Moreover, a statistically significant positive correlation between periostin concentration and vascularity (microvessel density and optical density of the vascular endothelial marker) in the pretreatment group is not observed (rho = -0.02, p = 0.907; rho = 0.07, p = 0.713, respectively).<h4>Conclusions</h4> The results support the preoperative administration of systemic corticosteroids and antibiotics to reduce the degree and intensity of inflammation in CRSwNP; this may impact the surgical field during ESS. Here, POSTN is linked to chronic rhinosinusitis with nasal polyps.