What are the steps for performing an endoscopic septoplasty, including identifying anatomical borders and controlling major blood supply from the sphenopalatine artery?

Endoscopic Septoplasty: Step-by-Step Technique, Anatomical Borders, and Blood Supply Management

Endoscopic septoplasty is superior to conventional septoplasty with significantly less blood loss, shorter operative time, fewer complications, and better quality of life outcomes. 1

Anatomical Borders and Planes

Before discussing the surgical steps, it's important to understand the anatomical borders and planes involved:

• Superior border: Junction of septal cartilage with ethmoid plate
• Inferior border: Junction of septal cartilage with maxillary crest
• Anterior border: Columella
• Posterior border: Sphenoid face
• Surgical plane: Subperichondrial and subperiosteal planes (between the perichondrium/periosteum and the septal cartilage/bone)

Step-by-Step Endoscopic Septoplasty Technique

1. Preparation and Anesthesia

• Position patient in supine position with slight head elevation
• Apply topical decongestant to reduce mucosal swelling and bleeding
• Administer local anesthesia with 1-2% lidocaine with 1:100,000 epinephrine

2. Initial Endoscopic Assessment

• Perform anterior rhinoscopy to identify the septal deviation 2
• Use 0° endoscope to visualize the entire nasal cavity
• Identify the site of maximal deviation and assess for any other pathology

3. Incision and Flap Elevation

• Make a hemitransfixion or Killian incision on the concave side of the deviation
• Elevate a mucoperichondrial flap using a Freer elevator under direct endoscopic visualization
• Work in the avascular subperichondrial plane to minimize bleeding
• Extend the dissection posteriorly as needed to address the deviation

4. Contralateral Flap Elevation

• Create a tunnel at the base of the septum to access the contralateral side
• Elevate the contralateral mucoperichondrial flap in the same subperichondrial plane
• Complete bilateral flap elevation around the area of deviation

5. Cartilage and Bone Modification

• Identify the specific septal deformity under endoscopic guidance
• Remove or reshape the deviated portion of cartilage or bone
• Preserve at least 1 cm dorsal and caudal strut for nasal support
• Use endoscopic scissors, forceps, or powered instruments as needed

6. Addressing Posterior Deviations

• Use a 0° or 30° endoscope to visualize posterior deviations
• Remove deviated portions of the perpendicular plate of ethmoid or vomer
• Take care near the skull base superiorly and the sphenopalatine foramen posteriorly

7. Management of Blood Supply

• Major blood supply: Sphenopalatine artery (terminal branch of maxillary artery)
• Identify the sphenopalatine foramen at the posterior attachment of the middle turbinate
• Preserve the mucosal flaps to maintain blood supply to the septum
• For significant bleeding, consider endoscopic cauterization at the bleeding site 3
• In cases of intractable posterior epistaxis, endoscopic transseptal sphenopalatine artery ligation may be performed 4

8. Flap Repositioning and Closure

• Reposition the mucoperichondrial flaps
• Close the incision with absorbable sutures
• Place silastic splints if necessary to prevent synechiae formation
• Consider transseptal quilting sutures to prevent septal hematoma

9. Post-operative Care

• Nasal packing (if used) removal after 24-48 hours
• Saline irrigation to cleanse the nasal cavity
• Follow-up endoscopic examination at 2 weeks, 4 weeks, and 8 weeks 1

Advantages of Endoscopic Septoplasty

• Better visualization, particularly for posterior deviations 5
• Limited dissection to the area of deviation, reducing morbidity 5
• Reduced blood loss (54.6 ± 7.18 mL vs. 88.67 ± 8.77 mL in conventional) 1
• Shorter operative time (39.7 ± 6.73 min vs. 60.47 ± 8.16 min in conventional) 1
• Fewer complications including pain, synechiae, and septal tears 6
• Improved teaching tool for residents and students 6

Common Pitfalls and How to Avoid Them

1. Mucosal tears

   • Maintain proper dissection in the subperichondrial/subperiosteal plane
   • Use gentle dissection techniques with appropriate instruments

2. Septal hematoma

   • Ensure adequate hemostasis before closure
   • Consider transseptal quilting sutures
   • Proper post-operative monitoring

3. Incomplete correction

   • Thorough pre-operative assessment with nasal endoscopy
   • Complete exposure of deviated segments
   • Address all components of the deviation

4. CSF leak

   • Maintain awareness of skull base anatomy
   • Avoid aggressive superior dissection

5. Nasal valve compromise

   • Preserve adequate dorsal and caudal septal support
   • Avoid over-resection of cartilage

By following these steps and being mindful of the anatomical borders and blood supply, endoscopic septoplasty can be performed safely and effectively with minimal complications and excellent outcomes.