3.1  Patient characteristics
The patient characteristics and operative data are shown in Table 1. The mean age of all 110 patients was 59.3 ± 11.9 years. The mean distance between the tumor and the dentate line was 5.6 ± 2.8 cm. Five of the 110 patients had a very low rectal tumor, which involved the dentate line and was classified as cT2N+ on preoperative evaluation. These patients received preoperative CRT to increase the possibility of a sphincter-preserving surgery. The mean time interval to surgery was 5.6 ± 2.8 weeks between completion of CRT and primary surgery. A sphincter-preserving surgery was performed in 102 (92.7%) patients. The remaining 8 patients underwent abdominoperineal resection for a very low tethered rectal tumor, which did not respond sufficiently to preoperative CRT. Ninety-nine (90%) patients underwent minimally invasive surgery (MIS), including laparoscopic and robotic surgery. There was no conversion to open surgery in patients who underwent MIS.
Table 1  Patients characteristics and operative data.