Introdution
Sphenoidotomy is a surgery to enlarge the opening of the sphenoid sinus, which gets blocked during sinusitis. A block in the sphenoid sinus can be catastrophic because the sphenoid sinus is located close to the brain, and the infection causing the block in the sinus can easily spread to the brain through connecting blood vessels. It is done when the patient fails to respond to medical therapy after 48 hours.
What Is A Sinus?
A sinus is an air-filled cavity lined with mucus inside the bones of the head. There are only four paired sinuses in the entire body, and all of them are located in the face and the head; they are:
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Maxillary Sinuses - One on each side of the upper jaw, located below the eyes.
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Ethmoid Sinuses - Located in between the eyes.
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Sphenoid Sinuses - These are present behind the eyes.
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Frontal Sinuses - Present in the forehead and above the eyes.
All of the above mentioned sinuses open into the nasal cavity through their respective channels.
These sinuses are interconnected and play an important role in the body’s defense mechanism. The air that we breathe might look clean, but it has different kinds of bacteria, viruses, and other microorganisms. The sinuses trap these infection-causing microbes and kill them, preventing their further spread into the body.
As mentioned above, sphenoid sinuses are sinuses located in the sphenoid bone. The sphenoid bone is a single bone present below and behind the forehead forming the posterior surface of the eye. It essentially connects the skull with the face. The sphenoid sinuses open into the nasal cavity and drain the impurities through the sphenoid ostium (opening of the sphenoid cavity). In sphenoid sinusitis, the sphenoid cavity gets filled with infected mucus and blocks the ostium, which might need surgical intervention to unblock and drain.
What Is Sphenoid Sinusitis?
Sinusitis is an infection of the sinuses, leading to inflammation and swelling of the mucus lining of the sinuses. When this inflammation happens in the sphenoid bone, it is known as sphenoid sinusitis. It can be of two types:
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Acute Sphenoid Sinusitis - Occurs in an isolated sphenoid sinus; the condition is considered acute when the symptoms are severe and sudden and continue for 48 hours even after antibiotic therapy. Surgery is often indicated to reduce complications and prevent rapid progression.
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Chronic Sphenoid Sinusitis - Also known as chronic sphenoid rhinosinusitis, is a spectrum of infectious diseases exclusively in the sphenoid sinus with symptoms that last for more than 12 weeks.
What Are The Symptoms Of Acute Sphenoid Sinusitis?
Isolated sphenoid sinusitis is a rare condition.The sphenoid bone is situated deep in the head and any infection that enters through the airway is kept in check at a superficial level by maxillary, ethmoid, and frontal sinuses.
The symptoms of acute sphenoid sinusitis are typical of a sinus infection. The most common symptom that helps diagnose sphenoid sinusitis is the onset of a sinus headache, especially around the forehead and the temples. Several symptoms that indicate sphenoid sinusitis are:
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Headache, especially in the occipital (back) region.
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Retro-orbital pain (pain behind the eyes).
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Otalgia (earache).
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Neck pain.
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Postnasal drip.
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Sore throat.
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Drowsiness and other symptoms are similar to meningitis.
It is often difficult to diagnose sphenoid sinusitis given its non-specific symptomatic nature, which delays diagnosis and proper management.
How Is Acute Sphenoid Sinusitis Treated?
Prompt and accurate diagnosis is necessary to avoid catastrophic consequences because the sphenoid sinus is located at the center of important structures like the pituitary gland, optic nerve, carotid artery, cavernous sinus, etc. Any infection causing sphenoid sinusitis can easily spread through the adjacent structures leading to permanent blindness, cavernous sinus thrombosis, and critical infections of the central nervous system.
Acute sphenoid sinusitis is confirmed with a computed tomographic (CT) scan; the patient is then admitted and started on intravenous (IV) antibiotics; if there is no improvement after 24 hours, a sphenoidotomy is scheduled. Several surgical techniques are available to address sinusitis with variable levels of complications and recurrence rates. The surgery aims to identify the sphenoid ostium, enlarge it and establish drainage. The sphenoid ostium can be approached through transseptal, transantral, transnasal, and external, but the transnasal endoscopic approach through the nose is the most commonly used method.
How Is the Surgery Performed?
Once the patient is anesthetized, an endoscope with a 3D intraoperative navigation system is inserted through the nose to identify the sphenoid ostium. The ostium is opened and enlarged with forceps or a drill, depending on the severity of the block. This is the least invasive way of draining the sphenoid sinus; however, in cases of polyposis or fungal infections, the surgeon will prefer a more expanded approach by including septectomy or removing frontal intersinus septal air cell, etc,.
The sinus cavity is then cleaned until healthy tissue is seen, followed by copious irrigation with saline. Post-surgery, the patient is continued on the broad-spectrum antibiotics and monitored closely; acute sphenoid sinusitis responds well to medical and surgical management.
What Are The Complications Of Sphenoidotomy?
Given the emergency of the situation, sphenoidotomy has its fair share of intraoperative and postoperative complications, some of which are:
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The carotid artery and cavernous sinus located in close proximity to the sphenoid bone can get damaged during the procedure leading to hemorrhage.
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The optic nerve might get resected (cut), leading to visual compromise.
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Nasal septum perforation can occur, leading to epistaxis (bleeding from the nose).
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A cerebrospinal fluid leak is possible if the roof of the sphenoid is violated.
What Precautions Should Be Taken Post-surgery?
The patient is instructed to perform nasal saline irrigation or lavage several times a day. Post-operative antibiotics and corticosteroids are prescribed to eliminate residual infection and manage postoperative pain. Patients are asked to come for a follow-up nasal endoscopy after one to two weeks of surgery to remove blood clots and crusts, and to identify any scar tissue that might prevent postoperative healing.
Conclusion
Sphenoidotomy is a well-tolerated surgical procedure with a moderate recurrence rate. Since acute sphenoid sinusitis has vague and non-specific symptoms, the success of the operation depends on the physician's ability to obtain a definitive diagnosis while evaluating the patient. The recurrence rate, however, depends on the type and severity of the infection and patient compliance.
