Purpose: Compared to traditionally used abdominoperineal resection and low anterior resection for the treatment of rectal neoplasm, transanal excision (TAE) has several benefits such as a lower complication rate, a shorter average hospital stay and improved quality of life. Transanal endoscopic microsurgery (TEM) was recently introduced for resecting rectal neoplasm. The aim of this study was to compare the therapeutic results between TAE and TEM in patients with rectal neoplasm.
Methods: From October 2000 to December 2008, 115 patients underwent TEM or TAE at the NCC. Among the patient with rectal neoplasm, the patients with recurred rectal cancer and pathologic T2 or T3 stage were excluded. Thirty four and 33 patients were included for this study in the TAE and TEM groups, respectively. The locations of the lesion, the average number of fragmented specimens, the resection margin, postoperative complications and recurrence were retrospectively compared between the TEM and TAE groups. For the patients with T1 cancer, the disease-free survival rates were compared between the TAE and TEM groups.
Results: The median distance of lesions from the anal verge in the TEM group was higher than that in the TAE group: (mean distance: 6.75 cm, range: 3∼15 cm) for TEM group and (mean distance: 3.13 (range: 1∼8 cm) for the TAE group, p＜0.001). The TAE group had more fragmented specimens than the TEM group (mean for the TAE: 1.44 (range: 1∼4), mean for the TEM group: 1.06 (range: 1∼2), p=0.031). For the patients with T1 cancer, the 3 year disease-free survival rate was not significantly different between the two groups (83.9% for the TAE group and 91.7% for the TEM group p=0.734).
Conclusion: TEM can remove higher located rectal neoplasm and a less fragmented specimen was aquired that that in TAE. TEM seems to have similar oncologic outcomes as compared with TAE.

Keywords: Transanal endoscopic microsurgery, Transanal excision, Early rectal cancer