In the 80s, the total mesorectal excision technique for the treatment of rectal cancer was described by Professor Heald, and was the basis for a drop in locoregional recurrence rates below 10%. In the early 90s, laparoscopic surgery was introduced, and was gradually applied to colon and rectal cancer. However, the oncological equivalence of laparoscopy has always been a concern, with several authors recommending using a different platform in low rectal cancers rather than pure abdominal laparoscopy. In this setting, a new method needed to be described: this is what has been called the transanal TME.
Since its first description in 2011, there has been enormous interest in the TaTME technique, with hundreds of publications and the establishment of the International TaTME Registry, all of which validated its oncological safety. The theoretical benefits and expectations of TaTME are improved quality of the specimen and therefore better oncological outcomes, a lower risk of abdominal conversions and permanent stomas, and improved anastomoses. Three different meta-analyses have found better histopathological outcomes compared to conventional laparoscopic TME, and radiological studies from Northern Europe described significantly less residual mesorectum on postoperative magnetic resonance imaging after transanal TME compared to laparoscopic TME.
However, the transanal TME is currently on the spot due to a recent publication regarding the implementation of the technique in Norway. According to the publication, 9.5% of the 110 patients presented with an unexpected pattern of early locoregional recurrence, characterized by rapid, multifocal growth in the pelvic cavity and sidewalls. This is unconsistent with the few observational studies that support that TaTME might be associated with a low risk of local recurrence, with rates rangomg between 0% and 2.5%, although median follow-up periods are still brief. What happened in Norway? The analysis of the full and as yetl unpublished article is mandatory. What were the pathological outcomes? How were the survival and time-to-event analyses performed? Whyhas this pattern of recurrence not been generalized and detected in other clinics? What we all agree on is that the transanal TME is a potentially advantegous technique but must be adequately performed, following the implementation steps described. The randomized multicenter COLOR III trial will definitely answer many of our current questions.