Expandacell, a new sponge for endoscopic sinus surgery.

Hydroxylated polyvinyl acetal (PVAc) sponges are routinely used for control of bleeding following endoscopic sinus surgery. The physical characteristics of the Meroce sponges and the new Expandacell sponges were evaluated, including pore diameter, sponge size and rate of expansion. The Expandacell sponges were found to have a smaller pore diameter and to expand more slowly, giving the surgeon a bit more time for placement of the pack in the middle meatal cavity. Changing the physical characteristics of the PVAc sponges, such as making the pore size smaller, decreasing the thickness, coating with a laminated polyethylene surface or placing a fenestration in the center of the sponge, resulted in a significant decrease in the degree of pain associated with removal of the sponge.