Effects of packing on the postoperative hearing after middle ear surgery.

CONCLUSION

The changes of hearing by packing after middle ear surgery should be anticipated and carefully interpreted.

OBJECTIVES

To evaluate the amount and patterns of hearing loss resulting from packing in middle ear cavity (MEC) and external auditory canal (EAC) after middle ear surgery.

METHOD

We obtained pure tone thresholds by bone (BC) and air conduction (AC) up to 12 weeks after middle ear surgery in 17 patients who had minimal middle ear pathology. To observe the effects of packing only in the EAC as in cases of explorative tympanotomy or stapes surgery, BC and AC threshold were obtained after packing only in the EAC in 18 volunteers. The changes of BC and AC thresholds in terms of pure tone average (PTA) and high frequency PTA were analyzed.

RESULTS

PTA by AC increased significantly by a maximal value of 38.7 dB at the second postoperative day, by 35.0 dB at 1 week after middle ear surgery. PTA by BC also increased maximally at the second postoperative day by 4.8 dB. The elevation of BC threshold at high frequencies (2, 3, 4 kHz) was more pronounced. Packing of EAC without MEC packing resulted in elevation of AC threshold by 43.0 dB, with similar patterns of BC threshold changes as MEC and EAC packing.