CoAxia, Inc. of Maple Grove, MN, is a firm developing an aortic device designed to restrict blood flow in the descending aorta, in the hope of diverting blood flow from the lower extremities to the brain via the cerebral collaterals, in patients with acute ongoing stroke. According to the latest reports from the company, “CoAxia’s ongoing SENTIS clinical trial has now passed 125 patients with participation from over 50 major stroke centers in North America and Europe. Analysis of interim safety data suggests that treatment with CoAxia’s NeuroFlo(TM) catheter is well tolerated with a very low rate of the complications normally associated with stroke patients. In addition, the FDA has recently approved an expansion in the scope of the trial to now treat patients up to 14 hours after symptom onset.”
Here’s what we know about the company’s NeuroFlo catheter:
The CoAxia technology is a potential alternative or complement to these clot-focused techniques. The brain has an extensive, interconnected collateral vascular network. Already somewhat active following an ischemic stroke, collateral pathways are capable of further increasing the delivery of oxygenated blood to the stroke’s ischemic penumbra. The ability to salvage that penumbra and minimize the eventual size of the infarct may lead to improved neurological recovery.
CoAxia has developed the NeuroFlo™ catheter as a device for augmenting the blood flow to the brain, and in particular to increase blood flow in the collateral blood vessels to augment perfusion in the ischemic penumbra. NeuroFlo partially restricts blood flow in the descending aorta, diverting blood flow from the lower extremities to the cerebral collaterals. The NeuroFlo catheter itself is a unique, dual-balloon endovascular device. It is inserted through the femoral (leg) artery into the descending aorta and has independently inflatable balloons located immediately above and below the renal (kidney) arteries. The balloons are sequentially inflated to produce occlusions of approximately 70%. The balloons are left inflated for 45 minutes and are then removed and treatment is complete.
This concept was first tested through animal experimentation which demonstrated that partial aortic occlusion could be accomplished without significant side effects, cerebral perfusion could be rapidly and significantly increased, and the size of a resulting infarct could be reduced. In April 2002, the first clinical studies began in humans to demonstrate the safety of the procedure. The images shown on this page (click to enlarge) are taken with a variety of techniques from patients treated with the NeuroFlo catheter.
In 29 stroke patients treated during CoAxia’s feasibility studies 61% of patients improved by more than 3 NIHSS points during the NeuroFlo procedure and 62% had an improvement of 3 NIHSS points at 24 hours. The significance of this improvement is reinforced by the fact that the average time to treatment in these patients was 7.5 hours after the symptom onset – well beyond the 3 Hour treatment window of the FDA-approved intravenous tPA. These feasibility results provided the basis for CoAxia’s current SENTIS pivotal trial, and its recent SafeFlo24 feasibility study (see ongoing clinical trials).
NeuroFlo, as the first device designed to utilize the brain’s own collateral, blood vessels, has a number of potentially important benefits. First, it does not involve intracranial access, instead requiring only a simple aortic placement – a procedure performed at thousands of hospitals throughout the world. In addition, since the therapy does not attempt to remove or disturb the clot, it may be less likely to cause hemorrhage – a common complication of other acute stroke treatments. In fact, current treatments are generally not attempted beyond 3-6 hours post stroke for this reason. NeuroFlo has been evaluated up to 12 hours beyond onset and could become a viable treatment alternative for the hundreds of thousands of patients that are too late to treat with current options.