Pathological Features of Free Graft and Pedicled Flap in the Nasal Cavity: An Animal Study

Abstract

Objectives/hypothesis: Recent developments in reconstructive techniques for mucosal defects using mucoperiosteal materials have enabled rapid recovery of physiological function after endoscopic sinus surgery. Clinical trials have described the advantages, disadvantages, and different outcomes of free graft and pedicled flap, which, respectively, sacrifice or preserve blood flow. However, histological changes, that affect the postoperative outcomes after reconstruction, remain unclear. We created an animal model for the reconstruction of mucosal defects using free grafts and pedicled flaps, and evaluated them histologically.

Study design: Animal study.

Methods: We created mucosal defects in the left nasal septum of 20 rabbits and performed reconstruction with free grafts and pedicled flaps. The distribution of ciliary and goblet cells at the reconstruction site was evaluated after 7 and 28 days using hematoxylin and eosin-stained sections to calculate the Ciliary Cell Index and Goblet Cell Index. The severity of inflammation was assessed using the Cartilage Inflammatory Cell Score.

Results: Crusting and changes in the mucosal morphology at the reconstruction site occurred only in the free graft group. In addition, the pedicled flap group had significantly greater preservation of ciliary and goblet cells and less inflammatory cell infiltration into the septal cartilage (P < .05) than the free graft group.

Conclusions: After reconstruction procedures for mucosal defects, histopathological differences were observed between the free graft and pedicled flap. Reconstruction with pedicled flaps had advantages including preservation of healthy mucosal epithelium and suppression of inflammation on the reconstruction site. This indicated that reconstruction with pedicled flaps might have advantages over that with free grafts.

Level of evidence: NA Laryngoscope, 131:E428-E433, 2021.

Keywords: Endoscopic sinus surgery; ciliary cell; goblet cell; nasal physiological function; reconstruction.