Poly(glycerol sebacate)-engineered plugs to repair chronic tympanic membrane perforations in a chinchilla model

To evaluate the degree of neovascularization and efficacy of repair of chronic tympanic membrane perforations in a chinchilla model using poly(glycerol sebacate) (PGS), a novel bioengineered scaffold material.

A feasibility study in which chinchilla ears with chronic perforations were randomly assigned to repair with PGS plugs or Gelfilm overlay myringoplasty.

Interventions were performed in the animal care facility of a tertiary care academic institution.

Sixteen adult female chinchillas. Perforations were established under microscopic visualization with thermal cautery. The animals were examined six weeks later, and those ears with stable perforations were randomly assigned to repair with PGS or Gelfilm. All ears were evaluated six weeks after repair, and resected membranes underwent histological evaluation.

Chronic perforations were established in 22 of 32 (69%) chinchilla tympanic membranes. Nineteen tympanic membranes were included in the study group (3 ears were excluded secondary to death from anesthesia during the repair); 11 were implanted with PGS, and eight underwent Gelfilm myringoplasty. Of the 11 tympanic membranes implanted with PGS, 10 were healed at six weeks, while six of the eight tympanic membranes repaired with Gelfilm had healed at six weeks. Imaging of the medial mucosal and lateral epithelial surfaces of the tympanic membranes revealed PGS plug incorporation with neovascularization. Histology demonstrated a confluent cell layer on both sides of the graft.

PGS plugs are easily placed and allow for perforation closure and graft neovascularization in a chinchilla model.