The efficacy of hyaluronic acid foam as a middle ear packing agent in experimental tympanoplasty.

The efficacy of hyaluronic acid (HA) foam in the prevention of middle ear adhesions and other structural abnormalities in guinea pigs undergoing experimental tympanoplasty was investigated. Postoperative changes in the middle ear were evaluated by light microscopy after 6 weeks. The presence of adhesions, diminution of airspace, new bone formation, tympanic membrane (TM) formation, and mucosal inflammation was characterized by an objective grading system. Results were compared to absorbable gelatin sponge (AGS) and a control group (no middle ear packing). The control group showed the best average scores for all parameters tested except for adhesion formation. However, these results were statistically significant only when compared with those of the AGS group for airspace preservation, new bone formation, and TM formation. Although the HA foam group showed better average results than did the AGS group for all parameters tested, none were statistically significant. Although HA foam appears to be a promising middle ear packing agent, further experimental trials are warranted before any firm conclusions may be made.