Vidian Neurectomy

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Continuing Education Activity

This activity describes vidian neurectomy, a surgical procedure aimed to treat refractory vasomotor rhinitis, along with the relevant anatomy, the indications/contraindications, and technical aspects of the procedure. This activity reviews the role of the interprofessional team in evaluating and managing these patients to provide optimal care.

Objectives:

  • Identify the indications for vidian neurectomy.
  • Describe the surgical anatomy relevant to vidian neurectomy, including technical details.
  • Summarize the potential complications of vidian neurectomy.
  • Review some interprofessional team strategies for improving care coordination and communication to advance vidian neurectomy and improve outcomes.

Introduction

The Vidian nerve supplies parasympathetic fibers to the nasal mucosa, palate, and lacrimal gland via the pterygopalatine ganglion. The sacrifice of this nerve by reducing the autonomic supply to the nasal cavity is proven to improve nasal hypersecretion.[1] This procedure, Vidian neurectomy, was first described by Golding-Wood in the 1960s to treat refractory vasomotor rhinitis.[2] 

Vasomotor rhinitis, believed to arise from an imbalance between parasympathetic and sympathetic supply to the nasal mucosa, was hence a reasonable indication. In the pre-endoscopic era, with challenges in localizing the vidian nerve, this procedure was accompanied by poor long-term outcomes and, therefore, was sporadically deployed. Open approaches to the pterygopalatine fossa, such as transantral or transpalatal, were fraught with patient morbidities, such as ophthalmoplegia, orbital complications, and palatal fistulae.[3] In 1991, Kamel and Zaher demonstrated endoscopic transnasal vidian neurectomy in cadaveric models.[4] 

Clinical studies have reported improved nasal outcomes using this technique compared to medical management or other surgical options such as turbinoplasty or septoplasty[5]. Though vidian neurectomy has received growing enthusiasm, there is limited evidence regarding long term results and complications. 

Anatomy and Physiology

Anatomy of the Vidian Nerve

The vidian nerve, along with the vidian artery, runs along the pterygoid canal - an osseous tunnel along the floor of the sphenoid sinus (hence also called the nerve of the pterygoid canal). Parasympathetic fibers from the greater superficial petrosal nerve, which runs along the floor of the middle cranial fossa, and the sympathetic fibers via the deep petrosal nerve from the ICA plexus merge to form the vidian nerve.  The pterygoid canal connects the foramen lacerum in the middle cranial fossa with the pterygopalatine fossa. This canal runs in a medial to lateral direction, traversing the floor of the sphenoid sinus, to its funnel-shaped opening into the pterygopalatine fossa at the pterygoid "wedge."[6] 

The pterygoid wedge, a useful landmark for identification of the vidian canal, is the base of the pterygoid plates - which is pyramid-shaped - with the apex pointed towards the sphenoid sinus floor. Along the floor of the sphenoid sinus, there are three openings, and the exact location of the vidian canal opening is to be ascertained pre- and intra-operatively. From medial to lateral, the openings are the palatovaginal canal, vidian canal, and foramen rotundum. 

It is critical to understand the variations in the course as well as location relative to the sphenoid sinus before embarking on surgery. The vidian canal has a medial to lateral course from the pterygopalatine fossa to foramen lacerum in 80 to 98% of radiographic studies.[7][8] The canal is approximately 18 mm in length. The location of the vidian nerve in the sphenoid sinus demonstrates considerable variation, not only in its protrusion from the floor (inside sphenoid corpus, partially protruding or inside the sinus connected by a bony stalk) but also in the angle formed by the floor with the nerve (flat, upsloping, downsloping and inverted V types).[9]

Endoscopic Landmarks for Vidian Canal

  • The vidian canal is visible as an elevation along the lateral aspect of the sphenoid sinus floor
  • The intersection between a line drawn along the posterior border of palatine bone and a horizontal line drawn along the sphenoid sinus floor denotes the opening of the vidian canal into the pterygopalatine fossa

Surgical Relevance of Vidian Canal

  • Endoscopic management of juvenile nasopharyngeal angiofibromas
  • As a landmark for petrous carotid artery in expanded endonasal approaches
  • Vidian neurectomy

Indications

  1. Refractory vasomotor rhinitis
  2. Perennial allergic rhinitis
  3. Chronic cluster headaches refractory to medical management[10]
  4. Chronic epiphora
  5. Senile nasal drip
  6. Crocodile tears, as an alternate option to tympanic neurectomy[3] 

Contraindications

There are no absolute contraindications. Relative contraindications are skull base defects or tumors in the pterygomaxillary region.

Equipment

Equipment required for vidian neurectomy include:

  • FESS instrument set
  • Endoscopic skull base instrument set, including endoscopic ligating clips, applicators, and endoscopic drill system
  • Endoscopes (0, 45, and 70 degrees)
  • Image-guided navigation system

Personnel

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. 

Preparation

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. 

Technique

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

Complications

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%)

Clinical Significance

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] 

Enhancing Healthcare Team Outcomes

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.


Article Details

Article Author

Arshad Zubair

Article Editor:

Savita Lasrado

Updated:

5/14/2022 6:01:03 AM

PubMed Link:

Vidian Neurectomy

References

[1]

Konno A, Historical, pathophysiological, and therapeutic aspects of vidian neurectomy. Current allergy and asthma reports. 2010 Mar;     [PubMed PMID: 20425502]

[2]

GOLDING-WOOD PH, Observations on petrosal and vidian neurectomy in chronic vasomotor rhinitis. The Journal of laryngology and otology. 1961 Mar;     [PubMed PMID: 13706533]

[3]

Golding-Wood PH, Vidian neurectomy: its results and complications. The Laryngoscope. 1973 Oct;     [PubMed PMID: 4758764]

[4]

Kamel R,Zaher S, Endoscopic transnasal vidian neurectomy. The Laryngoscope. 1991 Mar;     [PubMed PMID: 2000022]

[5]

Tan G,Ma Y,Li H,Li W,Wang J, Long-term results of bilateral endoscopic vidian neurectomy in the management of moderate to severe persistent allergic rhinitis. Archives of otolaryngology--head     [PubMed PMID: 22652948]

[6]

Kassam AB,Vescan AD,Carrau RL,Prevedello DM,Gardner P,Mintz AH,Snyderman CH,Rhoton AL, Expanded endonasal approach: vidian canal as a landmark to the petrous internal carotid artery. Journal of neurosurgery. 2008 Jan;     [PubMed PMID: 18173330]

[7]

Kim HS,Kim DI,Chung IH, High-resolution CT of the pterygopalatine fossa and its communications. Neuroradiology. 1996 May;     [PubMed PMID: 8811698]

[8]

Vescan AD,Snyderman CH,Carrau RL,Mintz A,Gardner P,Branstetter B 4th,Kassam AB, Vidian canal: analysis and relationship to the internal carotid artery. The Laryngoscope. 2007 Aug;     [PubMed PMID: 17572642]

[9]

Liu SC,Wang HW,Su WF, Endoscopic vidian neurectomy: the value of preoperative computed tomographic guidance. Archives of otolaryngology--head     [PubMed PMID: 20566911]

[10]

Liu SC,Kao MC,Huang YC,Su WF, Vidian Neurectomy for Management of Chronic Cluster Headache. Neurosurgery. 2019 May 1;     [PubMed PMID: 30535031]

[11]

Halderman A,Sindwani R, Surgical management of vasomotor rhinitis: a systematic review. American journal of rhinology     [PubMed PMID: 25785754]

[12]

Ikeda K,Oshima T,Suzuki M,Suzuki H,Shimomura A, Functional inferior turbinosurgery (FITS) for the treatment of resistant chronic rhinitis. Acta oto-laryngologica. 2006 Jul;     [PubMed PMID: 16803714]