['Many surgeons use absorbable packing materials after endoscopic sinus surgery (ESS). Despite their popularity, some of these agents have been shown to contribute to synechiae formation. Microporous polysaccharide hemospheres (MPH) is a plant-based hemostatic powder that does not interfere with regenerating sinus mucosa in the animal model. The goal of this study was to examine the impact of MPH on healing and synechiae formation after ESS in human subjects.', 'A prospective, randomized, controlled, double-blind study was performed. Forty consenting adult patients with chronic sinusitis requiring symmetric ESS were randomized to receive MPH unilaterally at the conclusion of surgery. The opposite side was untreated. Standard postoperative care was performed bilaterally. Outcomes measured included blinded observer ratings for synechiae formation, edema, and infection. Each side was examined endoscopically and scored at postoperative days 7, 14, and 30.', 'Twenty men and 20 women with an average age of 48.2 years were included. There were no complications and all patients were discharged home the same day. There was no significant difference in synechiae formation at any point postoperatively. The rate of synechiae formation was determined to be 10% (4/40) on the MPH-treated side versus 7.5% (3/40) on the untreated side (p = 0.7639). In addition, there were no significant differences observed in edema (p = 0.7480) or infection (p = 0.5533).'] Do microporous polysaccharide hemospheres increase synechiae after sinus surgery : randomized controlled study?