Evaluation of the histopathological modifications induced by the positioning of autologous platelet-rich plasma vs. biosynthetic, absorbable mesh as reinforcement of the cruroplasty: a study on an animal model

Introduction: Symptomatic hiatal hernia’s (HH) incidence, associated with gastroesophageal reflux disease (GERD), ranges between 10-20% in the general population. Laparoscopic suture of the diaphragmatic crura (posterior cruroplasty PC) during the HH’s surgical treatment determines good long-term results in the majority of cases, without cancelling the risks of recurrences or surgical revisions. Based on anatomical, physiological, morphological and evolution of certain diseases, the use of porcine model became one of the most important research fields, including laparoscopic implant of prosthetic materials. Cruroplasty’s reinforcement is widely used in large hiatal defects for recurrences’ reduction with no consensus on type or shape of mesh. The use of autologous platelet-rich plasma (PRP) concentrate, simple and cheap prepared, might be an alternative option. Aims: finding new solutions for the laparoscopic treatment of symptomatic HH, in particular comparing a biosynthetic, absorbable mesh, vs. autologous PRP in a porcine model, in order to determine local histopathological (HP) changes and complications. Rationale: the literature lacks on comparative studies on the use of PRP for the reinforcement of hiatal defects repair. Materials and methods: Prospective, randomized study on 12 pigs. The laparoscopic procedure consisted in creation of a hiatal defect, then sutured PC, reinforced with absorbable mesh (group A) or PRP positioning (group B). Blood withdrawal was made prior to surgery for autologous concentrate’s preparation in group B. The animals survived the procedure and professional care was taken for the next 7 months. Second procedure was performed afterwards, consisting in euthanasia, laparoscopy, and laparotomy for specimen retrieval (whole hiatal area). HP examination was performed, evaluating 4 main components: proliferative fibroblast – fibrocyte – collagen neoformation; vascular; inflammatory; and dystrophic. A semiquantative HP scoring of tissue reaction was elaborated. Expected Results: direct consequences on the public health for the management of the HH/GERD, definition of the technical indications, avoiding costly materials loss. Results: animals survived 7 months of postoperative care, with normal growth and without complications related to the surgical procedures. There were no complications, local or general, in both groups, with more intense adherential process in group A at the gross examination. Complete resorption of both products was demonstrated on gross and HP examination. Both reinforcements determined inflammatory infiltrates predominantly mononuclear, with induced local collagen production and tissue neo-vascularization. Animals in the mesh group had increased mean chronic inflammation score (2.66 vs. 1.83, p = 0.908) compared to the PRP group. Vascular network did not differ between groups (p = 0.3061), although there was an increased trend toward mean collagen fibers in the mesh group (score 2.83±0.4) compared to PRP (2.33±0.81), p=0.248. Conclusions: Our laparoscopic, animal model of hiatal hernia repair was reliable, feasible and reproductible. The comparative study of both materials, autologous and biosynthetic, did not show any specific complications, with no residual material found after 7 months. The mesh group showed a more important score of sclerotic collagenising process. PRP was shown to be an autologous source of pro-regenerative growth factors and chemokines suited to hiatal area wound healing, enhanced angiogenesis, myofibroblast recruitment and tissue ingrowth and less severe peritoneal adhesions. The novelty of the study and the histopathological results suggest the use of combined products, so autologous PRP could find a clinical application in the surgical treatment of the hiatal defects, as a promising co-adjuvant to local remodeling and healing in this animal model. Next studies should verify that the use of PRP could improve the crura’s weakness.