Surgical resection of intrinsic insular tumors: complication avoidance

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Object. Surgical resection of tumors located in the insular region is challenging for neurosurgeons, and few have published their surgical results. The authors report their experience with intrinsic tumors of the insula, with an emphasis on an objective determination of the extent of resection and neurological complications and on an analysis of the anatomical characteristics that can lead to suboptimal outcomes.

Methods. Twenty-two patients who underwent surgical resection of intrinsic insular tumors were retrospectively identified. Eight tumors (36%) were purely insular, eight (36%) extended into the temporal pole, and six (27%) extended into the frontal operculum. A transsylvian surgical approach, combined with a frontal opercular resection or temporal lobectomy when necessary, was used in all cases. Five of 13 patients with tumors located in the dominant hemisphere underwent craniotomies while awake. The extent of tumor resection was determined using volumetric analyses. In 10 patients, more than 90% of the tumor was resected; in six patients, 75 to 90% was resected; and in six patients, less than 75% was resected. No patient died within 30 days after surgery. During the immediate postoperative period, the neurological conditions of 14 patients (64%) either improved or were unchanged, and in eight patients (36%) they worsened. Deficits included either motor or speech dysfunction. At the 3-month follow-up examination, only two patients (9%) displayed permanent deficits. Speech and motor dysfunction appeared to result most often from excessive opercular retraction and manipulation of the middle cerebral artery (MCA), interruption of the lateral lenticulostriate arteries (LLAs), interruption of the long perforating vessels of the second segment of the MCA (M2), or violation of the corona radiata at the superior aspect of the tumor. Specific methods used to avoid complications included widely splitting the sylvian fissure and identifying the bases of the periinsular sulci to define the superior and inferior resection planes, identifying early the most lateral LLA to define the medial resection plane, dissecting the MCA before tumor resection, removing the tumor subpially with preservation of all large perforating arteries arising from posterior M2 branches, and performing craniotomy with brain stimulation while the patient was awake.

Conclusions. A good understanding of the surgical anatomy and an awareness of potential pitfalls can help reduce neurological complications and maximize surgical resection of insular tumors.

Article Information

Address reprint requests to: Frederick F. Lang, M.D., Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, Box 442, 1515 Holcombe Boulevard, Houston, Texas. email: flang@mdanderson.org.

© AANS, except where prohibited by US copyright law.

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Figures

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    Case 15. Preoperative (upper) and postoperative (lower) fluid-attenuated inversion recovery MR images demonstrating a well-demarcated, purely insular tumor in the dominant hemisphere. Upper: The sharp distinction between the expanded insula and the basal ganglia is evident. Also evident are flow voids on the medial aspect of the tumor that represent distal branches of the LLAs, which may be parasitized by the tumor (arrow). Lower: Postoperative images showing minimal residual tumor (92% resection). A transsylvian approach was used with awake craniotomy.

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    Case 8. Preoperative (upper) and postoperative (lower) axial T1-weighted MR images. The medial LLAs are evident (arrow), as are the MCA vessels surrounded by tumor on the surface (arrowhead). A 75% resection was achieved. The patient experienced postoperative hemiparesis and dysphasia, which resolved within 1 month after surgery.

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    Case 7. Axial (left) and coronal (right) T1-weighted MR images obtained before (upper) and after (lower) transsylvian resection of a purely insular tumor. A 99% resection was achieved.

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    Case 18. Preoperative (upper) and postoperative (lower) T1-weighted MR images. Resection was stopped because the patient exhibited speech dysfunction as the posterior aspect of the tumor was approached. Nevertheless, 75% of the tumor was resected.

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    Topography of an insular tumor and the anatomical basis for neurological dysfunction. The artist's depiction of an insular tumor and the surrounding structures is supplemented by six photographs of the normal topography and vasculature of the insular region, as viewed during a transsylvian approach in six latex-injected cadaveric hemispheres (obtained from the Department of Anatomy, Saint Louis University, St. Louis, MO). A: Splitting the sylvian fissure reveals the insular apex (asterisk) and anterior and posterior insular gyri.

    From this vantage point, the normal insula looks like an asymmetrical pyramid with a long axis directed posteriorly. In a tumorfilled insula, these gyri are typically distorted and expanded. Even in the normal anatomy, significant retraction is required to reach the periinsular sulci (note retractor blade). B: The large (2–3 mm) M2 branches pass over the insula on their way to becoming M3 branches and supplying the cortex (arrowhead). The branching pattern of these vessels was unique in each of our cadavers, although an anterior group of vessels typically passed over the insular apex to supply the anterior insula, and an inferior segment supplied the posterior insula. These vessels are often encased in tumor. Also shown are medium-sized vessels that branched from the parent M2 vessels and appeared to be end arteries (arrow). C: Multiple small (< 1 mm) vessels, which arise from the undersurface of the M2 branches (short M2 perforating arteries), are exposed by the spatula and are the primary blood supply to insular tumors. These vessels are best approached subpially. D: The LLAs can be identified by dissecting along the anterior aspect of the insula, starting from the limen of the insula and following the M1 branch. The first LLA usually appeared 1 cm from the insular surface in the cadaver (revealed by the spatula), but can be distorted in the presence of a tumor. E: Dissection of the LLAs along their course showed that they typically have multiple small branches arising from them and that they travel in a plane perpendicular to the M1 segment deep in relation to the insula. F: Dissection deep with respect to the superior periinsular sulcus leads to the corona radiata (top arrow). Laying deep in relation to the midportion of the insula is the basal ganglia (middle arrow). The inferior periinsular sulcus leads to the uncinate fasciculus (bottom arrow); thus, the corona radiata is at risk during dissection of the superior margin of an insular tumor. G: Also shown in the artist's drawing are the long perforating arteries arising from the M2 segment. Disruption of this vessel can lead to hemiparesis because it supplies the corona radiata.

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    An artist's depiction of the method of surgical resection. A: Initial splitting of the sylvian fissure allows identification of the apex of the insula and the posterior extent of the tumor. The MCA vessels are often seen but may be encased by tumor. B: The superior and inferior periinsular sulci are dissected to their bases to define the superior and inferior aspects of the tumor. C: The MCA is dissected proximally until the first LLA is identified. This defines the deep plane of the tumor and protects the LLA from injury. The MCA is dissected in a proximal to distal direction. D: Once the three planes of the tumor are defined, the tumor is resected in a subpial fashion with preservation of M2 vessels and coagulation of small M2 branches.

References

  • 1.

    Augustine JR: The insular lobe in primates including humans. Neurol Res 7:2101985Augustine JR: The insular lobe in primates including humans. Neurol Res 7:2–10 1985

    • Search Google Scholar
    • Export Citation
  • 2.

    Duffau HCapelle LLopes Met al: The insular lobe: physiopathological and surgical considerations. Neurosurgery 47:8018112000Duffau H Capelle L Lopes M et al: The insular lobe: physiopathological and surgical considerations. Neurosurgery 47:801–811 2000

    • Search Google Scholar
    • Export Citation
  • 3.

    Ebeling UKothbauer K: Circumscribed low grade astrocytomas in the dominant opercular and insular region: a pilot study. Acta Neurochir 132:66741995Ebeling U Kothbauer K: Circumscribed low grade astrocytomas in the dominant opercular and insular region: a pilot study. Acta Neurochir 132:66–74 1995

    • Search Google Scholar
    • Export Citation
  • 4.

    Gibo HCarver CCRhoton AL Jret al: Microsurgical anatomy of the middle cerebral artery. J Neurosurg 54:1511691981Gibo H Carver CC Rhoton AL Jr et al: Microsurgical anatomy of the middle cerebral artery. J Neurosurg 54:151–169 1981

    • Search Google Scholar
    • Export Citation
  • 5.

    Hatashita SSakakibara TIshii S: Lipoma of the insula. Case report. J Neurosurg 58:3003021983Hatashita S Sakakibara T Ishii S: Lipoma of the insula. Case report. J Neurosurg 58:300–302 1983

    • Search Google Scholar
    • Export Citation
  • 6.

    Heffez DS: Stereotactic transsylvian, transinsular approach for deep-seated lesions. Surg Neurol 48:1131241997Heffez DS: Stereotactic transsylvian transinsular approach for deep-seated lesions. Surg Neurol 48:113–124 1997

    • Search Google Scholar
    • Export Citation
  • 7.

    Kumabe TNakasato NSuzuki Ket al: Two—staged resection of a left frontal astrocytoma involving the operculum and insula using intraoperative neurophysiological monitoring—case report. Neurol Med Chir 38:5035071998Kumabe T Nakasato N Suzuki K et al: Two—staged resection of a left frontal astrocytoma involving the operculum and insula using intraoperative neurophysiological monitoring—case report. Neurol Med Chir 38:503–507 1998

    • Search Google Scholar
    • Export Citation
  • 8.

    Lacroix MAbi-Said DFourney DRet al: A multivariate analysis of 416 patients with glioblastoma multiforme: prognosis, extent of resection, and survival. J Neurosurg 95:1901982001Lacroix M Abi-Said D Fourney DR et al: A multivariate analysis of 416 patients with glioblastoma multiforme: prognosis extent of resection and survival. J Neurosurg 95:190–198 2001

    • Search Google Scholar
    • Export Citation
  • 9.

    Mesulam MMMufson EJ: The insula of Reil in man and monkey. Architectonics, connectivity, and function in Peters AJones EG (eds): Cerebral Cortex. New York: Plenum Press1985 Vol 4 pp 179226Mesulam MM Mufson EJ: The insula of Reil in man and monkey. Architectonics connectivity and function in Peters A Jones EG (eds): Cerebral Cortex. New York: Plenum Press 1985 Vol 4 pp 179–226

    • Search Google Scholar
    • Export Citation
  • 10.

    Morantz RA: Radiation therapy in the treatment of cerebral astrocytoma. Neurosurgery 20:9759821987Morantz RA: Radiation therapy in the treatment of cerebral astrocytoma. Neurosurgery 20:975–982 1987

    • Search Google Scholar
    • Export Citation
  • 11.

    Ojemann GAWhitaker HA: Language localization and variability. Brain Lang 6:2392601978Ojemann GA Whitaker HA: Language localization and variability. Brain Lang 6:239–260 1978

    • Search Google Scholar
    • Export Citation
  • 12.

    Penfield WFaulk ME Jr: The insula. Further observations on its function. Brain 78:4454701955Penfield W Faulk ME Jr: The insula. Further observations on its function. Brain 78:445–470 1955

    • Search Google Scholar
    • Export Citation
  • 13.

    Penfield WFlanigin H: Surgical therapy of temporal lobe seizures. Arch Neurol Psychiatry 64:4915001950Penfield W Flanigin H: Surgical therapy of temporal lobe seizures. Arch Neurol Psychiatry 64:491–500 1950

    • Search Google Scholar
    • Export Citation
  • 14.

    Pia HW: Microsurgery of gliomas. Acta Neurochir 80:1111986Pia HW: Microsurgery of gliomas. Acta Neurochir 80:1–11 1986

  • 15.

    Roper SNLevesque MFSutherling WWet al: Surgical treatment of partial epilepsy arising from the insular cortex. Report of two cases. J Neurosurg 79:2662691993Roper SN Levesque MF Sutherling WW et al: Surgical treatment of partial epilepsy arising from the insular cortex. Report of two cases. J Neurosurg 79:266–269 1993

    • Search Google Scholar
    • Export Citation
  • 16.

    Schatz CRKreth FWFaist Met al: Interstitial 125-iodine radiosurgery of low-grade gliomas of the insula of Reil. Acta Neurochir 130:80891994Schatz CR Kreth FW Faist M et al: Interstitial 125-iodine radiosurgery of low-grade gliomas of the insula of Reil. Acta Neurochir 130:80–89 1994

    • Search Google Scholar
    • Export Citation
  • 17.

    Shi WMWildrick DMSawaya R: Volumetric measurement of brain tumors from MR imaging. J Neurooncol 37:87931998Shi WM Wildrick DM Sawaya R: Volumetric measurement of brain tumors from MR imaging. J Neurooncol 37:87–93 1998

    • Search Google Scholar
    • Export Citation
  • 18.

    Silfvenius HGloor PRassmussen T: Evaluation of insular ablation in surgical treatment of temporal lobe epilepsy. Epilepsia 5:3073201964Silfvenius H Gloor P Rassmussen T: Evaluation of insular ablation in surgical treatment of temporal lobe epilepsy. Epilepsia 5:307–320 1964

    • Search Google Scholar
    • Export Citation
  • 19.

    Soffietti RChio AGiordana MTet al: Prognostic factors in well-differentiated cerebral astrocytomas in the adult. Neurosurgery 24:6866921989Soffietti R Chio A Giordana MT et al: Prognostic factors in well-differentiated cerebral astrocytomas in the adult. Neurosurgery 24:686–692 1989

    • Search Google Scholar
    • Export Citation
  • 20.

    Ture UYaşargil DCAl-Mefty Oet al: Topographic anatomy of the insular region. J Neurosurg 90:7207331999Ture U Yaşargil DC Al-Mefty O et al: Topographic anatomy of the insular region. J Neurosurg 90:720–733 1999

    • Search Google Scholar
    • Export Citation
  • 21.

    Ture UYaşargil MGAl-Mefty Oet al: Arteries of the insula. J Neurosurg 92:6766872000Ture U Yaşargil MG Al-Mefty O et al: Arteries of the insula. J Neurosurg 92:676–687 2000

    • Search Google Scholar
    • Export Citation
  • 22.

    Vanaclocha VSaiz-Sapena NGarcia-Casasola C: Surgical treatment of insular gliomas. Acta Neurochir 139:112611351997Vanaclocha V Saiz-Sapena N Garcia-Casasola C: Surgical treatment of insular gliomas. Acta Neurochir 139:1126–1135 1997

    • Search Google Scholar
    • Export Citation
  • 23.

    Varnavas GGGrand W: The insular cortex: morphological and vascular anatomic characteristics. Neurosurgery 44:1271381999Varnavas GG Grand W: The insular cortex: morphological and vascular anatomic characteristics. Neurosurgery 44:127–138 1999

    • Search Google Scholar
    • Export Citation
  • 24.

    Wolf BSHuang YP: The insula and deep middle cerebral venous drainage system: normal anatomy and angiography. AJR 90:4724891963Wolf BS Huang YP: The insula and deep middle cerebral venous drainage system: normal anatomy and angiography. AJR 90:472–489 1963

    • Search Google Scholar
    • Export Citation
  • 25.

    Yaşargil MG: Microneurosurgery. New York: Thieme Medical1996 Vol 4Yaşargil MG:Microneurosurgery. New York: Thieme Medical 1996 Vol 4

    • Search Google Scholar
    • Export Citation
  • 26.

    Yaşargil MGvon Ammon KCavazos Eet al: Tumours of the limbic and paralimbic systems. Acta Neurochir 118:40521992Yaşargil MG von Ammon K Cavazos E et al: Tumours of the limbic and paralimbic systems. Acta Neurochir 118:40–52 1992

    • Search Google Scholar
    • Export Citation
  • 27.

    Zentner JMeyer BStangl Aet al: Intrinsic tumors of the insula: a prospective surgical study of 30 patients. J Neurosurg 85:2632711996Zentner J Meyer B Stangl A et al: Intrinsic tumors of the insula: a prospective surgical study of 30 patients. J Neurosurg 85:263–271 1996

    • Search Google Scholar
    • Export Citation

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