RESUMO
In tracheal replacement transplantation, prelamination is a critical stage. Nowadays, the most widely used prelamination technique is the prethoracic fascia flap with lateral thoracic artery. We propose a flap based on the internal thoracic artery, which allows a relatively non-aggressive double organ implant, and we have tested its efficacy in decellularized tracheas. Tracheas of albino New Zealand rabbits were decellularized following a protocol that uses detergents and cryogenization, sterilized with 1kGy gamma radiation, and tutorized with a stent. Bilateral pedicled flaps made of pectoral fascia and a muscular component were harvested through a longitudinal 3-cm central thoracic incision, wrapping the tracheas with them in 16 rabbits, remaining them implanted for 2, 4, 8, and 12 weeks. The tracheas were then studied histologically using standard stainings plus immunohistochemistry (CD31). The models were adjusted with Bayesian statistics using ordinal regression; results as odds ratios and credibility intervals. All analysis were performed using R software. Acute inflammatory cell invasion was observed at 2 weeks, which almost disappeared at week 8 after implant. Only macrophages and giant cells increased between Weeks 8 and 12 (OR 10.487, CI [1.603-97.327]). The cartilage maintained its structure, with slight signs of ischemia in a few cases. New CD31-positive vessels were observed from Week 2 and increasing thereafter, reaching a maximum peak at Week 8. We propose a bilateral implant technique that is viable and effective as a prelamination option for two concurrent tracheas, achieving perfect vascularization and integration of the organ with hardly any inflammatory response in the medium or long term.
