Like all skull base procedures, this technique would require a coordinated multidisciplinary team approach. The operating team would include specialized nurses in rhinology/endoscopic skull base, an anesthetic team including operation department practitioners, an endoscopic skull base surgeon, and an assistant. 

A preoperative CT scan of the paranasal sinuses with 1 mm contiguous axial, coronal, and sagittal views is a prerequisite to surgical planning. Attention focuses on the vidian canal position in the sphenoid sinus, its relation to the sphenoid corpus, the thickness of bone over the roof of the canal, and the angle it forms with the canal.  After orotracheal intubation, the patient is positioned in a semi-Fowler position with the head in a horseshoe rest or Mayfield pin holder. Pterygopalatine ganglion block is performed transorally, via the greater palatine canal. The nasal cavity is prepared and decongested with adrenaline-soaked neuro sponges. 

There are numerous descriptions in the literature of approaches to the vidian nerve, including transantral via Caldwell-Luc approach, transpalatal, transseptal mucoperichondrial, and endonasal route. With advancements in endoscopic sinus surgery in the last three decades, the most preferred route for vidian neurectomy is the endoscopic endonasal route, using either transsphenoidal or transnasal approach. The transsphenoidal approach is preferable in cases with a prominent vidian canal in the sphenoid sinus floor. However, both techniques could be combined in varying degrees to trace the vidian nerve anatomy from sphenoid sinus to pterygopalatine ganglion. 

Surgical Steps of Transnasal or Retrograde Approaches

1. The lateral wall of the nasal cavity anterior to the posterior end of the middle turbinate is infiltrated with lignocaine mixed with adrenaline.
2. Posterior to the posterior fontanelle of the maxillary sinus, a U shaped posteriorly based flap is raised over the palatine bone.
3. The surgeon identifies the ethmoidal crest of the palatine bone, and it serves as a useful landmark for sphenopalatine foramen (SPF).
4. Sphenopalatine artery (SPA) is identified and coagulated or clipped with Ligar clips.
5. The mucosal flap is raised behind the foramen into the face of the sphenoid sinus.
6. There is confirmation of the sphenoid sinus with a minimal widening of the sphenoid ostium. 
7. The posteroinferior margin of the SPF (the sphenoidal process of the palatine bone) is removed, thereby taking off the medial wall of the pterygopalatine fossa.
8. Contents of the pterygopalatine fossa are pushed laterally to expose the vidian canal.
9. After clear visualization and positive identification of the vidian nerve, 2 to 3 mm of the vidian nerve is removed with a sickle knife or scissors.
10. The mucosal flap is reposited and supported with a small piece of Gelfoam.

Surgical Steps of Transsphenoidal or Anterograde Approaches

1. The sphenoid sinus ostium is identified 1.2 to 1.5 cm above the choana
2. Wide sphenoidotomy preserves sphenopalatine artery branches inferolaterally, and the sphenoid rostrum is removed.
3. The sphenoid sinus floor is thinned out.
4. Using a 70-degree endoscope, the vidian nerve is identified on the lateral aspect of the floor of the sphenoid sinus. If not easily visible, the canal is deroofed with a pricking probe, Kerrison's rongeur, or drill. 
5. Using an angled probe, the nerve is transected, and a segment of the nerve is removed.
6. Nasal packing is necessary in case of significant intraoperative bleeding.

Pitfalls in Surgery

• Palatovaginal canal: This structure can be mistaken for the vidian canal. It runs along the floor of the sphenoid sinus, transmits nerves, and their anterior openings are separated by only a few millimeters. The PVC opening is just medial to the vidian canal, much smaller in size, and transmits a smaller nerve (posterior pharyngeal nerve)
• Posterior pharyngeal nerve: Exits the PVC to run across the vidian canal in a lateral direction to join the pterygopalatine ganglion (PPG) in the PPF, while the vidian nerve, much bigger in thickness, has a slight lateral course before it joins the PPG. 
• Incomplete resection of vidian nerve

Immediate Complications

Postoperative bleeding: reported on an average of 1.5%. The likely source of bleeding is from sphenopalatine artery branches and is controllable with nasal packing or cautery. 

Long Term Complications [11]

• Dry eye: This is the most commonly reported complication in nearly 50% of cases, ranging between 35 to 72%. Xerophthalmia is significantly more likely to occur after transsphenoidal/intrasphenoidal approaches. Most studies reported the resolution of dry eyes in 1 to 5 months of surgery. 
• Palatal/Gingival/Cheek numbness (6.27%) - Incidence is more likely after the pterygopalatine approach. 
• Nasal crusting/dryness (3.7%)

Surgical management of refractory rhinitis is still an evolving surgical concept, with the aim of abolishing parasympathetic supply to the nasal mucosa. Endoscopic vidian neurectomy has proved to an effective procedure with long-term (2 to 5 years) control in nasal symptoms.[11]. In an effort to improve on complications of vidian neurectomy such as xerophthalmia, newer techniques, including posterior nasal neurectomy, are considerations.[12] 

Vidian neurectomy is not a commonly performed procedure and is a treatment modality offered in cases of refractory rhinitis. Before embarking on this procedure, there needs to be a clear discussion with the patient in terms of their expectations and possible outcomes of the procedure. As any skull base procedure, this procedure involves a multidisciplinary team, which includes rhinologists, anesthetists, radiologists, ophthalmologists, the nursing team as well as other theatre staff. 

The initial case evaluation occurs at the rhinology clinic, which allergy testing and endoscopic examination. CT scans require review for understanding the full course of the vidian nerve and pterygopalatine fossa. Intraoperative and postoperative optimization of the patient would need an expert neuro-anesthesia team effort. Finally, a postoperative follow-up would involve regular endoscopic examinations as well as ophthalmology clinic visits in case of dry eye.