title: Effects of platelet-rich plasma on intestinal anastomotic healing in rats: PRP concentration is a key factor.
abstract: BACKGROUND
  Few studies have examined the effects of platelet-rich plasma (PRP) on intestinal anastomotic healing. The applied preparation methods and PRP concentrations used in the few studies that have been carried out varied markedly. Therefore, the positive effects of PRP on the anastomotic healing process remain unclear. The aim of this study is to examine the effects of different concentrations of PRP on intestinal anastomotic healing.
  
  
  METHODS
  From SD rat blood, three different concentrations of plasma were prepared: high-concentrated PRP (H-PRP: platelet count 5 × 10(6)/mm(3)), low-concentrated PRP (L-PRP: 2 × 10(6)/mm(3)), and platelet-poor plasma (PPP). Male SD rats underwent proximal jejunal anastomosis and central venous catheterization. Rats were divided into four groups (n = 12 for each group): control, PPP, L-PRP, and H-PRP groups. Two types of PRP and PPP (0.21 mL) were applied to each anastomosis line, with the exception of the control group. Total parenteral nutrition (TPN) solutions were administered (151 kcal/kg/d). Five days after surgery, anastomotic bursting pressure (ABP) in situ and hydroxyproline concentration (HYP) in anastomotic tissue were evaluated.
  
  
  RESULTS
  The ABP values of control, PPP, L-PRP, and H-PRP groups were 171 ± 20, 174 ± 23, 189 ± 17, and 148 ± 25 mmHg, respectively. The HYP values of each group were 516 ± 130, 495 ± 123, 629 ± 120, and 407 ± 143 μg/g dry tissue. Compared with the other groups, the L-PRP group exhibited a significant increase in both ABP and HYP, while the H-PRP group exhibited a significant decrease in these two variables. As a result, L-PRP was considered to promote anastomotic wound healing, but H-PRP was considered to inhibit it. There was no significant difference between the PPP group and the control group.
  
  
  CONCLUSIONS
  PRP concentration plays a crucial role in the efficacy of PRP. PRP might exert positive effects on intestinal anastomotic healing in a dose-dependent manner up to a certain level, but adverse effects occur when it is highly concentrated. The essential PRP action appears to be driven by the platelets themselves.
authors.affiliation: Department of Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan. h-tera@md.tsukuba.ac.jp
authors.forename: Ryushiro
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Hideo
authors.initials: H
authors.lastname: Terashima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoneyama
authors.forename: Sosuke
authors.initials: S
authors.lastname: Tadano
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ohkohchi
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D003094:Collagen / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood; D007583:Jejunum / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D008297:Male; D009752:Nutritional Status; D053657:Platelet-Rich Plasma / Q000166:cytology / Q000502:physiology*; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D014945:Wound Healing
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D003094:Collagen