Four‐Month Evaluation of PVA‐Coated Polypropylene Meshes After Laparoscopic Intraperitoneal Implantation in an Exploratory Porcine Abdominal‐Wall Defect Model

ABSTRACT Postoperative intra‐abdominal adhesion remains a major limitation of intraperitoneal polypropylene (PP) mesh. We evaluated three poly(vinyl alcohol) (PVA)‐coated PP meshes—PVA–PP, rapamycin‐loaded liposome‐decorated PVA–PP (RPM@LPS/PVA–PP), and the corresponding NaHCO 3 ‐containing formulation [RPM@LPS(NaHCO 3 )/PVA–PP]—in a four‐month exploratory laparoscopic Bama miniature‐pig study. Two pigs received all four formulations at anatomically separated, randomized abdominal‐wall sites, yielding 12 implantation sites in total and three site‐level observations per formulation. Gross adhesion, abdominal‐wall tissue–mesh mechanics, histology, collagen composition, immunohistochemistry, and multiplex immunofluorescence were assessed. Unmodified PP produced dense visceral attachment at all three implantation sites (mean site‐level adhesion score, 4.00), whereas the mean scores for PVA–PP, RPM@LPS/PVA–PP, and RPM@LPS(NaHCO 3 )/PVA–PP were 0.50, 0.33, and 0.17, respectively. Adhesion area showed the same descriptive ordering. Mean abdominal‐wall tissue–mesh lap‐shear and peel strengths were also lowest with RPM@LPS(NaHCO 3 )/PVA–PP (0.0091 MPa and 0.1766 N mm −1 , respectively) compared with PP (0.0500 MPa and 0.7823 N mm −1 ), indicating reduced host‐wall integration rather than direct mechanical confirmation of weaker visceral adhesion. Modified interfaces showed less dense fibrous tissue, lower total and Type I collagen, and a higher Type III collagen fraction. The mean Type I/Type III collagen ratio decreased from 15.38 for PP to 2.27 for RPM@LPS(NaHCO 3 )/PVA–PP. Lower IL‐6‐, TNF‐α‐, α‐SMA‐, CD31‐, CD68‐, and iNOS‐associated signals, together with a higher CD206‐positive/CD68‐positive area ratio, accompanied these changes. These exploratory two‐animal findings show a descriptive association between the use of PVA‐coated PP meshes and reduced chronic visceral adhesion, while identifying host‐wall integration as a necessary safety consideration.