Overview of Vidian Neurectomy
The pterygoid canal nerve, often called the vidian nerve, is responsible for supplying special fibers to the areas in our nose, palate (roof of our mouth), and the gland that produces tears, known as the lacrimal gland, through a network called the pterygopalatine ganglion. A vidian neurectomy is a surgical procedure where this particular nerve is intentionally severed. It was first described by a scientist named Golding-Wood in 1961. After the surgery, the amount of supply directed to the nose is reduced, thus also lessening nasal secretions or runny nose.
This surgery, vidian neurectomy, is primarily performed on individuals suffering from vasomotor rhinitis, a condition thought to be caused by an imbalance in the supply between the parasympathetic and sympathetic nervous system to the nasal lining. In the past, before the use of endoscopes, finding the vidian nerve during surgery was difficult. As a result, the surgery was less frequently performed and the long-term results were not excellent. Surgical approaches at the time, using open methods, also came with severe possible side effects such as eye problems, complications in the orbit (the bone cavity that contains the eye), and small holes or abnormal connections in the palate.
However, in 1991, a significant medical innovation was made by Kamel and Zaher. They introduced a new way to perform the vidian neurectomy using an endoscope, which is inserted through the nose on corpse models. This method allowed for more precision in the surgery, with less severe side effects. The discoveries made by Kamel and Zaher have been instrumental in shaping the modern techniques used today.
Recent clinical studies indicate that having a vidian neurectomy can lead to better outcomes to overcome nasal symptoms compared to just using medications or going through other surgical procedures such as turbinoplasty or septoplasty. Despite an increase in interest about vidian neurectomy, more research is required to understand fully the long-term results, potential complications, and the overall effectiveness of the procedure, especially when considering long-term outcomes.
Anatomy and Physiology of Vidian Neurectomy
The vidian nerve is a nerve in your head that travels along with the vidian artery through a bony tunnel called the pterygoid canal or vidian canal. This canal lies along the bottom of a cavity in your skull called the sphenoid sinus. The vidian nerve is formed by the combination of nerve fibers from two other nerves: the greater superficial petrosal nerve and the deep petrosal nerve. It then extends to a bundle of nerves called the pterygopalatine ganglion, located in an area of your skull known as the pterygopalatine fossa.
There are three important structures beneath the sphenoid sinus floor, which are holes known as the palatovaginal canal, the vidian canal, and the foramen rotundum. These canals and foramen allow different nerves and arteries to pass through, connecting different areas of your head. For instance, the palatovaginal canal allows the pharyngeal branch of the internal maxillary artery and the posterior pharyngeal nerve to pass through. Meanwhile, the foramen rotundum enables the maxillary branch of a nerve known as the trigeminal nerve to reach the middle of your face.
The pterygopalatine fossa is a small, pyramid-shaped cavity just behind a larger cavity in your skull called the maxillary sinus. In addition to the vidian nerve, it contains other nerves as well. It is connected to the trigeminal nerve, which is a very important nerve for sensation in your face, and it sends out nerve fibers to different areas of your head, including your nose, palate, and the glands that produce tears and mucus in your nose.
Understanding the location of these structures is crucial, especially if surgery in this area is required. Making a mistake could lead to complications such as numbness and dry eyes (xerophthalmia). This is why having knowledge of the variations in the location and direction of the vidian nerve is extremely important for any surgical procedure in this region.
The vidian canal can be seen as a bump on the side of sphenoid sinus floor. Where it opens into the pterygopalatine fossa can be marked roughly by drawing a line along the back edge of a bone in your skull, the palatine bone, and a horizontal line along the sphenoid sinus floor.
The vidian canal is also important in some specific surgical procedures, such as the removal of certain types of tumors or in surgery involving a part of the internal carotid artery.
Why do People Need Vidian Neurectomy
A vidian neurectomy, which is a type of surgery that targets a specific nerve in the skull, might be recommended if you have the following conditions:
1. Vasomotor rhinitis or other types of nonallergic rhinitis that aren’t responding to usual treatments: If you have a chronically stuffy or runny nose that isn’t caused by an allergy and other treatments haven’t worked, this surgery might help.
2. Perennial allergic rhinitis: This is a year-round allergic reaction normally to indoor allergens like dust mites or mold, causing symptoms like a runny nose, itchy or watery eyes, sneezing, and itching of the roof of the mouth or throat.
3. Chronic cluster headaches that aren’t getting better with medication: Cluster headaches are extremely painful headaches that occur in cycles, or clusters. If medication isn’t easing the pain, this surgery might be an option.
4. Chronic epiphora: When the eyes produce too many tears and overflow, which can be caused by either excessive tear production, insufficient tear evaporation, or abnormal drainage of the tears.
5. Senile nasal drip: This is a condition in which there’s excessive mucus production from the nasal mucosa, making you constantly feel like you have to clear your throat.
6. Crocodile tears or Bogorad syndrome: This happens when you tear up while eating and it can be an alternate solution compared to a tympanic neurectomy, which is another type of nerve surgery.
When a Person Should Avoid Vidian Neurectomy
There are no complete reasons to avoid a vidian neurectomy, which is a type of surgery on a nerve in your head. However, certain conditions might make this procedure less safe. Those include problems or tumors at the base of the skull, or in the area behind your cheekbones (known as the pterygomaxillary region).
Equipment used for Vidian Neurectomy
For a procedure called a vidian neurectomy, which is a type of surgery involving certain nerves in your head, the following tools are necessary:
A set of tools specifically designed for a procedure known as Functional Endoscopic Sinus Surgery – This is a type of minimally invasive surgery that gives your doctor access to your sinuses.
A set of tools for endoscopic skull base surgery which includes special clips for sealing blood vessels, applicators (tools for applying these clips), and an endoscopic drill system (a special type of drill used during this type of surgery).
Different types of endoscopes which are essentially small cameras your doctor can use to see inside your body during the procedure. These come in different degrees, 0°, 45°, and 70°, to give the doctor various viewing angles.
An image-guided navigation system that allows your doctor to see a real-time image of the area they are operating on, which helps increase precision and control during the procedure.
Epinephrine-soaked sponges which are used to control bleeding during the surgery. Epinephrine is a drug that can constrict blood vessels thereby reducing bleeding.
Nasal packing materials that are inserted into the nose to prevent bleeding and keep the internal structures of the nose stable after surgery.
Who is needed to perform Vidian Neurectomy?
When having a procedure called a vidian neurectomy, several medical professionals will be involved in your care. These include specially trained nurses who focus on nose and skull base surgeries, an anesthesia provider (who helps you sleep during the procedure), a surgeon who specializes in endoscopic skull base surgeries, and an assistant who helps the surgeon. Everyone is there to make sure your procedure goes smoothly and safely.
Preparing for Vidian Neurectomy
Before a certain type of sinus surgery, it’s important for the doctor to get an in-depth look at your sinuses. This is done by using a special kind of x-ray called a computed tomography (CT) scan. This scan creates clear, detailed images of your sinuses from different angles. This helps the doctor to spot any issues and plan the operation. They particularly focus on the location of a small channel in your sinus, known as the vidian canal, among other details.
Once you’re ready for the operation, you will be put to sleep with medicines delivered through a tube inserted in your mouth that helps you breathe, this process is known as orotracheal intubation. You’ll then be positioned on your back with your head slightly elevated, either resting on a horseshoe-shaped pillow or held securely with a special tool called a Mayfield pin holder.
Afterward, to decrease pain during the operation, your doctor will temporarily block a bundle of nerves (pterygopalatine ganglion) in your face using a special procedure. This procedure is done through the mouth, via a channel called the greater palatine canal. Next, your nasal cavity is prepared and narrowed with medications that help reduce swelling, such as oxymetazoline or epinephrine. This is done using sponges soaked in the medication.
How is Vidian Neurectomy performed
There are various ways that doctors can get to the vidian nerve, a nerve in your skull that plays an important role in your nose and sinus functions. These include going through the cheek (transantral via a Caldwell-Luc approach), through the roof of your mouth (transpalatal), through the wall that separates your nostrils (transseptal), among others. However, with advancements in sinus surgery over the past 30 years, the preferred method has become the endoscopic endonasal route, where a doctor uses a small camera to look inside your sinus and perform the surgery. This can be done through the sinus behind your nose (transsphenoidal) or through your nostrils (transnasal). The transsphenoidal approach is preferred when the canal that carries the vidian nerve in your skull (vidian canal) is easy to access.
In the transnasal or retrograde approach, the procedure starts with numbing the side of your nasal cavity in front of the back of your middle nose ridge (turbinate). Then, a U-shaped flap is lifted to expose the bones of the palate. There’s a small opening there called the sphenopalatine foramen, which they find by looking for a special landmark: the ethmoidal crest of the palatine bone. Once the artery that passes through this foramen is sealed, the surgeon lifts the flap back onto the face of the sphenoid sinus. Removing a small part of the wall around the sphenopalatine foramen gives access to a little hollow space in your skull called the pterygopalatine fossa. The contents of the fossa are moved to the side to expose the vidian canal. Once the vidian nerve is visible and identified, it is cut and removed using a special surgical knife or scissors. To finish, the flap is replaced and supported with a small piece of a substance called Gelfoam.
In the transsphenoidal or anterograde approach, the surgery starts by finding the opening to the sphenoid sinus, located above the back of your nostrils (choana). To keep the artery branches in the area safe, a large sphenoidotomy is performed, and the central part of the anterior wall of the sphenoid sinus (sphenoid rostrum) is then removed. There’s a risk of damaging the posterior septal branch of the sphenopalatine artery because it runs very close to the choana and below the sphenoid sinus opening. Once the bottom of the sphenoid sinus is thinned out, the vidian nerve is found on one side of the sinus floor using a 70-degree camera (endoscope). This nerve might not be visible right away, and different tools might be needed to expose it. Once it’s found, the nerve is cut and removed. If there’s a lot of bleeding during this, a gauze or other material might be packed into your nose.
There are some common issues during this surgery to be aware of. The vidian canal and palatovaginal canal are very close to each other on the floor of the sphenoid sinus, which can cause confusion. The palatovaginal canal is smaller and located just to the side (medial) of the vidian canal. It also carries a smaller nerve known as the posterior pharyngeal nerve. This nerve could easily be mistaken for the vidian nerve because of their closeness, but they have different courses. The vidian nerve takes a slight course towards the side before it meets the pterygopalatine ganglion, a small nerve center in the pterygopalatine fossa. An incomplete removal of the vidian nerve during surgery is another potential issue.
Possible Complications of Vidian Neurectomy
Just like any other medical procedure, complications can occur after a surgery. These complications can be immediate or long term.
Among the immediate complications, bleeding is common. It generally happens from branches of a specific artery in the nose known as the sphenopalatine artery. This type of bleeding can be controlled with methods such as nasal packing (inserting material in the nose to control bleeding) or cautery (use of heat to treat a wound or injury).
As for long-term complications, dry eyes is the most frequently reported issue, affecting up to 35% to 72% of patients. This condition, medically termed as ‘xerophthalmia’, is more prone to occur after a specific kind of surgical approach called ‘transsphenoidal’. However, most times, dry eyes tend to get better within 1 to 5 months after the surgery.
Sometimes, patients might experience numbness in the roof of the mouth, gums, and cheeks. This happens in roughly 6.27% of patients and is more frequent with another type of surgical approach known as the ‘pterygopalatine’.
This is followed by nasal crusting and dryness, a less common yet possible complication that occurs in about 3.7% of patients.
What Else Should I Know About Vidian Neurectomy?
Doctors are constantly trying to improve the surgical treatment for stubborn cases of rhinitis, commonly known as a stuffy or runny nose, which doesn’t respond to normal treatments. They focus on reducing or getting rid of the activity of the nervous system in the areas found inside the nose (nasal mucosa). One current surgical procedure, called an endoscopic vidian neurectomy, has proven successful in controlling symptoms for a long period of time, typically two to five years.
However, experts are concerned about the drawbacks to the procedure, which can include dry eyes (xerophthalmia) and numbness in the cheek or roof of the mouth. Hence, they are studying new and better ways to handle the issue. One such technique includes a surgical procedure that targets a different nerve, called the posterior nasal nerve.
This nerve helps to provide sensation and automatic activity to the nose and is easy to reach with an endoscope (a thin, flexible tube with a light and camera attached). Cutting this nerve can relieve symptoms similarly to the old method, but it has a lower risk of long-term complications from injuries to nearby nerves. This technique is gaining popularity.
Similar endoscopic procedures can even be performed in a doctor’s office, using different methods to destroy the problematic nerve. The most common method is cryogenic (using extreme cold), which can be as effective as traditional surgery, but without the need for general anesthesia or high risk of dry eyes or numbness.
Other methods, such as radiofrequency and laser treatments, are emerging as safe and effective alternatives. They use heat or light energy to target the nerve, which could potentially reduce the need for traditional surgery.
