A COMPARISON OF THE BIOCOMPATIBILITY OF 3 ABSORBABLE HEMOSTATIC AGENTS IN THE RAT MIDDLE-EAR

Absorbable gelatin sponge (Gelfoam) has been used for many years in mi ddle ear surgery. Although the sponge is generally well tolerated, fib rosis occasionally forms in the mesotympanum some studies indicated th at the absorbable gelatin sponge may be responsible. Many of these stu dies lack statistical analysis. We prospectively studied three absorba ble hemostatic agents in the middle ear of adult male Sprague-Dawley r ats to determine which promotes fibrosis to the greatest degree: absor bable gelatin sponge (Gelfoam), absorbable gelatin sheet (Gelfilm), or absorbable collagen sheet (Instat). The materials were implanted in t he middle ear through a post-auricular approach and the temporal bones were serially harvested at different time intervals so we could exami ne histologic changes. The nonimplanted ear served as surgical control . Examination of the specimens at 6, 8, and in weeks by light microsco py revealed that although absorbable gelatin film and collagen-absorba ble hemostat are well tolerated in this animal model, absorbable gelat in sponge promoted the presence of fibrosis to a significantly greater degree, (p = 0.0344). We conclude that absorbable gelatin sponge prom otes fibrosis more frequently than do collagen-absorbable hemostat and absorbable gelatin film in this animal model.