Background and aim of the study: Radical prostatectomy (RP) is one of the most commonly used treatment options for localized prostate cancer (PCa). Blood loss and deterioration of erectile function is, however, a common unwanted side effect of RP. Previous series demonstrated that the robot-assisted RP (RARP) approach is associated with lower blood-loss rates than open RP. However, several factors might contribute to higher blood loss rates at RARP: First, ileus still represents a major complication. To further reduce complication rates of postoperative ileus most high-volume centers lower the intraabdominal pressure during RARP, which in turn might lead to higher estimated blood loss rates. Second, to improve functional outcomes such as erectile function and early recovery of urinary continence, many surgeons perform intrafascial nerve sparing, which is considered a dissection that follows the periprostatic fasica and allows a whole-thickness preservation of the neurovascular bundles. Ideally, many surgeons aim to avoid thermal application in favor of optimal nerve sparing quality. Moreover, partial or complete secondary resection in context of intraoperative frozen section protocols such as NeuroSafe might further increase risk of blood loss. Taken together, to enable best balance between low intraabdominal pressure as primary prevention of postoperative ileus, maximum nerve sparing quality (i.e. intrafascial approach) and low blood loss rates, atraumatic and athermal hemostatic measures such as polysaccharide application are needed. Thus, we perform a multicenter randomized controlled prospective study with superiority trial design, in which such hemostat agent is applied to the neurovascular bundle areas. We examine if such agent leads to a relevant clinical improvement indicated by higher postoperative hemoglobin levels compared to the control group. As an exploratory co-primary endpoint of interest, we examine erectile function after RARP. Erectile dysfunction (ED) after RP is caused by several different mechanisms and commonly multifactorial. However, one of the main reasons for ED after RP is injury to the cavernous nerves during surgery. Currently, nerve-sparing surgical approaches are commonly performed, if oncologically appropriate, to minimize postoperative potency decline. Notwithstanding improvements of nerve-sparing techniques, a certain degree of nerve damage during surgery is inevitable. In order to keep the rates of postoperative ED at a minimum, it is reasonable to stabilize the cavernous nerves during surgery. In a previous pilot conducted by Chedid et al, the polysaccharide ARISTA™ AH was applicated on the cavernous nerves during robot-assisted RP (RARP) to optimize hemostasis. Later analysis of the study results revealed unexpectedly high potency rates in those men. This observation raised the question, if ARISTA™ AH may have the potential to stabilize the cavernous nerves and thus ameliorate postoperative potency rates. As the previous study by Chedid et al was originally not designed for this endpoint and did not have a control group, we are planning to evaluate this question as a meaningful exploratory co-primary endpoint in the same study cohort.