Surgical and hearing results of the circumferential subannular grafting technique in tympanoplasty: a randomized clinical study.

PURPOSE

Circumferential elevation of the anullus away from its bony seat and extension of the graft onto the anterior bony canal increase the bed of the graft anteriorly but may be associated with anterior blunting, and so, a significant conductive hearing loss may result. The purpose of this study was to compare the surgical and audiologic success rates of circumferential subannular grafting with the conventional underlay tympanoplasty.

MATERIALS AND METHODS

A randomized clinical study was conducted from September 2007 to December 2010 at a tertiary referral center. Thirty-eight patients underwent circumferential subannular grafting (group A), and 25 patients underwent conventional underlay tympanoplasty with extension of the anterior edge of the graft forward against the lateral wall of the Eustachian tube, and therefore, the anterior sharp tympanomeatal angle remained unbroken (group B). All patients underwent preoperative and postoperative audiogram. Blunting and lateralization of the graft were evaluated 6 months after the surgery.

RESULTS

The surgical success rate was 97% in group A and 100% in group B patients. Improvement of the air conduction thresholds in all frequencies and closure of the mean air-bone gap were significant and similar among the 2 groups. There were no cases of significant blunting and tympanic membrane lateralization in the 2 groups.

CONCLUSION

This study showed underlay tympanoplasty with elevation of the annulus away from the sulcus tympanicus in the anterior sharp tympanomeatal angle and placement of the graft between it and anterior bony canal is not associated with increased risk of blunting and lateralization of the graft, if that sharp angle is adequately restored.