Long-term effects of pleural defect repair using sheet materials in a canine model

Abstract

A sheet material is widely used to repair pleural defects due to its excellent pressure resistance. We examined the long-term effects of sheet materials using an animal pleural defect model. Beagles were used for this study. The 5-mm circular pleural defects were created at 2 sites on each of the anterior, medial, and posterior lobe and repaired using a 2cm square sheet material. The frequency of adhesion of those sheets to the thoracic walls and histological changes was examined after 6months. In this study, three types of sheet materials were examined: polyglycolic acid, nano-polyglycolic acid, and oxidized regenerated cellulose where each sheet was tested with or without coating with fibrin glue, for a total of 6 groups. Each group contained an equal number of defect sites and evaluation of 12 defect sites was conducted. Adhesion was observed in 16 of 72 sites (22%). Presence or absence of adhesion was not affected by the repair method or by the type of sheet material used. However, the use of fibrin glue significantly reduced the occurrence of adhesion (p = 0.023). At the defected sites, the posterior lobe showed significantly less adhesion (p = 0.019). Histologically, the sheet materials caused a thickening of the pleural wall 6-10 times thicker than the normal pleural wall. No statistically significant differences regarding the presence or absence of adhesion to the thoracic wall were found among the sheet materials. The use of fibrin glue significantly reduced the adhesion to the thoracic wall.