Matrix metalloproteinase-9 concentration in the cerebral extracellular fluid of patients during the acute phase of aneurysmal subarachnoid hemorrhage

AbstractObjectives: The pathogenesis of delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH) is multi-factorial and not completely elucidated. Matrix metalloproteinase-9 (MMP-9) might participate in wall remodeling leading to luminal narrowing. The authors investigated MMP-9 concentration in brain extracellular fluid of aSAH patients and assessed whether this enzyme could have a predictive value for the risk of DCI.Methods: Patients were classified according to the grading of the World Federation of Neurological Surgeons (WFNS) in low- and high-grade patients (WFNS = 1–3, n = 9 and WFNS = 4–5, n = 12, respectively). Cerebral microdialysis probes were placed in brain parenchyma of the respective vascular territory of the aneurysm in 21 consecutive aSAH patients, enrolled in a prospective study on inflammation. Microdialysis samples, collected daily from day 0 until day 8 after aSAH, were retrospectively analyzed for MMP-9 by zymography.Results: Initial concentration of the MMP-9 pro...