Selection of a material suitable for pleural covering.

Microscopic findings of the visceral pleura in a Beagle dog 6 weeks after surgery to cover dog’s lung with either ORC mesh (A, B), VIC mesh (C, D) or PGA sheet (E, F), respectively. The photomicrograph of normal appearance of dog lung is presented (G) for comparison. The visceral pleura covered with ORC (A and B) was approximately 5 times thicker than untreated pleura. There was no adhesion between the visceral pleura and the chest wall. In contrast, VIC and PGA induced severe fibrotic changes associated with pleural symphysis (C, and E): Note that ORC was completely absorbed (B) whereas both VIC and PGA were not: the white dots indicate unabsorbable VIC mesh (D) or PGA sheet (F). A, C, E, andn G: Hematoxylin and eosin staining. B, D, and F: Masson-trichrome staining. A, B, C, E, andn G: low magnification view. D and F: high magnification view.