Delivered by Ingenta to: UCL LIBRARY IP: 91.215.136.37 On: Mon, 20 Jun 2016 20:08:44 Copyright (c) Oceanside Publications, Inc. All rights reserved. For permission to copy go to https://www.oceansidepubl.com/permission.htm Reduced nasal resistance after simple tonsillectomy in patients with obstructive sleep apnea Seiichi Nakata, M.D.,* Soichiro Miyazaki, M.D.,# Motofumi Ohki, M.D.,§ Mami Morinaga, M.D.,* Akiko Noda, Ph.D.,¶ Tatsuki Sugiura, M.D., Makoto Sugiura, M.D.,* Masaaki Teranishi, M.D.,* Naomi Katayama, Ph.D.,** and Tsutomu Nakashima, M.D.* (Japan) ABSTRACT Background: The aim of this study was to investigate the effects of simple tonsillectomy on nasal resistance in patients with obstructive sleep apnea syndrome (OSAS). Methods: Conventional tonsillectomy was performed in 20 patients who were refractory to treatment with continuous positive airway pressure. The subjects consisted of 17 men and 3 women (mean age, 32.9  6.3 years). The effects of tonsillectomy were evaluated with preoperative and postoperative polysomnography and nasal resistance. Results: After tonsillectomy, nasal resistance decreased significantly from 0.39  0.30 Pa/cm 3 per second to 0.27  0.16 Pa/cm 3 per second (p  0.05). Simultaneously, the apnea– hypopnea index decreased significantly from 55.7  22.5 to 21.2  14.2 (p  0.05). There was no significant correlation between tonsillar weight and percentage of change in bilateral nasal resistance (p  0.05). Conclusion: The reduction in nasal resistance induced by simple tonsillectomy could play an important role in improving OSAS, as does nasal surgery or adenotomy. (Am J Rhinol 21, 192–195, 2007; doi: 10.2500/ajr.2007.21.2965) Key words: CPAP treatment failure, nasal resistance, obstructive sleep apnea, polysomnography, rhinomanometry, tonsillar hypertrophy, tonsillectomy, treatment outcome G enerally, an increase in nasal resistance results in a de- crease in intraluminal pressure and the collapse of the pharyngeal tissues. Thus, it leads to various breathing distur- bances, including sleep apnea and a reduction in the lowest nocturnal oxygen saturation (SpO 2 ). However, little is known about the relationship between nasal resistance and adenoids or tonsils. Only two studies have addressed the reduction in children’s total nasal resistance induced by adenotonsillectomy 1,2 ; these showed a significant correlation between nasal resistance and adenoid weight. 2 However, no relationship between nasal resis- tance and the tonsils has been identified. Nonetheless, we have observed that nasal resistance tends to decrease after tonsillec- tomy. No studies have focused on the effects of tonsillectomy on nasal resistance, although several studies have addressed the effects of nasal surgery. 3–6 Accordingly, we investigated the ef- fects of simple tonsillectomy on nasal resistance in patients with obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS Polysomnographic Methods Standard polysomnography (ALICE3; Respironics, Yong- wood, PA) was performed in all patients with OSAS. Electro- encephalograms (C4-A1 and C4-O2), electrooculograms, elec- tromyograms, and electrocardiograms were recorded continuously and respiration was monitored with oronasal thermistors and thoracoabdominal strain gauges. Apnea was defined as the cessation of airflow through the mouth and nose for 10 seconds, and hypopnea was defined as the obvious reduction in airflow accompanied by either an oxy- gen desaturation of 3% or arousal, also for 10 seconds. The apnea–hypopnea index (AHI) was defined as the number of apnea and hypopnea episodes per hour. An AHI of 5/hour was the basis for a diagnosis of OSAS. 7 The time during which SpO 2 was 90% (oxygen desaturation time) and the lowest SpO 2 value during sleep were determined also with a pulse oximeter. Postoperative polysomnography was performed 3 months (3.6  1.7 months) before and 6 months after tonsil- lectomy (6.1  1.5 months). Patients and Surgery Selection The study was performed according to the principles de- fined in the Declaration of Helsinki. Subjects were OSAS patients who were refractory to treatment with continuous positive airway pressure (CPAP), with CPAP failure being defined as its use for 4 hours/night on 70% of nights or the lack of symptomatic improvement (or both). 8 The patients all experienced a feeling of pharyngeal obstruction under CPAP and tonsillar hypertrophy (criteria 3 and 4 of Fried- man’s classification, respectively 9 ). We excluded patients with a clinically relevant deviation of the nasal septum, inferior turbinate hypertrophy, or hypertrophy of the lingual tonsils, as revealed by nasopharyngoscopy. During an observation period of 3 years (August 2002–August 2004), 17 men and 3 women (mean age, 32.9  6.3 years; range, 23–50 years) gave their consent to examination and treatment (simple tonsillec- tomy) at Nagoya University. This study was designed to collect data from standard treatments. The patients voluntar- From the *Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, #Department of Sleep Medicine, Shiga University of Medical Science, Otsu, Shiga, §Second Department of Otorhinolaryngology, Toho University School of Medicine, Tokyo, ¶Nagoya University School of Health Sciences, Nagoya, Department of In-Home Medicine, Nagoya University Hospital, Nagoya, Aichi, and **Department of Housing and Nutrition, Nagoya Women’s University, Nagoya, Aichi, Japan Address correspondence and reprint requests to Seiichi Nakata, M.D., Ph.D., Depart- ment of Otorhinolaryngology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan E-mail address: seisay@med.nagoya-u.ac.jp Copyright © 2007, OceanSide Publications, Inc., U.S.A. 192 March–April 2007, Vol. 21, No. 2