Sinusitis affects approximately .5-5% of individuals suffering from viral upper respiratory tract infections. The exact percentage of persons developing frontal sinusitis is not known although roughly 3-6% of children with pansinusitis will have frontal disease.
Anatomically the frontal sinus is a pyramidal shaped structure with vertical and horizontal segments in the frontal bone. It borders the anterior cranial fossa and the roof of the orbit. The supratrochlear artery provides an inflow of blood while the dural, diploic, supraorbital, and ophthalmic veins drain the frontal sinus mucosa. Supraorbital and supratrochlear branches of the fifth cranial nerve supply sensation. The lining of all of the paranasal sinuses is pseudostratified ciliated columnar epithelium continuous with the posterior two-thirds of the nose. The anterior wall of the frontal sinus is cancellous bone while the floor is a laminar plate without a marrow cavity.
Fifty-five percent of frontal sinuses drain directly into the frontal recess, 30% above the ethmoid infundibulum, 15% into the infundibulum, and 1% above the ethmoid bulla. The frontal sinus, not present at birth, develops from either the frontal recess or from anterior ethmoidal cells. It is radiographically visible by seven years of age and reaches full size by adulthood.
The etiology of frontal sinusitis stems from blockage of the nasofrontal duct ostium. Mechanical obstruction and local mucosal edema lead to symptoms of frontal headache, fever, rhinorrhea and cough. Progression to chronic disease should be suspected with evidence of trauma near the sinus ostia, long standing inflammation of sinus mucosa, persistent headache or sinus opacification on radiographs.
Acute sinusitis in adults has been tied to non-typable H. influenza, S. pneumonia, S. pyogenes, alpha hemolytic streptococcus, and neisseria. S. pneumonia, B. catarrhalis, and H. influenza account for acute disease in children. Organisms associated with chronic sinusitis are the same in adults and children and include chronic respiratory anaerobes (streptococcus, bacteroides, veillonella), along with H. influenza, S. viridans, and an occasional staphylococcal species. Surface cultures of nasal mucosa do not correlate with sinus aspirates for bacterial identification.
Radiological work-up of frontal sinus disease should be guided by clinical suspicion. Caldwell and Water's views provide the best plain film evidence of opacification, mucosal thickening,and air/fluid levels. Computed tomography can be used to assess intracranial and bony involvement. Magnetic resonance imaging and A-mode ultrasound are of limited use in this disease.
Medical treatment consists of analgesics, topical decongestants, and antibiotics. Persistent frontal pain, periorbital edema, and forehead edema indicate disease progression mandating surgical intervention. Removal of intranasal foreign bodies, crushing the middle turbinate, and septoplasty focus on alleviating mechanical nasal obstruction. Trephination should be done in the floor of the sinus to avoid contamination of the cancellous bone with bacteria predisposing to future osteomyelitis. A drain placed through the trephine allows extrusion of sinus contents and can be used to irrigate with antibiotic solutions. External approaches by Reidel, Killian, Lothrop, and Lynch have been abandoned in most cases due to the cosmetic deformities they produce. The Sewall-Boyden procedure of trephination, external ethmoidectomy, and nasofrontal duct reconstruction has been proposed with recurrence of sinusitis in 14% of patients.
The osteoplastic flap with frontal sinus obliteration using abdominal fat is considered the definitive procedure of choice for treating chronic frontal sinusitis. Recently, however, endoscopic enlargement ot the frontal sinus ostium has gained attention. Removal of agar nasi cells and entrance through the floor of the frontal sinus with silastic stenting provides drainage without disfiguring skin incisions. Endoscopic frontal sinus approaches have not gained wide popularity in the pediatric population. More study with attention to long term follow-up is needed before endoscopic therapies can become preferred methods of treatment.
Complications of frontal sinusitis include recurrent sinusitis, mucocele, pyocele, orbital sequelae, and intracranial spread of infection. Mucoceles develop from inadequately removed sinus mucosa in a poorly drained space. They expand locally and erode bone due to the secretion of high levels of PGE-2. Pyoceles form when mucoceles become secondarily infected. Orbital complications include optic neuritis, cellulitis, subperiosteal abscess formation, and intraorbital abscess.
Intracranial spread of infection leads to meningitis, subdural empyema, brain abscess, and cavernous sinus thrombosis. The consortium of frontal osteomyelitis and subperiosteal abscess have been termed Pott's Puffy Tumor. Signs and symptoms include a soft and fluctuant forehead mass, headache, photophobia and fever. The patient presented in this grand rounds had these findings and illustrated the need for aggressive operative treatment
and consultation by the neurosurgical service. The initial trephination did not drain the abscess because the pus had tracked in the cancellous meshwork of the frontal bone and was not localized to the frontal sinus. Violation of the posterior table of bone in the sinus mandated removal of involved bone and inspection of the dura. This patient also received six weeks of intravenous antibiotics and will have close long term follow-up.
In summary, frontal sinusitis is a very serious condition requiring aggressive medical
management with a low index of suspicion for the development of complications requiring surgical intervention. Intracranial complications often require evaluation by the neurosurgical service with a combined surgical approach to remove infected tissues. The length of antibiotic therapy is dictated by the seriousness of disease. Long term follow-up is mandatory.
A 15 year old white male referred with left frontal headaches and a soft mass over his left forehead. The pain started two months prior to presentation after a contact lens caused left eye irritation with orbital swelling. He had received courses of Keflex and Cefotetan prior to admission. He denied nasal obstruction, rhinorrhea, fever, head trauma, and could not relate the onset of pain to swimming. His physical exam revealed full function in all cranial nerves, mild left upper eyelid edema, and a three centimeter swelling over the left eyebrow. His left turbinate was pale, edematous and refractory to treatment with neosynephrine drops.
A CT scan of the head revealed left ethmoid and frontal opacification with left maxillary mucosal thickening. Also noted was a left frontal mass consistent with a subperiostial abscess. A frontal trephination did not relieve the mass on his forehead necessitating frontal sinus obliteration and removal of osteomyelitic cranial bone. He will have a complete six week course of intravenous antibiotics with close follow-up in Nacogdoches. His final culture results revealed alpha hemolytic streptococcus (not pneumococcus).
History of the Procedure: Rhinology and sinus surgery have undergone a tremendous expansion since the discourses of Messerklinger and Wigand in the late 1970s. Imaging advances, increased understanding of the anatomy and the pathophysiology of chronic sinusitis, and image-guided surgery have allowed surgeons to perform more complex procedures with increased safety.
Outstanding short- and long-term results have been reported in the literature. Senior et al reported that symptoms improved in 66 of 72 (91.6%) patients following endoscopic sinus surgery, with a mean follow-up time of 7.8 years. In addition, endoscopic sinus surgery significantly influences quality of life; Damm et al reported an improvement in quality of life for 85% of their patient population, with a mean follow-up time of 31.7 months.
Although functional endoscopic sinus surgery is the primary approach used today for the surgical treatment of chronic sinusitis, the time-honored external approaches still play a role. Therefore, familiarity with both approaches, in conjunction with a precise understanding of the anatomy, ensures optimal patient care and outcome.
Clinical: The cornerstone of accurate diagnosis and treatment of chronic sinusitis is a thorough history and a complete physical examination, including nasal endoscopy. Before considering surgery, the evaluation should clearly indicate that chronic sinusitis is responsible for the patient's constellation of symptoms.
The history should elucidate the frequency of infections, the type and the duration of symptoms, and the response to medical therapy. Patients with chronic or recurrent symptoms typically report nasal congestion, purulent drainage, postnasal drip, facial pressure and headache, hyposmia or anosmia, and nasal obstruction; however, other conditions can mimic chronic sinusitis, causing one or more of the above symptoms. Therefore, ruling out other etiologies for the patient's symptoms is imperative. For example, patients with allergic rhinitis may have similar problems, such as sneezing, watery eyes, itchy eyes, nasal congestion, and postnasal drip. If the patient's only problem is allergic rhinitis, then endoscopic sinus surgery is not the solution, and proper medical treatment should be prescribed.
The physical examination is an excellent adjunct to the history in diagnosing or excluding chronic sinusitis. A complete head and neck examination, along with anterior rhinoscopy, should be performed. If further nasal examination is required, a full nasal endoscopy should be performed. The patient should be assessed for the following conditions: septal deviation; turbinate hypertrophy; nasal polyps; nasal airway problems, including dynamic internal or external valve collapse; ostiomeatal complex, if visible; and adenoidal hypertrophy. Percussion of the sinuses to elicit tenderness may provide additional information; however, this is an imperfect technique in terms of both sensitivity and specificity.
The history and the physical examination can often be used to confirm a diagnosis of chronic sinusitis. Because ascertaining the contribution of confounding factors to the patient's symptoms is difficult, a reasonable approach is to provide maximal medical therapy (see Treatment) for chronic sinusitis and then to perform a paranasal sinus CT scan. In difficult cases, the findings on CT scans after appropriate medical treatment may assist in diagnosing or ruling out ostiomeatal disease or chronic sinusitis as the etiology for the patient's complaints. In patients with normal CT findings and no change in symptoms after undergoing medical treatment, a diagnosis of chronic sinusitis is suspect at best. These patients should not be offered functional endoscopic sinus surgery as a treatment for their symptoms.
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Endoscopic sinus surgery is most commonly performed for inflammatory and infectious sinus disease. The most common indications for endoscopic sinus surgery are as follows:
- Chronic sinusitis refractory to medical treatment
- Recurrent sinusitis
- Nasal polyposis
- Antrochoanal polyps
- Sinus mucoceles
- Excision of selected tumors
- Cerebrospinal fluid (CSF) leak closure
- Orbital decompression (eg, Graves ophthalmopathy)
- Optic nerve decompression
- Dacryocystorhinostomy (DCR)
- Choanal atresia repair
- Foreign body removal
- Epistaxis control
Typically, endoscopic sinus surgery is reserved for patients with documented rhinosinusitis, based on a thorough history and a complete physical examination* including CT scans if appropriate, and in whom appropriate medical treatment has failed. Patients with nasal polyposis commonly have poor results with medical therapy alone; therefore, surgical intervention may be considered earlier in the course of treatment. Similarly, antrochoanal polyps require surgical removal.
Increasingly, selected nasal masses and tumors are being removed endoscopically. Endoscopic removal of inverted papilloma is controversial. Endoscopic surgery can be performed for limited lesions in which definitive control and margins can be obtained endoscopically; this circumstance can be predicted preoperatively via nasal endoscopy and imaging. More extensive lesions should be approached externally with use of either a lateral rhinotomy method or a midfacial degloving method in order to perform en bloc tumor removal. Further research with long-term monitoring in this area will better delineate the optimal treatment for these patients.
CSF leaks associated with CSF rhinorrhea can be managed endoscopically. Success rates of 80% have been reported in the literature with primary endoscopic attempts; success rates increase to 90% if revision endoscopic closures are included. With endoscopic repair of CSF leaks, the more extensive neurosurgical external approaches via craniotomy can be avoided. In certain clinical settings, endonasal encephaloceles are repaired via endoscopic approaches.
Endoscopic approaches may also be applied for ophthalmologic procedures, including orbital decompression, endoscopic DCR, and optic nerve decompression for traumatic indirect optic neuropathy. Traditionally, these procedures were performed through external approaches, but, with increasing experience in nasal endoscopic techniques, they are now performed endoscopically. Only surgeons with extensive training in and expertise with endoscopic techniques should perform these procedures.
||RELEVANT ANATOMY AND CONTRAINDICATIONS
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Relevant Anatomy: Knowledge of the anatomy of the lateral nasal wall and the sinuses is critical for performing safe and complete endoscopic sinus surgery. This description of endonasal anatomy is roughly based on the order of dissection during nasal endoscopy and surgery.
Immediately upon entering the nasal cavity, the first structures encountered are the nasal septum and the inferior turbinate. The nasal septum consists of the quadrangular cartilage anteriorly, extending to the perpendicular plate of the ethmoid bone posterosuperiorly and the vomer posteroinferiorly. Recognizing deflections of the nasal septum preoperatively is important because they may significantly contribute to nasal obstruction and limit endoscopic visualization during surgery. As appropriate, patients with septum deflections may be counseled regarding the need for septoplasty in conjunction with functional endoscopic sinus surgery.
The inferior turbinate extends along the inferior lateral nasal wall posteriorly toward the nasopharynx. In patients with a significant allergic component to their problems, the inferior turbinates may be edematous. These patients may benefit from a turbinate reduction at the same time as the endoscopic sinus surgery. The inferior meatus, where the nasolacrimal duct opens, is located approximately 1 cm beyond the most anterior edge of the inferior turbinate.
As the endoscope is further advanced into the nose, the next structure encountered is the middle turbinate. The middle turbinate is a key landmark in endoscopic sinus surgery. It has both a vertical component (lying in the sagittal plane, running from posterior to anterior) and a horizontal component (lying in the coronal plane, running from medial to lateral). Superiorly, the middle turbinate attaches to the skull base at the cribriform plate. As such, care should always be taken when manipulating the middle turbinate. The horizontal component of the middle turbinate is referred to as the basal (or grand) lamella, and it represents the dividing point between anterior and posterior ethmoid air cells. Posteriorly and inferiorly, the middle turbinate attaches to the lateral nasal wall at the crista ethmoidalis, just anterior to the sphenopalatine foramen.
The uncinate process is the next key structure to be identified in endoscopic sinus surgery. This L-shaped bone of the lateral nasal wall forms the anterior border of the hiatus semilunaris, or the infundibulum. The infundibulum is the location of the ostiomeatal complex, where the natural ostium of the maxillary sinus opens. For patients with sinus disease, a patent ostiomeatal complex is critical for an improvement of symptoms. Anteriorly, the uncinate process attaches to the lacrimal bone, and, inferiorly, the uncinate process attaches to the ethmoidal process of the inferior turbinate. Once the uncinate process is removed, the natural maxillary ostium can be seen, typically just posterior to the uncinate process, roughly one third of the distance along the middle turbinate from its anterior edge. It lies at approximately the level of the inferior border of the middle turbinate, superior to the inferior turbinate.
The natural maxillary ostium is the destination for the mucociliary flow within the maxillary sinus. Therefore, for optimal results, the surgically enlarged maxillary antrostomy must include the natural ostium. In fact, failure to include the maxillary ostium in endoscopic surgical antrostomy is one of the key patterns of failure in functional endoscopic sinus surgery. The maxillary sinus, approximately 14-15 mL in volume, is bordered superiorly by the inferior orbital wall, medially by the lateral nasal wall, and inferiorly by the alveolar portion of the maxillary bone.
The next structure to be encountered is the ethmoid bulla, which is one of the most constant anterior ethmoidal air cells. It is just beyond the natural ostium of the maxillary sinus and forms the posterior border of the hiatus semilunaris. The lateral extent of the bulla is the lamina papyracea. Superiorly, the ethmoid bulla may extend all the way to the ethmoid roof (the skull base). Alternatively, a suprabullar recess may exist above the roof of the bulla. A careful preoperative review of the patient's CT scan clarifies this relationship.
The ethmoid sinus consists of a variable number (typically 7-15) of air cells. The most lateral border of these air cells is the lamina papyracea, and the most superior border of these cells is the skull base. Supraorbital ethmoid cells may be present. A review of the patient's CT scan alerts the surgeon to these variations. The basal lamella of the middle turbinate separates the anterior ethmoid cells from the posterior ethmoid cells. Anterior ethmoid cells drain to the middle meatus, and the posterior cells drain into the superior meatus.
Exenteration of the posterior ethmoid cells leads to the face of the sphenoid. The sphenoid sinus is the most posterior of the paranasal sinuses, sitting just superior to the nasopharynx and just anterior and inferior to the sella turcica. The anterior face of the sphenoid sits approximately 7 cm from the nasal sill on a 30Ãƒâ€šÃ‚Â° axis from the horizontal.
Several important structures are related to the sphenoid sinus. The internal carotid artery is typically the most posterior and medial impression seen within the sphenoid sinus. In approximately 7% of cases, the bone is dehiscent. The optic nerve and its bony encasement produce an anterosuperior indentation within the roof of the sphenoid sinus. In 4% of cases, the bone surrounding the optic nerve is dehiscent. Therefore, controlled opening of the sphenoid sinus, typically at its natural ostium, is critical for a safe outcome. The location of the natural ostium of the sphenoid sinus is variable; approximately 60% are located medial to the superior turbinate, and 40% are located lateral to the superior turbinate.
The frontal recess, or the frontal outflow tract, is the tract that leads from the frontal sinus into the nasal cavity. Often, the ethmoid bulla is the posterior border of the frontal sinus outflow tract. Anteriorly, the frontal sinus outflow tract is bordered by the uncinate process or the agger nasi cells (frontal anterior ethmoid air cells). If any of these cells are enlarged or if scarring is present from a previous surgery, resultant outflow tract obstruction, leading to frontal sinusitis, may occur. Typically, the medial wall of the frontal recess is formed by the lamina papyracea.
Intimate knowledge and understanding of the anatomy, in conjunction with a careful preoperative review of CT scans, are paramount in the safe and complete performance of endoscopic sinus surgery.
Contraindications: Certain conditions may require an external approach for complete treatment of disease; these include intraorbital complications of acute sinusitis, such as orbital abscess or frontal osteomyelitis with Potts puffy tumor. An open approach in these instances, with or without additional endoscopic assistance, may be preferable. A careful review of preoperative CT scans or MRI films helps to guide the surgeon.
After 2 failures to endoscopically manage CSF leaks associated with CSF rhinorrhea, patients should be referred to a neurosurgeon for closure using a neurosurgical approach. Likewise, after failure to endoscopically manage frontal sinus disease, open approaches should be considered.
- A paranasal sinus CT scan is often obtained after maximal medical therapy for chronic sinusitis in order to ascertain the contribution of confounding factors.
- Findings on CT scans after appropriate medical treatment may assist in diagnosing or excluding ostiomeatal disease or chronic sinusitis as the etiology for the patient's problems.
- In patients with normal findings on CT scans and no change in symptoms after medical treatment, a diagnosis of chronic sinusitis is suspect at best.
- If surgery is to be performed, careful preoperative review of CT scans is essential for safe and complete performance of endoscopic sinus surgery.
- Conditions such as intraorbital complications of acute sinusitis (eg, orbital abscess or frontal osteomyelitis with Pott puffy tumor) may require an external approach for complete treatment of disease. In these cases, a careful review of preoperative CT scans or MRI films helps to guide the surgeon.
- To diagnose or exclude chronic sinusitis, a complete head and neck examination, along with anterior rhinoscopy, should be performed. If further nasal examination is required, a full nasal endoscopy should be performed.
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Medical therapy: Medical therapy is the mainstay of treatment for most patients with recurrent or chronic sinusitis. Surgery may serve as an adjunct and provide significant relief for these patients, but medical treatment should always be instituted before surgery is considered for these patients. Frequently, medical treatment is also required after surgery.
Treatment of chronic or recurrent sinusitis consists of a 3- to 6-week course of antibiotics, with coverage for gram-positive and gram-negative bacteria. Augmentin and levofloxacin are antibiotics that are typically used. Nasal steroids should be instituted to decrease intranasal edema and inflammation. Improvement with nasal steroids might not be seen for days or weeks. Saline irrigations are also important for nasal toilet. If nasal congestion is a significant complaint, a short course of decongestants (3 d if intranasal, 7 d if oral) may be used. If thick nasal mucous is noted, guaifenesin, taken orally at a high dosage (600 mg bid for 3 wk), may provide significant relief as a mucolytic.
Patients with nasal polyps may undergo the above treatment, plus a 1-week course of oral steroids (40-60 mg/d) beginning 5 days prior to surgery. (Steroids may decrease intraoperative bleeding and inflammation.) Patients should be carefully counseled regarding possible adverse effects, including hyperglycemia (especially in patients with diabetes), gastritis, and even psychosis. Steroids shrink polyp size and significantly improve symptoms, but the patient should be counseled that surgery is still required to eradicate the remaining nasal polyps.
After a full course of medical treatment, a paranasal CT scan should be obtained to assess treatment and to confirm radiographic evidence of chronic sinusitis. Patients with residual symptoms and radiographic findings consistent with recurrent or chronic sinusitis may be considered as candidates for surgery. If findings on CT scans do not reveal significant mucosal thickening or sinus opacification, the diagnosis of sinusitis should be reassessed. Patients with recurrent sinusitis may have normal findings on CT scans after treatment or between episodes, but they should have positive radiographic findings during episodes.
Every effort should be made to confirm the diagnosis of chronic or recurrent sinusitis prior to initiating endoscopic sinus surgery. Limited data exist for operating on patients whose clinical picture is consistent with chronic or recurrent sinusitis despite normal findings on CT scans. This finite subset of patients represents the exception, not the rule, for endoscopic sinus surgery operative candidates
There are eight paranasal sinuses, four on each side of the midline. They are the paired frontal, ethmoidal (anterior and posterior), maxillary and sphenoidal sinuses. They are lined with a pseudostratisfied columnar (respiratory) epithelium which is continuous with the nasal mucosa. The lining provides a mucous secretion which traps bacteria and subsequently extrudes the mucous and bacteria through the sinus ostia to be swallowed or expectorated. Under normal conditions, the sinuses are air filled and communicate directly with the nasal passages through patent ostia.
The sinuses are divided into two groups, the anterior and posterior sinuses, which drain into the middle meatus and above the middle meatus, respectively. The posterior group is comprised of the sphenoid sinuses and the posterior ethmoid sinuses, whereas the anterior group are the frontal, maxillary and anterior ethmoidal sinsuses. The drainage site into the middle meatus of the anterior sinuses is the infundibulum.
The ethmoidal labyrinth appears during the third month of fetal development as evaginations of the lateral nasal wall. The anterior ethmoids arise near the middle meatus and the posterior ethmoids arise near the superior meatus. Along with the maxillary sinus, the ethmoids are the only sinuses usually present of birth. They reach adult size by age 12. Anatomically, the ethmoids lie medial to the orbit in the superior nasal vault. There are vertical and horizontal plates, with the vertical plate known as the perpendicular plate of the ethmoid inferiorly and the crista galli superiorly. Horizontally, the lateral aspect is called the fovea ethmoidalis and the medial portion the cribriform plate. The most medial and also the thinnest portion of the ethmoid bone abuts the orbit, and is the lamina papyracea. The anterior and posterior ethmoids are separated by a bony plate, known as the ground lamella. Additional findings include an aerated portion of the middle turbinate, the concha bullosa, as well as anteriorly located cells which frequently extend into the uncinate process.
The blood supply to the ethmoids is from both the external and internal carotid arteries. The external carotid supply is from the sphenopalatine artery, and the internal carotid artery derivatives are the anterior and posterior ethmoidal arteries. Innervation is from V2 and V3, with the contributions from V2 being the anterior and posterior ethmoidal nerves and V3 being the sphenopalatine nerve.
The maxillary sinus occupies the body of the maxilla and is the largest of the paranasal sinuses. Although present at birth, they are usually not visible on plain x-rays until about 3 or 4 months of age. They are pyramidal shaped, with the apex near the zygomatic arch and the base at the lateral nasal wall. In the child, the inferior border is usually at the nasal floor, whereas in the adult the sinuses may extend a full centimeter below the nasal floor. The anterior wall is the canine fossa, and the posterior wall is the infratemporal fossa. The floor consists of the premolars and molars, and often there is only a thin mucous covering, leaving easy extension of infection from a tooth root into the sinuses, or the possibility of an oroantral communication with tooth extraction. The roof of the sinus is the orbital floor, with the infraorbital nerve usually lying in a midline groove. This nerve is often dehiscent, making it at risk during antral procedures. The sinus communicates with the nose at the infundibulum of the middle meatus through the sinus ostium. These true ostia are located anteriorly and superiorly, although with chronic infection there is sometimes accessory ostia located more posterioly. The accessory ostia are not felt to be congenital. In general, the ostia are surrounded by a membranous portion, with the bony portion being larger than the actual opening. Most nerves and vessels enter through the membranous portion.
Drainage of mucous from the maxillary sinus is now believed to be dependent on the natural ostia, with mucociliary clearance patterns directed in a circular pattern towards these ostia, even in the presence of accessory drainage sites.
Blood supply to the maxillary sinus is predominantly from the divisions of the maxillary artery, including greater palatine, posterosuperior and anterosuperior alveolar arteries and the lateral nasal branches of the sphenopalatine artery. Innervation is via the maxillary nerve, including the greater palatine, posterolateral nasal and the alveolar branches of the infraorbital nerve. CN VII, through the greater superficial petrosal nerve, supplies postganglionic parasympathetic innervation.
The frontal sinus begins as an evagination of the anterior nasal capsule around the fourth month of fetal development, but it is rarely radiographically visible until around the second year of life and does not reach adult size until the teenage years. Great variability in size exists, and approximately 5% of people have absent frontal sinuses. The sinus connects with the middle meatus via the frontal recess near the upper portion of the infundibulum. The anterior plate of the frontal sinus is diploic bone, whereas the posterior plate is compact bone. Like the maxillary sinuses, the frontal sinuses have circular mucociliary clearance.
Blood supply is from the supraorbital and supratrochlear arteries derived from the ophthalmic artery, a branch of the internal carotid artery. Innervation is from the supraorbital and supratrochlear branches of the frontal nerve.
The sphenoidal sinuses begin as outpouchings of the superior nasal vault around the fourth month of gestation. The sinuses are not radiographically present at birth, with pneumatization beginning around the fourth year and ending around age 15. The sinuses are usually asymmetric, being separated by a septum, and each drains into the superior meatus in the sphenoethmoidal recess through variable sized ostia. Once again, these ostia are primarily membranous, with the bony portion being much larger.
Structures of great importance surround the sphenoids. The optic nerve lies superiorly and the pons posteriorly. Lateral are the cavernous sinuses and their associated structures, along with the superior orbital fissure and the carotid artery. The carotid artery forms a indentation in over 50% of specimens, and in many the wall of the sinus is dehiscent, leaving this vital structure exposed during surgical procedures.
Both the external and internal carotids are responsible for the blood supply. The posterior ethmoidal branch of the ophthalmic artery contributes vessels to the roof whereas the sphenopalatine artery supplies the floor. Innervation is from both V2 and V3 via the posterior ethmoid nerve and the sphenopalatine nerve.
The linings of the paranasal sinuses are composed of respiratory epithelium, ie, pseudostratified columnar epithelium, with interspersed goblet cells. There is a double layer of mucous with a superficial viscid layer and an underlying serous layer. The cilia of the respiratory epithelium beat predominantly in the serous layer, and move the mucous toward the natural ostia. It is now believed the primary factors of normal physiology are the patency of the ostia, the function of the cilia, and the quality of the mucous blanket.
The most important pathologic process in sinus disease is obstruction of the natural ostium. The obstruction leads to hypooxygenation which in turn leads to ciliary dysmotility. When ciliary motility is compromised, the mucous blanket does not function properly, leading to retention of secretions and intranasal pressure. Thus, an ideal environment for bacterial invasion is created.
Both local and systemic factors can contribute to sinusitis. Local causes predominantly result in impaired mucociliary clearance. Cold air is believed to "stun" the epithelium which leads to decreased ciliary action. Dry air is believed to dessicate the mucous blanket. Anatomical blockage of the ostia by polyps, tumors, and foreign bodies also predispose to sinus disease. Kartagener's Syndrome (immotile cilia syndrome) leads to sinus disease and bronchitis by similar methods. Systemic factors leading to sinus disease include malnourished or immunocompromised states.
There are three classifications of sinus disease, acute, subacute and chronic. Acute sinusitis is defined as disease lasting less than one month. Subacute is defined as one month to three months, and chronic is longer than three months duration. Chronic sinusitis usually results from acute sinusitis that has been inadequately treated, and the pathophysiologic process is considered irreversible by medical therapy. Surgical therapy, i.e., opening of the sinus ostia to oxygenate the sinuses is the primary therapy for chronic sinusitis, whereas acute and subacute sinusitis are generally treated medically.
HISTORY and PHYSICAL FINDINGS:
The symptoms of bacterial sinusitis relate to the duration of symptoms and the location of disease. Acute sinusitis primarily presents as pain over the infected area with or without headache and associated facial pain. The patient may complain of a "cold." Pain over the infected sinus is possible to elicit with the anterior sinuses, but the usual presenting symptom of posterior sinusitis is bitemporal or vertex headaches. There is usually a mucopurulent greenish or yellow discharge from the nose, which may be bilateral. There is often associated fever and malaise. In chronic sinusitis, there is usually a discharge but pain and fever are more often than not absent. Acute sinusitis can be superimposed on chronic sinusitis, and it is sometimes found these patients have pansinusitis.
The diagnosis of sinusitis is primarily clinical, but radiographs and cultures can be helpful. Any facial edema should be noted, particularly around the orbit. Any tenderness should then be assessed. Palpate and percuss the sinuses, including the medial orbital regions to assess the ethmoids. Intranasally, any mucosal edema should be noted, as should any purulence, masses or septal deviation. The nasopharynx should be examined for evidence of obstruction, including choanal atresia, adenoidal hypertrophy and unusual masses. An otoscopic exam should be performed to rule out concommitant otitis media. Transillumination of the maxillary and frontal sinuses can be performed, but as these sinuses are sometimes hypoplastic, decreased illumination is not always indicative of sinus disease.
The most significant advances have occurred in the area of diagnois. With nasal endoscopy, the sinuses involved and any local pathology can be determined with a high degree of certainty. This exam should be performed both pre and post nasal decongestion.
Antral lavage can be performed in select cases through an anterior maxillary puncture or by an inferior meatal window. These procedures are simply performed using topical anesthetics followed by puncture of the sinus wall using a trochar. Cultures can be obtained as necessary. The main indications for this procedure are the presence of mucopurulent material in an immunosuppressed patient or with known sinusitis that has failed medical management.
ACUTE BACTERIAL SINUSITIS:
Acute sinusitis can be thought of as an abscess or empyema, and like all abscesses the cornerstone of treatment is drainage and antibiotics. The drainage in most cases can be accomplished medically with topical decongestants and sometimes systemic antihistamines. In those rare cases where the sinus is insufficiently drained medically, surgical drainage may be necessary.
Antibiotic coverage is aimed at the most common pathogens, including s. pneumoniae, H. influenzae and M. catarrhalis. As a first line antibiotic, amoxicillin is adequate. If a patient fails to improve in 3-5 days or has symptoms beyond 10 to 14 days, either the drainage has been inadequate or resistant organisms have developed. Under these circumstances, proper antibiotic coverage is essential, and fluid should be obtained for culture and gram stain, and coverage broadened, usually with the addition of clavulonic acid. If the infection continues to worsen, surgical drainage of the sinuses is required.
Different techniques are available for surgical drainage of the sinuses. The maxillary sinuses can be irrigated using the above methods for antral lavage or middle meatal antrostomy. In refractory cases, endoscopic enlargement of the osteomeatal complex can be undertaken. The traditional approach tot he frontal sinus is to trephinate the sinus. This is done through an incision in the medial aspect of the upper eyelid, exposing the floor of the frontal sinus. The bone is removed with a drill, and a drain placed. The sinus must be irrigated twice a day until free drainage is noted through the nasofrontal duct. Oftentimes, this takes a week or more. The traditional approach to the ethmoid sinuses is an external ethmoidectomy, but more common today is the endoscopic approach.
ACUTE FUNGAL SINUSITIS:
Fungal infections of the paranasal sinuses are uncommon. Aspergillosis, mucormycosis, candidiasis, histoplasmosis and coccidiomycosis occur. Aspergillosis is the most common pathogen seen, and usually occurs in the maxillary sinuses. Recognition of acute fungal sinusitis requires a high index of suspscion. Immunosuppressed patients are at highest risk. The final diagnosis is usually made by antrostomy and biopsy or culture.
Aspergillus is common pathogen of soil, decaying fruits and vegetables and grains, as is pathogenic in humans, birds and other animals. An infection should be suspected if dark, thick greasy material is seen in the sinuses. Of note, a culture of the nose or even an aspirate of the sinus is usually not diagnostic. An antrostomy with a biopsy is usually required. The diagnosis is usually made using a fungal stain such as Gridley's or PAS. The hyphae are septate with 45 degree branching angles. The infections may be invasive, noninvasive, or fulminant. The noninvasive form results in a fungus ball within the sinus, and this is usually surgically removed. Invasive aspergillosis may behave much like a malignant neoplasm, with destruction of bone. Treatment involves wide surgical debridement and amphotericin. Fulminant aspergillosis most commonly occurs in immunocompromised patients and is characterized by the spread of organisms beyond the sinuses and into surrounding structures. Again, therapy is wide excision and amphotericin.
Mucormycosis is a fungi of the Phycomycetes class. They are encountered in dust and soil and enter the host through the respiratory tract. The fungus directly invades vascular channels and causes hemorrhagic ischemia and thrombosis. The disease is frequently fatal, with even normal hosts having up to a 40% mortality rate. Immunocompromised hosts have an approximately 90% mortality rate.
Ketoacidosis predisposes to severe mucormycosis as the fungus thrives in acidic, glucose rich areas. Other patients at risk are any immunocompromised patient, including those on steroids, chemotherapy or receiving broad spectrum antibiotics.
The initial signs of infection include engorgement of the turbinates and obstruction, followed by ischemia and thrombosis leading to necrosis of the turbinates and a bloody discharge. The area typically appears black. Progession to invasive disease is the usual course, heralded by proptosis, ptosis, ophthalmoplegia and facial palsy. The diagnosis is made by fungal stains, including PAS and methenamine-silver. In fulminant cases, the characteristic non-septate hyphae can be seen on frozen section.
Management of mucormycosis involves radical surgical debridement with aggressive correction of underlying immunocompromised states as well as high doses of amphotericin. Amphotericin alone is ineffective.
A mucocele is a chronic, cystic lesion of the sinuses which is lined by pseudostratified or columnar epithelium. These lesions expand slowly, often requiring more than ten years to become symptomatic. Symptoms include bony erosion of adjacent structures.
The etiology of mucoceles is debated, but two general theories exist. The first suggests obstruction of the ostium results in the retained mucocele, while the other postulates obstruction of a minor salivary gland is all that is required. Regardless, nearly half of all patients have chronic obstruction of the ostia or have an antecedent trauma to one of the sinuses. In nearly 30%, no prior nasal symptoms can be elicited.
Maxillary mucoceles are frequently noted on routine CT scans. In general, these cysts are asymptomatic and do not require treatment, unless they are blocking a natural ostium. If therapy is warranted, these cysts can often be aspirated through an antral puncture.
Frontal sinus mucoceles are the most clinically significant mucoceles. They often cause proptosis and double vision. Therapy involves complete removal and obliteration of the frontal sinus.
Sphenodoethmoidal mucoceles are more subtle. Vertex headaches and deep nasal headaches are common complaints. These must be widely drained into the nasal vault.
The orbit is separated from the ethmoidal sinuses by the thin lamina papyracea, making orbital involvement the most common complication of sinusitis. The first indication is inflammatory edema of the eyelids which progresses to cellulitis, proptosis, chemosis and ophthalmoplegia. There are five classifications of orbital involvement:
- 1) Inflammatory edema: lid edema otherwise normal
- 2) Orbital cellulitis: diffuse edema but no abscess
- 3) Subperiosteal abscess: purulent collection beneath lamina papyracea periostium
- 4) Orbital abscess: purulent collection within the orbit
- 5) Cavernous sinus thrombosis: bilateral eye findings, meningism
Of note, purulent frontal sinusitis may also result in orbital complications. The floor of the sinus is thin, leading to easy transmission to the orbit. An abscess in this area leads to osteomyelitis of the frontal bone and an abscess and is known as Pott's puffy tumor.
Orbital inflammation and cellulitis is treated with IV antibiotics with or without sinus drainage, depending upon the severity of symptoms, and patients should be hospitalized for close evaluation. If an abscess develops, immediate surgical drainage is necessary to avoid possible permanent sequelae. Indications for surgical drainage include:
- 1) progressive orbital cellulitis despite appropriate antibiotics,
- 2) symptoms that regress initially but then stabilize or worsen,
- 3) evidence of abscess,
- 4) loss of visual acuity. Surgical treatment includes drainage of the affected sinus by frontal sinus trephination or ethmoidectomy and drainage of any abscess.
Cavernous Sinus Thrombosis:
Most cases of cavernous sinus thrombosis are caused by infections of the middle one third of the face as the ophthalmic veins are valveless and lead directly to the cavernous sinus. Sinus disease is also a common finding.
Clinical findings include palsies of cranial nerves 3, 4, V1, V2 and 6 as these are located in or near the cavernous sinus. Severe frontal and ethmoid headaches are seen, as are fever, and progressive unilateral or bilateral orbital findings. Initially, the eye becomes proptotic and chemotic with subsequent 6th and 3rd nerve palsies. As there are no ophthalmic valves, the other eye is subsequently affected.
Although the diagnosis is primarily clinical, CT scans show a filling defect of the involved sinus with a dilated ophthalmic vein. Treatment is intravenous antibiotics and surgical drainage of the affected sinuses. Heparinization, although controversial, is sometimes performed. Mortality rates are 30%, but less than half survivors are neurologically intact.
Nearly one in seven brain abscesses are from sinususitis, and the mortality rate is 20%. Clinically, the most important prognostic sign is the degree of neurological deficit, with those alert and oriented at presentation having minimal mortality.
Treatment includes drainage of the affected sinus and the abscess along with intravenous antibiotics. The frontal, ethmoidal and sphenoid sinuses are commonly involved.
Since sustained bacteremia is primarily seen in the young, menigitis is more often found in children. Sinusitis accounts for nearly one in nine cases. The clinical findings of nuchal rigidity and fever are well known. Focal neurological deficits are uncommon. The mortality for adults is nearly 20%, but much lower for children. Therapy is intravenous antibiotics and surgical drainage of the affected sinus.
Most cases of subdural abscesses result from sinusitis. The clinical presentation is characterized by swift neurological deterioration, with hemiparesis, seizures and aphasia commonly found. The mortality rate is 20%, with 1/3 of survivors remaining neurologically impaired. Treatment is intravenous antibiotics and surgical drainage.
There are generally two commonly performed radiographic studies of the paranasal sinuses, plain films and computed tomography. Customarily, plain films include the Waters', Caldwell's and lateral views of the sinuses. They are useful in evaluating the transparency, size and integrity of these structures, but are limited in their evaluation of the sphenoids and ethmoids due to overlapping structures. In general, bony structures are seen with far more detail than soft tissue. Computed tomography has largely replaced plain films, as it simultaneously displays bone, soft tissue and air, and their evaluations of the sinuses is in much greater detail and at an increasingly competitive cost.
The Waters view is a posteroanterior projection performed with the patient's nose and chin on the film. This view is useful for evaluating the maxillary sinuses. The Caldwell view is taken with the nose and forehead on the film, and is useful in evaluation the frontal and ethmoid sinuses. The lateral view is most useful for evaluating the sphenoid sinuses. The basal view can evaluate the sphenoid and ethmoid sinuses.
Viral sinusitis is classically seen as slight mucoperiosteal thickening. Bacterial sinusitis usually has an air fluid level, with one sinus affected greater than the others. In allergic rhinitis, bilateral mucoperiosteal thickening is seen, thus helping differentiating it from bacterial sinusitis.
Computed Tomography Since CT can simultaneously display bone and soft tissue and has the additional property of displaying selected anatomical areas, it has largely made plain films obsolete.
In normal sinuses, mucosa is usually barely perceptible and the air appears to nearly abut against the bone. With chronic disease, the mucosa becomes more clearly defined. Care must be taken to not construe the normal nasal cycle as sinusitis. Allergic fungal sinusitis is seen as the characteristic double density.
Two series of views are obtained, the coronal and the axial. The coronal cuts are much more useful as the ostiomeatal complex is more clearly seen. In some instances, the coronal cuts are adequate for diagnosis, while the axial views must be obtained if one contemplates surgery upon the sinuses.
Discussion (Dr. Quinn):
In the matter of surgical drainage of the acute frontal sinus empyema, it was the discussant's view, shared by the faculty then present, that the standard external trephine is superior to the intranasal endoscopic approach and is to be preferred.
Drs. Quinn and Deskin remarked upon the severity of acute frontal sinusitis when its onset is immediately preceded by swimming or diving, and comments were offered regarding the suitability of various local bodies of water for recreational bathing.
Dr. Quinn suggested that an acute viral rhinosinusitis might be distinguished from a bacterial sinusitis by the simple expedient of a "snot smear" stained with Gram's method. In viral sinusitis, bacteria may be seen in assocation with clusters of epithelial cells as from the nasal vestibule, while in bacterial sinusitis bacteria are seen generously admixed with and occasionally within the overwhelming number of polymorphonuclear leucocytes in the nasal discharge. While current doctrine espouses (and patients expect) antibiotic treatment when a diagnosis of sinusitis has been made, the recent emergence of resistant strains of common pathogens may cause us to reconsider this practice.
It cannot be denied that when a patient observes his physician obtaining a sample of nasal discharge, then studying it intently through a microscope (in the same room as the patient, of course) that patient leaves with the conviction that his doctor regards his complaint of "a terrible sinus problem" with serious concern as well as with sympathy.
Finally, the assemblage failed to resolve the question of why the nose runs in cold weather. One faction contends that the phenomenon is a response of the nasal mucosal secretory apparatus, while a minority claimed that the fluid represents excessive lacrimal secretion (in response to cold wind striking the conjunctiva and cornea) issuing though the nasolacrimal duct, emerging from the nostrils. The question clearly offers a sound basis for external funding of studies to determine the effectiveness of Atrovent nasal spray in conditions experienced by cross-country and downhill skiers. A number of individuals immediately volunteered to act as subjects, contingent upon suitable grant support.
Allergic Fungal Sinusitis:
1981- Millar et al. recognize histologic resemblance between chronic fungal sinusitis and allergic bronchopulmonary aspergillosis
1983- Katzenstein et al. - resemblance between ABPA (allergic bronchopulmonary aspergillosis) and seven cases of chronic sinusitis associated with fungal hyphae (allergic Aspergillus sinusitis)
1988- Sher and Schwartz report the first case of concurrent ABPA and AFS
1991- Allphin et al. and Manning et al. - fungi of the Dematiaceae family, not Aspergillus species, were the primary etiologic agent in AFS
1994- Kinsella et al - double density sign
1995- Rassekh et al - Skull base allergic fungal sinus disease
1. acute fulminant - pt immunocompromised, usually caused by Mucormycosis Aspergillus, life threatening
2. chronic indolent - immunocompetent host, disease escapes confines of sinus cavities and invades tissue. Rx includes surgery and antifungals
1.mycetoma - proliferation of fungal elements, no immune response, simple debridement sufficient
2. AFS - intense immune reaction to fungal antigen, requires surgical debridement and steroid therapy
Approximately 7% of chronic sinusitis cases requiring surgery are caused by AFS. As the entity is gaining recognition, reports of its incidence are increasing. Most series of AFS reports are from medical centers in the southern United States. A warm humid climate may enhance fungal growth and amplify disease prevalence.
Most common etiologic agent in ABPA is Aspergillus. In AFS, fungi in the Dematiaceae (black) family (Curvularia, Bipolaris, Alternaria, Exserohilum) are responsible in the majority of cases.
Predisposing factors: 1. Atopic host
2. mechanical obstruction (deviated septum, mucosal hypertrophy, polyps, OMC disease)
3. Exposure to ubiquitous fungus
Mucus- allergic mucin very tenacious, thick, and pasty and resembles peanut butter. Color ranges from light green to dark brown.
Histology- layers of mucus mixed with sheets of eosinophils Can see Charcot Leyden crystals (necrotic eosinophils) on high power
Fungal hyphae can be seen on H&E stain but best seen on methanamine silver stains If allergic mucin with hyphal element is seen, the diagnosis of AFS can be made. However, fungal elements in AFS are relatively scarce and do not dominate the histologic specimen as in mycetoma. The surgical specimen must be analyzed promptly as the scant fungal elements deteriorate in vitro. The morphology of various fungi is similar on tissue examination, therefore fungal cultures must be obtained. The absence of fungal invasion in to removed mucosa and bone is necessary to rule out invasive fungal sinusitis.
ABPA - elevated levels of IgE and IgG to the specific fungal agent. AFS is the counterpart of ABPA manifested in the sinuses, so it is also thought to represent Gell and Coombs type I and type III responses.
Type I immunity - emphasized by Manning et al. who demonstrated elevated levels of total IgE and Bipolaris specific IgE in nine consecutive patients.
Type III - IgG antibodies (in addition to IgE antibodies) to the specific fungus in the serum can be demonstrated. There is no cytotoxic event associated with these IgG antibodies (as in type II), therefore it is thought to be a type III, non IgE mediated, noncytotoxic, antibody-dependent immune response. Complement mediated immune response has not been demonstrated in AFS.
The role of hypersensitivity vs. true infection in the pathogenesis of AFS is still controversial. Clinical, histologic and serologic support for allergic causes include the incidence of AFS in young immunocompetent atopic patients, allergic mucin and lack of invasion on histology, serologic and skin test evidence of IgE mediated fungal hypersensitivity, and the presence of IgG and precipitating antibodies to fungal antigens. Mabry and Manning recently showed not only elevated total IgE levels in patients with AFS but also a significant degree of allergen-specific IgE for other inhalants such as grasses, weeds, trees, and dust mite. This also supports the idea that AFS is a true allergic rather than infectious disease.
The CT and MRI findings in AFS is important for distinguishing fungal sinusitis from bacterial sinusitis and sinus neoplasms. Serpiginous areas of increased attenuation on noncontrast CT, particularly on bone windows are characteristic of AFS. These hyperdense and heterogenous densities in an opacified sinus are also referred to as the “double density” sign and most likely represent higher levels of magnesium, manganese, and iron in fungal mucin. T1-weighted MRIs of fungal sinusitis demonstrate isointense or slightly hypointense regions surrounded by mucosal inflammation; T2 images often have a signal void and are black. This is in contrast to MRIs of neoplasms and bacterial infections which are hyperintense. AFS tends to affect multiple sinuses with a unilateral predominance. It is a slow growing and chronic entity, and bone erosion is not uncommon. This occurs in the same manner as mucoceles and polyps. Evidence of bony erosion on radiography should not be interpreted as invasion without histologic evidence of invasion..
Clinical Presentation and Diagnosis
AFS occurs in adolescents and young adults who often have asthma that is exacerbated by their sinusitis. There is no male or female predominance. All patients are immunocompetent and have a strong history of atopy. All have nasal polyps and chronic sinusitis; many have had multiple sinus surgeries. There is no increased aspirin sensitivity despite the association with asthma and nasal polyps. Patients typically present to the otolaryngologist with acute worsening of their chronic sinusitis with nasal obstruction, headache, proptosis, and at times intracranial erosion.
Diagnostic criteria have been suggested by Bent and Kuhn and include
(1) type I hypersensitivity confirmed by history, skin tests, or serology;
(2) eosinophilic mucus without fungal invasion of sinus tissue;
(3) positive fungal stains of sinus contents removed during surgery.
The current therapy for AFS involves surgical extirpation of all allergic mucin if possible with aeration of diseased sinuses. Endoscopic surgical decompression with adjunctive steroids are considered initially. Most patients will experience rapid relief of nasal congestion, drainage, headache and other associated symptoms; however, this is transitory as the polyps and associated AFS symptomatology almost always recurs. The hallmark of this disease is multiple sinonasal surgeries (including external approaches and frontal sinus obliteration) with recurrence of symptoms. These recurrences may be treated with adjunctive steroids and office debridement. Other patients may require repeat radiographic studies and repeat operative debridement. Total and fungal-specific IgE levels are useful laboratory studies and can be used to follow the course of the disease.
Steroids Systemic steroids are the mainstay of therapy in ABPA flairs and have been used successfully in recurrent cases of AFS. However, steroids have multiple side effects and their use is controversial. Since surgical drainage and ventilation is possible in the sinuses but not in the lungs, some authors reserve systemic steroids for difficult or refractory cases of AFS. Others believe that systemic low dose steroids should be used indefinitely. Topical intranasal steroid sprays and saline irrigations have minimal side effects and are used routinely in the postoperative management of AFS. However, the duration and effectiveness of steroid sprays in AFS has not been proven scientifically.
The use of topical and systemic antifungal agents is controversial. No indication exists for the use of toxic antifungal agents (amphotericin B, Fluconazole) to treat noninvasive fungal sinusitis. Both amphotericin B and Fluconazole are ineffective against the Dematiaceous fungi and Aspergillus species. Since AFS is thought to be an allergic disease caused by an extrinsic fungal antigen rather than a true infection, systemic antifungals should be ineffective. Itraconazole, a relatively benign and oral antifungal agent, has had some usefulness in treatment of ABPA and may be of adjunctive use in management of AFS associated with Aspergillus. However, the efficacy of itraconazole against dematiaceous has not been studied.
Immunotherapy based on mold desensitization with serial end point titration would theoretically blunt the type I immune response. However, antigen injections, while blunting type I hypersensitivity, increase IgG levels as blocking antibodies are made.This increase in IgG could theoretically potentiate the pathologic type III response. However, the role of the type III response in AFS is debated. Immunotherapy for other inhalants is recommended to reduce the antigenic load presented to the patient.
AFS is a newly recognized noninvasive disease that accounts for approximately 7% of all chronic sinusitis requiring surgical intervention. The vast majority of causative fungal agents belong to the Dematiaceae family. AFS should be suspected in any atopic patient with refractory nasal polyposis and characteristic radiographic signs. Thick, tenacious, allergic mucin encountered at surgery can be confirmed histologically and hyphae can be demonstrated on special fungal stains or confirmed by a positive fungal culture. Current therapy includes conservative but complete removal of all allergic mucin, which usually can be accomplished endoscopically. Although the use of steroids is controversial, adjunctive systemic steroids are used short term and topical nasal steroids long term. Recurrence of AFS with associated symptomatology is common, necessitating close clinical, endoscopic, and radiographic follow-up.
Sinusitis In Children
The diagnosis of sinusitis is being made more often in the pediatric population. Although many clincians once doubted the existence of sinusitis as a separate clinical entity in this group of patients, it is now recognized by many primary care physicians and otolaryngologists as being distinct from other forms of upper respiratory tract infection in children. In otherwise healthy children, sinusitis is thought to complicate upper respiratory tract infections in as many as five percent of the cases. In other subgroups of patients, such as those with nasal allergy, cystic fibrosis, immunodeficiencies, or chronic pulmonary disease, the incidence is even greater. The degree of morbidity and the impact on the overall health and well-being of the children within these groups is often heightened as well. The signs and symptoms are often subtle and may wax and wane over an extended period of time. This aspect of sinus disease in children, and the fact that the history may be limited to the observations of the parent with a physical examination highly dependent upon the cooperation of the young patient, places greater emphasis on the newer diagnostic imaging modalities in evaluating the extent of sinus involvement. The purpose of this presentation is to discuss sinusitis in children in terms of its etiology and pathogenesis, diagnosis, medical and surgical management, and complications.
ETIOLOGY AND PATHOGENESIS:
Normal paranasal sinus function and health is dependent upon several variables, including proper mucociliary defense, adequate patency of the sinus ostia, and local as well as systemic immunity. Any condition which alters one or more of these variables may predispose to the development of acute or chronic sinusitis.
The respiratory epithelium of the sinonasal tract consists principally of a ciliated pseudostratified columnar epithelium upon which rests a blanket of mucus with an outer viscid gel layer and an inner thin, watery sol layer, and these together constitute the mucociliary apparatus. The cilia lie primarily within the sol layer, with only their tips contacting the gel layer. The cilia beat in a biphasic fashion with a rapid effective stroke to propel the layer of mucus in a forward direction, and a slower recovery stroke within the sol layer. The orientation of the cilia within a given sinus is specific, such that secretions are propelled toward the sinus ostia and from there toward the nasopharynx and oropharynx where these cleared secretions are subsequently swallowed.
Alterations of mucociliary defense are most commonly the result of viral upper respiratory infection. Viral infection has been shown to alter ciliary function with a decrease in beat frequency and subsequent stasis of secretions. The incidence of viral upper respiratory infections has risen, possibly as a result of the increase in the number of children in the day care setting. Visits to the physician have also risen, with a significant amount of time lost from work by parents and further heightening of the impact of upper respiratory tract infections, including sinusitis. Nasal allergy is perhaps the second most common predisposing factor in the development of pediatric sinusitis and may be seasonal or perennial. The resultant mucosal edema causes obstruction of sinus ostia with decreased drainage and ventilation of the affected sinuses. Dessication by dry air and/or an alteration in the patterns of nasal airflow may lead to impaired mucociliary function by increasing the viscosity of secretions and alterations in the nasal epithelium, perhaps to the point of replacement of the normal epithelium with squamous metaplasia and loss of functional cilia.
Barotrauma as a result of swimming and diving or rapid ascent or descent may also overcome local mucociliary defenses with alterations in the clearance of secretions. Cystic fibrosis (mucoviscidosis) is an autosomal recessive condition manifested as impaired exocrine gland function with an increase in the viscosity of secretions. These patients suffer recurrent infections of both the upper and lower respiratory tracts with a large number of them demonstrating evidence of sinus disease. Alterations in the structure or function of the cilia themselves, as seen in primary ciliary dyskinesia, understandably impair the function of the mucociliary apparatus and are associated with episodes of recurrent otitis media, sinusitis, and pulmonary infection. Kartagener's syndrome serves as an example and consists of sinusitis, situs inversus, and bronchiectasis.
Anatomic obstruction of the sinus ostia encompasses a variety of conditions. Septal deviation of any significance is uncommon in children, and, unless quite symptomatic, is often best left untreated until later in the teenage years as there are concerns of altering nasal growth centers. Oddly, septal deviation has been known to result in sinusitis on the side opposite the deviation, possibly by the alteration of the inflow of air on the opposite side with dessication of the nasal mucosa and a resultant impairment of mucociliary clearance. Craniofacial anomalies, as seen in children with craniofacial dysostoses, cleft lip and cleft palate, and Down Syndrome are often associated with an increased incidence of sinusitis, as is choanal atresia. Foreign bodies in children are often notable for a unilateral foul-smelling rhinorrhea and may produce obstruction of the sinus ostia of sufficient degree and duration to produce an ipsilateral sinusitis. Of no small consequence are those foreign objects placed by healthcare personnel such as nasogastric and nasotracheal tubes. Intranasal tumors and polyps may also lead to obstruction. The appearance of nasal polyposis in a child is uncommon and should prompt a sweat chloride test in the evaluation for cystic fibrosis.
Primary and acquired immunodeficiencies may result in an increase in recurrent episodes of sinusitis which may be refractory to treatment. Local and systemic immunity play a role in the defense against bacterial invasion. Secretory IgA is found in nasal secretions, and serum IgG is essential as well. Intact cell-mediated immunity helps confer resistance against invasive fungal infections of the paranasal sinuses. The signs and symptoms of sinusitis in the immunocompromised child may be subtle and nonspecific, with nasal congestion, rhinorrhea, or chronic cough. Immunocompromise serves to dampen the host's response to the offending agent, thereby leading to a possible reduction in the degree of clinical or radiographic manifestations of sinus disease. An underlying immunodeficiency may also lead to infection with organisms which are atypical or more difficult to treat, such as resistant Gram positives, Gram negatives, anaerobes, of fungi.
The immune system in children normally undergoes a maturational process in which the components of cell-mediated and humoral immunity eventually rise to a level of immunocompetence equal to that of adults. The implication is that the pediatric patient is thus in a state of physiologic immunocompromise during the period of time that it takes for these functional changes to occur and may explain the predisposition of children to more frequent upper respiratory infections and why most children seem to "outgrow" this tendency. As an example, it is known that immunoglobulins such as IgG play a role in the defense against polysaccharide-encapsulated bacteria and that certain subclasses, namely IgG2 and Ig4, do not reach adult levels until approximately 10 years of age. In a child with refractory sinusitis in whom no other predisposing factors exist, measurement of immunoglobulin levels and various assays of immune function may demonstrate a deficiency more significant than the expected physiologic norm.
Selective IgA deficiency and common variable immunodeficiency are other examples of primary states often associated with an increased frequency of pediatric sinusitis. Imunosuppressive therapy employed in organ transplantation and chemotherapy utilized in the treatment of neoplastic disease has produced a subset of pediatric patients with iatrogenic immunocompromise and predisposition toward many kinds of infection, including sinusitis. Maternally-acquired AIDS and AIDS acquired as a result of transfusion of blood products is another cause of immunodeficiency in the pediatric age group. The suspicion of sinusitis in the immunocompromised child with its potential for substantial morbidity in this patient population requires timely evaluation and intervention.
Chronic pulmonary disease:
It has long been postulated that a relationship exists between the upper and lower respiratory systems such that sinonasal and lower respiratory tract function are intimately connected via a complex and poorly understood neurologically mediated reflex pathway. Investigators have thus far been unsuccessful in elucidating the exact mechanism by which this phenomenon occurs. Anecdotal evidence exists concerning exacerbation of chronic lower respiratory disease coinciding with the appearance of rhinosinusitis in the patient with preexisting pulmonary disease. Conversely, improvement in lower respiratory tract symptoms have been noted following adequate treatment of sinonasal disease. The alteration of normal nasal physiologic function with disease in this area results in a loss of filtering and conditioning of the ispired air which may have a detrimental effect on already tenuous lower respiratory tract function.
Asthma is a common pulmonary disease in the pediatric population, and an increase in its incidence has been noted in recent decades. The occurrence of upper respiratory tract infections in these patients may be more frequent with an increase in predisposition toward the development of sinusitis. The sinusitis may then serve to create an exacerbation in pulmonary symptoms in the asthmatic patient, resulting in significant morbidity and a further negative impact on overall health and well-being in these children.
Cystic fibrosis (also known as mucoviscidosis) is a common genetic disease of autosomal recessive inheritance which may be thought of as a generalized defect in exocrine gland function throughout the body. An increase in the viscosity of the secretions of various organs result in the common manifestations of this disease, including recurrent sinopulmonary and gastrointestinal disease. Patient age at the time of presentation is variable with the majority of cases being detected in infancy or early childhood. Increased viscosity of nasal secretions results in impairment of mucociliary function and stasis. Bacterial infection often ensues, leading to chronic sinusitis. Nasal polyposis may be noted in these patients, and the appearance of nasal polyps in an otherwise healthy child should prompt an evaluation for the presence of cystic fibrosis with a sweat chloride test. Pseudomonas is often detected in cultures obtained from these patients and requires appropriate antibiotic coverage during medical management.
Studies to discern the bacteriology involved in the development of pediatric sinusitis have been relatively few in number. This may be due at least in part to the inaccessibility of the paranasal sinuses in children and the inherent difficulty in obtaining sinus aspirates for culture. Most studies involve aspirates obtained from the maxillary sinuses. Viral upper respiratory infection is known to be associated with the development of sinusitis, and although viral cultures obtained from sinus aspirates are very rarely positive, viruses are known to predispose to subsequent bacterial infection via such mechanisms as viral-induced impairment of the mucociliary apparatus.
The bacterial pathogens most commonly implicated in acute sinusitis are similar to those found in otitis media, including Streptococcus pneumoniae, Moraxella catarrhalis, and Hemophilus influenzae (non-typable). These same aerobic organisms are commonly found in subacute and chronic sinusitis as well. However, other aerobes such as Staphylococcus and alpha-hemolytic Streptococcus are noted to be more prevalent in chronic sinusitis, as are anaerobes like Peptococcus, Peptostreptococcus, and Bacteroides. Pseudomonas aeruginosa is often cultured from patients with cystic fibrosis.
Fungal infections of the paranasal sinuses are most frequently seen in those patients with some form of immunodeficiency. Some of the pediatric patients at highest risk are those receiving immunosuppressive therapy following organ transplantation or chemotherapy for the treatment of neoplastic disease. Aspergillus is a common offender in this patient population, and treatment involves the administration of systemic anti-fungal agents.
Signs and symptoms:
As previously mentioned, the signs and symptoms of sinusitis in children are quite often subtle and nonspecific and may wax and wane over an extended period of time. The typical uncomplicated viral upper respiratory infection usually resolves within 5-7 days. Symptoms may not have resolved completely by 10 days, but clinical improvement should have been noted by this time. Should symptoms of upper respiratory infection persist beyond 10 days without evidence of improvement, the possibility of the development of sinusitis should be considered. Also, the symptoms of a "cold" which seem more severe than usual and are accompanied by a fever of >39 degrees Celsius should raise this suspicion.
Symptoms may be quite difficult to distinguish from viral upper respiratory infection or allergic inflammation, the two most common predisposing factors in the development of sinusitis in children. Nasal discharge is of variable appearance and consistency and may be thin, thick, or mucoid with a predominantly clear appearance or obviously purulent. Nasal airway obstruction is a common complaint, as is cough, which often occurs during the day and then worsens at night. Facial pain and headache, which may be described by older children, are less common in the younger patient. However, the younger child may demonstrate irritability. Fever, when present, is often low grade. More significant fever accompanied by purulent rhinorrhea is most often noted in acute cases of sinusitis. There may also be postnasal drip and malodorous breath noted.
The physical examination in pediatric patients with sinusitis is often unrewarding. Inspection should begin during the history-taking portion of the evaluation when evidence of nasal obstruction, rhinorrhea, or cough may become apparent. There may be hyponasal speech or dark discoloration of the lower eyelids. Stigmata of nasal allergy may be evident, such as facial pruritus indicated by the classic "allergic salute".
Physical examination is limited by the inaccessibility of the paranasal sinuses and the sometimes uncooperative nature of the pediatric patient. Anterior rhinoscopy is usually all that is possible in these patients, and if adequately performed, may yield useful information. Older children may tolerate examination with a nasal speculum, but for the younger patient, an otoscope is a useful diagnostic tool for visualization of the nasal cavity. There may be evidence of nasal mucosal edema or erythema, and purulent secretions may noted. Polyps may be visualized, as well as anterior septal deviations. It is important to attempt visualization of the middle meatus by directing attention in a posterosuperior fashion toward the medial canthus in order to inspect the middle turbinate and then the middle meatus, where purulent secretions may be noted. The osteomeatal complex, as the area of drainage for the frontal, maxillary, and anterior ethmoid sinuses, necessitates careful attempts at inspection of the all-important middle meatus for purulent secretions or other signs of pathology. Examination of the oropharynx may reveal evidence of purulent secretions or tonsillar disease. Due to the small size of the sinuses in the pediatric patients and the amount of intervening soft tissue and bone, transillumination of the sinuses is felt to be of little diagnostic value.
Historically, plain radiographs have been obtained as the initial study in the evaluation of the paranasal sinuses, but in the absence of complete sinus opacification or an air-fluid level, their findings may correlate poorly with clinical evidence of disease. Plain films also provide inadequate evaluation of the ethmoid sinuses in most instances.
Computed tomography has evolved as the study of choice for evaluating the presence and extent of sinus disease. It has the ability to provide resolution of both bone and soft tissue, and coronal views through the paranasal sinuses and area of the osteomeatal complex provide essential anatomical information for those patients undergoing preoperative evaluation. Indications for obtaining a CT of the sinuses include evidence of severe, persistent sinus disease following maximal medical therapy, sinus disease in the immunocompromised patient, and suspicion of a suppurative complication of sinus disease. Of significant interest is the finding of some degree of sinus mucosal thickening in a significant number of patients having no evidence of sinus disease for whom CT studies were obtained for other reasons. This emphasizes the need to correlate radiographic findings with clinical evidence of disease in the therapeutic decision-making process and that CT findings, in and of themselves, do not constitute an indication for intervention. Disadvantages of computed tomography include exposure of the patient to ionizing radiation and the need for the use of sedation in some younger patients in order to obtain an adequate study.
The management of sinusitis in the pediatric population encompasses a spectrum of interventions, ranging from the safer, more conservative medical therapeutics on the one hand to the more invasive surgical therapeutics on the other. Efficacy and safety are the key issues, particulary since these interventions are being applied to a disease process which, in its uncomplicated form in the otherwise healthy patient, is often observed to resolve spontaneously in a large number of cases. Medical therapy is the mainstay of treatment with the majority of patients experiencing resolution of their sinus disease. Surgery is viewed as an adjunct to medical therapy and is reserved for those patients in whom complications arise or who have comorbid conditions or disease which is particularly refractory to medical management.
Conservative medical therapy may begin with an attempt to improve nasal hygiene with a spray of a pH neutral saline preparation to each nostril once or twice daily. This serves to mechanically remove potential allergens and improve mucociliary function by increasing humidification. Attempts at irrigation may carried one step further with the Proetz procedure in the hopes of irrigating sinuses with incomplete occlusion of their ostia. With the patient in the supine position and the head hyperextended, the nose and nasopharynx are partially filled with a saline solution to which a topical decongestant may be added. Suction is then applied to one nostril while the other is occluded in order to remove the irrigating solution along with the secretions. These steps may be repeated in order to achieve irrigation and drainage of the sinuses.
The use of antihistamines and topical or oral decongestants has an uncertain role in the management of upper respiratory infections but have not been shown to prevent these infections nor significantly alter their course. These preparations are probably best employed for short-term symptomatic relief. Theoretically, these medications should result in decreased mucosal edema with improved patency of sinus ostia and an increase in the clearance of secretions. However, their use may result in drying of the mucosa and thickening of secretions with further impairment of mucociliary function.
Specific antimicrobial therapy is essential in the management of sinusitis. Antimicrobial coverage should include the most common organisms, Streptococcus pneumoniae, Moraxella catarrhalis, and Hemophilus influenzae. A significant number of isolates of Moraxella catarrhalis and Hemophilus influenzae have been shown to be producers of beta lactamase and may require administration of a broader spectrum, beta lactamase-resistant antibiotic for adequate coverage. There is some uncertainty as to the appropriate length of treatment, but for uncomplicated acute sinusitis, a 10-14 day course of amoxicillin at a dose of 40 mg/kg per day divided in three doses has been found to be efficacious. Improvement is ususally seen within 48-72 hours after starting treatment. If symptoms have not improved during this time, an alternative antibiotic should be considered, possibly one which is beta lactamase-resistant, such as amoxicillin-potassium clavulanate. Other alternatives include erythromycin ethylsuccinate-sulfisoxazole, trimethoprim- sulfamethoxazole, or cefuroxime axetil. If symptoms have improved but not completely resolved by the end of a standard course of therapy, an additional 7 days of therapy may be indicated.
For the treatment of recurrent or chronic sinusitis, a more lengthy course of therapy, usually with a beta lactamase- resistant antibiotic, is desirable. Most clinicians advocate a 3-4 week course of an appropriate antibiotic. Anaerobes should also be considered in the treatment of chronic sinusitis. In the immunocompromised patient, prophylactic antibiotic regimens are often utilized in addition to aggressive general management. Commonly used regimens include amoxicillin 20 mg/kg once daily and sulfisoxazole 30 mg/kg twice daily.
In the patient with nasal inhalant allergy, therapy begins with avoidance of the offending allergen(s). Topical nasal steroids such as beclomethasone dipropionate have been approved for use in children age 6 years and older and may provide long- term benefits. Cromolyn sodium, administered intranasally, stabilizes mast cells thereby preventing degranulation and release of histamine and other inflammatory mediators. It is most effective if administered prior to encountering the specific sensitizing allergen. For those patients in whom specific sensitizing allergens have been identified, immunotherapy may prove beneficial.
Surgical therapy for sinus disease may broadly be classified into indirect sinus procedures and direct sinus procedures. Indirect sinus procedures are those which attempt to improve sinus function without directly involving the sinuses. Direct sinus procedures involve surgical manipulations of the sinuses themselves.
Examples of indirect procedures are septoplasty and adenoidectomy. Septal deviation of sufficient degree to cause nasal obstruction and ipsilateral sinusitis is uncommon in the pediatric population but may benefit from limited septoplasty. Adenoidectomy is of limited value in the management of sinusitis. However, in appropriately selected patients with an adenoid pad large enough to result in nasal obstruction, adenoidectomy may be a reasonable first choice in the attempt to alleviate the symptoms of chronic sinusitis.
Antral lavage is probably the most commonly performed direct sinus procedure, and sinus aspiration may be achieved via a puncture site usually placed in the inferior meatus. The sinus aspirate may then be used for culture and sensitivity studies in order to appropriately tailor antimicrobial therapy. The evaluation is limited to the maxillary sinus and is not without the possibility of significant complication, including injury of orbital contents. The procedure is probably of greatest value the evaluation of sinusitis in the immunocompromised patient in whom rapid identification of the offending pathogen is of utmost importance.
Nasal antral windows are used to promote sinus drainage and ventilation and are often placed in the inferior meatus. Their long-tern efficacy in the pediatric population has been questioned, and a significant number of the windows have been found to lose patency with a subsequent recurrence of sinusitis. The mucociliary apparatus within a given sinus is oriented such that sinus secretions are propelled toward the natural sinus ostia, often bypassing the nasal antral window in the dependent area of the sinus. If sufficient disease exists to significantly impair mucociliary function or if primary ciliary dysfunction is present, gravity may play a larger role in enhancing sinus drainage via the dependent window thereby increasing its efficacy.
The Caldwell-Luc procedure is less frequently used as a method of maxillary sinus drainage due to concerns of potential damage to the unerupted permanent dentition and the uncommon finding of sinus disease of a sufficiently extensive and irreversible nature as to benefit from removal of sinus mucosa.
Middle meatal antrostomy attempts to promote drainage and ventilation of the maxillary sinus by opening the natural sinus ostium thereby enhancing the natural clearance of secretions. This procedure has been shown to be effective but has the disadvantage of not addressing disease of the anterior ethmoid sinuses, which are more frequently involved than the maxillary sinuses.
Interest has grown in recent years with regard to the application of the techniques of functional endoscopic sinus surgery in the treatment of sinus disease in children. Endoscopic sinus surgery in the pediatric patient is challenging to say the least. The small space of the nasal cavity in these patients and the proximity of the lateral nasal wall to the contents of the orbit and anterior cranial fossa make serious complications a very real possibility. However, these techniques may be performed in a safe manner and have been shown to be effective. The indications are not well-defined but include therapy for suppurative complications of sinus disease, severe sinusitis leading to exacerbation of comorbid conditions, and chronic sinusitis unresponsive to maximal medical management having a significant impact on overall health and well-being. Most procedures involve maxillary antrostomy with anterior or anterior and posterior ethmoidectomy. Achieving the maximum amount of benefit with the least amount of anatomical manipulation at the osteomeatal complex is the goal. A pre- operative coronal CT is essential in defining the location and extent of disease as well as the pertinent anatomy at the site of the proposed endoscopic procedure.
Suppurative complications of acute and chronic sinusitis are most often orbital or intracranial and require rapid diagnosis and treatment. Orbital complications are most common and are more likely to occur in younger children. The infectious process usually reaches the orbit by direct extension. A system has been suggested by Chandler which is clinically useful in categorizing the extent of orbital involvement and aids in selection of the appropriate therapy. Preseptal orbital inflammation suggests nontender eyelid edema with no loss of ocular mobility or visual acuity. Orbital cellulitis results in diffuse infection of the orbital contents without abscess formation. Subperiostial abscess formation involves the space between orbital periostium and the bony wall of the orbit. There is often asymmetric proptosis with displacement of the globe in an inferolateral direction with decreased ocular mobility and visual acuity. Orbital abscess formation usually results in severe symmetric proptosis with worsening ocular mobility and visual loss. Cavernous sinus thrombosis may occur with sphenoid sinusitis and involves further posterior extension of the infection. This may result in bilateral symptoms. Orbital complications are best evaluated with axial computed tomography. Initial therapy usually consists of aggressive intravenous antibiotic therapy with surgical drainage directed by the presence or absence of discrete abscess formation.
Intracranial suppurative complications are more often seen in older children and include meningitis, epidural abscess, subdural abscess, and brain abscess. Epidural abscess is the most common and the frontal lobes are most often involved in brain abscess formation. Patients may display fever, headache, nuchal rigidity, altered mental status, or focal neurologic signs. Aggressive intravenous antibiotic therapy is again directed toward the most common offending pathogens with surgical therapy dictated by the location and degree of intracranial involvement.
Sinusitis in children is now recognized as a distinct clinical entity which may have significant morbidity. Medical management remains the mainstay of therapy with surgery reserved for those patients in whom sinus disease represents a significant threat to overall health despite maximal medical management. Further inquiry is required to expand our understanding of the etiology and natural history of sinus disease with additional definition of the indications for specific forms of medical and surgical therapeutic intervention.
Complications of Sinusitis:
Sinonasal disease accounts for the majority of orbital infections (up to 85%). Ethmoid sinuses are almost always implicated in orbital disease; maxillary and frontal sinuses may also be involved. Spread may be direct with erosion of the lamina or through a prior fracture or by thrombophlebitic spread into the orbit. Orbital complications as staged by Chandler (1970) are: preseptal cellulitis, orbital cellulitis, subperiosteal abscess, orbital abscess, and cavernous sinus thrombosis (dural thrombophlebitis).
Preseptal cellulitis is an inflammation and infection of the eyelids, outside the orbital septum. Orbital cellulitis is a diffuse infiltration of bacteria and inflammatory cells in the orbit. A subperiosteal abscess is a collection of pus between the periorbita and the bony orbit walls. Orbital abscess refers to a discrete collection of pus within the orbital tissues; systemic symptoms are common and orbital apex syndrome may occur. Cavernous sinus thrombosis is a late stage and highly morbid disease. Infection is spread posteriorly through the venous channels; patients have proptosis, ophthalmoplegia, decreased visual acuity, paplliedema, dilated pupil, mental status decline, and superior orbital fissure syndrome; bilateral symptoms herald this entity.
Symptoms of orbital disease include: erythema or edema of the eyelids (common to all orbital infections), proptosis and ophthalmoplegia (suggestive of orbital cellulitis or orbital or subperiosteal abscess), decreased visual acuity (associated with advanced infection.) Evaluation should include a thorough ophthalmologic examination and thin cut CT with contrast of the orbits and paranasal sinuses. The offending organisms include: Strep pneumo and microaerophilic Strep (#1 in adults), H.flu (#1 in children), S. aureus, S. epidermidis, gram negative organisms and anaerobes; in adults, the infection is usually mixed. Empirically B-lactamase resistant antibiotics are indicated. Then treat as cultures direct. In the treatment of sinusitis, local and systemic decongestion play an important role. Surgical intervention is frequently required and should be considered as indicated. Frank abscesses should be evacuated urgently. Small subperiosteal abscesses with normal vision, normal EOMI, mild proptosis may be treated conservatively with IV antibiotics. All patients with orbital complications managed medically should be closely observed with frequent visual checks. Patients who experience a decrease in visual acuity, worsening extraocular muscle function or failure to improve in 48-72 hours should undergo surgical sinus drainage.
Intracranial (CNS) complications, namely, meningitis, subdural empyema, epidural abscess and cerebral abscess may all complicate acute and chronic sinusitis. The ethmoids, frontal, and sphenoid sinusitis primarily responsible. Infection is spread via thrombophlebitis or less commonly via direct extension of infection. Common symptoms of increased intracranial pressure (ICP) (headache, altered mental status, fever, vomiting, and stiff neck) as well as systemic toxicity usually occur. However, the infection may be "silent" in the frontal lobes with only subtle personality changes until late in the process. High morbidity and mortality despite antibiotics and aggressive treatment still exist. The offending organisms are the same ones implicated in sinusitis (Strep, Staph, anaerobes and GNR). Streptococcal species are most commonly responsible for CNS complications. Exceptions include cerebral abscess and epidural abscess near a focus of osteomyelitis when Staph is more common.
The treatment for each of these complications is similar. A CT scan to evaluate for other CNS complications and cerebral midline shift or mass effect is necessary. In cases of meningitis, this is followed by lumbar puncture and culture if safe. High dose IV antibiotics with CSF penetration are begun. Neurosurgical consultation is strongly recommended, even in cases that are not clearly immediately surgical. Management of ICP and seizure prevention are necessary.
Meningitis is probably best treated by medical management initially, after meningitis is controlled and if it is believed to be due to sinusitis, the offending sinuses can be opened and drained. If the meningitis cannot be controlled, then more emergent sinus drainage may be required. In general, for the other CNS complications it is necessary to provide drainage of the offending sinus; this may be performed at the same time as any drainage of intracranial abscesses if that is being undertaken. In some cases of epidural abscess, frontal trephination and removal of the posterior sinus wall to drain the purulent collection may be sufficient ,but others will require a craniotomy. Later, in most cases the frontal sinus should be definitively addressed, usually by cranialization or obliteration. A subdural empyema should be addressed by a neurosurgical approach for drainage of the subdural collection and by an otolaryngologic approach to surgically address sinuses. Cerebral abscess may be treated by high dose antibiotics and drainage of offending sinus; some cerebral abscess may resolve with this regimen, others will require CT guided or surgical drainage. Mortality is still 20%-40% with death resulting from rupture of abscess into a ventricle or mass effect with brain stem compression or herniation.
Osteomyelitis (and osteitis) are usually related to acute frontal sinusitis and may be associated subperiosteal abscess, the "Pott's puffy tumor" first described by Sir Percival Pott (1760.) Presentation is that of brawny edema of the brow with soft doughy swelling; usually there is forehead pain, low grade fever and leukocytosis. The spread of infection from the sinus is either by the hematogenous route (retrograde thrombophlebitis) or direct (via erosion or through existing fractures or dehiscences.) CT scan can delineate the extent of disease and evaluate for other CNS complications. Staph is implicated in the majority of cases, also seen are Strep pneumo, B-hemolytic strep, anaerobes in a few cases.
Long term IV antibiotics, as in other cases of osteomyelitis, is required. Empirically nafcillin is used, followed by culture specific antibiotics when cultures available. Drainage of sinus as in the other types of complicated sinusitis is necessary, usually via trephination or frontoethmoidectomy; ESS can be used by experienced surgeons, but it may be difficult and success is less reliable. Patients may require debridement of infected bone if fails to respond to antibiotics. After osteomyelitis is controlled, more definitive surgical treatment of the frontal sinuses is considered. If there is any question of chronic or persistent frontal sinusitis then a bilateral osteoplastic flap sinus obliteration with fat graft should be undertaken. Radionucleotide scanning can be used to follow the resolution of disease, similar to other cases of osteomyelitis and malignant otitis externa.
A 45-year-old white male presented to Ophthalmology service with right orbital swelling and pain. He had a temperature of 99Â° and reported a several day history of sinus congestion and rhinorrhea. The patient had a long history of heavy alcohol use and previous blunt trauma and a frontal sinus fracture was suspected. On exam he had significant periorbital erythema and edema, as well as a fluctuant mass in the R upper eyelid. The vision was 20/20. The WBC = 14.9. The patient was placed on Nafcillin and Fortax. A CT scan revealed a R preseptal (upper eyelid) abscess and pansinusitis. The eyelid abscess was drained by the Ophthalmology service.
Three days following admission the Otolaryngology service was consulted for evaluation. At this time he had significant improvement in the periorbital edema and a follow-up CT showed no progression of disease and no intracranial involvement. Local and systemic decongestants were added to his regime and broad spectrum antibiotics were continued. The abscess cultures grew anaerobic strep and B-hemolytic Strep. Culture specific antibiotics were given for a total of 6 weeks. The patient underwent frontal sinus obliteration from which he had an uneventful recovery. Intraoperatively the sinus floor was found to have a linear dehiscent area consistent with prior fracture. On follow-up he has been doing well.