Knowledge of the roles of extracellular vesicles (EV) in intercellular communication has led to study the production of EV-rich preparations (i.e., isolates) to be used in diagnostics or treatment. However, the preparation of EV isolates for these purposes remains a challenge. Instead of isolates, EV were intended to be used via other therapeutic preparations. Due to the known beneficial effects of platelet-rich plasma (PRP) in regenerative medicine and the important roles of EV in it, we developed a unique platelet- and extracellular vesicle-rich plasma (PVRP) preparation protocol. PVRP contained high platelet and EV concentrations (M = 592 x 109/L, SD = 198 x 1012/L) and was used in a randomized controlled clinical trial to treat patients with chronic postoperative temporal bone cavity inflammation who have undergone surgical and exhaustive standard conservative treatment. PVRP had better treatment effects compared to standard conservative methods according to reduction of inflammation area in the group of patients treated with PVRP (p < 0,0005), and the absence of this difference in the group treated with standard conservative methods (p = 0,152). In addition, the intervention group had a statistically significant effect on the patients' quality of life over treatment time (p < 0,0005), due to statistically significant lower COMQ-12 (chronic otitis media questionnaire 12) score in patients treated with PVRP compared to control group at the second, third and fourth check-up. Moreover, there was COMQ-12 score improvement in patients treated with PVRP and decrease in score in control group.