title: Resection of insular gliomas: the importance of lenticulostriate artery position.
abstract: OBJECTIVE
  The object of this study was to identify characteristic preoperative angiographic and MR imaging features of safely resectable insular gliomas and describe the surgical techniques and postoperative clinical outcomes.
  
  
  METHODS
  Thirty-eight patients with insular gliomas underwent transsylvian resection between 1995 and 2007. Patient demographics, presenting symptoms, pathological findings, and neurological outcomes were retrospectively reviewed. Preoperative MR imaging-defined tumor volumes were superimposed onto the preoperative stereotactic cerebral angiograms to determine whether the insular tumor was confined lateral to (Group I) or extended medially around (Group II) the lenticulostriate arteries (LSAs).
  
  
  RESULTS
  Twenty-five patients (66%) had tumors situated lateral to the LSAs and 13 (34%) had tumors encasing the LSAs. Insular gliomas situated lateral to the LSAs led to significant medial displacement of these vessels (161 +/- 39%). In 20 (80%) of these 25 cases the boundaries between tumor and brain parenchyma were well demarcated on preoperative T2-weighted MR images. In contrast, there was less displacement of the LSAs (130 +/- 14%) in patients with insular gliomas extending around the LSAs on angiography. In 11 (85%) of these 13 cases, the tumor boundaries were diffuse on T2-weighted MR images. Postoperative hemiparesis or worsening of a preexisting hemiparesis, secondary to LSA compromise, occurred in 5 patients, all of whom had tumor volumes that extended medial to the LSAs. Gross-total or near-total resection was achieved more frequently in cases in which the insular glioma remained lateral to the LSAs (84 vs 54%).
  
  
  CONCLUSIONS
  Insular gliomas with an MR imaging-defined tumor volume located lateral to the LSAs on stereotactic angiography displace the LSAs medially by expanding the insula, have well-demarcated tumor boundaries on MR images, and can be completely resected with minimal neurological morbidity. In contrast, insular tumors that appear to surround the LSAs do not displace these vessels medially, are poorly demarcated from normal brain parenchyma on MR images, and are associated with higher rates of neurological morbidity if aggressive resection is pursued. Preoperative identification of these anatomical growth patterns can be of value in planning resection.
authors.affiliation: Department of Neurosurgery, New York University School of Medicine, New York, New York 10016, USA.
authors.forename: Yaron A
authors.initials: YA
authors.lastname: Moshel
authors.forename: Joshua D S
authors.initials: JD
authors.lastname: Marcus
authors.forename: Erik C
authors.initials: EC
authors.lastname: Parker
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Kelly
mesh_terms: D000293:Adolescent; D000328:Adult; D001479:Basal Ganglia / Q000473:pathology; D001932:Brain Neoplasms / Q000601:surgery*; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D002540:Cerebral Cortex / Q000601:surgery; D005260:Female; D005910:Glioma / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D010291:Paresis / Q000209:etiology / Q000517:prevention & control; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D055815:Young Adult