Effect of submucosal diathermy to the inferior turbinates on unilateral and total nasal airflow in patients with rhinitis

The efficacy of the controversial treatment of submucosal diathermy to the inferior turbinates (SMDIT) was evaluated objectively. Twenty-seven patients with chronic rhinitis were investigated by hourly posterior rhinomanometry to assess changes in total and minimum (Fmin) and maximum (Fmax) unilateral nasal airflow over 5 h, before and 2-3 months after standardized SMDIT treatment. Nasal airflow was recorded at a sample pressure of 75 Pa and the results are reported as medians with interquartile range. Whilst SMDIT caused a significant 51% increase (p < 0.0001) in total nasal airflow from 246 cm3/s (131) to 371 cm3/s (133) the changes in unilateral airflow provided further evidence which strongly supported the benefits of this operation. Unilateral Fmin significantly increased by 136% (p < 0.0001) from 69 cm3/s (82) to 163 cm3/s (74) and Fmax significantly increased by 23% (p < 0.0001) from 171 cm3/s (74) to 211 cm3/s (59). The effect of surgery was to "splint" to the turbinate in a state of relative vasoconstriction. Our findings therefore provide functional evidence of submucosal fibrosis following SMDIT. The greater percentage change in unilateral Fmin suggests that this parameter is a more sensitive index of the effect of nasal surgery than total nasal airflow measurements. The importance of considering the nose as two separate airways in the evaluation of nasal treatments is emphasized.