Obsidian®ASG in anastomotic healing after rectal cancer resection—OBANORES: a prospective clinical feasibility study

Purpose: Anastomotic leakage following rectal cancer resection is a serious complication. Despite efforts to prevent it, the risk remains high. Obsidian®ASG, an AUTOLOGOUS fibrin matrix with thrombocytes derived from the patient’s blood, shows promise but has not been thoroughly tested in rectal anastomosis. The aim of this study was to assess the feasibility of using Obsidian®ASG as a supplement in rectal anastomosis creation during minimally invasive rectal cancer resection. Methods: This prospective IDEAL stage 2a development cohort study included 50 patients undergoing rectal cancer resection with anastomosis using minimally invasive surgery at Aarhus University Hospital, Denmark. Obsidian®ASG application was assessed using a predefined rating scale: “Complete” (applied in all three prescribed steps), “Almost complete” (applied in at least the first or second step), and “Incomplete” (all others). Feasibility required “Complete” or “Almost complete” application in at least 90% of patients. Results: Obsidian®ASG application was “Complete” in 15 cases (30%) and “Almost complete” in 35 cases (70%), meeting feasibility criteria in all patients. No “Incomplete” applications occurred. Difficulties in achieving “Complete” application included anatomical constraints, material depletion, machine error, and time constraints. Conclusion: Obsidian®ASG was successfully applied in all patients undergoing minimally invasive rectal cancer surgery. These findings suggest its feasibility, but further large-scale, multi-center randomized trials are needed to fully assess its potential benefits for patient outcomes.