| Factors | Group A (n = 20) | Group B (n = 40) | p value |
| Male/Female | 17/3 | 23/17 | 0.033 |
| Age (years) | 63.3 (44 - 78) | 61.9 (47 - 77) | ns |
| Depth of cancer invasion | |||
| T1 (n = 44) | 70.0% (14/20) | 75.0% (30/40) | ns |
| T2 (n = 16) | 30.0% (6/20) | 25.0% (10/40) | |
| Lymph node metastasis | |||
| No | 100% (20/20) | 100% (40/40) | ns |
| Pathological stage | |||
| Stage I | 100% (20/20) | 100% (40/40) | ns |
| Preservation of bilateral hypogastric nerves and pelvic plexuses | |||
| Preservation | 100% (20/20) | 100% (40/40) | ns |
| Level of anastomosis from the dentate line (cm) | |||
| 2.4 ± 1.7 cm | 4.3 ± 0.9 cm | <0.001 | |
| (2 - 4) | (3 - 6) | ||
| Past history | |||
| No | 100% (20/20) | 100% (40/40) | ns |
| Postoperative complications | |||
| Wound infection | 10% (2/20) | 10% (4/40) | ns |