrence and an improved 3-year DFS compared with patients not receiving AC, irrespective of age and performance status.

Adjuvant therapy decisions based on magnetic resonance imaging of extramural venous invasion and other prognostic factors in colorectal cancer.

INTRODUCTION: There remains a lack of high quality randomised trial evidence for the use of adjuvant chemotherapy in stage II rectal cancer, particularly in the presence of high risk features such as extramural venous invasion (EMVI). The aim of this study was to explore this issue through a survey of colorectal surgeons and gastrointestinal oncologists. METHODS: An electronic survey was sent to a group of colorectal surgeons who were members of the Association of Coloproctology of Great Britain and Ireland. The survey was also sent to a group of gastrointestinal oncologists through the Pelican Cancer Foundation. Reminder emails were sent at 4 and 12 weeks. RESULTS: A total of 142 surgeons (54% response rate) and 99 oncologists (68% response rate) responded to the survey. The majority in both groups of clinicians thought EMVI was an important consideration in adjuvant treatment decision making and commented routinely on this in their multidisciplinary team meeting. Although both would consider treating patients on the basis of EMVI detected by magnetic resonance imaging, oncologists were more selective. Both surgeons and oncologists were prepared to offer patients with EMVI adjuvant chemotherapy but there was lack of consensus on the benefit. CONCLUSIONS: This survey reinforces the evolution in thinking with regard to adjuvant therapy in stage II disease. Factors such as EMVI should be given due consideration and the prognostic information we offer patients must be more accurate. Historical data may not accurately reflect today's practice and it may be time to consider an appropriately designed trial to address this contentious issue.

The rationale behind complete mesocolic excision (CME) and a central vascular ligation for colon cancer in open and laparoscopic surgery : proceedings of a consensus conference.

BACKGROUND: It has been evident for a while that the result after resection for colon cancer may not have been optimal. Several years ago, this was showed by some leading surgeons in the USA but a concept of improving results was not consistently pursued. Later, surgeons in Europe and Japan have increasingly adopted the more radical principle of complete mesocolic excision (CME) as the optimal approach for colon cancer. The concept of CME is a similar philosophy to that of total mesorectal excision for rectal cancer and precise terminology and optimal surgery are key factors. METHOD: There are three essential components to CME. The main component involves a dissection between the mesenteric plane and the parietal fascia and removal of the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains all lymph nodes draining the tumour area (Hohenberger et al., Colorectal Disease 11:354-365, 2009; West et al., J Clin Oncol 28:272-278, 2009). The second component is a central vascular tie to completely remove all lymph nodes in the central (vertical) direction. The third component is resection of an adequate length of bowel to remove involved pericolic lymph nodes in the longitudinal direction. RESULT: The oncological rationale for CME and various technical aspects of the surgical management will be explored. CONCLUSION: The consensus conference agreed that there are sound oncological hypotheses for a more radical approach than has been common up to now. However, this may not necessarily apply in early stages of the tumour stage. Laparoscopic resection appears to be equally well suited for resection as open surgery.

A pictorial description of extralevator abdominoperineal excision for low rectal cancer.

AIM: Extralevator abdominoperineal excision in the prone position has been reported as a method to improve the poor outcome sometimes observed after abdominoperineal excision (APE) for low rectal cancer. In this paper a pictorial guide is presented describing the key anatomical steps and landmarks of the operation. METHOD: Intraoperative footage of five APE operations filmed in high definition was reviewed and key stages of the operation were identified. Still frames were captured from these sequences to illustrate this guide. An edited video sequence was produced from one of these operations to accompany this paper. CONCLUSION: The prone APE allows improved visualization of the perineal portion of the operation by the surgeon, assistants and observers. It permits clear demonstration for teaching. Prospective evaluation is still required to identify patients who would benefit from extralevator APE.