ESSM Newsletter # 38

5 ESSM Today Platelet Rich Plasma (PRP) is prepared by cen- trifugation of the patient’s own blood to remove red blood cells [1]. The plasma obtained is rich in platelets that contain various growth factors, such as platelet-derived growth factor (PDGF), transforming growth factor (TGF)-b, IGF-I and VEGF. When platelets are activated, they release those factors, which play important biological roles in various conditions [2]. During the last 15 years PRP has been used to encourage a brisk healing response across several specialties, in particular dentistry, orthopedics and dermatol- ogy. Basically, patient’s blood is collected and centrifuged at varying speeds until it separates into 3 layers: Platelet Poor Plasma (PPP), PRP, and red blood cells. Usually 2 spins are used. The first spin (“Hard spin”) separates the Platelet Poor Plasma (PPP) from the red fraction and platelet rich plasma (PRP). The second spin (“Soft spin”) separates the red fraction from the PRP. The material with the highest specific gravity (PRP) will be deposited at the bottom of the tube. Immediately prior to application, a platelet activa- tor/agonist (topical bovine thrombin and 10% calcium chloride) is added to activate the clotting cascade, producing a platelet gel. The whole process takes approximately 12 minutes and produces a platelet concentration of 3 – 5 x that of native plasma [3]. Growth factors are involved in key stages of wound healing and regenerative processes in- cluding chemotaxis, proliferation, differentiation, and angiogenesis [4]. An advantage of PRP over the use of single recombinant human growth factor delivery is the release of multiple growth factors and differentiation factors upon platelet activation [5]. The morphologic and molecular configuration of PRP was reported, it showed PRP is a fibrin framework over platelets that has the potential to support regenerative matrix [6]. In humans, PRP has been evaluated and used as a injective “drug” for several types of medical treatments, including chronic tendinitis,[7] osteo- arthritis,[8] for bone repair and regeneration,[9] in oral surgery,[10] and in plastic surgery,[11]. Accumulating evidence indicates that neuro- immunophilin ligand and many growth factors, such as insulin growth factor-1 (IGF-1), brain- derived growth factor (BDNF) and vascular en- dothelial growth factor (VEGF) play a significant role in neural regeneration and up-regulation of neuronal nitric oxide synthase (nNOS), as well as in the recovery of erectile function after CN injury [12]. This evidence is the starter point for a speculative research in Uro-andrological field evaluating the use of PRP by corpus cavernosus (CC) injection in “patients” (rat models) undergone anatomic nerve-sparing Radical Prostatectomy which often cause incomplete or delayed recovery of erectile function. In many instances, the cavern- ous nerves (CNs) may have been inadvertently damaged by manipulation during nerve-sparing prostatectomy. The recovery of erectile function may depend on re-growth of nerves from the remaining neural tissue [12]. In two different studies Ding X-G et al. [12] and Wu YN et al. [13] evaluated different preparation of PRP in recovery of erectile func- tion after bilateral cavernous nerve injury in a rat model. Despite differences of methods and quality of PRP (different production methods), both studies demonstrated that the injection into the corpus cavernosum facilitated recovery of erectile function. Although the interesting premises, real RCTs are lacking and even in the sports medicine literature was not demonstrating any benefit. A Cochrane review that reviewed PRP therapy studies in musculoskeletal injuries, demonstrated no significant difference in treatments groups versus controls [14]. Another note that contribute to conceal a possible effectiveness of PRP is that there are no listings on www.clinicaltrials. gov for PRP and ED. Things changes when we put the key words “PRP, erectile dysfunction” on Google. A research performed in October 2017 showed 133.000 re- sults (147,000 for “Platelet Rich Plasma, erectile dysfunction”). The results were all about the ef- fectiveness and safety of the procedure. A similar research on Google was performed by Lawrence Marco Franco MD Department of Urology Federico II University of Naples, Italy marcofranco87@gmail.com Eduardo García-Cruz Department of Urology Hospital Clinic of Barcelona, Spain edu_garcia_cruz@yahoo.com