Introduction: The relevance of cerebral venous system is often underestimated during neurosurgical procedures. Damage to this draining system could lead to catastrophic implications for the patient. Surgical decision making and planning must consider each components of the venous compartment, from the medullary draining vein to the dural sinuses and extra-cranial veins. Intra-operative ultrasound (ioUS) permits the real-time study of venous compartments, with different modalities, thus obtaining a complete characterization of its anatomical and functional features. B-mode offers a high-resolution anatomical representation of veins and their relationships with lesions. Doppler modalities (color-, power-, spectral-) allow the study of blood flow and to identify vessels characterizing their functional characteristics. Contrast-enhanced ultrasound allows to perform a real-time angiosonography showing both functional and anatomical aspects of vessels.
Methods: we review different clinical scenarios, demonstrating how the combination of different US modalities has the potential to detect all those dynamic changes that take place within the venous system during cranial surgery and also discuss the importance of the assessment of the extra-cranial venous system and its impact on cerebral venous drainage
Results: ioUS permits a real-time, dynamic intra-operative characterization of the venous compartment, not limited to the anatomical representation with B-mode, but through multiple modalities allows to evaluate blood flow, tissue and tumor perfusion, changes in venous districts and extra-cranial outflow.
Conclusions: Multi-modal ioUS is a great adjunct, alone or used in a synergistic manner with other imaging modalities, to the surgical armamentarium.
Patient Care: Intra-operative ultrasound can provide real-time useful information in planning management of vessels, notably venous structures: it is a rapid tomographic modality, not requiring any changes in patient positioning or of intra-operative setting, offering at the same time a significant spatial and temporal resolution
Learning Objectives: The purpose of this work is to further familiarize readers with US application other than B-mode, such as Doppler modalities, CEUS and fusion imaging, particularly their specific strength for vessels visualization, in neurosurgical procedures.