Hammock Middle Cerebral Artery and Delayed Infarction in Lenticulostriate Artery After Staged Resection of Giant Insular Glioma.

BACKGROUND: Delayed infarction in the lenticulostriate artery (LSA) area after insular glioma resection is not common, and its pathophysiology remains unknown.

CASE DESCRIPTION: A 32-year-old right-handed man with a giant insular low-grade glioma with frontal and temporal extension underwent awake craniotomy with an intentional staged surgery strategy. Preoperative radiologic images demonstrated a diagonally elevated middle cerebral artery (MCA) by the temporal tumor and a significantly compressed striatum. With intraoperative subcortical direct electrical stimulation, the resection was finalized in the temporal part of the tumor due to the semantic paraphasia induced in the temporal stem, fatigue, and loss of concentration. The immediate postoperative clinical course was uneventful. However, on postoperative day 20, he suddenly experienced right hemiparesis. Repeated images revealed infarction in the LSA area. The previously compressed striatum was then relieved and relocated to its original position in just 20 days, and the M1 segment of the MCA was remarkably downward, in which the MCA resembled a hammock. Angiography confirmed the hammock-shaped MCA and significantly stretched LSA, suggesting the combination of freed striatum from the compression and loss of temporal structure by the tumor resection as the key mechanism of severe dislocation of the MCA and delayed ischemia.

CONCLUSIONS: In a staged resection of giant insular glioma, attention should be paid to a possible severe dislocation of the MCA in a delayed postoperative period, which may lead to LSA stretching and delayed infarction.