Neurosurgery notes/Procedures/Cranial procedures/Approaches/Skull base approaches/Anterior fossa approaches/Supraorbital vs endoscopic approaches to the anterior cranial fossa

Supraorbital vs endoscopic approaches to the anterior cranial fossa

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Anterior fossa approaches

Issues

  • Complication
  • Technical Skills
  • Can you reconstruct the skull plate
  • If central its good for endonasal apprach
    • Lateraly has carotids and eyes in the way
    • Yellow endoscopic approach
    • Blue supraorbital approach
    A close-up of a skull AI-generated content may be incorrect.
    • Presentation + Imaging
      • Isolated Visual Deficit
        • Planum Meningioma
        • Cavernous Sinus Meningioma
        • Arachnoid Cyst
        • Carotid / Intracavernous Aneurysm
        • Primary Bone Disease
      • Pit Dysfunction and Visual Deficit
        • Craniopharyngioma
        • Rathke’s Cleft Cyst
        • Large Meningioma
        • Metastasis (DI)
      • Isolated Pituitary Dysfunction + Lesions of Stalk and Hypothalamus
        • Neuro-sarcoidosis
        • Langerhans Histiocytosis
        • Wegener’s
        • Lymphocytic Hypophysitis
        • Small Rathke’s / Cranio of the Stalk
        • Germinoma
        • Fungal / Bacterial infection
      • Incidental Finding
        • Smaller parasellar lesions
        • Small Rathke’s cleft cyst
        • Benign Stalk lesions
        • Large Cavernous Sinus lesions
        • Intracavernous aneurysm
    • Craniopharyngioma
      • First step is establishing degree of endocrine disturbance and visual deficit
        • Small lesion of stalk with intact vision:
          • Option for surveillance with MRI
          • If enlarges then operate
      • If Symptomatic hydrocephalus this may need urgent treatment first
        • Larger lesion with visual disturbance or chiasmatic compression:
          • Surgery with total resection if safe
          • If not, subtotal resection and DXT
      • Correct endocrine deficiencies but consider timing of puberty and growth in a child
        • Very Large lesions:
          • May need combination of transventricular cyst aspiration, direct approach to tumour and DXT.
          • Repeated surgery and shunts common
      • Imaging and management
          • Tend to push chiasm ant and sup (but variable)
          • Often partly cystic
          • Adherent to chiasm/perforators/IIIrd V and Hypothalamus
          • Hypopituitarism
          • Radical removal optimal, but can be associated with significant morbidity/mortality
          A screenshot of a computer AI-generated content may be incorrect.
    • Suprasellar Meningioma
        • Imaging and management
        • Tend to push chiasm posteriorly
        • Ant clinoid meningioma may invade carotid and/or optic canal and be behind optic nerve
        • Optic canal invasion under diagnosed on imaging
        • Usually arachnoid plane posteriorly preserved i.e. pit stalk and post fossa good dissection planes
        • Can invade / be adherent to chiasm / optic nerves and involve perforating vessels
        A screenshot of a computer AI-generated content may be incorrect.

    Extended endonasal technique

    • Binasal 3-4 hands
    • Pin Headrest
    • Fascia lata / naso-septal flap
    • Irrigating diamond drill
    • Micro doppler
    • Navigation
    • Sonopet / Cusa
    • ? Lumbar drain
    A screenshot of a computer AI-generated content may be incorrect.
    • Flap
      • Do not let it kink
      • It will shrink 25%
      • Needs to be in contact to bone throughout
      • Do not have anything between bone and flap like glue or what
      • Have the flap overlap with the surrounding mucosa
      Tuberculum saellae meningioma can pneumatize the sphenoid sinus and make it hard to do supraorbital hence choose endonasal
       
      A screenshot of a computer AI-generated content may be incorrect.
      • The optic chiasm is a pyramidal shaped allowing you to playing underneath it to get tumours out
          • A screenshot of a computer screen showing a diagram of the internal organs AI-generated content may be incorrect.
          A screenshot of a computer showing anatomy AI-generated content may be incorrect.
        Protect the sup and inf hypophyseal artery
         
        A screenshot of a medical video AI-generated content may be incorrect.
        • Outcome
          • Reference: https://pubmed.ncbi.nlm.nih.gov/28128693/
          • Conclusion: In this small single-institution study of similarly sized and located PS and TS meningiomas, EEA provided equivalent rates of resection with better visual results, less trauma to the brain, and fewer seizures. These preliminary results merit further investigation in a larger multiinstitutional study and may support EEA resection by experienced surgeons in a subset of carefully selected PS and TS meningiomas.
          • Csf leak rates
            • Reference: https://pubmed.ncbi.nlm.nih.gov/28598276/
              • Results: Of the 615 patients studied, 103 developed a postoperative CSF leak (16.7%). Sex and perioperative lumbar drainage did not affect CSF leakage rates. Posterior fossa tumors had the highest rate of CSF leakage (32.6%), followed by anterior skull base lesions (21.0%) and sellar/suprasellar lesions (9.9%) (p < 0.0001). There was a higher leakage rate for overweight and obese patients (BMI > 25 kg/m²) than for those with a healthy-weight BMI (18.7% vs 11.5%; p = 0.04). Patients in whom a pedicled vascularized flap was used for reconstruction had a lower leakage rate than those in whom a free graft was used (13.5% vs 27.8%; p = 0.0015). In patients with a BMI > 25 kg/m², the use of a pedicled flap reduced the rate of CSF leakage from 29.5% to 15.0% (p = 0.001); in patients of normal weight, this reduction did not reach statistical significance (21.9% [pedicled flap] vs 9.2% [free graft]; p = 0.09).
              • Conclusions: Preoperative BMI > 25 kg/m² and tumor location in the posterior fossa were associated with higher rates of postoperative CSF leak. Use of a pedicled vascularized flap may be associated with reduced risk of a CSF leak, particularly in overweight patients.
              • Patient demographics
                  • Variable
                  No CSF Leak (n = 512)
                  CSF Leak (n = 103)
                  p Value
                  Sex, no.
                  ㅤ
                  ㅤ
                  0.371
                  Male
                  221
                  50
                  ㅤ
                  Female
                  291
                  53
                  ㅤ
                  Mean age (yrs)
                  50.4
                  50.0
                  0.899
                  Mean BMI (kg/m²)
                  29.2
                  30.4
                  0.0803
                  Mean length of stay (days)
                  5.7
                  19.8
                  <0.001
                  Staged procedure, no. (%)
                  40 (7.8)
                  24 (23.1)
                  <0.001
                  Lumbar drain, no. (%)
                  115 (22.5)
                  32 (30.8)
                  0.081
                  Preop hydrocephalus, no. (%)
                  23 (4.5)
                  12 (11.5)
                  0.008
              • Multivariate logistic regression for predictors of postoperative CSF leak
                  • Variable
                  OR (95% CI)
                  p Value
                  Age
                  1.00 (0.99–1.01)
                  0.839
                  Sex: female
                  0.93 (0.59–1.45)
                  0.739
                  BMI: >25 kg/m²
                  1.75 (1.01–3.03)
                  0.047
                  Lumbar drain
                  1.61 (0.99–2.62)
                  0.056
                  Vascularized reconstruction
                  0.70 (0.36–1.37)
                  0.296
                  Surgery prior to 2006
                  2.64 (1.25–5.60)
                  0.011
                  Preop hydrocephalus
                  2.8 (1.29–6.07)
                  0.009

        Mini (not minimal) supraorbital eyebrow approach

        • Single surgeon
        • Pin Headrest
        • Avoid frontal air sinus (navigation)
        • Flatten inner table / roof orbit
        • Minimal brain retraction
        • Sonopet / Cusa
        • Specialist instruments / tubular scissors et
        • Endoscopic assistance
        • Low risk CSF leak
        A screenshot of a computer AI-generated content may be incorrect.
        • Hard to see down into the olfactory groove → cant get complete resection of tumour
        • Enter Right side to get left side: cross court
            • Easier to see under optic nerve on the contralateral side
            • Dont do the Right bottom image: so much touching and retracting the optic nerve
             
            A screenshot of a computer AI-generated content may be incorrect.
        • Positioning
            • Right A: pterional B: mini pterional; C: mini supraorbital
            • Extend head and slightly rotated 30
             
            A screenshot of a computer AI-generated content may be incorrect.
        • Incision
            • 1: supraorbital notch; 4: zygomatic arch; 5: supraorbial nerve and artery; 6: temporal branch of facial nerve
            • Medial limit is the supraorbital notch → nerve
            A screenshot of a medical procedure AI-generated content may be incorrect.
            • The last figure showing bevelling of the inner table of the skull can dramatically increase your exposure
            • Burr hole angle it cranially to not enter orbital vault
            A screenshot of a computer screen AI-generated content may be incorrect.
            • If you want to go even more lateral to increase exposure you can drill off the zygomatic arch but place the plates first so that when you close the arch does not have a step on it
            A screenshot of a computer screen AI-generated content may be incorrect.
        • ? Lumbar drain Does it need to be use
          • Preop and intra-op no
          • Post op: It does reduce CSF leak for big extension approach
            • Reference: https://pubmed.ncbi.nlm.nih.gov/30485224/
            • Demographic information within the LD and no-LD groups
                • Variable
                LD (n = 85)
                No LD (n = 85)
                p Value
                Mean age ± SD, yrs
                51.0 ± 15.1
                52.3 ± 15.5
                0.572
                Females, n (%)
                56 (65.9%)
                49 (57.7%)
                0.269
                Mean BMI ± SD, kg/m²
                27.6 ± 5.6
                28.7 ± 5.2
                0.178
                Pathology
                ㅤ
                ㅤ
                ㅤ
                Anterior, n (%)
                18 (21.2%)
                17 (20.0%)
                ㅤ
                Posterior, n (%)
                24 (28.2%)
                26 (30.6%)
                ㅤ
                Suprasellar, n (%)
                43 (50.6%)
                42 (49.4%)
                0.942
                CSF leaks, n (%)
                7 (8.2%)
                18 (21.2%)
                0.017
        • Strip superiorly don't strip the periosteum inferiorly otherwise get bruising of the eye
        • Avoid frontal sinus with navigation
        A screenshot of a computer AI-generated content may be incorrect.

        Diseases dealt by extended endonasal vs mini-supraorbital

        Extended Endonasal
        Mini-Supraorbital
        Both
        Craniopharyngioma
        Large olfactory groove meningioma (no cuff)
        Esthesioneuroblastoma
        Small OLF groove / planum / tuberculum meningioma (cuff)
        Larger planum / tuberculum meningioma (no cuff)
        Invasive meningioma
        Lesions of stalk
        Meningioma ext lateral to carotid
        Malignant nasoethmoid tumour
        Pituitary macroadenoma
        Meningioma with cav sinus involvement
        ㅤ
        Suprasellar biopsy
        Solid craniopharyngioma
        ㅤ
        Retrochiasmatic lesions
        Aneurysm
        ㅤ
        • Cuff is a cuff of normal brain between tumour and vessel.
        • Large groove meningioma, larger planum and small olf groove can be either way

        Meningioma – Decision Making

        • Size ? relevant
        • Bone of skull base invaded → endonasal
        • Vascularity
        • Cortical Cuff → endoscopic
        • Olfaction present
        • Anterior / posterior extent
        • Reconstruction possible
        • Invasion of medial optic canal → endonasal
        • Sense of smell
        • If is too lateral: not for endonasal
         
        A screenshot of a computer AI-generated content may be incorrect.
        Type I: ONE segment or size < 2 cm “Small”; Type II: TWO segments or size 2 - 3.9 cm “Moderate”; Type III: THREE segments or size 4 - 5.9cm “Large”; (Type IV: FOUR segments or size > 6 cm “GIANT”

        Summary

        • Extended endonasal endoscopic approach is not minimally invasive
        • Approach should be tailored to pathology and patients’ preference, not fashion
        • Choose approach that offers total resection if possible
        • Choose approach that offers minimal morbidity
        • Nasal morbidity is real
        • CSF leaks are a headache
        • Impact on driving licence (DVLA out of date here)
        • Craniotomy: need
          stop driving endonasal no need to do but based on experiment even endonasal
          should stop driving too. Because extended endonasal has seizure risk although
          low as it allows air enters
         
        A screenshot of a computer AI-generated content may be incorrect.