[An evaluation of nasal patency with acoustic rhinometry--preop. and postop. comparisons]

Changes in nasal patency after nasal surgeries were evaluated with acoustic rhinometry. Fourteen cases (20 sides) were included in the evaluation and the following types of nasal surgery were performed: 2 partial maxillectomies, 11 Caldwell-Luc operations, 4 endonasal ethmoidectomies, 1 endonasal maxillary sinusectomy and 2 septoplasties. The evaluation with acoustic rhinometry was routinely performed on two occasions; the day before and 7-14 days after the surgery. The preop. and postop. results of the evaluations of nasal volume (6.9-14.1 cm by the area-distance curve) and nasal area (averaged areas at 11.0 cm and 13.4 cm by the area-distance curve) were compared. Postop. results in all but one case demonstrated increases in both nasal volume and nasal area, indicating that acoustic rhinometry has practical applications in preop. and postop. evaluations of nasal patency. Three aspects remain to be clarified. The first is the influence of the nasal cycle, which varies considerably at the time of both preop and postop evaluations. The second is the influence of the paranasal sinuses. When the results of cases who had undergone endonasal ethmoidectomy or septoplasty were compared to those who had received partial maxillectomy or Caldwell-Luc operation, the latter showed greater increases in nasal patency, suggesting that the cavities of paranasal sinuses, especially of the maxillary sinus, influence the results of acoustic rhinometry. The third is the size of the anterior entrance of the middle meatus. When the entrance is narrow, the acoustic pulse generated by acoustic rhinometry will not reach up to the paranasal sinuses so that the size of the entrance will again influence the results.(ABSTRACT TRUNCATED AT 250 WORDS)