The evaluation of two new hyaluronan hydrogels as nasal dressing in the rabbit maxillary sinus.

BACKGROUND The postoperative scaring, ostial stenosis, and adhesions after functional endoscopic sinus surgery for chronic rhinosinusitis remains a major problem. This study was designed to evaluate two new hyaluronan (HA) hydrogels for neo-ostium antistenosis and promoting wound healing in a rabbit maxillary sinus model. METHODS The anterior wall of the maxillary sinus of 48 rabbits was removed to create a 4-mm circumferential wound both on the nasal and on the sinus sides. A rapid-gelling HA hydrogel or preformed HA hydrogel was filled randomly into the right or left sinus, while the opposite sinus served as blank control or was treated with Merogel (Medtronic Xomed Surgical Products, Jacksonville, FL) as control. The neo-ostium diameter and histological scores were evaluated and analyzed postoperatively. RESULTS The neo-ostium diameter in the rapid-gelling HA hydrogel-treated side was significantly larger than that in the blank control side with a mean difference of 1.46 ± 0.99 mm (p = 0.03), 1.30 ± 0.61 mm (p = 0.0087), and 1.60 ± 0.25 mm (p = 0.00015) at 2, 3, and 4 weeks, respectively; the neo-ostium diameter in the preformed HA hydrogel-treated side at 2 weeks was significantly larger than that in the blank control side or Merogel control side with a mean difference of 1.46 ± 0.76 mm (p = 0.002) or 0.54 ± 0.36 mm (p = 0.007), respectively. The preformed HA hydrogel-treated side showed better histology scores at 2 weeks in heterophils, fibrosis, and osteogenesis than the blank control, and the chronic inflammation (lymphocyte/plasmacyte infiltration) was not prevalent. CONCLUSION During the postoperative follow-up period both of the two HA hydrogels significantly prevented neo-ostium stenosis and the preformed HA hydrogel promoted wound healing.