Excerpt from Sinusitis, Sphenoid, Acute, Surgical Treatment
Synonyms, Key Words, and Related Terms: acute
sphenoiditis
Acute sphenoid sinusitis is relatively uncommon. Signs and symptoms are
often subtle; therefore, the diagnosis can be difficult to make. However,
early diagnosis and treatment are essential because the disease can be
rapidly progressive and complications can be devastating. Complications
arise from the relationship of the sphenoid sinus to vital vascular,
neurological, and optic structures. Treatment is initially medical;
surgery is reserved for unresponsive disease and impending complications.
Surgical treatment involves opening the sphenoid sinus, establishing
drainage, and obtaining material for culture. Endoscope methods of
sphenoidotomy are now accepted, and several approaches have been
described. Open approaches, including an external ethmoidectomy or
transept approach, can also be used. The outcome of sphenoid sinusitis is
highly dependent on the speed of diagnosis.
History of the Procedure: The sphenoid sinus has been
described as the forgotten sinus or neglected sinus because of its
anatomical location and the difficulty in diagnosing disease there.
Diseases of the sphenoid often were determined only when complications
arose. With the advent of modern imaging techniques and a higher index of
suspicion, diseases of the sphenoid are much more easily found and
treated. Modern imaging, antibiotic, and surgical options have changed the
presentation and, often, the treatment of acute sphenoid sinusitis.
Problem: According to the American Academy of
Otolaryngology–Head and Neck Surgery (AAO-HNS) task force on rhino
sinusitis, sinusitis is defined as an inflammatory response involving
mucous membranes of the nasal cavity and Para nasal sinuses, fluids within
these cavities, and/or bone. The condition is classified as acute if it
persists for 4 weeks or fewer. In contrast, a sub acute infection is
defined as lasting 4-12 weeks, and a chronic infection persists for more
than 12 weeks.
When this inflammatory response occurs in the sphenoid sinus, the
result is sphenoid sinusitis or sphenoiditis. The disease may be limited
to the sphenoid sinus or, more commonly, may involve multiple sinuses or
pan sinusitis.
Frequency: Sphenoid sinusitis often occurs in the
context of pan sinusitis. In the preantibiotic era, Teed reported an
incidence of sphenoid involvement of 33% in patients with pan sinusitis. A
1977 study by Wisberger and Dedo suggested that in the antibiotic era,
incidence decreased to 8%. Isolated sphenoid sinusitis is much less
common. Law reported a 2.7% incidence in patients hospitalized for
sinusitis in a 12-year period. Of these incidences, only one half had
acute disease. Hnatuk et al suggest that the incidence is actually much
lower, and that sphenoid sinusitis represents fewer than 1% of all cases
of sinusitis.
Etiology: The microbiology of acute sphenoid sinusitis
differs from that of uncomplicated maxillary sinusitis. Whereas maxillary
sinusitis is caused predominantly by Streptococcus pneumonia,
Homophiles influenza, and Mirabella catarrhalis, sphenoid
sinusitis has a different profile. Gram-positive organisms predominate,
with Staphylococcus aureus most common, followed by
Streptococcus pneumonia. Chronic sphenoid sinusitis can be caused by
both gram-negative and gram-positive organisms, anaerobes, and mixed
flora, which are more common. Fungal disease also must be considered,
especially in the context of a patient who is immunocompromised.
Path physiology: The path physiology of sphenoid
sinusitis involves blockage of sinus ostia and impaired mucociliary
clearance leading to stasis and secondary bacterial infection. Several
predisposing factors have been implicated. Anatomic differences include
variations in the position of the intersinus septum and small or
abnormally placed ostia. Blunt, penetrating, or surgical trauma can alter
drain.
