Augmentation of the Porcine Vocal Fold Using Autologous Composite Cervical Fascia and Fat Graft. Comparison Between the Transmuscular and Submuscular Approaches

Objectives To assess the integration of an autologous composite fascia and fat graft implanted into the lamina propria of a porcine vocal fold using two different approaches. Study Design An experimental prospective study on the porcine larynx was conducted at a tertiary research institution. Methods An external cervical approach was used to expose the thyroid cartilage of 24 healthy minipigs under general anesthesia. The composite fascia/fat graft was implanted through two distinct approaches, transmuscular and submuscular. Animals were sacrificed at 7, 30, 90, and 180 days for macroscopic and histological study of the larynx. Graft integration and local inflammatory response were studied. Results The survival rate of the experimental model was 100% and all animals had local inflammatory response to the surgical procedure. Only 41.7% of the grafts placed inside the thyroarytenoid (TA) muscle fibers were identified postmortem, whereas 83.3% of the submuscular grafts remained intact. Conclusions Graft incorporation was better and there was less inflammation when the architecture of the TA muscle fibers was preserved. Graft extrusion was observed in the most of the cases where it was placed inside the muscle.