Transanal Endoscopic Microsurgery for T1 and T2 Rectal Cancers: A Meta–Analysis and Meta-Regression Analysis of Outcomes

Abstract

The objective of this study is to assess transanal endoscopic microsurgery (TEM) as a surgical strategy for stage I rectal cancer. The literature lacks level I and level II evidence of the oncologic competence of TEM. Three randomized controlled, one prospective, and seven retrospective comparative studies were evaluated. End-points included perioperative outcomes, margin involvement, disease-free and overall survival, and recurrence. The number of patients with major (odds ratio (OR) = 0.24,95% confidence interval (CI) 0.07–0.91) and overall postoperative complications (OR = 0.16, 95% CI 0.06-0.38) were significantly lower in TEM. The disease-free survival was higher in standard resection (SR) group compared with TEM (OR = 0.46, 95% CI 0.24-0.88). The number of patients with positive margins were less in the SR group (OR = 6.49, 95% CI 1.49-24.91), which was associated with lower local recurrence (OR = 4.92,95% CI 1.81-13.41) and overall recurrence rate (OR = 2.03, 95% CI 1.15-3.57). No survival advantage was observed in favor of either procedure. TEM had lower rate of positive margins and longer disease-free survival when compared with transanal excision (TAE). TEM seems to be superior to SR concerning morbidity whilst less effective in obtaining negative surgical margins, and it is associated with higher local and overall recurrence. No survival advantage was observed in favor of either procedure. Unfavorable tumor preoperative histology does not seem to influence the selection between TEM and SR. TEM is more effective than TAE in obtaining negative surgical margins and shows a greater disease-free survival.

Transanal endoscopic microsurgery (TEM) for T1 rectal cancer

“…A meta-analysis comparing short and long-term outcomes of TEM for early rectal cancer management, as compared to the standard transanal technique, was published in 2011 28 . The authors identified 11 studies, including a total of 514 patients managed with TEM and 386 patients managed with the standard transanal technique.…”

Preclinical cadaveric study of transanal endoscopic da Vinci® surgery

“…The technique of TEM, developed in 1980 by Gerhard Buess, has stood the test of time1, 9. Although developed initially and used primarily for resection of rectal adenoma, its role in rectal cancer treatment is evolving and various other applications have been reported3, 5, 15–18. The increased interest in TEM in recent years came at the same time as that in single‐port surgery.…”

“…Since its introduction in the early 1980s, transanal endoscopic microsurgery (TEM) has proved to be the technique of choice for surgical resection of benign rectal adenomas and is increasingly being considered for early rectal cancers1–5. The magnified and clear visualization of the rectal lesion within a stable pneumorectum allows more precise dissection and resection with clear surgical margins, translating into superior clinical results.…”

Local resection of early rectal cancer

“…Different procedures have been used for the local resection of ERC. The conventional transanal approach should be abandoned due to a higher rate of positive margins and poorer disease‐free survival compared to the more advanced transanal endoscopic microsurgery (TEM) . Endoscopic mucosa or submucosa resections (ESD) are, in general, not recommended for rectal cancer surgery as in‐depth dissection is performed in the sub‐mucosal layer, although a recent retrospective study in a highly selected material showed similar oncological results with ESD compared to TEM .…”