The effect of insulin-like growth factor 1 incorporated into a hyaluronic acid-based nasal pack on nasal mucosal healing in a healthy sheep model and a sheep model of chronic sinusitis.

Endoscopic sinus surgery (ESS) is the accepted surgical treatment for chronic refractory rhinosinusitis. Prolonged healing and adhesion formation remain common problems. This study investigates the use of a hyaluronic acid-based pack impregnated with insulin-like growth factor (IGF) 1 to facilitate more rapid and effective healing after ESS in a healthy sheep model and a sheep model of chronic sinusitis. This study used 12 healthy sheep and 9 sheep with chronic sinusitis. In each sheep one side (computer randomized) was used as a control. Under endoscopic guidance, mucosal injuries and adhesions were created on both sides and were either packed with a hyaluronic acid pack impregnated with IGF-1 or left unpacked as a control. Serial biopsies were performed for 4 months. In the healthy sheep there was a statistically significant (p < 0.05) improvement in reepithelialization in IGF-1 packed wounds at day 28 (89% for IGF-1 versus 44% for controls). In both healthy sheep and sheep with sinusitis there was no significant difference in mucosal reepithelialization at any of the other measured time points. In the sinusitis group, there was a significant decrease in ciliary regeneration at day 56 in the Merogel/IGF-1 group compared with the control group: 59.20% versus 77.68% (p < 0.01) and at day 112, 69.70% versus 87.26% (p < 0.01). Hyaluronic acid impregnated with IGF-1 improved reepithelialization in the healthy sheep but not in the sheep with chronic rhinosinusitis. These packs had a detrimental effect on mucosal ciliary regeneration in the sheep with chronic rhinosinusitis.