ABC Surgical Risk Scale for skull base meningioma: a new scoring system for predicting the extent of tumor removal and neurological outcome

Clinical article

Restricted access

Object

Surgery for skull base meningiomas (SBMs) can lead to complications because these lesions are difficult to approach and can involve cranial nerves and arteries. The authors propose a scoring system to evaluate the relative risks and benefits of surgical treatment of SBMs.

Methods

The authors used a 2-step process to construct their scale. First, they derived significant predictive variables from retrospective data on 132 SBM cases treated surgically (primary surgeries only) between May 2000 and December 2005. Next, they validated the predictive accuracy of their scoring system in 60 consecutive cases treated surgically between January 1995 and April 2000, including both primary and repeated surgeries. Finally, they investigated the effect of the surgery on the patients' preoperative symptoms for consecutive cases treated surgically between January 1995 and December 2005, including both primary surgeries and retreatments.

Results

Five items that predicted surgical risk were identified: 1) tumor attachment size; 2) arterial involvement; 3) brainstem contact; 4) central cavity location; and 5) cranial nerve group involvement. The authors named their scoring system the ABC Surgical Risk Scale, after the initial letters of these items. Each factor was assigned a score of 0–2 points, and an additional point was added for previous surgical treatment or for radiation, giving a possible total score of 12 points. On average, the scoring system allocated 2 points for gross-total resections, 6.1 points for near-total resections, and 9 points for subtotal resections, with significant differences between groups. For cases scoring ≥ 8 points, the percentage of cases showing neurological deterioration postoperatively exceeded the percentage showing improvement.

Conclusions

The authors conclude that this scoring system can be used to predict the extent of tumor removal and that the scores reflect the surgical risk.

Abbreviations used in this paper: CN = cranial nerve; CS = cavernous sinus; GTR = gross-total resection; KPS = Karnofsky Performance Scale; NTR = near-total resection; SBM = skull base meningioma; STR = subtotal resection.

Article Information

Address correspondence to: Kazuhide Adachi, M.D., Ph.D., or Takeshi Kawase, M.D, Ph.D., Department of Neurosurgery, School of Medicine, Keio University, 35 Shinano-machi, Shinjyuku-ku, Tokyo 160-8582, Japan. email: kazu-adachi@rio.odn.ne.jp.

Please include this information when citing this paper: published online January 2, 2009; DOI: 10.3171/2007.11.17446.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Schematic depictions of the central cavity (left) and the CN groups (right) used for evaluation of tumor extension on preoperative neuroimages. Left: The central cavity is the space encircled by the dural entry of CN II–XII. Right: To simplify the scoring for CN involvement, the 4 CNs groups were defined as follows: Group 1 consists of only the optic nerve; Group 2, the oculomotor to abducent nerves; Group 3, the facial, cochlear, and vestibular nerves; and Group 4, the glossopharyngeal to hypoglossal nerves.

  • View in gallery

    The ABC Surgical Risk Scale. Attachment size refers to the greatest diameter on contrast-enhanced axial, sagittal, or coronal MR images. Brainstem contact is scored according to whether a CSF-filled space is visible between the tumor and brainstem on the T2-weighted MR image and whether perifocal edema is present when the CSF space has been lost. Tumor location relative to the central cavity (defined in Fig. 1) is a significant predictive variable. Cranial nerve involvement is scored by anatomical tumor extension along defined groups of CNs. (See text and Fig. 1 for details.)

  • View in gallery

    Graphs showing the relationship between the extent of tumor removal and the 5 items included in the ABC Surgical Risk Scale: attachment size (A), arterial involvement (B), brainstem contact (C), tumor location relative to the central cavity (D), and CN group involvement (E).

  • View in gallery

    Graphs showing the results of evaluation of the ABC Surgical Risk Scale. A: Significant positive correlations between the extent of tumor removal and the surgical risk score evaluated in 60 cases with our ABC Surgical Risk Scale (p < 0.0001). B: Significant correlation between the ABC surgical risk grades and the extent of tumor removal (p < 0.0001). C: Correlation of ABC surgical risk grades and tumor location. The most risky tumors were mainly located in the posterior fossa (p = 0.0002). D: Correlation of ABC surgical risk grades and neurological changes after operation. For higher grades, there were significant correlations with less improvement of the preoperative symptoms and increased clinical deterioration postoperatively (p < 0.0001).

  • View in gallery

    Illustrative Case 1. Example of scoring and grading using the ABC Surgical Risk Scale in a case of an anterior clinoid meningioma in a 59-year-old woman. A: Table showing details of scoring. B: Preoperative axial T2-weighted MR image. The white arrowheads in this image and in panel C indicate SBM involvement with the internal carotid artery tree. C and D: Postoperative T1-weighted Gd-enhanced coronal (C) and axial (D) MR images. The patient had no symptoms associated with the SBM. The tumor attachment size was 3.5 cm (1 point). There was SBM involvement with the internal carotid artery, anterior cerebral artery, and middle cerebral artery (2 points) (B and C). Cerebrospinal fluid space was visible between the brainstem and the SBM (0 points) (B). The SBM was partially within the central cavity (1 point) (B). There was no CN involvement (0 points), although a slight upward elevation of the optic nerve was visible (C). The patient's visual acuity and visual field were unaffected. No new symptoms emerged postoperatively. The tumor was dissected completely (Simpson Grade I, GTR) (D).

  • View in gallery

    Illustrative Case 2. Example of scoring and grading using the ABC Surgical Risk Scale in a case of a petroclival meningioma in a 38-year-old woman. A: Table showing details of scoring. B: Preoperative axial T2- weighted MR image. Doublefeathered arrow indicates perifocal edema. C–E: Preoperative axial (C and D) and sagittal (E) T1-weighted Gd-enhanced MR images. White arrowheads indicate SBM involvement with the basilar artery (C), anterior inferior cerebral artery (D), and vertebral artery (E). Wavy arrows indicate tumor invading the jugular foramen (C) and internal acoustic meatus (D). F: Postoperative axial T1-weighted Gd-enhanced MR image. White arrow indicates tumor area postsurgery. The patient complained of dysarthria, right facial paresthesia (V2–3 area), right-side deafness, and ataxic gait. The tumor attachment size was 5 cm (2 points). The SBM had involved the basilar artery (C), anterior inferior cerebral artery (D), and vertebral artery (E) (2 points). No CSF space was visible, and perifocal edema was present (2 points) (B). The SBM was mainly inside the central cavity (2 points) (B–D). There was involvement with CN Groups 2, 3, and 4 (2 points) (C–D). The tumor was subtotally removed by means of a 2-stage surgery that combined petrosal and suboccipital approaches (Simpson Grade IV, STR) (F). Postoperatively, right abducens nerve palsy and right facial nerve palsy (House-Brackmann Grade V) appeared. The residual tumor was treated by means of Gamma Knife surgery.

  • View in gallery

    Graph showing the association between the extent of tumor resection and the postoperative neurological changes in each ABC grade.

References

  • 1

    Chin LSSzerlip NJRegine WF: Stereotactic radiosurgery for meningiomas. Neurosurg Focus 14:5E62003

  • 2

    Cusimano MDSekhar LNSen CNPomonis SWright DCBiglan AW: The results of surgery for benign tumors of the cavernous sinus. Neurosurgery 37:1101995

    • Search Google Scholar
    • Export Citation
  • 3

    DeMonte FSmith HKal-Mefty O: Outcome of aggressive removal of cavernous sinus meningiomas. J Neurosurg 81:2452511994

  • 4

    Kawase TShiobara RToya S: Middle fossa transpetrosaltranstentorial approaches for petroclival meningiomas. Selective pyramid resection and radicality. Acta Neurochir (Wien) 129:1131201994

    • Search Google Scholar
    • Export Citation
  • 5

    Lanzino GHirsch WLPomonis SSen CNSekhar LN: Cavernous sinus tumors: neuroradiologic and neurosurgical considerations on 150 operated cases. J Neurosurg Sci 36:1831961992

    • Search Google Scholar
    • Export Citation
  • 6

    Lee JYNiranjan AMcInerney JKondziolka DFlickinger JCLunsford LD: Stereotactic radiosurgery providing longterm tumor control of cavernous sinus meningiomas. J Neurosurg 97:65722002

    • Search Google Scholar
    • Export Citation
  • 7

    Levine ZTBuchanan RISekhar LNRosen CLWright DC: Proposed grading system to predict the extent of resection and outcomes for cranial base meningiomas. Neurosurgery 45:2212301999

    • Search Google Scholar
    • Export Citation
  • 8

    Little KMFriedman AHSampson JHWanibuchi MFukushima T: Surgical management of petroclival meningiomas: defining resection goals based on risk of neurological morbidity and tumor recurrence rates in 137 patients. Neurosurgery 56:5465592005

    • Search Google Scholar
    • Export Citation
  • 9

    Maiuri FIaconetta Gde Divitiis OCirillo SDi Salle FDe Caro ML: Intracranial meningiomas: correlations between MR imaging and histology. Eur J Radiol 31:69751999

    • Search Google Scholar
    • Export Citation
  • 10

    Nicolato AForoni RAlessandrini FBricolo AGerosa M: Radiosurgical treatment of cavernous sinus meningiomas: experience with 122 treated patients. Neurosurgery 51:1153 11612002

    • Search Google Scholar
    • Export Citation
  • 11

    Park CKJung HWKim JEPaek SHKim DG: The selection of the optimal therapeutic strategy for petroclival meningiomas. Surg Neurol 66:1601662006

    • Search Google Scholar
    • Export Citation
  • 12

    Pistolesi SFontanini GCamacci TDe Ieso KBoldrini LLupi G: Meningioma-associated brain oedema: the role of angiogenic factors and pial blood supply. J Neurooncol 60:1591642002

    • Search Google Scholar
    • Export Citation
  • 13

    Saberi HMeybodi ATRezai AS: Levine-Sekhar grading system for prediction of the extent of resection of cranial base meningiomas revisited: study of 124 cases. Neurosurg Rev 29:1381442006

    • Search Google Scholar
    • Export Citation
  • 14

    Sekhar LNSwamy NKJaiswal VRubinstein EHirsch WE JrWright DC: Surgical excision of meningiomas involving the clivus: preoperative and intraoperative features as predictors of postoperative functional deterioration. J Neurosurg 81:8608681994

    • Search Google Scholar
    • Export Citation
  • 15

    Sen CHague K: Meningiomas involving the cavernous sinus: histological factors affecting the degree of resection. J Neurosurg 87:5355431997

    • Search Google Scholar
    • Export Citation
  • 16

    Shrivastava RKSen CCostantino PDDella Rocca R: Sphenoorbital meningiomas: surgical limitations and lessons learned in their long-term management. J Neurosurg 103:4914972005

    • Search Google Scholar
    • Export Citation
  • 17

    Simpson D: The recurrence of intracranial meningiomas after surgical treatment. J Neurol Neurosurg Psychiatry 20:22 391957

  • 18

    Spiegelmann RNissim OMenhel JAlezra DPfeffer MR: Linear accelerator radiosurgery for meningiomas in and around the cavernous sinus. Neurosurgery 51:137313802002

    • Search Google Scholar
    • Export Citation
  • 19

    Suzuki YSugimoto TShibuya MSugita KPatel SJ: Meningiomas: correlation between MRI characteristics and operative findings including consistency. Acta Neurochir (Wien) 129:39461994

    • Search Google Scholar
    • Export Citation
  • 20

    Yamaguchi NKawase TSagoh MOhira TShiga HToya S: Prediction of consistency of meningiomas with preoperative magnetic resonance imaging. Surg Neurol 48:5795831997

    • Search Google Scholar
    • Export Citation

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 139 138 5
Full Text Views 153 107 2
PDF Downloads 95 78 2
EPUB Downloads 0 0 0

PubMed

Google Scholar