Novel Therapy for Acquired Tracheomalacia with a Tissue-Engineered Extraluminal Tracheal Splint and Autologous Mesenchymal-Derived Chondrocytes

Abstract Introduction Acquired tracheomalacia (ATM) is characterized by a loss of structural strength of the tracheal framework, resulting in airway collapse during breathing. Near half of the patients undergoing prolonged invasive mechanical ventilation will suffer tracheal lesions. Treatment for ATM includes external splinting with rib grafts, prosthetic materials, and tracheal resection. Failure in the use of prosthetic materials has made reconsidering natural origin scaffolds and tissue engineering as a suitable alternative. Objective To restore adequate airway patency in an ovine model with surgicallyinduced ATM employing a tissue-engineered extraluminal tracheal splint (TE-ETS). Methods In the present prospective pilot study, tracheal rings were partially resected to induce airway collapse in 16 Suffolk sheep (Ovis aries). The TE-ETS was developed with autologous mesenchymal-derived chondrocytes and allogenic decellularized tracheal segments and was implanted above debilitated tracheal rings. The animals were followed-up at 8, 12, and 16 weeks and at 1-year postinsertion. Flexible tracheoscopies were performed at each stage. After sacrifice, a histopathological study of the trachea and the splint were performed. Results The TE-ETS prevented airway collapse for 16 weeks and up to 1-year postinsertion. Tracheoscopies revealed a noncollapsing airway during inspiration. Histopathological analyses showed the organization of mesenchymal-derived chondrocytes in lacunae, the proliferation of blood vessels, and recovery of epithelial tissue subjacent to the splint. Splints without autologous cells did not prevent airway collapse. Conclusion It is possible to treat acquired tracheomalacia with TE-ETS without further surgical removal since it undergoes physiological degradation. The present study supports the development of tissue-engineered tracheal substitutes for airway disease.

Reducción del tiempo de cicatrización por medio de laser de helio-neón. Modelo experimental en conejos / Reduction in wound healing by treatening wounds by helius-neon laser. An experimental model in rabbits

El objetivo del trabajo fue determinar las condiciones óptimas para una aceleración de la cicatrización en piel de conejos mediante el tratamiento de la herida con laser de helio-neón HeNe (632.8 nm). Para este fin se usaron dos grupos de 5 conejos cada uno, en uno se aplicó el tratamiento con laser y el otro sirvió de control. A los animales se les realizó un resección de piel de 2 x 5 cm. El grupo experimental se irradió con laser helio-neón con una potencia de 0.1 mW a una distancia aproximada de 3 cm, con un barrido en toda la herida, por un lapso de 5 min/día. Se tomó biopsia después de las 24 horas al primer conejo, posteriormente, cada 24 horas se tomó un conejo distinto y se realizó el análisis histológico. En el grupo experimental se observó un aumento en la actividad de los procesos de reparación, en comparación con el grupo control, como fue la proliferación de fibroblastos y el incremento en la fibras de colágena que sellaron la herida a partir del cuarto día. En las condiciones antes mencionadas se redujo el tiempo de cicatrización, por lo menos en un 40 por ciento comparado con el grupo control