Infarction after surgery of chiasmatic gliomas B. Bison 1, M. Warmuth-Metz 1, M. Hupp 1, F. Falkenstein 3, C. Mirow 3, J. Krauß 2, AK Gnekow 3 Referencecenter for Neuroradiology for the HIT-Studies Department for Neuroradiology (1) and Department for Neurosurgery (2) University Hospital, Würzburg, Germany SIOP-LGG study center Children‘s Hospital Augsburg, Germany (3)

HIT-Studies (Society of Ped. Hematology and Oncology) HIT‘ patients HIT/SIOP-LGG1379 patients HIT/SIOP-HGG – 328 outside Pons – 273 pontine gliomas HIT Kranio 244 patients HIT REZ 108 patients SIOP CPT 68 patients SIOP ATRT 85 patients SIOP Germinom 61 patients

Backgroud Currently in the SIOP-LGG-study chiasmatic gliomas are identified on basis of their charcteristic neuroradiological appearance and can be treated without histological verification. Actually surgery is recommended when the tumor do not has the typical appearance or when it is symptomatic with hydrocephalus due to obliteration of the foramina of Monroi

Background complete resection is difficult to achieve because of the infiltrating nature of chiasmatic gliomas. Partial resections did not show a better prognosis in the LGG- study. As some tumors, especially in very young children, do not respond well to treatment there is the search for histopathological and immunhistochemical markers in future studies.

Background After surgery of chiasmatic LGGs the number of infarctions in the territory of the middle and anterior cerebral artery, seen during the standard staging, seemed to be high. When future studies require the excision of tumor material, surgery will be done more frequently, and the risk factors of surgery are of increasing importance. To compare infarctions after surgery of chiasmatic gliomas we chose patients after surgery for LGGs of the cerebellum.

Patients 88 patients after stereotactic or open biopsy, partial or total resection of chiasmatic gliomas Controls: out of 238 patients after surgery of cerebellar LGGs we chose by chance the first 51 patients of the alphabet and did the evaluation

Surgical technique - chiasm 102 surgeries in 88 patients 18 stereotactic biopsies 11 open biopsies 3 endoscopic biopsies 68 partial resections 2 complete resections time of surgery: Patients‘ ages at surgery: 4 months to 17 years (median: 5 years)

Surgical technique - cerebellum 65 surgeries in 51 patients 2 biopsies 22 partial resections 41 complete resections Time of surgery: patients‘ ages at surgery: 4 months to 16 years (median 7 years)

Time of surgery Time of surgery of chiasmal LGGs Unklar Year of sugery Number of surgeries Time of surgery cerebellar LGGs year of surgery Number of surgeries

Chiasm/ Cerebellum 16 infarcts (16%) – 8 ant. cerebral artery – 8 med. cerebral artery 1 infarct (2.5%) - 1 PICA

MCA infarction

ACA infarction Preop FLAIR 9d FLAIR 9d DWI 3 m FLAIR

Chiasm all infarcts occured after resections and none after biopsies 16 infarcts following 70 resections (23%) ACA infarcts after subfrontal access MCA infarcts after pterional access except one patient after chemotherapy no previous treatment age at the time of surgery: 5 months to 12 years (median: 1 y 9 m)

Chiasm 14 infarcts were clinically symptomatic or had complications of the operation 9 hypothalamic- pituitary-dysfunction 1 memory-deficit 1 aphasia 4 seizures 4 CSF-leakage 3 hygroma 1 meningitis 1 shunt-insufficiency

Chiasm no non-LGG-histology 13 pilozytic astrocytomas -10 pilocytic astrocytoma I° - 3 pilocytic astrocytoma II° 3 pilomyxoid astrocytoma II°

Cerebellum 1 infarct (PICA) following 66 surgeries (1.5%) infarct after complete resection (2007) relative to the number of resections (n=41) the incidence is 2.4% patient‘s age at the time of surgery: 10 years

Conclusion I biopsies in chiasmatic tumors were much safer than resections resections of chiasmatic gliomas bear a much higher risk of infarction compared to cerebellar glioma resections; possibly it is due to the central localization of the tumor young children are more prone to infarctions than older children

Conclusion II if histology is needed for exact classification and evaluation of prognostic factors a biopsy should be performed histology is not always the typical pilocytic astrocytoma I° knowledge of the differential diagnostic characteristics and the reliable diagnosis of suprasellar tumors in young children is important

Thank you The Reference Center for Neuroradiology for the HIT-studies and the HIT LGG-study are supported by: