The effects of nasal surgery on airflow.

Although nasal surgery for form and function is commonplace, knowledge of its effects on nasal airflow has been scanty. This study was undertaken to clarify that relationship. Prior to our investigation, we reviewed the pertinent physics of airflow. We noted that during laminar flow, the air in contact with the walls of a tube is motionless, whereas the air in the center moves. Moreover, according to Poiseuille's law, as the radius of the tube increases, the flow increases to the fourth power. Finally, tubes that are irregular, such as the nose, cause turbulent flow. When air passes through the nose, the flow is regulated by four values: the external valve, the internal valve (the angle formed by the junction of the upper lateral cartilages and the septal cartilages are the most important), the nasal turbinates, and the septum. Using anterior rhinomanometry, the nasal airflow was measured in 69 control subjects and in 329 patients who underwent a rhinoplasty, septoplasty, septectomy (submucous resection), or inferior turbinate resection, alone or in combination. We found that a rhinoplasty does not adversely affect the nasal airflow, and those patients who had procedures to improve their nasal airflow did indeed obtain it. These data were statistically significant. The data from our airflow studies frequently failed to correlate with patient assessments of their own nasal airways as well as our evaluations by rhinoscopy. Furthermore, rhinomanometric findings varied considerably even within the same testing session. At present, on the basis of our investigations, we cannot recommend rhinomanometry with enthusiasm because of its questionable reliability and validity.