Short-term effects of perichondrium preservation on chondrocyte survival and chondrogenesis of auricular cartilage grafted in rabbit tympanic bullae.
BACKGROUND
Obliteration of the mastoid cavities with auricular cartilage is a frequently used method to minimize the open cavity problem in cholesteatoma surgery. However, the method of cartilage preparation and histopathologic changes of the grafted cartilage in patients receiving mastoid obliteration are rarely reported. Hence, the authors developed rabbit tympanic bulla obliteration with auricular cartilage as an animal model and studied the effects of perichondrium preservation on the grafted cartilage.


METHODS
Auricular cartilage with or without perichondrium was prepared and cut into small pieces to obliterate rabbit tympanic bullae. Four weeks after surgery, the viable chondrocyte ratio indicated by the number of viable chondrocytes divided by the total number of chondrocytes, the microvascular density shown by CD31-labeled vessels, and the chondrogenesis ratio represented by the ratio of the cross-sectional areas of the newly formed cartilage and the originally grafted cartilage were calculated and compared.


RESULTS
The viable chondrocyte ratio was 49.21 +/- 10.17% in the perichondrium-preserved group (n = 12) and 35.46 +/- 3.96% in the perichondrium-removed group (n = 12, p = 0.001). The CD31 microvascular density was significantly higher in the perichondrium-preserved group than in the perichondrium-removed group (167.77 +/- 15.83 vs. 77.17 +/- 19.67 microvessels/mm(2), p < 0.001). The chondrogenesis ratios were 27.58 +/- 12.44% in the perichondrium-preserved group and 0.45 +/- 0.63% in the perichondrium-removed group (p < 0.001).


CONCLUSIONS
Obliteration of tympanic bullae with perichondrium-preserved cartilage results in faster restoration of circulation, higher survival of chondrocytes and more cartilage regeneration than with perichondrium-removed cartilage.
Tu
Tzong-Yang
TY
Department of Otolaryngology, Taipei Veterans General Hospital, Taipei, Taiwan. tytu@vghtpe.gov.tw
Yang
An-Hang
AH
Fan
Chi-Chen
CC
D000818:Animals; D002356:Cartilage / Q000098:blood supply / Q000637:transplantation*; D002452:Cell Count; D002470:Cell Survival / Q000502:physiology*; D019902:Chondrocytes / Q000473:pathology / Q000502:physiology*; D020219:Chondrogenesis / Q000502:physiology*; D003238:Connective Tissue / Q000473:pathology / Q000502:physiology; D004432:Ear, Middle / Q000098:blood supply / Q000473:pathology / Q000601:surgery*; D005260:Female; D007124:Immunoenzyme Techniques; D008297:Male; D008833:Microcirculation / Q000502:physiology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D011817:Rabbits; D012038:Regeneration / Q000502:physiology; D014021:Tissue Preservation / Q000379:methods*
D019408:Platelet Endothelial Cell Adhesion Molecule-1