Minimally invasive cleft palate repair using injectable hydrogels

Introduction and objectives: In cleft palate (CP) patients, traditional palatoplasty seems to impair mid-facial growth due to the extensive mucoperiosteal flaps. In this study we aimed to develop a novel flapless procedure for CP repair by injecting a BMP-2 containing hydrogel: the injection/adhesion technique [Martínez-Álvarez C, González-Meli B, Berenguer-Froehner B, Paradas-Lara I, López-Gordillo Y, Rodríguez-Bobada C, González P, Chamorro M, Arias P, Hilborn J, Casado-Gómez I, Martínez-Sanz E: Injection and adhesion palatoplasty: a preliminary study in a canine model. Journal of Surgical Research 2013, in press, doi:10.1016/j.jss.2013.03.009]. Material and methods: We used the Old Spanish Pointer dog breed, which develops CP in 15-20% of the offspring. Twenty pups were included in 4 groups. A: normal palate controls (n=5), B: CP controls (untreated) (n=4), C: CP individuals repaired with 2-flap palatoplasty (n=6) and D: CP individuals repaired with the injection/adhesion technique (n=5) as the novel experimental approach which consisted in the injection of a hyaluronan based hydrogel (Termira, Sweden), containing BMP-2 and nanohydroxyapatite, in the CP edges of pups aged 6 weeks, followed by the removal of the overlying mucosa and suture at week 10. Both techniques were compared in terms of results of repaired tissues, difficulty, duration, and complications. Results: Compared to palatoplasty, the injection/adhesion technique was easier, and the post-surgical recovery was faster and better, although it required two sessions. Lateral scar and denuded bone were avoided with the experimental approach. The palatal bones did not show overlapping or bone defects in the experimental or untreated controls, as observed in the palatoplasty group. No adverse effects were observed although small fistulas were observed in the first experimental pups. Conclusion: The injection/adhesion technique may represent an attractive clinical alternative to traditional palatoplasty for CP patients. Keywords: cleft palate, BMP-2, hyaluronic acid, hydrogels, dog, palatoplasty