Surgical relevance of pediatric skull base maturation for the far-lateral and extreme-lateral infrajugular transcondylar–transtubercular exposure approaches

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OBJECTIVE

Lesions of the foramen magnum, inferolateral-to-midclival areas, and ventral pons and medulla are often treated using a far-lateral or extreme-lateral infrajugular transcondylar–transtubercular exposure (ELITE) approach. The development and surgical relevance of critical posterior skull base bony structures encountered during these approaches, including the occipital condyle (OC), hypoglossal canal (HGC), and jugular tubercle (JT), are nonetheless poorly defined in the pediatric population.

METHODS

Measurements from high-resolution CT scans were made of the relevant posterior skull base anatomy (HGC depth from posterior edge of the OC, OC and JT dimensions) from 60 patients (evenly distributed among ages 0–3, 4–7, 8–11, 12–15, 16–18, and > 18 years), and compared between laterality, sex, and age groups by using t-tests and linear regression.

RESULTS

There were no significant differences in posterior skull base parameters by laterality, and HGC depth and JT size did not differ by sex. The OC area was significantly larger in males versus females (174.3 vs 152.2 mm2; p = 0.01). From ages 0–3 years to adult, the mean HGC depth increased 27% (from 9.0 to 11.4 mm) and the OC area increased 52% (from 121.4 to 184.0 mm2). The majority of growth for these parameters occurred between the 0–3 year and 4–7 year age groups. Conversely, JT volume increased nearly 3-fold (281%) from 97.4 to 370.9 mm3 from ages 0–3 years to adult, with two periods of substantial growth seen between the 0–3 to 4–7 year and the 12–15 to 16–18 year age groups. Overall, JT growth during pediatric development was significantly greater than increases in HGC depth and OC area (p < 0.05). JT volume remained < 65% of adult size up to age 16.

CONCLUSIONS

When considering a far-lateral or ELITE approach in pediatric patients, standard OC drilling is likely to be needed due to the relative stability of OC and HGC anatomy during development. The JT significantly increases in size with development, yet is only likely to need to be drilled in older children (> 16 years) and adults.

ABBREVIATIONS ELITE = extreme-lateral infrajugular transcondylar–transtubercular exposure; HGC = hypoglossal canal; JT = jugular tubercle; OC = occipital condyle.

Article Information

Correspondence Michael L. Levy: University of California, San Diego, CA. mlevy@rchsd.org.

INCLUDE WHEN CITING Published online April 26, 2019; DOI: 10.3171/2019.2.PEDS18621.

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

© AANS, except where prohibited by US copyright law.

Headings

Figures

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    Measurements of skull base parameters (double-headed arrows) based on high-resolution CT. A: HGC depth measured on axial CT as distance from posterior edge of the OC to posterior edge of the HGC, along the axis of the foramen magnum. B: OC area measured on axial CT as an ellipse (π*OC length/2*OC width/2). C: JT length and thickness measured on axial CT. D: JT width measured on coronal CT. JT volume was calculated as a partial ellipsoid (4/3*π*JT length/2*JT width/2*JT thickness)/2. Figure is available in color online only.

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    Development of skull base parameters with age. HGC depth (A) and OC area (B) display modest growth with normal development, primarily between the ages of 0–3 and 4–7 years. C: JT volume nearly triples in size with pediatric development, with two main growth periods between the ages of 0–3 to 4–7 years and 12–15 to 16–18 years. Asterisk indicates p < 0.01 on linear regression. Figure is available in color online only.

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    Standardized growth curves of skull base parameters. After normalization to the mean, scatterplot and linear regression analysis demonstrated that the slope of JT volume growth by age is significantly greater than the slopes of both HGC depth and OC area (*p < 0.05). Figure is available in color online only.

  • View in gallery

    Examples of posterior skull base bony structure growth with pediatric development. CT measurements of OC length and width (panel i), HGC depth (panel ii), JT length and thickness (panel iii), and JT width (panel iv) from representative patients from the 0–3 year (A) and 16–18 year (B) age groups. Whereas OC area and HGC depth demonstrate moderate increases with aging, JT size significantly increases with pediatric development. Brown arrows indicate the anterior intraoccipital synchondrosis running through the posterior aspect of the OC and the middle of the JT, noted in patients < 7 years old. Figure is available in color online only.

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    ELITE approach case example in a pediatric patient. A 6-year-old boy presented with a sixth cranial nerve palsy and was found to have a large clival chordoma exerting mass effect on the pons and upper cervical cord (A: axial T2-weighted MRI). He underwent an endoscopic transnasal/oral tumor resection requiring an odontoidectomy, C1 anterior arch resection, and posterior occipitocervical fusion. Follow-up MRI demonstrated residual tumor along the ventrolateral brainstem bilaterally that prevented proton therapy (B: axial T2-weighted MRI). He then underwent staged bilateral ELITE approaches for further tumor debulking. Based on preoperative CT posterior skull base measurements (C: OC [panel i], HGC depth [panel ii], JT [panels iii, iv]), standard drilling of the OCs was performed without the need for JT removal. Postoperative MRI demonstrated a small residual tumor (D: axial T2-weighted MRI) that was treated with proton therapy. Twenty months postoperatively the patient remains neurologically intact with stable imaging. Asterisks indicate tumor on MR images. Figure is available in color online only.

References

  • 1

    Alalade AFOgando-Rivas EBoatey JSouweidane MMAnand VKGreenfield JP: Suprasellar and recurrent pediatric craniopharyngiomas: expanding indications for the extended endoscopic transsphenoidal approach. J Neurosurg Pediatr 21:72802018

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2

    Avci EDagtekin AOzturk AHKara EOzturk NCUluc K: Anatomical variations of the foramen magnum, occipital condyle and jugular tubercle. Turk Neurosurg 21:1811902011

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3

    Brockmeyer DGruber DPHaller JShelton CWalker ML: Pediatric skull base surgery. 2. Experience and outcomes in 55 patients. Pediatr Neurosurg 38:9152003

  • 4

    Cavalheiro SYagmurlu Kda Costa MDNicácio JMRodrigues TPChaddad-Neto F: Surgical approaches for brainstem tumors in pediatric patients. Childs Nerv Syst 31:181518402015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5

    Day JDFukushima TGiannotta SL: Cranial base approaches to posterior circulation aneurysms. J Neurosurg 87:5445541997

  • 6

    Gump WC: Meningiomas of the pediatric skull base: a review. J Neurol Surg B Skull Base 76:66732015

  • 7

    Heros RC: Lateral suboccipital approach for vertebral and vertebrobasilar artery lesions. J Neurosurg 64:5595621986

  • 8

    Katsuta TRhoton AL JrMatsushima T: The jugular foramen: microsurgical anatomy and operative approaches. Neurosurgery 41:1492021997

  • 9

    Klimo P JrBrowd SRPravdenkova SCouldwell WTWalker MLAl-Mefty O: The posterior petrosal approach: technique and applications in pediatric neurosurgery. J Neurosurg Pediatr 4:3533622009

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    Lang DANeil-Dwyer GIannotti F: The suboccipital transcondylar approach to the clivus and cranio-cervical junction for ventrally placed pathology at and above the foramen magnum. Acta Neurochir (Wien) 125:1321371993

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11

    Lang J: Skull Base and Related Structures: Atlas of Clinical Anatomy. New York: Schattauer1995

  • 12

    Mintelis ASameshima TBulsara KRGray LFriedman AHFukushima T: Jugular tubercle: morphometric analysis and surgical significance. J Neurosurg 105:7537572006

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13

    Muthukumar NSwaminathan RVenkatesh GBhanumathy SP: A morphometric analysis of the foramen magnum region as it relates to the transcondylar approach. Acta Neurochir (Wien) 147:8898952005

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14

    Patel AJGressot LVCherian JDesai SKJea A: Far lateral paracondylar versus transcondylar approach in the pediatric age group: CT morphometric analysis. J Clin Neurosci 21:219422002014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 15

    Rennert RCHoshide RCalayag MKemp JGonda DDMeltzer HS: Extended middle fossa approach to lateralized pontine cavernomas in children. J Neurosurg Pediatr 21:3843882018

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16

    Rhoton AL Jr: The far-lateral approach and its transcondylar, supracondylar, and paracondylar extensions. Neurosurgery 47 (3 Suppl):S195S2092000

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17

    Scuderi AJHarnsberger HRBoyer RS: Pneumatization of the paranasal sinuses: normal features of importance to the accurate interpretation of CT scans and MR images. AJR Am J Roentgenol 160:110111041993

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18

    Sen CNSekhar LN: An extreme lateral approach to intradural lesions of the cervical spine and foramen magnum. Neurosurgery 27:1972041990

  • 19

    Spektor SAnderson GJMcMenomey SOHorgan MAKellogg JXDelashaw JB Jr: Quantitative description of the far-lateral transcondylar transtubercular approach to the foramen magnum and clivus. J Neurosurg 92:8248312000

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20

    Suslu HTGayretli OCoskun OBozbuga MSerifoglu LGurses IA: Anatomical and morphometrical evaluation of the jugular tubercle. Br J Neurosurg 28:5035062014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 21

    Tedeschi HRhoton AL Jr: Lateral approaches to the petroclival region. Surg Neurol 41:1802161994

  • 22

    Venkataramana NKAnantheswar YN: Pediatric anterior skull base tumors: our experience and review of literature. J Pediatr Neurosci 5:1112010

  • 23

    Wen HTRhoton AL JrKatsuta Tde Oliveira E: Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach. J Neurosurg 87:5555851997

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24

    Wu AZabramski JMJittapiromsak PWallace RCSpetzler RFPreul MC: Quantitative analysis of variants of the far-lateral approach: condylar fossa and transcondylar exposures. Neurosurgery 66 (6 Suppl Operative):1911982010

    • PubMed
    • Search Google Scholar
    • Export Citation

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