Long-term in vivo stability of rabbit nasal septal cartilage following laser cartilage reshaping: a pilot investigation.
OBJECTIVE
To evaluate the long-term effect of laser cartilage reshaping on rabbit nasal septal cartilage viability and mechanical integrity in an in vivo model.


METHODS
In vivo animal investigation. Rabbit septal cartilage specimens were laser (Nd:YAG, lambda = 1.32 mum, spot size 5.4-mm diameter, 10 W, 10 seconds, 50 Hz PPR) reshaped and subsequently reimplanted into an interscapular subcutaneous pocket. Specimens were harvested at 8 and 12 months and evaluated using photography, flow cytometry, and histology.


RESULTS
Grossly, specimens showed alteration in the physical integrity with varying degrees of tissue resorption. The non-irradiated control specimens demonstrated significantly increased stiffness. Histologically, there was marked depletion of the extracellular matrix and an overall reduction in tissue mass in laser irradiated tissues. However, flow cytometry data identified viable chondrocytes in laser-irradiated specimens that were identical to those observed in controls.


CONCLUSIONS
Study results demonstrate that the rabbit nasal septal cartilage model can be effectively used to study laser reshaping, however alternative recipient sites with perichondrial lining, such as the pinna, may provide a more realistic physiologic environment for reshaped graft tissue. The dosimetry used in this pilot study likely led to significant thermal injury. Study results underscore the importance of elucidating the optimal laser dosimetry required to initiate permanent shape change while minimizing thermal damage.
Karamzadeh
Amir M
AM
Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine Medical Center 101, The City Drive South, Bldg. 25, Rt. 81, Orange, California 92868-3201, USA.
Chang
John C
JC
Diaz
Sergio
S
E Milner
Thomas
T
Wong
Brian J F
BJ
D000818:Animals; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D005434:Flow Cytometry; D007150:Immunohistochemistry; D053685:Laser Therapy; D008297:Male; D009297:Nasal Mucosa / Q000473:pathology / Q000528:radiation effects; D009300:Nasal Septum / Q000473:pathology* / Q000528:radiation effects*; D010865:Pilot Projects; D011817:Rabbits; D012016:Reference Values; D012680:Sensitivity and Specificity