The Effect of Rhinoplasty Dissection Planes (Sub-SMAS, Subperichondrial, and Subperiosteal) on the Viability of Diced Cartilage Grafts in a Rabbit Model.

Abstract

Dorsal preservation surgeries in which the subperichondral and subperiosteal planes are used to elevate the soft tissue envelope of the nose have become increasingly widespread because they can reduce postoperative edema and promote faster healing. However, the effects of surgical dissection planes on the viability of cartilage grafts are not known. The aim of this study was to determine, in a rabbit model, the viability of diced cartilage grafts in different rhinoplasty dissection planes (sub-superficial musculoaponeurotic system [SMAS], subperichondral, subperiosteal). Diced cartilage samples were placed in the sub-SMAS, subperichondrial, and subperiosteal planes, and after 90 days, histopathologic analysis was performed. Cartilage graft viability was evaluated based on the loss of chondrocyte nuclei in the lacuna, the presence of peripheral chondrocyte proliferation, and the loss of matrix metachromasia in the chondroid matrix. The median [interquartile range] percentages of live chondrocyte nucleus viability in the sub-SMAS, subperichondrial, and subperiosteal groups were 67.5% [18.75%] (range, 60%-80%), 35% [17.5%] (range, 20%-45%), and 20% [30.0%] (range, 10%-45%), respectively; and the percentages of peripheral chondrocyte proliferation were 80.0% [22.5%] (range, 60%-90%), 30% [28.75%] (range, 15%-60%), and 20% [28.75%] (range, 5%-60%), respectively. There was strong statistical significance in both parameters (P = .001). Intergroup examination revealed a difference between the sub-SMAS and the other surgical planes (P = .001 for both parameters). A smaller loss of chondrocyte matrix was observed in the sub-SMAS group compared with the other 2 groups, which supports the findings of cartilage viability (P = .006). Elevating the soft tissue envelope of the nose in the sub-SMAS surgical plane preserves the viability of cartilage grafts better than subperichondrial and subperiosteal elevation.