The expert consensus statement published on ALES is an interesting survey among opinion leaders in colorectal surgery about evidence and perspectives of complete mesocolic excision (CME) for colonic cancer.
The concept of removal the complete envelope and of embryological surgery are principles that when applied to other organs as rectum or stomach demonstrated better oncological outcome with significant reduction of local recurrence rate (1,2).
This expert consensus statement reports extensively the thoughts of some opinion leaders about CME in colon cancer, even if cannot be considered a true “consensus”, because are not reported the levels of evidence and the grades of recommendations. Nevertheless, questions are appropriated and also literature review is exhaustive.
The first questions about definition, description and safety of the technique reaches a good agreement among the experts.
Some theoretical concern remains about the “correct” definition of CME, if we intend the technique described by Hohenberger (3), associated to an extended Kocher manoeuvre or we can define CME even when is performed a high vascular ligation (HVL) and the sheets of the mesentery, ascending colon and transverse mesocolon are respected. I have defined this concerns just “theoretical”, because, in my opinion, both descriptions sufficiently delineate the concept of CME and the oncologic safety of the procedure is not modified.
I agree with the experts that the concept of CME nowadays is enough clearly defined, embryology and anatomy of the colon is well described, also for left colon and splenic flexure cancer the concept of CME and the anatomy of the fascias is enough clear.
The principle of embryologic surgery is gaining more popularity among colorectal surgeons and the improvement in knowledge of embryologic based anatomy is probably correlated to the technologic development of high quality video surgery. The availability of high definition, 3D 4K imaging systems and the increased diffusion of robotic platform permitted to surgeons to develop even more precise, plane-based surgical techniques.
Probably this is one of the reasons because a well-known technique as CME associated to HVL, is recently returned popular and matter of debate.
About an adequate description of minimally invasive CME, consensus among experts is less, particularly in robotics and single port procedures. In our experience with robotic surgery right colectomy with CME and HVL is a feasible operation and also oncologic results are good and maybe better than with standard resection (4).
The poor oncologic outcome of right colon cancer is a matter of fact, and also quality of surgery could be responsible of this result (5,6). Therefore, it is appropriate the question about the specific oncologic outcome of CME. About this question the agreement is less, and if the majority of the experts agree about the better staging and the higher number of lymph nodes retrieved with CME, one third of the experts are not convinced about the better oncologic outcome in term of survival rates and local recurrence rate, potentially obtained by the technique. At the moment the data reported by the literature review cannot state with formal evidence that oncologic outcome is better. More studies are needed to evaluate the oncologic value of CME.
About how CME fare compared to D3 resection, the majority of the Authors agree that CME does not improve radicality of the resection, compared to D3 lymphadenectomy. The differences among the 2 techniques are probably mainly theoretical, but the common aim of both techniques is to enlarge lymphadenectomy to the root of superior mesenteric vessels. CME can be considered more focused on embryological planes of mesentery, trying to obtain a more extensive length of resection.
About specific indications of CME there is a general agreement of the experts in considering CME indicated to all locations, rather than for left-sided cancer. This is strange, because standardized left colectomies are usually performed with HVL and maintenance of the integrity of the mesocolon.
The less consensus among the expert is regarding the potential oncologic benefits of an extended resection and lymphadenectomy. As clearly reported in the paper, at the moment strong levels of evidence that CME improves oncologic outcomes are lacking. Nonetheless at the end the majority of the experts, 10 up to 14 (71%), consider CME as the gold standard approach.
At this regard it is interesting to consider that oncologic surgery in other big killer cancer as breast, lung and prostate cancer is going to the direction of a selection and a possible reduction in the extension of resection and lymphadenectomy. On the contrary in colorectal surgery the hot topics are CME, extended lymphadenectomy or lateral pelvic nodes dissection in rectal cancer.
In my opinion we should evaluate if the direction in colorectal oncologic surgery is an extension of surgery rather than a better lymph nodal status evaluation and a more accurate biologic mapping of the disease. Moreover the screening programs are increasing the number of early stages colorectal cancer and genetic platform mapping of the disease probably will be able, in a near future, to define even more precisely the profiles of the disease and its evolution.
Probably a more careful staging of the disease is needed, with a major role of preoperative imaging, of intraoperative lymphatic mapping, awaiting the improvement in genetic mapping techniques to define a tailored surgical strategy.
Personally I am not convinced that an extended resection as CME is necessary for all the patients. Nevertheless, patients with a clinical N positive disease, a T3 tumor of right colon flexure or proximal transverse colon, could benefit in term of better staging and oncologic outcome of a CME and HVL.
Conflicts of Interest: The author has no conflicts of interest to declare.
- Xie D, Yu C, Liu L, et al. Short-term outcomes of laparoscopic D2 lymphadenectomy with complete mesogastrium excision for advanced gastric cancer. Surg Endosc 2016;30:5138-9. [Crossref] [PubMed]
- How P, Shihab O, Tekkis P, et al. A systematic review of cancer related patient outcomes after anterior resection and abdominoperineal excision for rectal cancer in the total mesorectal excision era. Surg Oncol 2011;20:e149-55. [Crossref] [PubMed]
- Hohenberger W, Weber K, Matzel K, et al. Standardized surgery for colonic cancer: complete mesocolic excision and central ligation--technical notes and outcome. Colorectal Dis 2009;11:354-64; discussion 364-5. [Crossref] [PubMed]
- Spinoglio G, Bianchi PP, Marano A, et al. Robotic Versus Laparoscopic Right Colectomy with Complete Mesocolic Excision for the Treatment of Colon Cancer: Perioperative Outcomes and 5-Year Survival in a Consecutive Series of 202 Patients. Ann Surg Oncol 2018;25:3580-6. [Crossref] [PubMed]
- Yahagi M, Okabayashi K, Hasegawa H, et al. The Worse Prognosis of Right-Sided Compared with Left-Sided Colon Cancers: a Systematic Review and Meta-analysis. J Gastrointest Surg 2016;20:648-55. [Crossref] [PubMed]
- Lee L, Erkan A, Alhassan N, et al. Lower survival after right-sided versus left-sided colon cancers: Is an extended lymphadenectomy the answer? Surg Oncol 2018;27:449-55. [Crossref] [PubMed]
Cite this article as: Bianchi PP. Complete mesocolic excision for colonic cancer: remarks on an experts’ consensus statement. Ann Laparosc Endosc Surg 2019;4:19.