It is a great pleasure and honor to comment on the article entitled “Transanal Total Mesorectal Excision: International registry results of the first 720 cases” by Penna and her colleagues in the “Annals of Surgery” (1). In 2014, the registry went online via the Low Rectal Cancer Development (LOREC) website (
The gold standard for the surgical treatment of rectal cancer is a total mesorectal excision. A well-performed TME requires meticulous and precise surgical technique along embryological (“Holy”) planes. Although this procedure has extensively been studied regarding surgical anatomy, it remains a difficult operation whether performed open, laparoscopically, or robotically, especially in an obese male patient with a narrow pelvis and/or low bulky tumor. A minimally invasive approach to rectal cancer, particularly low tumors (<5 cm from the anal verge), has a steep learning curve and is a technique difficult to master, because of poor visualization deep down in the bony pelvis, and the use of non-adapted instruments (such as inadequate staplers). This is why surgical innovation plays an important role in the development of new instruments and techniques to dissect the most distal and most difficult part of a TME. Continuous innovation of surgical techniques and perioperative surgical care is necessary, but may complicate formal assessment by randomized controlled trials. Therefore, it can be useful to assess the process of innovation of a surgical intervention. Definition of an innovative surgical procedure has been stated as ‘a new or modified surgical procedure that differs from currently accepted local practice, the outcomes of which have not been described, and which may entail risk to the patient’ (15). A comprehensive model to describe and assess the development of surgical innovation is to divide it into different sequential stages (IDEAL paradigm) (16). In 2013, professor Heald predicted that 2013 would be the year of new endoscopic transanal approaches to distal rectal dissection (17). Combined experience in laparoscopic techniques, single port surgery, transanal approaches (such as TATA, TEM and TAMIS), and NOTES has led to the birth of what we now call ‘Transanal Total Mesorectal Excision’ (taTME). I believe that taTME could be the next incremental step in the minimally invasive approach to TME. The problem with surgical innovation is adoption and implementation into practice and formal assessment. Adoption of a new technique is defined by the increase in the number of surgeons performing the procedure over time, either until accepted or discarded by them. A tipping point, describing the onset of a peak rate of diffusion of new technology is usually identified anywhere between 10–20% of surgeons having adopted the technique (18). However, innovation of a surgical procedure often continues after adoption into clinical practice, and it is therefore necessary to formally assess a novel surgical procedure. Indeed, for these novel surgical approaches, it can be difficult to decide when to shift from exploratory stages to more formal assessment. The learning curve might not be overcome and technique refinement might not be fully optimized. It is clear that with the results of the present study, published outcome still reflects surgeons in the developmental and exploratory stages of the taTME-technique. Indeed, on average 634/66=10 taTME cancer cases were included per center, with the following caseload distribution: 0–5 (50%), 6–10 (18%), 11–20 (12%), and >20 (20%). So, only one fifth of the collaborating centers contributed data of more than 20 taTMEs. It has already been shown that high-volume centers (>30 cases) have lower conversion rates with better quality TME specimens when compared to low-volume centers (<30 cases) (19). In future, when more and more surgeons will gain experience with this technique, which should be standardized at some point, even better short-term oncologic results light be expected. Therefore, I’m hopeful and enthusiastic about the further development of this technique to continuously optimize outcomes in the interest of the patient.
The authors conclude that taTME appears to be an oncologically safe and effective procedure for distal mesorectal dissection with acceptable short-term patient outcomes and good specimen quality. An important advantage of taTME is that the bottom-up dissection technique is equally appropriate to perform sleeve mucosal and/or partial intersphincteric resection, depending on the level of the tumor as classified by Rullier et al. (20). A distal purse string will close the rectal tube and depending on that level of closure, either a single stapled or a hand-sewn coloanal anastomosis can be performed. Whether this could result in a significantly decreased anastomotic leak rate is of major interest and results of studies investigating single-stapled coloanal anastomosis are eagerly awaited. Although expectations from taTME such as, shorter operating times (13), better short-term outcome with lower conversion rates, and better oncological outcome are clear, no randomized clinical trials have been performed yet. Although we might be at the tipping point, having ‘the early majority’ of surgeons performing taTME, some balance is needed. TaTME seems to gain fast in popularity, but we are still in the exploratory stage with inherent shortcomings and learning curve issues. A word of caution regarding required skills and complications unique to this operation might therefore be necessary. Different skill sets are required to safely implement taTME. Advanced laparoscopic skills and experience with laparoscopic colonic and rectal resections is required, as taTME is a hybrid laparoscopic procedure. Furthermore, the surgeon should be trained in colo-anal anastomosis and have experience with sleeve resections. Finally, basic skills for and experience with TAMIS are necessary to allow a safe transanal approach. Different skills labs, including cadaver courses, have been offered for surgeons to acquire confidence with TAMIS and should be part of formal surgical training to master this technique (21). There are pitfalls linked to taTME and they are inherent to a change in anatomic landmarks. Recently, two publications specifically highlighted the anatomical peculiarities of this approach (22,23). Too large an anterior dissection puts the bulbar urethra at risk. Indeed, in the pilot series of Rouanet et al., two urethral lesions occurred in a series of 30 difficult male patients (24). A lateral dissection that is too broad easily directs the surgeon lateral to the pelvic nerve plexus and can lead not only to autonomic nerve damage (sacral nerve plexus) but also to major vascular (internal iliac vein) and ureteral injuries. Therefore, it is of paramount importance to distinguish the plane between the mesorectal fascia and the presacral fascia posteriorly, and Denonvilliers’ fascia and the prostate capsula or dorsal vaginal wall, anteriorly. The lateral dissection margins are subtler and should respect the pelvic nerve plexus. From our own combined experience, a dissection beginning at the anorectal junction (just above the level of the puborectalis muscle) is more straightforward than an intersphincteric resection (25). In the future, taTME should be compared to laparoscopic TME in a randomized controlled trial regarding postoperative outcome (e.g., anastomotic leak rate of a single stapled anastomosis), functional and oncological results. In my humble opinion, taTME is definitely there to stay and will be an important tool in the armamentarium of colorectal surgeons involved in the treatment of ultra-low rectal cancer. As such, it’s not a one-size fits all, or one operation fits all rectal cancer patients. The way we look at rectal cancer has changed in every sense of the word and it goes without saying that Hompes and colleagues have heavily contributed to this outstanding achievement.
Conflicts of Interest: The author has no conflicts of interest to declare.
- Penna M, Hompes R, Arnold S, et al. Transanal Total Mesorectal Excision: International Registry Results of the First 720 Cases. Ann Surg 2017;266:111-7. [Crossref] [PubMed]
- Heald RJ, Ryall RD. Recurrence and survival after total mesorectal excision for rectal cancer. Lancet 1986;1:1479-82. [Crossref] [PubMed]
- Vennix S, Pelzers L, Bouvy N, et al. Laparoscopic versus open total mesorectal excision for rectal cancer. Cochrane Database Syst Rev 2014.CD005200. [PubMed]
- Bagshaw PF, Allardyce RA, Frampton CM, et al. Long-term outcomes of the australasian randomized clinical trial comparing laparoscopic and conventional open surgical treatments for colon cancer: the Australasian Laparoscopic Colon Cancer Study trial. Ann Surg 2012;256:915-9. [Crossref] [PubMed]
- Deijen CL, Vasmel JE, de Lange-de Klerk ESM, et al. Ten-year outcomes of a randomised trial of laparoscopic versus open surgery for colon cancer. Surg Endosc 2017;31:2607-15. [Crossref] [PubMed]
- Fleshman J, Sargent DJ, Green E, et al. Laparoscopic colectomy for cancer is not inferior to open surgery based on 5-year data from the COST Study Group trial. Ann Surg 2007;246:655-62; discussion 662-4. [Crossref] [PubMed]
- Jayne DG, Guillou PJ, Thorpe H, et al. Randomized trial of laparoscopic-assisted resection of colorectal carcinoma: 3-year results of the UK MRC CLASICC Trial Group. J Clin Oncol 2007;25:3061-8. [Crossref] [PubMed]
- Guillou PJ, Quirke P, Thorpe H, et al. Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): multicentre, randomised controlled trial. Lancet 2005;365:1718-26. [Crossref] [PubMed]
- van der Pas MH, Haglind E, Cuesta MA, et al. Laparoscopic versus open surgery for rectal cancer (COLOR II): short-term outcomes of a randomised, phase 3 trial. Lancet Oncol 2013;14:210-8. [Crossref] [PubMed]
- Shawki S, Liska D, Delaney CP. Laparoscopic surgery for rectal cancer: the verdict is not final yet! Tech Coloproctol 2017;21:241-3. [Crossref] [PubMed]
- Abbas SK, Yelika SB, You K, et al. Rectal cancer should not be resected laparoscopically: the rationale and the data. Tech Coloproctol 2017;21:237-40. [Crossref] [PubMed]
- Arezzo A, Passera R, Salvai A, et al. Laparoscopy for rectal cancer is oncologically adequate: a systematic review and meta-analysis of the literature. Surg Endosc 2015;29:334-48. [Crossref] [PubMed]
- Fernandez-Hevia M, Delgado S, Castells A, et al. Transanal total mesorectal excision in rectal cancer: short-term outcomes in comparison with laparoscopic surgery. Ann Surg 2015;261:221-7. [Crossref] [PubMed]
- Velthuis S, Nieuwenhuis DH, Ruijter TE, et al. Transanal versus traditional laparoscopic total mesorectal excision for rectal carcinoma. Surg Endosc 2014;28:3494-9. [Crossref] [PubMed]
- Biffl WL, Spain DA, Reitsma AM, et al. Responsible development and application of surgical innovations: a position statement of the Society of University Surgeons. J Am Coll Surg 2008;206:1204-9. [Crossref] [PubMed]
- McCulloch P, Altman DG, Campbell WB, et al. No surgical innovation without evaluation: the IDEAL recommendations. Lancet 2009;374:1105-12. [Crossref] [PubMed]
- Heald RJ. A new solution to some old problems: transanal TME. Tech Coloproctol 2013;17:257-8. [Crossref] [PubMed]
- Wilson CB. Adoption of new surgical technology. BMJ 2006;332:112-4. [Crossref] [PubMed]
- Deijen CL, Tsai A, Koedam TW, et al. Clinical outcomes and case volume effect of transanal total mesorectal excision for rectal cancer: a systematic review. Tech Coloproctol 2016;20:811-24. [Crossref] [PubMed]
- Rullier E, Denost Q, Vendrely V, et al. Low rectal cancer: classification and standardization of surgery. Dis Colon Rectum 2013;56:560-7. [Crossref] [PubMed]
- Francis N, Penna M, Mackenzie H, et al. Consensus on structured training curriculum for transanal total mesorectal excision (TaTME). Surg Endosc 2017;31:2711-9. [Crossref] [PubMed]
- Aigner F, Hormann R, Fritsch H, et al. Anatomical considerations for transanal minimal-invasive surgery: the caudal to cephalic approach. Colorectal Dis 2015;17:O47-53. [Crossref] [PubMed]
- Bertrand MM, Colombo PE, Alsaid B, et al. Transanal endoscopic proctectomy and nerve injury risk: bottom to top surgical anatomy, key points. Dis Colon Rectum 2014;57:1145-8. [Crossref] [PubMed]
- Rouanet P, Mourregot A, Azar CC, et al. Transanal endoscopic proctectomy: an innovative procedure for difficult resection of rectal tumors in men with narrow pelvis. Dis Colon Rectum 2013;56:408-15. [Crossref] [PubMed]
- Wolthuis AM, de Buck van Overstraeten A, D'Hoore A. Dynamic article: transanal rectal excision: a pilot study. Dis Colon Rectum 2014;57:105-9. [Crossref] [PubMed]
Cite this article as: Wolthuis AM. Transanal total mesorectal excision international registry results of the first 720 cases. Ann Laparosc Endosc Surg 2017;2:152.