Complications of Rhinosinusitis
Carla M. Giannoni
Acute bacterial sinusitis occurs commonly, usually as a sequela of an upper respiratory infection. Symptoms include cough, purulent nasal discharge, headache, facial pain and pressure, nasal congestion, fetid breath, fever, malaise, and lethargy. Spread of infection outside the sinuses results in complicated sinusitis. The incidence of complications from both acute and chronic sinusitis has decreased fourfold since the 1950s but appear to have stabilized in the past several decades (1,2,3). This has been attributed to the widespread use of antibiotics for rhinosinusitis but clinical data are lacking in this area (see “Prevention of Complications for Sinusitis” later in this chapter for further discussion). Complications of sinusitis can be divided into three categories: orbital, intracranial, and bony. This chapter reviews each of these complications in detail, describing the pathophysiology, evaluation, microbiology, and medical and surgical treatments.
ORBITAL COMPLICATIONS
Anatomic Considerations
The close proximity of the orbit to the paranasal sinuses, especially the ethmoid sinuses, make it the most commonly involved structure in complications of sinusitis. Orbital complications have a seasonal variation indicating a viral role in the initiation of sinusitis. Children appear to be more prone to orbital complications of sinusitis, probably because of their relatively higher rates of upper respiratory tract infections and sinusitis. Gender has not been identified as a risk factor in preseptal disease. Male gender has been identified as a risk factor in postseptal infections in some series (4) but not in others (5,6,7) and it appears that the gender predilection becomes more dominant in older children.
Orbital involvement primarily results from a thrombophlebitis and interference with the venous drainage of the orbital contents. The superior and inferior ophthalmic veins are valveless, allowing direct communication between the nose, ethmoid sinuses, face, orbit, and cavernous sinus. In addition, congenital or other dehiscences in the lamina papyracea, which separate the ethmoid sinuses from the orbit, expose the orbital contents to direct extension of sinusitis. The combination of phlebitis and direct entry of bacteria into perivascular structures results in what is generally a continuum of inflammatory and infectious changes. The orbital periosteum, the periorbita, is an important structure because it is the only soft tissue barrier between the sinuses and the orbital contents. It comprises loose fibrous tissue that can be easily elevated off the underlying bone. The orbital septum is a reflection of the periorbita at the margins of the orbit and it passes centrally to fuse with the tarsal plates. The orbital septum lacks lymphatic channels and thus forms a barrier limiting infections from passing directly through the eyelids into the orbit. Orbital infections are divided into two groups based on this element of orbital anatomy: preseptal and postseptal infections.
Classification
Chandler et al. (8) classified the orbital complications of sinusitis into five groups: preseptal cellulitis, orbital cellulitis, subperiosteal abscess, orbital abscess, and cavernous sinus thrombosis (Fig. 38.1). The first complication, preseptal cellulitis is a preseptal infection and the latter four are postseptal. Although often thought of as a continuum, each of these complications should be considered separately and treatment individualized (Table 38.1). These infections are not exclusive and multiple complications can occur in the same patient. A number of other classifications schemes have been proposed but the Chandler classification remains the most widely utilized in clinical practice.
PRESEPTAL CELLULITIS
Preseptal infections are far more common than postseptal infections. Preseptal cellulitis can be a complication of ethmoid sinusitis but it can also occur as a result of infection of the eyelids and orbital adnexa, trauma (including insect
bites), or a foreign body (6,7). In contrast to other orbital complications, medical comorbidities such as cystic fibrosis, HIV, leukemia, diabetes, and other immune deficiencies are risk factors for preseptal cellulitis (7). Preseptal cellulitis manifests as eyelid swelling, erythema, and tenderness. Occasionally these may progress to an eyelid abscess (Fig. 38.2) and can also be associated with edema of the orbital (postseptal) contents. There are no limitations of extraocular movements and no impairment of visual acuity. Sinonasal infections cause periorbital swelling due to impaired venous drainage of the ethmoidal vessels that are obstructed by inflammation and pressure.
bites), or a foreign body (6,7). In contrast to other orbital complications, medical comorbidities such as cystic fibrosis, HIV, leukemia, diabetes, and other immune deficiencies are risk factors for preseptal cellulitis (7). Preseptal cellulitis manifests as eyelid swelling, erythema, and tenderness. Occasionally these may progress to an eyelid abscess (Fig. 38.2) and can also be associated with edema of the orbital (postseptal) contents. There are no limitations of extraocular movements and no impairment of visual acuity. Sinonasal infections cause periorbital swelling due to impaired venous drainage of the ethmoidal vessels that are obstructed by inflammation and pressure.
 Figure 38.1 Chandler classification of orbital complications of sinusitis. A: Preseptal cellulitis (eyelid edema), (B) Subperiosteal abscess, (C) Orbital cellulitis, (D) Orbital abscess, |
 Figure 38.1 (Continued) (E) Cavernous sinus thrombosis. |
TABLE 38.1 ORBITAL COMPLICATIONS OF SINUSITIS | |||||||||||||||||||||
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SUBPERIOSTEAL ABSCESS
With subperiosteal abscess, a collection of pus forms at the medial aspect of the orbit between the periorbita and the lamina papyracea (Fig. 38.3). This is the second most common orbital complication of sinusitis. In response to inflammation in the ethmoid sinus, an inflammatory tissue collection beneath the orbital periosteum can develop and become a subperiosteal phlegmon (9). This subperiosteal phlegmon can then progress into a discrete abscess. A subperiosteal phlegmon or abscess can displace the orbital contents and globe downward and laterally with normal mobility in the early stages. An abscess may occasionally rupture through the orbital septum and present in the eyelids.
Typically, younger children develop isolated orbital complications, especially medial subperiosteal abscesses associated with acute ethmoiditis. Interestingly, a second, notable subset of patients has been identified: teenage males, who develop simultaneous orbital and intracranial complications (10,11,12,13,14). This phenomenon is likely related to the agedependent development of the frontal and sphenoid sinuses.
ORBITAL CELLULITIS
Orbital cellulitis is a postseptal infection that manifests as diffuse edema of the orbital contents without a discrete abscess (Fig. 38.4). There is eyelid edema and erythema, proptosis, and chemosis with limited or no impairment of extraocular movements and normal visual acuity early in the disease process. Visual changes and ophthalmoplegia
indicating optic neuritis and/or ischemia can occur as the disease progresses; these are prognostically worrisome findings. Not all cases of orbital cellulitis are due to sinusitis, however. Patients presenting with pain and diplopia and a history of recent orbital trauma or dental surgery should be assessed for orbital cellulitis. In diabetic patients with ketoacidosis and immunocompromised patients, more severe infections such as invasive fungal sinusitis should be considered. Orbital cellulitis is more concerning than preseptal cellulitis because it can evolve into an orbital abscess.
indicating optic neuritis and/or ischemia can occur as the disease progresses; these are prognostically worrisome findings. Not all cases of orbital cellulitis are due to sinusitis, however. Patients presenting with pain and diplopia and a history of recent orbital trauma or dental surgery should be assessed for orbital cellulitis. In diabetic patients with ketoacidosis and immunocompromised patients, more severe infections such as invasive fungal sinusitis should be considered. Orbital cellulitis is more concerning than preseptal cellulitis because it can evolve into an orbital abscess.
 Figure 38.2 Preseptal abscess secondary to preseptal cellulitis. A: Axial CT scan taken on admission showing the patient with left ethmoid sinusitis and left preseptal cellulitis (arrow); patient also had frontal sinusitis (not pictured). B: Axial CT scan after 4 days of IV antibiotic treatment showing progression of infection to left preseptal abscess (arrow). The patient also developed an orbital subperiosteal abscess, scalp abscess, and small epidural abscess. |
ORBITAL ABSCESS
An orbital abscess occurs when orbital cellulitis coalesces into a discrete collection of pus within the orbital tissues. This is a serious complication that can be associated with severe exophthalmos and chemosis, complete ophthalmoplegia and visual impairment with a risk for progression to irreversible blindness. On rare occasions there is spontaneous drainage of purulent material through the eyelid.
 Figure 38.3 Axial CT scan demonstrating a left subperiosteal orbital abscess. The abscess is immediately adjacent to the lamina papyracea (the arrow is inside the abscess and identifies the lateral edge of the abscess); note the proptosis and the displacement of the orbital periosteum and medial rectus muscle. |
CAVERNOUS SINUS THROMBOSIS
Cavernous sinus thrombophlebitis or thrombosis is a complication that can be considered an orbital as well as an intracranial complication of sinusitis. Venous congestion
in the orbit results in orbital pain, chemosis, proptosis, and ophthalmoplegia. Cranial nerves III, IV, V1, V2, V3, and VI traverse the sinus and can all be affected. Extension of the phlebitis posteriorly into the cavernous sinus results in progression of symptoms in the opposite eye. This contralateral involvement is a distinguishing feature of cavernous sinus thrombosis. It can be associated with sepsis and meningismus or frank meningitis may be present.
in the orbit results in orbital pain, chemosis, proptosis, and ophthalmoplegia. Cranial nerves III, IV, V1, V2, V3, and VI traverse the sinus and can all be affected. Extension of the phlebitis posteriorly into the cavernous sinus results in progression of symptoms in the opposite eye. This contralateral involvement is a distinguishing feature of cavernous sinus thrombosis. It can be associated with sepsis and meningismus or frank meningitis may be present.
 Figure 38.4 Axial CT scan showing right orbital cellulitis with diffuse orbital inflammatory changes that are intra- and extraconal (open circle); there is concurrent preseptal edema and inflammatory changes (arrow). |
DIAGNOSIS AND TREATMENT EVALUATION
A history including recent upper respiratory infection, duration and progression of symptoms, recent trauma (including insect bites and conditions involving the skin such as chicken pox), swimming, ear infection, dental surgery or dental infection, and other systemic illnesses should be obtained when evaluating a patient with orbital findings. Decongestion and examination with anterior rhinoscopy and nasal endoscopy may demonstrate polyps or purulent material under the middle turbinate. The eye must be opened to assess visual acuity, extraocular movements, and proptosis. When orbital infection is suspected, ophthalmologic consultation should be obtained immediately to assess visual status as this may impact the aggressiveness of surgical treatment (5,6,7). Close follow-up of patients with orbital infections is needed as the infection may evolve or progress during the course of treatment with development of new complications.
Radiography
Imaging is often necessary to appropriately classify orbital complications. Conventional plain film radiography is of limited value in the evaluation of sinusitis because of poor anatomic detail and poor correlation with clinical symptoms. Computed tomography (CT) is considered the gold standard for sinus imaging because it can better depict the anatomy of the globe, retro-orbital tissues, sinuses, and cranium, and provides information for surgical planning. It has been shown to demonstrate good accuracy in diagnosing pediatric chronic rhinosinusitis (9,15). CT of the sinuses and orbits with contrast is indicated when postseptal infection is suspected clinically based on findings of proptosis, gaze restriction or changes in visual acuity, when intracranial complications are suspected, or when symptoms of preseptal inflammation progress in 24 to 48 hours despite treatment (6). The study consists of contrast-enhanced axial and coronal thin cuts of the sinuses and orbits. CT of the brain with contrast and/or magnetic resonance imaging (MRI) may also be indicated if there are symptoms of a concurrent intracranial complication.
In preseptal cellulitis, CT reveals a diffuse increase in density and thickening of the lid and conjunctiva. Postseptal inflammation is characterized by a soft tissue density or low-attenuation area adjacent to the lamina papyracea (9,16). It should be noted that the medial rectus muscle may be displaced, enhanced, or thickened by inflammatory edema in many orbital infectious processes. Abscesses appear as hypodense areas with rim enhancement and mass effect. Subperiosteal abscesses arise adjacent to the lamina papyracea but can also occur in a superior location, adjacent to the orbital roof secondary to frontal sinusitis (17). Extension of the inflammatory process into the intraconal space appears on CT as an illdefined infiltration of the orbital fat with obliteration of the optic nerve and extraocular muscles. Cavernous sinus thrombosis is better demonstrated on MRI but may be suggested by poor venous enhancement on contrast CT. Contrast-enhanced MRI is performed when intracranial complications are suspected and includes axial and coronal T1 and T2 images (9,16).
Microbiology of Orbital Complications
There is usually little correlation between cultures taken randomly from the nose or nasopharynx and those obtained from sinus aspiration. Culture material can be obtained directly from the sinus by sinus puncture and lavage or during surgical exploration. An exception to this rule is endoscopically directed middle meatal nasal cultures where there may be a more accurate correlation between these nasal cultures and those obtained from the maxillary sinus (18). The organisms responsible for acute suppurative sinusitis are similar for both adults and children and do not always reflect the common causative pathogens of acute and chronic sinusitis (19,20) (Table 38.2). The most commonly identified organisms in acute rhinosinusitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella, other streptococcal species, and less commonly anaerobes. Staphylococcus aureus can be seen in adults and in children with serious sinus infections. Chronic sinusitis in both adults and children is more commonly due to anaerobes as well as alpha-hemolytic streptococci, S. aureus, H. influenzae, and S. pneumoniae.
Streptococcal organisms play a major role in complicated sinusitis. A thorough understanding of the taxonomy of these organisms is necessary. The majority of streptococci fall into two broad categories: beta-hemolytic and nonbeta-hemolytic, which includes alpha-hemolytic and nonhemolytic organisms. The beta-hemolytic group includes Group A and Group B Streptococci. The non-beta-hemolytic group is further subdivided into optochin-susceptible, which includes S. pneumoniae, and optochin-resistant, which includes Streptococcus viridans. The viridans group includes Streptococcus bovis group, Streptococcus milleri group and more than 20 other species of viridans streptococci. S. milleri, Streptococcus constellatus, and Streptococcus anginosus constitute the S. milleri group (21).
Excluding preseptal cellulitis, orbital complications are often polymicrobial. S. viridans, especially the S. milleri group organisms, and S. aureus have been implicated as the most common causes of both orbital and intracranial complications of sinusitis in most contemporary
series (5,6,7,22) (Table 38.2). Less common but consistent causes of complicated sinusitis are S. pneumoniae, other Streptococci, and anaerobic microorganisms. H. influenza, Eikenella, and other gram-negative bacilli are also implicated in some cases of complicated sinusitis.
series (5,6,7,22) (Table 38.2). Less common but consistent causes of complicated sinusitis are S. pneumoniae, other Streptococci, and anaerobic microorganisms. H. influenza, Eikenella, and other gram-negative bacilli are also implicated in some cases of complicated sinusitis.
TABLE 38.2 MICROBIOLOGY OF SINUSITIS AND RELATED COMPLICATIONS | |||||||||
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