Sinusitis: A Head and Neck Surgeon's Perspective

, The Good Samaritan Hospital, Baltimore, Md.

Disclosures

Medscape General Medicine. 1997;1(2) 

In This Article

Abstract and Introduction

Abstract

Inflammation of the mucosa in the area of the osteomeatal complex is a major factor in the pathogenesis of sinusitis, a common disease which afflicts 35 to 40 million Americans. Relatively minor swelling of the mucosa in the anterior ethmoid-middle meatal complex (osteomeatal complex) leads to frontal or maxillary sinus obstruction and secondary disease. The primary bacterial pathogens in acute sinusitis include Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella catarrhalis. Chronic sinusitis is associated with anaerobes, usually Bacteroides species, anaerobic gram-positive cocci, Fusobacterium species, Streptococcus, Veillonella, and Corynebacterium species. Radiologic studies complement the history and physical examination and include conventional sinus radiographs and computerized tomography (CT) scans. Magnetic resonance imaging is useful in the differentiation of soft tissue disease, but it is not the study of choice in the evaluation of sinus disease. Only CT provides excellent visualization of the fine bony anatomy and its important anatomic variants. Medical treatment of sinusitis consists of antibiotics and decongestants and the avoidance of any exacerbating environmental factors. Functional endoscopic surgery (FESS) is the surgical option of choice. This procedure removes the obstruction in the anterior ethmoids and permits spontaneous resolution of disease in the ethmoids, maxillary and frontal areas. Indications for FESS include chronic sinusitis that persists beyond 3 months of medical therapy, or documented recurrent acute sinusitis with related structural or inflammatory abnormalities in the osteomeatal unit. Indications for external sinus surgery include osteomyelitis, orbital complications, intracranial complications, and failure of the functional approach.

Introduction--Anatomy and Precipitating Factors

Anatomy and physiology of the sinuses and sinusitis. Sinusitis is defined as an inflammation of the lining of the membranes of any of the paranasal sinuses. The sinuses are lined with ciliated stratified columnar epithelium and are contiguous with the upper respiratory tract via the sinus ostia. Inflammation of the sinuses causes mucosal edema and increased sinonasal secretions. While the most common etiology is an upper respiratory tract infection, an acute exacerbation of allergic rhinitis, dental infection or manipulation, or trauma to the sinuses may also be causative. If sinus obstruction occurs, the retained secretions create a milieu that is ideal for bacterial growth resulting in bacterial sinusitis.

The anterior ethmoid-middle meatal complex (osteomeatal complex) is a key area in the pathogenesis of sinusitis.[1] The osteomeatal complex contains the narrow channels that provide for mucociliary clearance and ventilation of the anterior ethmoid, maxillary, and frontal sinuses. Relatively minor swelling of the mucosa in this area, such as those associated with viral upper respiratory tract infections or allergic rhinitis, may lead to frontal or maxillary sinus obstruction and secondary disease within these sinuses. Foreign bodies, including nasogastric tubes, nasotracheal tubes, and nasal packing risk blocking the osteomeatal complex and causing nosocomial sinusitis. When sinus drainage is obstructed, mucus, inflammatory cells and bacteria accumulate, oxygen tension in the sinuses is reduced, and opsonization/phagocytic, as well as immunoglobulin-dependent activities are impaired. Drainage and ventilation of the major paranasal sinuses are dependent on the patency of the osteomeatal complex.

Precipitating factors of sinusitis. A number of host factors predispose the patient to sinusitis.[2] They include immunodeficiency, acetylsalicylic acid-asthma-polyposis triad, abnormal mucociliary clearance secondary to ciliary structural abnormalities, as in Kartagener's syndrome, or secretory disturbances, such as those in cystic fibrosis. Local anatomic factors such as severe septal deviation also contribute to disease, but localized abnormalities in the area of the anterior ethmoid middle meatal area appear to be even more important.

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