Duke Engineers Test Catheter Prototype for Brain Tumors

Delivering chemotherapy to brain tumors is particularly challenging because of the blood-brain barrier (BBB), the collection of tight junctions between endothelial cells in cerebral blood vessels. When intact, these protective junctions prevent the passage of a number of substances—including chemotherapeutic molecules—from the systemic circulation into the brain tumor bed. The key to effective, targeted therapy of brain tumors is to 1) selectively disrupt the BBB to allow the entry of cancer-killing drugs and then 2) reestablish the BBB so that chemotherapeutic agents are retained within the tumor bed.

Biomed engineers at Duke have constructed a prototype of an intravascular catheter, which can deliver BBB-busting hyperthermia* and provide real-time 3D imaging of brain tumors. The thin, flexible catheter is intended to be snaked through the internal jugular vein (which obviates the need for invasive cranial surgery) and manipulated into the dural venous sinuses. The investigators' proof-of-concept experiments, performed in dogs, was published in this month's issue of Ultrasonic Imaging.

The investigators concluded that their next-generation device must be smaller and more flexible than the prototype, to negotiate the curves of the cerebral vasculature. The long-term plan for the catheter is to obtain fluoroscopic-guided access to brain tumors through the venous sinuses, administer BBB-disrupting heat, which would then trigger the release of chemotherapeutic agents to the tumor bed.

* A temperature rise of approximately 5 degrees C.

Depiction of dural sinus system from Gray's Anatomy.