Table 2. Characteristics of the included studies.
| Included studies | Country | Study design | Treatment plan | No. of cases |
|---|---|---|---|---|
| Palma2009[9] | Germany | Cohort study | TEM/TME | 34/17 |
| De Graaf2009[10] | Netherlands | Cohort study | TEM/TME | 80/75 |
| Ptok2007[11] | U.S.A | Cohort study | TEM/TME | 35/359 |
| Lee2003[12] | Korea | Cohort study | TEM/TME | 52/17 |
| Langer2003[13] | Germany | Cohort study | TEM/TME | 20/18 |
| Heintz1998[14] | Germany | Cohort study | TEM/TME | 58/45 |
| Winde1996[15] | Germany | RCT | TEM/TME | 24/26 |
RCT: Randomized-controlled trial; TEM: Transanal endoscopic microsurgery; TME: Total mesorectal excision