Herniation despite Decompressive Hemicraniectomy in Large Hemispherical Ischemic Strokes

Background Despite decompressive hemicraniectomy (DHC), progressive herniation resulting in death has been reported following middle cerebral artery (MCA) strokes. We aimed to determine the surgical parameters measured on brain computed tomography (CT) scan that are associated with progressive herniation despite DHC in large MCA strokes. Methods Retrospective chart review of medical records of patients with malignant hemispheric infarction who underwent DHC for cerebral edema was performed. Infarct volume was calculated on CT scans obtained within 24 hours of ictus. Radiological parameters of craniectomy bone flap size, brain volume protruding out of the skull, adequate centering of the craniectomy over the stroke bed, and the infarct volume outside the craniectomy bed (volume not centered [VNC]) were measured on the postoperative brain CT. Results Of 41 patients who underwent DHC, 7 had progressive herniation leading to death. Radiographic parameters significantly associated with progressive herniation included insufficient centering of craniectomy bed on the stroke bed ( P  = .03), VNC ( P  = .011), additional anterior cerebral artery infarction ( P  = .047), and smaller craniectomy length ( P  = .05). Multivariate logistic regression analysis for progressive herniation using craniectomy length and VNC as independent variables demonstrated that a higher VNC was significantly associated with progressive herniation despite surgery ( P  = .029). Conclusions In large MCA strokes, identification of large infarct volume outside the craniectomy bed was associated with progressive herniation despite surgery. These results will need to be verified in larger prospective studies.