Plastic surgery of a critical defect in the tracheal wall using a cell engineering design and a stent in an experiment

Aim. To experimentally test a new method for plastic surgery of a critical defect in the tracheal wall using a cell engineering construction and a stent. Materials and methods. The object of the experiment was 13 Oryctolagus Chinchilla rabbits. To determine the critical size of the tracheal defect, a “Defects Group” (n=11) was created, divided into two subgroups depending on the width of the mucous and submucosal defect, the length of the defect was standard – 15 mm. Subgroup 1 included animals with a defect width of <50% of the tracheal circumference (n=5), subgroup 2 – animals with a defect width of ≥50% of the tracheal circumference (n=6). After critical tracheal defects were created, two more rabbits underwent plastic surgery using a cell-engineering construct fixed in the trachea's lumen using a vascular stent. (“Reconstruction Group”). After removing animals from the experiment, we performed a macro and microscopic examination. Results. In subgroup 1, postoperative mortality was not registered, animals were withdrawn from the experiment on the 14th day. Macroscopically: a slight but noticeable tracheal narrowing, microscopically: a thin, weak submucosal layer and an epithelial film without purulent inflammation. In subgroup 2, postoperative mortality was 100% on the 4th day. Macroscopically: a hematoma at the site of defect, the mucous membrane is swollen, the lumen of the trachea and large bronchi is obstructed by mucus, microscopically: massive detritus. We recognise the defect in subgroup 2 as critical. In the “Reconstruction Group” postoperative mortality was not registered. Animals were withdrawn from the experiment on the 14th and 20th days. The trachea is separated from the stent, the lumen is not narrowed, and the matrix is partially fragmented. Macroscopically: absence of severe hematoma and oedema, microscopically: multiple zones with the regeneration of the submucosal layer and mucosa. Conclusions. A critical tracheal defect in rabbits is an epithelial and submucosal defect with a length of 15 mm and a width of ≥50% of the circumference of the trachea. The plasticity of a critical defect with the help of a cell engineering design and a stent showed its viability in the experiment.