What is the role of nasal endoscopy in the diagnosis of chronic rhinosinusitis?

Abstract

BACKGROUND Chronic rhinosinusitis (CRS) is one of the most common chronic conditions in the United States, but clinical diagnostic criteria remain controversial. Nasal endoscopy is frequently employed by otolaryngologists in cases of suspected CRS. Although endoscopy allows visualization of pathology that may provide objective evidence for the diagnosis of CRS in the posterior nasal cavity, nasopharynx, and the middle and superior meati that would not be visible on anterior rhinoscopy, its appropriate role in the evaluation of CRS has been the subject of controversy. In 2007, the American Academy of Otolaryngology– Head and Neck Surgery (AAO-HNS) published guidelines for diagnosis of CRS that utilize a combination of symptom criteria and objective findings. A positive diagnosis was defined as 12 weeks or longer of two or more of the following signs and symptoms: mucopurulent drainage; nasal obstruction; facial pain, pressure, or fullness; or decreased sense of smell. In addition, an objective measure, such as evidence on nasal endoscopy of nasal polyps or purulent mucus in the middle meatus or ethmoid region, or radiographic evidence of paranasal sinus inflammation are also recommended. Given the high utilization rate and availability of computed tomography (CT) for CRS diagnosis, these guideline criteria designated nasal endoscopy as an optional diagnostic measure. Although endoscopic findings are frequently used to support a diagnosis of CRS, the true diagnostic value of nasal endoscopy in diagnosing CRS has not been clearly defined. LITERATURE REVIEW The diagnostic utility of nasal endoscopy, in relation to common clinical and radiologic criteria, has been assessed in relatively few clinical studies. A 1997 study by Benninger evaluated the role of nasal endoscopy in the diagnosis and treatment planning in 100 consecutive new clinic patients with sinonasal complaints. Of those, only 28 patients were diagnosed with CRS, and all diagnoses were made based on history and physical examination that included anterior rhinoscopy. The role of endoscopy in this study was to determine if the endoscopic findings contradict the established diagnosis. The study did not compare the results of endoscopy with CT scans. Although the addition of endoscopy did not change any of the diagnoses of CRS, the study concluded that it was useful in evaluating patients in whom anterior rhinoscopy is limited by anatomic abnormalities or in whom the diagnosis is otherwise unclear. A 1998 study by Rosbe et al. prospectively compared results of nasal endoscopy, CT scanning, and a symptom questionnaire, with a goal of determining whether a combination of patient symptoms and nasal endoscopy could accurately predict CRS on CT in 92 consecutive patients referred for sinonasal symptoms. The study obtained CT scans on all patients with endoscopic findings positive or equivocal for CRS. They found that 91% of patients with positive findings on endoscopy had CT scans consistent with CRS. Of the patients with a chief complaint of nasal obstruction who had a positive finding on nasal endoscopy, 100% had CT findings consistent with CRS. This study did calculate positive predictive values (PPVs) or negative predictive values (NPVs) for endoscopy as compared with CT results. The study concluded that combined with a symptom history, nasal endoscopy can be a highly specific technique for predicting positive CT findings of CRS. In a 2002 study of 78 patients meeting the current symptom-based definition of CRS, Stankiewicz and Chow evaluated the relationship between symptom history, nasal endoscopy, and CT findings. Nasal endoscopy was considered positive for CRS if it demonstrated purulence, nasal polyps, or watery congested From the Massachusetts Eye and Ear Infirmary (J.S.), Department of Otolaryngology–Head and Neck Surgery, Boston; the Division of Otolaryngology (N.B.), Brigham and Women’s Hospital, Boston, Department of Otology and Laryngology (J.S., N.B.), Harvard Medical School, Boston, Massachusetts, U.S.A. Editor’s Note: This Manuscript was accepted for publication April 5, 2012. Neil Bhattacharyya, MD, is a consultant for Intersect-ENT, Inc. and Entellus, Inc. The authors have no other funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Neil Bhattacharyya, MD, Division of Otolaryngology, 45 Francis St., Boston, MA 02115. E-mail: neiloy@massmed.org