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Biomedical subjects

Jin Soon Chang

Publications and source records attributed to Jin Soon Chang.

2 recordsLinked to original sources

Nasal reconstruction: the state of the art.

PURPOSE OF REVIEW: Cutaneous malignancies of the nose are common problems and create the need for nasal reconstruction within many otolaryngology practices. In spite of the fact that such reconstruction is an ancient art, there continue to be innovations and advances that allow for more predictable and functional long-term results. RECENT FINDINGS: Analyzing the nasal defect through an organized algorithm can be useful in many circumstances, especially when one needs to consider vectors of tension, minimizing alar base asymmetry, resultant scars, and preservation of the intranasal airway. Application of the principle of aesthetic subunits has greatly improved the cosmetic results for many large nasal defects, and there have been some proposals to modify the original definitions and concept. Structural reconstruction is paramount with complex defects that involve the nasal framework or with those that are located in functionally critical areas. Autogenous cartilage grafting remains the gold standard, but the use of alloplastic and homograft materials for grafting continues to be reported as an alternative. Internal lining repair is essential with larger defects and the versatility of intranasal flaps is understood, but at times not available. Other flaps have been described and may be useful on such occasions. SUMMARY: There are many considerations during nasal reconstruction, and the surgeon must be facile with a variety of options within his/her armamentarium.

Algorithms↗

Transplanted tissue-engineered cartilage.

OBJECTIVE: To evaluate the feasibility of transplanting sculpted autogenous tissue-engineered cartilage (TEC) with the hope that it will retain precise 3-dimensional morphologic features after transplantation. Transplanted TEC is described in terms of the gross morphologic and histologic characteristics in contrast to pretransplanted TEC. METHODS: Synthetic scaffolds of a polyglycolic acid and poly-l-lactic acid polymer, coated with chondrocytes derived from rabbit auricular cartilage in concentrations ranging from 2.7 x 10(6)/mL to 6 x 10(7)/mL, were incubated in vivo on the dorsum of a rabbit for 8 weeks and then retrieved. The resultant TEC specimens were then sculpted into defined shapes and transplanted into a different location in the same rabbit, where they were allowed to incubate for another 8 weeks. The specimens were then retrieved and compared with the TEC before transplantation according to size, weight, and histomorphometric analysis. RESULTS: Thirteen chondrocyte-laden templates were successfully engineered to develop TEC. In each case, they were sculpted and transplanted to a different site in the same rabbit. Eight weeks after transplantation, all sculpted TEC specimens lost their original 3-dimensional morphologic features and experienced a significant decrease in mass. Histologically, the staining intensity of both hemotoxylin-eosin and safranin O was dramatically reduced following transplantation. In addition, there was a reduction in chondrocyte viability. Two consistent histologic findings were a foreign-body reaction to the synthetic polymer and ongoing cellular activity directed toward the formation of bone. CONCLUSIONS: Transplanting autogenous TEC does not allow the preservation of precise morphologic features that are needed for clinical implantation. The osteogenic progression and foreign-body reaction must also be controlled.

Animals↗