Artikel
Changes in leptomeningeal collateralization after standard extra-intracranial arterial bypass surgery in steno-occlusive cerebrovascuar disease
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Veröffentlicht: | 28. April 2011 |
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Gliederung
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Objective: To prospectively investigate the effects of extracranial-intracranial (EC/IC) arterial bypass surgery on leptomeningeal collateralization patterns in patients with steno-occlusive cerebrovascular disease and hemodyamic compromise as an indicator for functional and vascular plasticity.
Methods: Twenty consecutive patients (female/male 17/3, age: 3–57) undergoing standard EC/IC bypass surgery were included into this study. All patients underwent 6-vessel-DSA before and after bypass surgery. We examined each projection of integrated DSA images before surgery and 6 months (± 1 month) after surgery. Angiographic procedures were standardized in order to allow for comparison of the vascular territories (VT). Color-coding of VT was performed by defining anterior (ACA and MCA) and posterior circulation. Fractions of respective VT were obtained by pixel counting and relating pixels of the respective territory to the total number of pixels in the image. By this semi-quantitative approach the size of the VT was established and the changes in VT size and distribution were assessed in comparison with the adjacent VT, prior to and after surgery.
Results: We found significant shifts of VT in 18 patients (90%) over time, of which 17 (85%) showed an increase of the anterior VT, that was accompanied by a significant (p < 0.05) decrease of posterior VT size in 13 patients (65%). Thus, extended vascularization by posterior VT prior to surgery due to natural collateralization on the symptomatic hemisphere was reduced significantly after surgery and substituted by bypass flow. We found a positive correlation between VT augmentation by the bypass and the clinical outcome (p < 0.05).
Conclusions: Flow augmentation induced by standard EC/IC bypass surgery in the related VT potentially induces the restoration of physiological leptomeningeal collateralization patterns and might therefore exhibit positive effects on remote vascular territories as well as on direct bypass-benefitting territories.