June 17, 2024
Neurovascular Devices

Neurovascular Devices: Enabling Less Invasive Treatment of Cerebrovascular Conditions

History and Evolution of Neurovascular Devices

When treating conditions that affect the brain’s blood vessels, minimally invasive techniques are crucial given the sensitive nature of the brain and surrounding tissues. For decades, traditional “open” surgeries involving cutting open the scalp and sawing through bone were the standard approach. However, this caused significant trauma, lengthy recovery times and risks of complications. In the 1970s, the first catheters designed to access the brain’s blood vessels from an artery in the groin emerged, paving the way for less invasive neurovascular procedures.
Over subsequent decades, catheter technology advanced rapidly. New designs with improved steerability and trackability allowed navigation through ever more tortuous vascular paths to reach previously inaccessible areas deep within the brain. Additional breakthroughs included retrievable stent technology in the 1990s and the arrival of flow diverter stents a decade later. The integration of advanced imaging like 3D rotational angiography further enhanced procedural accuracy and safety.

Modern Neurovascular Device Components

Today’s Neurovascular Devices fall under several key categories to treat a range of cerebrovascular conditions. Guidewires allow catheter placement and come in varying stiffness for different vascular access routes. Microcatheters possess exceptional flexibility to deliver other devices precisely to the target location. Self-expanding stents physically hold open narrowed or bulging vessels. Coils are thin platinum wires used to occlude aneurysms and block blood flow. Balloons are inflated to widen stenosed vessels or to assist with coil deployment. Stent retrievers extract clots causing ischemic strokes. Flow diverters reroute blood flow away from damaged areas of vessel wall.

Treating Cerebral Aneurysms

One of the most common uses of neurovascular devices is to treat cerebral aneurysms, weak bulges in the blood vessel wall that carry risks of rupture and life-threatening hemorrhage. Previously, surgery involving clipping the aneurysm neck from outside the vessel was often needed but carried risks. Now, endovascular coiling via a microcatheter has become the standard first-line treatment in many cases.
To perform coiling, the neurointerventionist navigates microcatheters and guidewires through the femoral artery towards the target aneurysm, guided by live imaging. Tiny platinum coils are then delivered through the catheter and deployed one by one into the aneurysm sac. Over 10-20 coils may be required to stabilize a large aneurysm, depending on its size and shape. Once filled, the coils alter blood flow dynamics and stimulate clotting to isolate the aneurysm from circulation.

Treating Acute Ischemic Stroke

In cases of acute ischemic stroke caused by an arterial clot blocking blood flow to the brain, time lost is brain lost. Rapid restoration of blood flow is crucial to limit permanent neurological damage. Recently developed stent retrievers enable minimally invasive clot removal in a similar fashion to coiling for aneurysms.
During a stroke thrombectomy procedure, a microcatheter is steered close to the clot. The folded stent retriever is then pushed out of the catheter and self-expands within the clot. After a few minutes, the stent with captured clot is pulled back into the guide catheter and removed from the body, hopefully restoring normal blood flow. Large clinical trials have demonstrated the safety and efficacy of this endovascular approach compared to traditional intravenous clot-busting drugs alone.

Treating Complex Vascular Malformations

For some rare but devastating cerebrovascular conditions like cerebral arteriovenous malformations (AVMs), a multifaceted treatment strategy combining different neurovascular devices may be necessary. These tangled, abnormal connections between arteries and veins can hemorrhage with catastrophic results if left untreated.
During embolization procedures to selectively block the AVM’s feeder arteries and reduce its size/risk, microcatheters may deliver detachable platinum coils. Liquid embolic agents injected through calibrated microcatheters offer another option. Self-expanding stents can protect parent vessels during aggressive embolization. For complex remaining portions, the latest high-coverage flow diverters redirect blood away from fragile areas, encouraging controlled regression of the abnormality over time without open surgery.

Role of Neurovascular Simulation

With continual technical progress enabling ever more complex endovascular treatments, remaining safe and minimizing adverse events is paramount. Virtual and augmented reality neurovascular simulations provide a controlled training environment far removed from patients. Trainees can repeatedly practice navigating virtual catheters and devices through life-like three-dimensional renderings of diseased cerebral vessels under expert proctoring. As neurointerventional skills progress, more challenging simulated case scenarios expose learners to diverse pathologies before independent clinical work. Simulation serves an important role complementing real-world experience to maximize outcomes from minimally invasive neurovascular therapies.

1. Source: Coherent Market Insights, Public sources, Desk research.
2. We have leveraged AI tools to mine information and compile it.