Investigation of the Benefit of Using an Autologous Platelet-rich Fibrin Matrix (Obsidian ASG®) for Treatment of Anastomosis During Rectal Surgery

Inclusion Criteria: The following inclusion criteria will be considered: * Written informed consent * Age \> 18 years * Indication for elective oncological rectal resection in the presence of malignant rectal disease and the lower edge of the tumor, measured from the anal verge with the rigid rectoscope, ≤ 14cm * Use of a circular anastomosis using the "double stapling technique"(6) during creation of the anastomosis * Expected availability within the maximum 45-day period of study participation * The use of "golden standard" stapling technology devices; 3 rows endo linear stapler; 2 rows circular stapling devices should be used in an open and laparoscopic approach Exclusion Criteria: The following exclusion criteria will be considered: * Pregnancy, or the non-exclusion of pregnancy (for women of childbearing potential). In the case of menopause having occurred more than 2 years ago or postmenopausal sterilization or surgical sterilization, the authorized physician is free to classify the female study participant as non-pregnant, so that the pregnancy test otherwise required at the beginning of study participation (or during subject screening) may be omitted. * Risk of pregnancy occurring while taking part in the study in women not meeting at least one of the following criteria: Onset of menopause more than 2 years ago, postmenopausal sterilization, surgical sterilization, a promise to use contraception (with hormones, coil or diaphragm/condom + spermicide), while enroll…