Transanal total mesorectal excision: full steam ahead.

Abstract

The article by Araujo [1] in this month’s issue documents the dramatic climb of transanal total mesorectal excision (transanal TME) with the most comprehensive review on this topic to date and a revelation of published numbers that are approximately double what they were just 1 year ago [2]. While it may seem as if transanal TME materialized overnight, in actuality, its foundation had been quietly in development for three decades. The seeming sudden ascent of transanal TME is analogous to a building under construction. Developing a proper foundation is a time-intensive and critical first step. To naive observers of a construction site, it may appear as though no progress is underway, until the foundation is completed and suddenly a building begins to rise ten stories high, filling in the skyline with striking speed. The foundation for transanal TME began 30 years ago with the innovative efforts of Gerald Marks and later carried on with his son John Marks. In the early 1980s, G. Marks pioneered the technique of what he termed the transabdominal–transanal (TATA) operation for rectal cancers involving the distal one-third of the rectum [3], performing a meticulous dissection from below and adapting Bill Heald’s concept of TME, albeit ‘in reverse.’ This predated the era of laparoscopy and the first TATA operations were completed with an open approach before transitioning to the use of laparoscopic assistance in the 1990s [4]. For 30 years, Marks’ TATA operation laid down the foundation for modern transanal TME, spelling out very clearly why this approach was preferred for distal rectal cancer. Principally, the advantages of TATA were (a) definition of the distal margin from below, thereby assuring no tumor involvement at the line of distal division and (b) obviating the need for stapling devices for transection, which do not comply with boney constraints of— in particular—the narrow male pelvis. Even when staplers could be negotiated into pelvic confines from above, there was still the risk of inadvertently stapling across tumor, thereby irreversibly compromising the oncologic integrity of the operation. While Marks’ rationale behind TATA was perfectly on point, the technique required specialized retractors with limited exposure, and thus few were able to replicate this approach. In parallel with TATA, the transanal endoscopic microsurgery (TEM) scope was developed by Buess [5] and considerable experience was gained with TEM for local excision of rectal neoplasia, though primarily for nonmalignant lesions. TEM was, for many, an unaffordable privilege of the elite; most colorectal surgeons, to this day, are not privy to TEM nor have they had formal training with this exquisite device. TEM’s penetration had remained limited due to prohibitive upfront costs and also the complexity it mandates from surgeons. During a recent lectureship webcast, a renowned colorectal surgeon remarked that, ‘in [the year] 2000, TEM was dead.’ This statement was not intended to discredit the otherwise precocious TEM marvel. Implicit, however, was that the technique failed to gain universal adoption by colorectal surgeons due to the reasons cited. But in the mid-2000s, an important innovation would set TATA and TEM on a collision course with one another; it would not only resurrect TEM, but it would also spawn the next generation of advanced transanal platforms. That innovation was natural orifice translumenal surgery (NOTES) [6]. Those with skepticism about NOTES asked: What for? But the innovators of the time asked: What next? It immediately set off a worldwide quest to determine what S. Atallah (&) Florida Hospital, Winter Park, FL, USA e-mail: atallah@post.harvard.edu