Innovative Ultrasound Technique Enables Real-Time Brain Blood Flow Monitoring During Surgery

Neurosurgeons at UMC Utrecht have achieved a significant breakthrough with the development of a novel ultrasound method that allows them to observe brain blood flow live during surgical procedures. Collaborating with researchers from Eindhoven University of Technology, they introduced a technique that can detect early signs of stroke risk during operations, potentially preventing severe complications. This advancement employs Ultrafast Power Doppler Imaging (UPDI), a specialized ultrasound technology that visualizes microvascular blood flow, measures cerebral perfusion, and provides real-time feedback.

The innovative approach is particularly impactful during surgeries involving brain vessels, such as aneurysm repairs or bypass surgeries, where temporary interruption of blood flow can lead to strokes. Currently, the risk of stroke during aneurysm procedures ranges from approximately 8% in simpler cases to nearly 50% in more complex surgeries. In brain tumor surgeries like gliomas, the risk varies between 12.5% and 44%. Until now, surgeons lacked a direct method to monitor ongoing blood flow, relying instead on post-operative imaging, which often delayed critical interventions.

The UPDI technique allows surgeons to continuously monitor cerebral blood flow during procedures, providing immediate insights into tissue perfusion. In a pilot study involving 10 patients, researchers used this ultrasound method to measure blood flow changes during surgery. They observed real-time variations in blood supply to brain tissue, such as reductions or transient increases following vessel clamping. These findings, published in Scientific Reports, demonstrate the potential for enhanced intraoperative decision-making.

"With this technology, effects that previously could only be identified post-surgery through MRI scans can now be detected instantly, enabling timely corrective actions," explains lead neurosurgeon Dara Niknejad.

Beyond neurosurgery, the technique holds promise for other types of operations where continuous tissue perfusion is critical, including organ transplants like kidneys. Massimo Mischi of Eindhoven University highlights that the technology relies on high-frequency ultrasound signals from multiple angles, processed to produce high-resolution images of cerebral perfusion. This allows early detection of reduced blood flow, assisting surgeons in preventing adverse outcomes like cerebral infarctions.

The development team aims to further refine this technique, which could lead to fewer complications and safer surgeries. In future studies, they plan to assess how well the ultrasound monitoring predicts stroke occurrence and how to better integrate it into surgical protocols. Ultimately, the goal is to enhance surgical safety and improve patient outcomes through real-time, precise blood flow monitoring.