see also: Transnasal Transsphenoidal Approach to Pituitary

return to: Paranasal Sinus Surgery Protocols

Note: last updated before 2015

Definition

Vascular pedicled mucosal flap of the nasal septum mucoperichondrium and mucoperiosteum based on the nasoseptal artery. Considered the "work-horse" flap for anterior skull base reconstruction.

Indications

• Skull base reconstruction after endonasal surgery
• Prevents communication between brain and sinuses 
• Advantages:
  • Well vascularized with robust pedicled blood supply (nasoseptal artery)
  • Superior arc of rotation
  • Customizable surface area/modifiable
  • Provides enough surface area to cover the entire anterior skull base
  • Can be stored in the nasopharyx during the extirpative portion of the procedure
  • Promotes fast healing and decreases risk of CSF leak
  • Endonasal (no external incisions)
  • Sturdy, pliable
  • Can be taken down and re-used in revision cases

Preop considerations

• Case in conjunction with neurosurgery
  • Lumbar drain or ventriculostomy placement
  • Size of anticipated post-surgical defect
  • History of prior nasal septal flap harvest, nasal or endoscopic sinus surgery, or septoplasty
  • History of nasal trauma and septal fracture
  • History of septal perforation
  • This flap may not be a viable option for reconstruction of very anterior fossa defects or when cancer involves septal tissue or if the sphenoid rostrum is involved by malignancy.
  • This flap may not be viable option in children less than 10 years old, as the size of the flap may not be adequate to cover the skull base defect in this population

Anatomy

Pedicled flap based upon blood supply from the nasoseptal artery, a branch of the posterior septal artery which is a tributary from the sphenopalatine artery.

Instruments

• Nasal/septal tray
• Nasal prep tray
• Endoscopic nasal/sinus telescopes (zero degree)
• Oto or neurosurgery endoscopic tower/screens
• Endoscrub
• Suction Freer (Gorney)/Cottle
• Extended length angled Colorado tipped Bovie cautery
• 12 French Foley catheter
• Doyle splint/silastic nasal splint
• 4-0 Nylon

Consent

• Nasoseptal flap, placement of Foley balloon catheter, placement of nasal splint, possible septal cartilage harvest.
  • Risks: septal perforation, CSF leak, anosmia, meningitis, bleeding, infection, flap loss, synechiae

Anesthesia

• General anesthesia
  • Oral endotracheal tube – taped to lower left corner of the mouth
• Topical/Local
  • Topical: 4% cocaine (40mg/cc) total of 4 cc on 4 pledgets
  • Local injection: 1% lidocaine with 1:100,000 epinephrine

Technique

• Trim nasal hairs
• Examine nasal passages and remove mucus
• To decongest the nose you can use nasal pledgets soaked in 4% cocaine or oxymetazoline
• Perform injections for sinonasal surgery (with 1% lidocaine with 1:100,000 epinephrine sublabial, posterior septum, the posterior portion of the middle turbinate, the anterior face of the sphenoid, and over the sphenopalatine artery)
• Inject 1% lidocaine with 1:100,000 epinephrine into anterior portion of the nasal septum on the operative side
• Using an extended length angled Colorado tipped Bovie cautery set to 10, make the posterior incisions first:
  • The superior incision is made just underneath the sphenoid os that was identified before making the incisions. This is carried forward onto the nasal septum at a level approximately 1-2 cm below and parallel the most superior aspect of the septum (avoiding the olfactory epithelium). The incision is carried forward along the septum until it is across from the anterior edge of the inferior turbinate 
  • At this point, the incision is carried downwards (vertically) in order connect it with the planned inferior aspect of the flap.
  • The inferior posterior portion of the incision is then made above the level of the choana. This is then carried down onto the septum, and just above the maxillary crest, all the way forward to meet the vertical limb of the incision (this incision can be carried onto the nasal floor to create a larger flap).
• Elevate the flap from anterior to posterior using a Cottle elevator, once started may use the suction Freer to elevate the flap.  Flap incision can be completed using the sharp edge of the Cottle or Freer. 
• The nasoseptal flap is elevated in a subperichondrial and subperiosteal plane back to the anterior face of the sphenoid sinus between where the posterior superior and inferior incisions had been made preserving the pedicle.
• Once fully elevated the flap is tucked into the nasopharynx until it is needed for closure.
• At the conclusion of neurosurgery's portion of the case, they may place Duragen or Fat and Otolaryngology is then oriented to what they have done.
• The nasoseptal flap is then teased out of the nasopharynx and unfurled in proper orientation along the septum in order to insure it is not rotated or twisted.
• The flap is then laid into the defect, primarily covering the neurosurgical defect and the DuraGen/Fat. Again, make sure the the flap is not twisted and ensuring that the mucosal surface is facing the nasal cavity, not the intracranial defect, and that the flap is covering the bony edges of the defect.
• DuraSeal is then used (or other fibrin glue) to help secure the flap.
• Several pieces of Gelfoam are then laid into secure this.
• A 12-French Foley catheter is then placed through the nasal passage and the balloon centered over the nasoseptal flap in the sphenoid to hold pressure and keep the flap in place.
• Fill the balloon to the appropriate amount based on visualization – make sure to fill with sterile water (NOT saline).
• A Doyle splint is then fashioned with removal of the air column, and incising the posterior portion to fit and accommodate the Foley balloon. This splint should cover any area of the denuded mucosa on the septum to fully cover the mucosal defect.
• Secure the splint into place with a 4-0 nylon through-and-through the membranous septum tied with an air knot.
• The patient’s oral cavity and nasopharynx should copiously be suctioned before the conclusion of the case.

Post op

• No nose blowing
• Humidified air to reduce crusting at flap donor site
• Avoid increasing intracranial pressure:
  • No straining, leaning forward or lifting > 15lbs
  • Stool softeners
  • Open mouth sneezing
• Perioperative third generation cephalosporin
• Routine post op MRI or CT within 24 hrs after surgery
  • Rule out post op bleed, injury, pneumocephalus
  • Confirm placement of balloon catheter
• Foley balloon catheter removed at 3 – 5 days post op, can remove small amounts of fluid daily prior to removing entire catheter
  • Depends on size defect, risk factors, patient’s BMI
• Post op nasal saline spray to start earliest POD#3, later depending on risk factors for CSF leak/clinical picture
• Modified Doyle splint or Silastic nasal septal splint removed at 2 – 4 weeks post op
• Office nasal debridement at 2 weeks post op and every 1 – 2 weeks after until no further crusting
  • Do NOT debride over the defect/flap as can disrupt the flap and cause CSF leak
• Crusting of the septal mucosa harvest site is common and may require debridement. Resurfacing of this defect normally takes 6-8 weeks.
• Resurfacing of the septal mucosa harvest site with mucosal free grafts has been reported.

References

Hadad G, Bassagasteguy L, Carrau R, Mataza J, Kassam A, Snyderman C, Mintz A.  A novel reconstructive technique after endoscopic expanded endonasal approraches: Vascular pedicle nasoseptal flap. Laryngoscope 2006;116:1882-- 1886.

Kassam A, Thomas A, Carrau R, Snyderman C, Vescan A, Prevedell D, Mintz A, Gardner P.  Endoscopic reconstruction of the cranial base using a pedicled nasoseptal flap.  Operative Neursurgery 2008;63:44-53.

Patel MR, Stadler ME, Snyderman CH, Carrau RL, Kassam AB, Germanwala AV, Gardner P, Zanation AM. How to Choose? Endoscopic Skull Base Reconstruction Options and Limitations. Skull Base. 2010 Nov;20(6):397-404

Rivera-Serrano CM, Snyderman CH, Gardner P, Prevedello D, Wheless S, Kassam AB, Carrau RL, Germanwala A, Zanation A. Nasospetal "rescue" flap: a novel modification of the nasoseptal flap technique for pituitary surgery. Laryngoscope. 2011 May;121(5):990-3.