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Functional Endoscopic Sinus Surgery (FESS) is a surgical
modality for some diseases of the nose and paranasal sinuses. It is a
relatively recent surgical procedure that uses the help of nasal
endoscopes (which make use of Hopkins rod lens telescopes): these are
endoscopes which have diameters of 4mm and 2.7mm and come in varying
angles of vision from 0 degrees to 30, 45, 70, 90, and 120 degrees.
These provide good illumination and can be introduced into the nose
after anesthetising. It has now become the main-stay in the surgical treatment of sinusitis and nasal polyposis including fungal sinusitis: this technique of functional endoscopic sinus surgery came into existence because of pioneering work of Messerklinger and Stamberger (Graz, Austria.) Other surgeons have made additional contributions (first published in USA by Kennedy in 1985). The surgical technique usually adopted is the Messerklinger technique. There are four sinuses dealt with by means of this surgery: The frontal sinus with frontal recess dissection, the maxillary by uncinectomy and antrostomy, the anterior and posterior ethmoids which require careful dissection to the skullbase and orbital lamina, and finally the sphenoid sinus which is managed via a sphenoidotomy. Maxillary Sinus One of the most accepted means of functionally enlarging the maxillary ostium is to perform an uncinectomy via the "swing door" technique. This initially removes the vertical process of the uncinate via backbiter inferiorly and sickle knife superiorly. The uncinate is swung medially and then severed at its lateral attachment. This is followed by a submucosal removal of the horizontal process of the uncinate and subsequent trimming of the mucosa to fully visualize the maxillary os. Controversy exists as to whether or not the maxillary ostium should be enlarged or not depending on the disease status of the maxillary sinus. However, the medical literature would support a wide antrostomy and complete clearance down to healthy mucosa if fungal mucin is present within the sinus. In this circumstance, the ostium is enlarged superiorly to orbital floor and posteriorly to posterior fontanelle to allow wide access for clearance. Complete maxillary debridement can be accomplished via either trans-ostial clearance which can be quite tedious. A newer technique, canine fossa trephination, can accomplish this same task faster and with few side effects. Extended Approaches More recently, the paranasal sinuses have been found to be a relatively low-morbidity approach to selected tumors of the anterior and posterior cranial fossa. Endoscopic access to pituitary tumors has been found to be quite useful as well. Using endoscopes for hypophysectomy allows excellent visualization within the sella and more complete tumor removal than would be available via microsurgical technique. This can be divided into: 1. approaches to the anterior cranial fossa 2. approaches to the mid cranial fossa 3. approaches to the posterior cranial fossa 4. access to the infratemporal fossa (incl. pterygopalatine fissure) 5. access to the sella turcica 6. orbital access 7. optic nerve access Word of Caution Extreme care is required with this surgery due to the paranasal sinus' proximity to the orbits, brain, internal carotid arteries, and optic nerves. However, even with these possible serious risks, there are many benefits to be reaped by a patient with appropriate indications from a well-performed ESS. As the degree of difficulty increases with these surgeries, a surgeon with appropriate experience must be present to manage the procedure. This is especially true in approaches to neurosurgical procedures Chronic sinusitis Chronic sinusitis is a complicated spectrum of diseases that share chronic inflammation of the sinuses in common. It is divided into cases with polyps and cases without, and the former is sometimes called chronic hyperplastic sinusitis. The causes are poorly understood and may include allergy, environmental factors such as dust or pollution, bacterial infection, or fungus (either allergic, infective, or reactive). Non allergic factors such as vasomotor rhinitis can also cause chronic sinus problems. Abnormally narrow sinus passages, which can impede drainage from the sinus cavities could also be a factor. A combination of anaerobic and aerobic bacteria are observed, including Staphylococcus aureus and coagulase-negative Staphylococci. Typically antibiotics provide only a temporary benefit, although mechanisms involving hyperresponsiveness to bacteria have been proposed for sinusitis with polyps. Most Symptoms include: nasal congestion; facial pain; headache; fever; general malaise; thick green or yellow discharge; vertigo or lightheadedness; blurred vision, feeling of facial 'fullness' or 'tightness' which worsens on bending over; aching teeth, and halitosis; and occasionally diarrhea with a mucus-like substance in it. Very rarely, chronic sinusitis can lead to Anosmia, the inability to smell or detect odors. In a small number of cases, chronic maxillary sinusitis can also be brought on by the spreading of bacteria from a dental infection. Attempts have been made to provide a more consistent nomenclature 6 for subtypes of chronic sinusitis. Many patients have demonstrated the presence of eosinophils in the mucous lining of the nose and paranasal sinuses. As such the name Eosinophilic Mucin RhinoSinusitis (EMRS) has come into being. Cases of EMRS may be related to an allergic response, but allergy is often not documentable, resulting in further subcategorization of allergic and non-allergic EMRS. A more recent, and still debated, development in chronic sinusitis is the role that fungus may play. Fungus can be found in the nasal cavities and sinuses of most patients with sinusitis, but can also be found in healthy people as well. It remains unclear if fungus is a definite factor in the development of chronic sinusitis and if it is, what the difference may be between those who develop the disease and those who do not. Trials of antifungal treatments have had mixed results. Symptoms Sinus headacheHeadache/facial pain or pressure of a dull, constant, or aching sort over the affected sinuses can be seen with either acute or chronic stages of sinusitis. This pain is typically localized to the involved sinus and may worsen when the affected person bends over or when in the supine position. Acute and chronic sinusitis may be accompanied by thick purulent nasal discharge (usually green in colour and with or without blood) and localized headache (toothache) are present and it is these symptoms that can differentiate sinus related (or rhinogenic) headache from other headache phenomena such as tension headache and migraine headache. Migraine misdiagnosisRecent studies suggest that up to 90% of "sinus headaches" are actually migraines. The confusion occurs in part because migraine involves activation of the trigeminal nerves which innervate both the sinus region but also the meninges which surround the brain. As a result, direct determination of the site of pain origination can be confused on a cortical level. Additionally, nasal congestion is not an uncommon result of migraine headaches, due to the autonomic nervous stimulation that can also result in tearing (lacrimation) and a runny nose (rhinorrhea). A study found that patients with "sinus headache" respond to triptan migraine medications, and state dissatisfaction with their treatment when they are treated with decongestants or antibiotics.[ Predisposing factors Factors which may predispose to developing sinusitis include: allergies; structural problems such as a deviated septum or small sinus ostia; smoking; nasal polyps; carrying the cystic fibrosis gene (research is still tentative); prior bouts of sinusitis as each instance may result in increased inflammation of the nasal or sinus mucosa and potentially further narrow the openings. Role of biofilms Biofilms are complex aggregates of extracellular matrix and inter-dependent microorganisms from multiple species, many of which may be difficult or impossible to isolate using standard clinical laboratory techniques. Bacteria found in biofilms may show increased antibiotic resistance when compared to free-living bacteria of the same species. It has been hypothesized that biofilm-type infections may account for many cases of antibiotic-refractory chronic sinusitis. A recent study found that biofilms were present on the mucosa of 3/4 of patients undergoing surgery for chronic sinusitis.[ Diagnosis Acute sinusitisUsually sinusitis is diagnosed clinically. Bacterial and viral acute sinusitis are difficult to distinguish however, disease duration less than 7 days is considered as a viral whereas more than 7 days are considered as a bacterial sinusitis (usually 30% to 50% are bacterial sinusitis). Nosocomial acute sinusitis is confirmed with the help of CT scan of the sinuses. Chronic sinusitisFor sinusitis lasting more than 12 weeks, criteria are lacking. A CT scan is recommended, but insufficient to confirm diagnosis. Nasal endoscopy, a CT scan, and clinical symptoms are used together. A tissue sample for histology and cultures can also be used. Allergic fungal sinusitis are seen in a person with asthma and nasal polyps. Multiple biopsy is informative to confirm the diagnosis. Nasal endoscopy involves inserting a flexible fiber-optic tube with a light and camera at its tip into the nose to examine the nasal passages and sinuses. This is generally a completely painless procedure which takes between 5 to 10 minutes to complete. Treatment Acute sinusitis
Over the counter (OTC) medication such as acetaminophen and ibuprofen can relieve some of the symptoms associated with sinusitis, such as headaches, pressure, fatigue and pain. Nasal irrigation or jala neti using a warm saline solution may also be effective.
Even though antibiotics are prescribed to 60 - 90% of patients in the USA and Western Europe they have not been shown to be effective. The vast majority of cases resolve without antibiotics, however if the symptoms are prolonged amoxicillin is a reasonable first choice with amoxicillin/clavulanate (Augmentin) being indicated for patients who fail amoxicillin alone. Fluoroquinolones, some of the newer macrolide antibiotics such as clarithromycin, and doxycycline, are used in patients who are allergic to penicillins.
Nasal corticosteroids have not been found to be better than placebo either alone or in combination with antibiotics. Chronic sinusitis
Nasal irrigation may help with symptoms of chronic sinusitis.
Based on the recent theories on the role that fungus may play in the development of chronic sinusitis. Trials of antifungal treatments however have had mixed results.
For chronic or recurring sinusitis, referral to an otolaryngologist may be indicated for more specialist assessment and treatment, which may include nasal surgery. However, for most patients the surgical approach is not superior to appropriate medical treatment. Surgery should only be considered for those patients who do not experience sufficient relief from optimal medication. A relatively recent advance in the treatment of sinusitis is a type of surgery called functional endoscopic sinus surgery (FESS), whereby normal clearance from the sinuses is restored by removing the anatomical and pathological obstructive variations that predispose to sinusitis. This replaces prior open techniques requiring facial or oral incisions and refocuses the technique to the natural openings of the sinuses instead of promoting drainage by gravity, the idea upon which the Caldwell-Luc surgery was based. Another recently developed treatment is balloon sinuplasty. This method, similar to balloon angioplasty used to "unclog" arteries of the heart, utilizes balloons in an attempt to expand the openings of the sinuses in a less invasive manner. Its final role in the treatment of sinus disease is still under debate but appears promising. A number of surgical approaches can be used to access the sinuses and these have generally shifted from external/extranasal approaches to intranasal endoscopic ones. The benefit of the Functional Endoscopic Sinus Surgery FESS is its ability to allow for a more targeted approach to the affected sinuses, reducing tissue disruption, and minimizing post-operative complications. For persistent symptoms and disease in patients who have failed medical and the functional endoscopic approach, older techniques can be used to address the maxillary sinus such as the Caldwell-Luc radical antrostomy (e.g. incision in the upper gum, opening in the anterior wall of the antrum, removal of the entire diseased maxillary sinus mucosa and drainage is allowed into inferior or middle meatus by creating a large window in the lateral nasal wall.)
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