JACKSONVILLE, FLA. – Over the past 30 years, transanal endoscopic microsurgery (TEM) has emerged as a technique for localized rectal cancer, but the need for expensive specialized equipment put it beyond the reach of most hospitals.
Now, early results with transanal minimally invasive surgery (TAMIS) may open the door to an option that achieves the benefits of TEM while using commonly available and less expensive equipment, according to a study presented at the Association for Academic Surgery/Society of University Surgeons Academic Surgical Congress.
Dr. John Costello, general surgery resident at Georgetown University, Washington, presented a poster summarizing the findings of a systematic literature review of TEM and TAMIS studies. The experience with TAMIS is more limited since Dr. Sam Atallah of Sebring, Fla., first introduced it in 2010. The review included the only head-to-head study of the technical aspects of TAMIS and TEM to date.
“Overall the results are very similar between the two approaches,” Dr. Costello said. “In many ways there are, at least anecdotally, some benefits potentially toward the TAMIS technique aside from cost: The perioperative morbidity may be a little lower and, particularly, there seemed to be fewer early problems with continence after surgery.”
The review found similar outcomes between the two approaches: low recurrence rates for small tumors (up to 3 cm) of 4% for TAMIS and 5% for TEM, although the study found that the recurrence rate for TEM increased with larger tumors. Surgery-related deaths with TAMIS ranged from 7.4% to19% and TEM from 6% to 31% across the studies reviewed.
The challenge with the systematic review was that the population of patients who had TAMIS was fewer than 500.
Dr. Costello elucidated the reasons that rectal cancer surgery has proved so challenging to surgeons over the years. The choice of operation was either limited to transabdominal or transanal excision, but the transanal approach had limitations anatomically and was found to be oncologically inferior for early stage cancer. Even with the evolution of the TEM approach, its adoption has been slow.
Either TEM or TAMIS would be a good option for patients too frail for the radical resection that low anterior resection or abdominal perineal resection demand, and would offer an option for palliation for advanced disease, Dr. Costello said. “You could locally resect patients in a way that they go home the same day or at most stay one day in the hospital,” he said.
“The challenge with TEM is that, although the oncologic outcomes are quite good with early-stage disease, the adoption has been very poor over 3 decades mainly because it requires specialized equipment with a very large upfront cost that is limited to use in the rectum,” Dr. Costello said. He estimated the initial capital investment cost for TEM equipment at up to $60,000 on average.
The TAMIS approach, on the other hand, carries a per-procedure equipment cost of about $500 over traditional laparoscopic surgery, he said. It can utilize the single-incision laparoscopic port (SILS) for the transanal approach. TAMIS sacrifices the three-dimensional view of TEM for two-dimensional, but it does provide 360-degree visualization. The surgeon must also be facile with the laparoscopic technique. “In the past that was a big challenge, but now all trainees are very familiar with laparoscopic surgery,” Dr. Costello said.
While the paucity of data on the TAMIS approach makes it difficult to make a strong case for the procedure, the path forward is clear, Dr. Costello said.
“We feel, as do a number of authors of the most papers, that the time truly is now for an actual prospective randomized trial to compare these techniques head-to-head, because colorectal surgeons now have the skill set to be facile at both,” Dr. Costello said.
The investigators had no financial relationships to disclose.