Microsurgical tracheotomy: a pediatric model in growing rats.

Previous studies described controversial opinions about pediatric tracheotomy concerning type of tracheal incision and long-term results, which remain as important research subjects. Experimental studies on rat tracheas are scarce, probably because of technical difficulties related to the structures' small dimensions. As many rat organ and system operative procedures were studied successfully by using microsurgical techniques, we decided to develop a pediatric tracheotomy model in growing rats which would permit long-term studies. Forty-four Wistar EPM-1 growing rats weighing 86 g and aged 35 days were divided into three groups: submitted to longitudinal, transverse, and segment excision of the trachea. Under sterile technique and intramuscular anesthesia (ketamine/xylazine), the trachea was exposed and incised, according to group, and a hand-made endotracheal cannula was inserted into the organ. This cannula was assembled using a segment of 1.5-cm-long 3 French silicone catheter passed through hexagonal-shaped silicone screen. The tracheal cannula was removed after 7 days, when we evaluated body weight, secretions, and dehiscence. In conclusion, this microsurgical tracheotomy model in growing rats is feasible, allowing studies on long-term repercussions of pediatric tracheotomy.