Wilson's Transpalatal Approach

Classification

Indications

• Malignant tumours of the posterior nasopharyngeal wall (no larger than ~2 cm)
• Salvage nasopharyngectomy for recurrent/residual nasopharyngeal carcinoma (NPC) after radiotherapy
• Access to the lower clivus and craniovertebral junction
• Small benign nasopharyngeal tumours (e.g., juvenile nasopharyngeal angiofibroma, stage I JNA)
• Choanal atresia repair (historically, now largely replaced by endoscopic approaches)

Contraindications

• Tumours >2 cm
• Internal carotid artery encasement or extensive skull base infiltration
• Significant dural invasion or intracranial extension
• Lesions extending into the parapharyngeal space, cavernous sinus, or infratemporal fossa (limited lateral access)
• Tumours extending lateral to the nasopharyngeal sidewalls

Surgical Anatomy

Operative Steps (Classic Technique)

• Supine, head extended (Mayfield clamp or horseshoe rest)
• Preliminary tracheostomy to secure the airway and give unobstructed oropharyngeal access (patients develop significant lingual and oropharyngeal oedema postoperatively)
• Lumbar CSF drainage if dura may be opened
• Crockard wide-field retractors are commonly used

1. Mouth gag inserted; oral cavity retracted
2. Soft and hard palate infiltrated with 1:200,000 adrenaline
3. The soft palate is split to one side of the midline
4. Hard palate mucosa incised along the ipsilateral junction of hard and soft palate, within 5 mm of maxillary dentition
5. Incision extended along the palatal aspect of the alveolar ridge to the first molar, then arced across the palate to the opposite side (Figure 109.2a, Scott-Brown's)
6. A mucoperiosteal flap is elevated, exposing the bony hard palate
7. The greater palatine neurovascular bundle is coagulated and divided on the operative side (the contralateral pedicle is preserved for flap viability)
8. Soft palate muscular insertions are dissected from the hard palate to increase nasopharyngeal exposure - great care taken to maintain the remaining contralateral vascular pedicle
9. A self-retaining retractor keeps the two halves of soft palate out of field
10. Posterior hard palate may be removed with rongeurs to increase exposure
11. Dissection through the posterior nasopharyngeal wall gives access to the lower clivus

• Transverse incision through nasal mucosa of the posterior floor of nose
• Tumour isolated and removed under direct vision
• If lesion extends toward sphenoid floor or upper clivus: removal of palatal vomerine bone, or a Le Fort I osteotomy with midline palate split displacing each maxilla laterally (extended access)

• Palatal flap re-sutured to anterior hard palate mucosa
• Nasal packing (Xeroform gauze)
• Palate closed with interdental vertical mattress sutures (3-0 or 4-0 Vicryl)
• Palatal splint secured (custom or reinforced silastic sheeting) with circumdental silk sutures or Woodruff screw technique

Variants

Advantages

• No facial incision or scar
• Minimal bone removal
• Direct inferior approach with good visualization of posterior nasopharyngeal wall
• Straightforward technique

Disadvantages / Complications

• Limited lateral access - cannot easily reach the parapharyngeal space or lateral nasopharynx
• Risk of palatal fistula (a key morbidity)
• Velopharyngeal insufficiency / nasopharyngeal regurgitation
• Trismus (especially with mandibular extension)
• Dysphagia postoperatively due to oropharyngeal oedema
• Difficult assessment of margin status in malignancy

Oncological Outcomes (NPC Salvage)

• 5-year overall survival: 52%
• Local control: 67%