[Cellular viability of cryopreserved cartilage grafts]. / Viabilidad celular de injertos de cartílago crioconservados.

Transplantation of preserved cartilage has an important role in reconstructive surgery. Opinions vary with regard to the performance of cryopreserved cartilage. We studied the functional state of chondrocytes after cryopreservation. Cellular survival was studied using the trypan blue dye exclusion test, a functional assay for cell adhesion, and transmission electron microscopy. Most chondrocytes were irreversibly damaged by cryopreservation and the cartilage could not originate new cartilage. Therefore, cryopreserved cartilage tends to generate fibrosis and resorption and is not practical for reconstructing skeletal parts exposed to mechanical stress.

Laryngeal reconstruction using allogeneic cartilages.

Preserved allogeneic cartilage has been used to reconstruct laryngeal defects. The most important problem with this approach has been graft resorption, which seems to be caused by devitalization of the grafts as a consequence of preservation. In this study, the authors compared the in vivo behavior of vital and nonvital preserved cartilage used to reconstruct the larynx of New Zealand white rabbits. The vital cartilage grafts were stored using organ culture procedures, and the nonvital grafts were stored in formaldehyde. While the formaldehyde-preserved cartilage showed inflammatory changes, the transplanted vital cartilage was well accepted and showed no evidence of immune cell infiltrations. The authors concluded that viable cartilage grafts are preferable to grafts of chemically preserved cartilage.

[Vital preservation of cartilage transplants with tissue culture methods]. / Vitale Konservierung von Knorpeltransplantaten mittels Gewebekulturmethoden.

Cartilage grafting is one of the most common procedures in plastic surgery. Since storage of both autologous and allogenic cartilage is necessary, different preservation methods have been used with more or less success. The use of chemical preservation procedures like formaldehyde, Merthiolate or Cialit lead to a loss of the vitality of the graft. This work presents a study of the cell vitality and the matrix of cartilage grafts stored in different solutions (formaldehyde, saline, RPMI 1640, Ham F-12 and DMEM 4500) during 150 days. The cell viability was assessed using tissue sections (neutral red supravital staining and trypan blue dye exclusion test) and isolated cells (trypan blue dye exclusion test and cell adhesion in monolayer culture). The state of the cartilage matrix was analysed by means of the azan, alcian and toluidine blue staining). Cartilage immersed in formaldehyde solution lost 100% of the vitality after a storage period of 10 days, the one immersed in saline solution after 30 days. Cartilage stored in tissue culture media retained its vitality (> 85%) during the whole storage time. Histological staining methods showed a decrease of the staining intensity after 10 days storage in formaldehyde and after 30 days storage in saline solution. No differences in vitality and the matrix staining were found among all three culture media. Our results suggest that viable cartilage tissue can be successfully stored for a long time using tissue culture methods.

[Fundamental concepts in the implementation of the spectroscopic magnetic resonance for the determination of the biological quality of human cartilage transplants]. / Conceptos básicos en el empleo de la resonancia magnética espectroscópica para determinar la calidad biológica de trasplantes de cartílago humano.

Cartilage grafts are often used in reconstructive surgery for compensating loss or defect in tissues. Future progress in this field are related to the resolution of some problems concerning the preservation in our tissue-banks. Several time-expensive biochemical, histological and autoradiographic methods have been employed in the past to describe the metabolic properties and pathological changes of preserved and transplanted cartilage grafts. In this article we show that magnetic resonance spectroscopy offers the possibility to recognize metabolic changes in cartilage tissues as a consequence of storage conditions: anaerobic metabolism (lactacte) and lysis of collagenic structures of the matrix. In this way objective parameters assessing the biologic quality of grafts can be obtained without any destructive impact on the specimen.

[Rabbit's middle ear as a practical model for the initiation in otosurgery]. / El oído medio del conejo como modelo práctico en la iniciación a la otocirugía.

The rabbit's head is a practical model which make easy at beginning the practical for the knowledge and the use of specific instruments in ear surgery, as well as the handling of the microscope. The raw material is cheap and its obtention is easy. The grip of the rabbit's temporal bone facilitates a lot preparation of the human temporal bone, nowadays harder to get. In our Laboratory of otologic dissection the first resident's contact with the ear surgery, since years, is through the rabbit's head. The experience so gained by young specialists is excellent.