COMPLICATOINS OF RHINOSINUSITIS: SYNOPSIS OF CRITICAL SEQUELAE A= pril 22, 2011

TITLE: Complications of Rhinosinusitis: Synopsis of Critical Sequelae
SOURCE: Grand Rounds Presentation,
The University of Texas Medical Br= anch (utmb= Health), Department of Otolaryngology
DATE: April 22, 2011
RESIDENT PHYSICIAN: <= span style=3D'font-family:"Calibri","sans-serif"'>Viet Pham, M.D.
FACULTY PHYSICIAN: Patricia Maeso, M.D.
SERIES EDITOR: Francis B. Quinn, Jr., M.D.
ARCHIVIST: Melinda Stoner Qui= nn, MSICS

&q= uot;This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program = of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purp= ose of stimulating group discussion in a conference setting. No warranties, eit= her express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes= of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion."

RHINOSINUSITIS

&= nbsp; Rhinosinusitis describes the presence of inflammation of the nasal mucosa and paranasal si= nus lining. The fundamental pathophysiology behind this process revolves around obstruction of the sinus ostia, often attributed to an anatomical blockage or from impaired ciliary transport. Symptoms regarded = as “major” diagnostic criteria include facial pain or pressure, na= sal obstruction, hyposmia or anosmia, and purulent nasal discharge—especi= ally if noted emanating around from the middle meatus. “Minor” symptoms inclu= de headache, halitosis, fatigue, dental pain, cough, or otalgia or aural pressure. A diagnosis of rhinosinusitis is supported with the presence of either two major symptoms = or one major one and two minor ones.

&= nbsp; While many patients who present with such symptoms often implore for antibiotics,= the majority of cases arise from a viral etiology such as rhinovirus, coronavir= us, influenza A and B, parainfluenza, respiratory syncytial virus, adenovirus, = and enterovirus. A superimposed bacterial infection is usually present in only up to 2% of cases. Suspicion of a concurrent bacterial process should be considered if symptoms have been present for at least 7-10 days or if there is a symptomatic worsening after 5-7 days. For the pediatric and adult popula= tions, the most common bacterial agents responsible for rhinosinusitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.<= /span>

&= nbsp; The term acute rhinosinusitis (ARS) denotes that symptoms have been present for= no more than four consecutive weeks. Recurrent ARS refers to when four distinct episodes of ARS have transpired, each lasting at least 7-10 days. When symptoms of rhinosinusitis ha= ve been present for at least three consecutive months, it is considered to be chronic rhinosinusitis (CRS) while a duration between 4-12 weeks is understandably labeled as subacute rhinosinusitis.

&= nbsp; Chronic inflammation of the paranasal sinuses is the key characteristic of CRS, but there is no clear consensus as to what leads to this persistent process. Although there are those who belie= ve that CRS is related to a chronic infectious presentation like its acute cou= nterpart, others have advocated alternative factors such as allergic, immunological, anatomic, and genetic ones that may play a more significant role. One major problem with ascertainin= g a clear pathogenesis of CRS is that symptoms, findings, and radiographs, when taken independently, have not been found to provide a sufficient basis for a diagnosis (Stankiewicz 2002). Some of the more commonly identified microbial agents associated with CRS include anaerobes, Staphylococcus aureus, and Haemophilus influenzae.

COMPLICATIONS OF RHINOSINUSITI= S

        &= nbsp;   The incidence of rhinosinusitis-related complications has fortunately decreased since the introduction of antibiotics, but they result in devastating consequences if they are not promptly recognized and treated. They are often categorized based on orbital, intracranial, or osseous involvement. In general, computed tomography (C= T) is considered ideal for radiographical evaluation of the orbit while magnetic resonance imaging (MRI) is better utilized for the intracranium.=

ORBITAL COMPLICA= TIONS

        &= nbsp;   Its close proximity to the paranasal sinuses makes the orbit the most commonly involved structure in rhinosinusitis-related complications, encompassing between 60-75% of such events. This is usually attributed to the ethmoid sinuses although the frontal and maxil= lary sinuses may occasionally contribute to these conditions. The orbit is often the first to experience sequelae of rhinosinusitis in light that the bony lamina papyrac= ea and the fibrous periorbita and orbital septum are the only major anatomic barriers protecting the orbit from direct extension of the inflammatory and infectious changes occurring in the neighboring sinuses. Furthermore, the valveless superio= r and inferior ophthalmic veins facilitate a relatively unimpeded route for infectious thrombophlebitis to travel past the periorbita and affect the orbital contents.

        &= nbsp;   Children tend to experience orbital complications more than the adult population, but they do not always exhibit typical clinical findings suggestive of acute infection such as complaints of pain or a general deterioration, and leukocytosis is found only in approximately half of cases. Among the pediatric population its= elf, there is an age-dependent dichotomy in complication susceptibility. Individuals younger than seven year= s of age are usually afflicted solely with orbital manifestations while older children often experience both orbital and intracranial complications. This difference is thought to be r= elated to the age-related sinus development of the frontal sinus. Streptococcus and Staphylococcus species are = the more commonly responsible microbial agents involved in pediatric orbital complications, while Streptococcus pneumoniae, Haemophilus influen= zae, and Moraxella catarrhalis usual= ly affect adult patients.

        &= nbsp;   Although it has been altered and modified over the years since its inception in 1970= , Chandler devised a classification scheme that categorizes the various forms of rhinosinusitis-related orbital complications and seemingly triages them in increasing severity: preseptal cellulitis, orbital cellulitis, subperiosteal abscess, orbital abscess, and cavernous sinus thrombosis. Despite five distinct processes described with this classification scheme, it is important to appreciate th= at they are not mutually exclusive and may occur concurrently.

Preseptal Cellul= itis

        &= nbsp;   Eyelid edema and erythema is quite noticeable with preseptal cellulitis, but a sma= ll eyelid abscess may occasionally be encountered. A key characteristic is the integr= ity of both extraocular muscle movment and inherent vision. CT images will only reveal diffuse thickening of the eyelids and conjunctiva, all of which should occur superficial to the orbital septum. As such, medical therapy is typically sufficient to adequately treat cases of preseptal cellulitis with the initiation of intravenous antibiotic= s, application of warm compresses, and elevating the head of the bed. Additionally, facilitating sinus drainage with nasal saline irrigations, decongestants, and mucolytics may provide some benefit.

Orbital Cellulit= is

        &= nbsp;   Progression of the inflammatory changes deep to the orbital septum constitutes orbital cellulitis. While eyelid edem= a and erythema will also be present, the eye may demonstrate proptosis and chemos= is. Some patients may complain of pain= or diplopia due to impaired extraocular muscle movement, but the vision itself remains unaffected. Low-atten= uation adjacent to the lamina papyracea is often noticed on CT, but a discrete abs= cess should not be encountered. As= with preseptal cellulitis, medical management with antibiotics and nasal drainag= e is often successful. Clinical reassessment and surgical drainage should be considered if visual acuity is= at 20/60 or worse or if there is no improvement or even symptomatic progression within 48 hours.

Subperiosteal Ab= scess

        &= nbsp;   As the two major structural barriers between the orbit and the paranasal sinus= es, the coalescence of purulent material between the lamina papyracea and the periorbita is one of the first signs of compromise to this protective role against rhinosinusitis. This subperiosteal collection typically displaces orbital contents inferiorly-laterally with subsequent exophthalmos. While some may exhibit normal extraocular muscle movement early on, patients will present with proptosis, chemosis, and ophthalmoplegia leading to complaints of orbital pain, diplop= ia, and reduced visual acuity. So= me abscesses may extrude through the eyelid.&= nbsp; CT imaging is diagnostically accurate in 86-91%, revealing a rim-enh= ancing hypodensity adjacent to the lamina papyracea with mass-effect, although a m= ore superior location should raise awareness of an origin from the frontal sinu= s.

        &= nbsp;   Acquiring the assistance from the ophthalmologist and pursuing prompt surgical interv= ention is clearly warranted since drastic visual sequelae may result if this condi= tion is not addressed, especially in the face of progressively worsening vision = or extraocular muscle movement or if there is a lack of improvement after 48 hours. There is a small conti= ngent that advocates medical therapy alone may be sufficient in 50-67%, but this notion is usually reserved for children less than four years of age with sm= all abscesses. Ultimately, a comb= ined surgical and medical treatment plan should achieve complete resolution in 95-100% of cases.

        &= nbsp;   The chosen surgical approach varies by surgeon but is often set with the goal of removing the lamina papyracea and opening the ethmoid cells to remove the abscess and facilitate sinus drainage.&nbs= p; Most prefer an external incision, such as the Lynch incision, along = the medial-superior aspect of the orbital rim to provide access to the subperiosteal plane. An endos= copic approach may be ideal for more medially located collections, allowing the removal of the lamina papyracea while sparing the patient an external facial incision. Some have advocated= a transcaruncular approach implementing a transconjunctival incision and extending it around the lacrimal caruncle.= It is felt that a subperiosteal dissection may be facilitated in this fashion as with a traditional external approach but without a noticeable external incision.

Orbital Abscess<= o:p>

        &= nbsp;   An abscess formation within the orbital tissues themselves will present with a similar clinical picture as a subperiosteal abscess. Ophthalmoplegia and reduced visual acuity is also present, but the degree of exophthalmos and chemosis is felt= to be more severe compared to that experienced with subperiosteal abscesses. A similar rim-enhancing hypodensit= y is noted on CT, but it is not relegated solely to near the lamina papyracea. In conjunction with draining the responsible paranasal sinuses, incising the periorbita and draining the intraconal abscess with the assistance with ophthalmology is paramount to a= void the significant risk of irreversible blindness.

Cavernous Sinus Thrombosis

        &= nbsp;   Just as serious with its clinical implications, cavernous sinus thrombosis often manifests with similar signs as an orbital abscess as the inflammatory and infectious process traverses posteriorly from the orbit toward the intracra= nium. Orbital pain, proptosis, chemosis, ophthalmoplegia, and impaired vision are also present, but the key distinguishing feature is that there is also contralateral involvement. Poor venous enhancement may be noted on CT, but the presence of heterogeneity and increased size of the cavernous sinus on MRI is considered a more confirmat= ory radiographical finding.

        &= nbsp;   Cavernous sinus thrombosis is often associated with meningismus and sepsis, and not surprisingly carries a mortality rate up to 30%. High-dose intravenous antibiotics = that can cross the blood-brain barrier and surgical drainage of the paranasal sinuses are clearly warranted, but the use of anticoagulation to prevent thrombus propagation has been highly controversial. While there have been a number of = case reports that mention it use, two of the more commonly cited studies were retrospective ones investigating the potential risks and benefits to anticoagulation. Southwick concluded that there was a reduction in mortality with such therapy but did= not recommend it for similar applications with thrombotic involvement of other dural sinuses (1986). Levine = was not able to ascertain a significant difference in mortality rates but did i= nsinuate that a reduction may be attainable if begun early (1988). In an extensive literature review, Bhatia suggested that maintaining a prothombin time ratio between 1.5-2.5 a= nd an international normalized ratio between 2-3 for three months would provide therapeutic alleviation. This= was countered with some caution as Bhatia commented on cases of fatal hemorrhag= ic cerebral infarction and a subarachnoid hemorrhage that required reversal wi= th protamine (2002).

INTRACRANIAL COMPLICATIONS

        &= nbsp;   Rhinosinusitis-related intracranial complications tend to occur in the setting of CRS, possibly attributed to hidden infectious foci within the mucosal scarring and polypo= id changes inherent with CRS that diminishes antibiotic penetration. Other etiologies include direct extension of infectious and inflammatory agents via erosion of the sinus bo= ny walls or traversing through past traumatic fracture lines or naturally occurring neurovascular foramina such as for the optic and olfactory nerves. It is also possible f= or infectious thrombophlebitis to affect the diploic emissary skull veins that= may result in subdural infections without contaminating the intermediary structures. For example, a su= bdural empyema may exist without evidence of an extradural infection or osteomyeli= tis.

        &= nbsp;   Male teenagers tend to experience intracranial complications more often than you= nger children, and this is thought to be related to the development of the front= al and sphenoid sinuses. Fever, headache, nausea, and vomiting are commonly observed symptoms, signs compat= ible with the increased intracranial pressure that can occur with the pathologic= al process. Other affected indiv= iduals often demonstrate an altered level of consciousness, seizures, hemiparesis, visual disturbances, and meningismus. Keeping in mind that they are not mutually exclusive, the five main types of rhinosinusitis-related intracranial complications are meningitis, epidural abscess, subdural abscess, intracerebral abscess, and dural venous sinus thrombosis.

Meningitis<= /o:p>

        &= nbsp;   Inflammation of the meninges is the most common intracranial complication of rhinosinusi= tis, but it should be noted that rhinosinusitis itself is an unusual cause of meningitis. The involved sinu= ses are typically the ethmoid and sphenoid sinuses and are usually caused by Streptococcus pneumoniae, Staphylococcus auerus, and Hemophilus influenzae.   Symptoms tend to include fev= er, headache, meningismus, and an overall septic-like presentation similar to o= ther cases of meningitis. Medical management alone is often sufficient, but facilitating sinus drainage shoul= d be considered if no improvement is appreciated after 48 hours. Prompt treatment is important in l= ight of the high incidence of neurologic sequelae such as sensorineural hearing = loss and seizures.

Epidural Abscess=

        &= nbsp;   A collection of purulent material between the skull and the dura often hails = from frontal sinusitis and is regarded as the second-most common intracranial complication. As with meningi= tis, affected individuals will present with signs reflective of increased intrac= ranial pressure including fever, headache, nausea, vomiting, and papilledema, but others may also exhibit hemiparesis and seizures. A crescent-shaped hypodensity is appreciated on CT with similar radiographical findings on MRI.

        &= nbsp;   Resolution of this process is best achieved with concurrent medical and surgical modal= ities, and consequently, quick neurosurgical involvement is vital. Broad-spectrum antibiotic coverage= with good cerebral penetration is often initiated with a combination of a third-generation cephalosporin, vancomycin, and metronidazole for 4-8 weeks. Prophylactic seizure t= herapy is not typically necessary, and a lumbar puncture is contraindicated to pre= vent cerebral herniation. The absc= ess and the affected sinuses can be surgically drained through an external appr= oach using either a frontal sinus trephination or cranialization, although some = have advocated stereotactically-guided drainage of the intracranial component and allowing any external drainage to be limited to the sinuses alone.

Subdural Abscess=

        &= nbsp;   While it can originate from the frontal sinus, a purulent collection just deep to= the dura mater may also arise from the ethmoid sinuses. The presenting signs are similar to epidural abscesses and may even accompany 10% of epidural abscesses, but patients may present with lethargy or comatose states in more severe cases. Although it is only the third-most common rhinosinusitis-related intracranial complication, this condition is notable for rapid clinical deterioration resulting in mortalit= y in up to 35% and residual neurological sequelae in 35-55% of those who survive= .

        &= nbsp;   A similar long-term regimen of broad-spectrum antibiotics with good blood-bra= in penetration is clearly warranted as with epidural abscesses. Lumbar punctures are also contraindicated, and there is a general consensus to initiate prophylactic anticonvulsants and decreasing intracranial pressure with hyperventilation = or mannitol. Some have mentioned= the potential benefit to steroids citing its beneficial anti-inflammatory properties, but others have countered that they may impair the abscess encapsulation process, increase necrosis, reduce antibiotic penetration into the abscess, and alter the appearance on CT scans.

        &= nbsp;   Surgical drainage of the abscess and the involved paranasal sinuses should be pursue= d. The intracranial approach depends = on the preference of the neurosurgeon, but a craniotomy is often favored over burr hole placement due to its improved exposure. There have been some reports of successful medical management for abscesses less than 1.5cm in size, but it= is often reserved for patients less than four years of age.<= /p>

Intracerebral Ab= scess

        &= nbsp;   An uncommon complication, purulent coalescence within the brain parenchyma its= elf can have devastating results with mortality rates up to 30% and neurological sequelae in 60%. The frontal = and frontoparietal lobes are usually afflicted and may be attributed to rhinosinusitis of the frontal, sphenoid, and ethmoid sinuses (in descending order of frequency). In addit= ion to the common clinical signs of increased intracranial pressure, individuals t= end to demonstrate altered mentation, focal neurological deficits, and seizures. Patients have been = known to exhibit mood swings and behavioral changes if the frontal lobe is involv= ed, and a progressively worsening headache with meningismus should raise concern for a possible abscess rupture.

        &= nbsp;   A combined medical and surgical endeavor similar with subdural abscesses is t= he treatment modality of choice. Antibiotics, anticonvulsants, hyperventilation, mannitol, and steroi= ds carry the same considerations. While there have been reports of successful resolution of intracereb= ral abscesses less than 2.5cm with medical management alone, most cases are dea= lt with stereotactically-guided aspiration in conjunction with external or endoscopic surgical drainage of the involved sinuses.

        &= nbsp;   The majority of microorganisms responsible for epidural, subdural, and intracerebral abscesses are anaerobes, accounting for 60-100% of cases, whi= le Staphylococcus and Streptococcus species, and gram-negative bacilli have been note= d.

Venous Sinus Thrombosis

        &= nbsp;   Similar to the cavernous sinus thrombosis encountered with orbital-pertaining complications, any of the dural venous sinuses may be affected by rhinosinu= sitis. The sagittal sinus is the most com= monly involved, often attributed to retrograde thrombophlebitis from frontal rhin= osinusitis. Patients are extremely ill with a significantly elevated mortality rate and will almost always have an associ= ated intracranial abscess formation. MRI can help confirm the suspicion with the presence of a decreased cavernous carotid artery flow void.

        &= nbsp;   Medical and surgical therapy is similar to other suppurative intracranial complications, but there remains a significant amount of controversy regard= ing systemic anticoagulation. Supporters believe that alleviating the increased intracranial press= ure outweighs the risk for bleeding. Heparin is often started on an inpatient basis before conversion to warfarin in the outpatient setting, and thrombus resolution is usually achieved after six w= eeks of therapy.

BONY COMPLICATIO= NS

        &= nbsp;   First described by Sir Percivall Pott in 1768, “Pott’s Puffy Tumor” denotes the simultaneous presence of a subperiosteal purulent collection an= d osteomyelitis due to frontal rhinosinusitis, resulting in a “puffy” appearanc= e on radiographical images. This i= s not a common occurrence, and the exact prevalence is unknown with one report of 20-25 cases mentioned in the post-antibiotic era (Raja 2007) and another one citing less than 50 pediatric cases in the past ten years (Blumfield 2010). In addition to headach= e, fever, nasal complaints, and neurological findings, Po= tt’s Puffy Tumor is well recognized for the prominent frontal swelling on physic= al examination.

        &= nbsp;   An associated intracranial abscess is encountered in approximately 60%, and ot= her cases may involve cortical vein thrombosis or a fronto= cutaneous fistula. Some organisms that = have been reported with Pott’s Puffy Tumor inc= lude Streptococcus mil= leri, Staphylococcus aureus, and Bacteroides and Proteus species. A multidisciplinary approach invol= ving the otolaryngology, neurosurgery, and infectious disease services is warran= ted to concurrently drain the abscess and responsible paranasal sinuses, remove= the infected bone, and direct a six-week regimen of intravenous antibiotics, respectively. The frontal sin= us may have to be obliterated in situations of recurrence.

CONCLUSION

        &= nbsp;   The frequency of rhinosinusitis-related orbital, intracranial, and bony complications has decreased since the advent of antibiotics, but they still occur and must not be regarded lightly due to the drastic consequences that= may result. Concurrent medical and surgical intervention is the best way to achieve resolution, necessitating = the close cooperation of other specialties.

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