Embolic filters protect downstream vessels while thrombectomy devices actively remove clots, but both face the same engineering challenge: capturing debris is only step one. The true test of a device is what happens after the material is captured. What happens after material is captured ultimately determines whether a device is safe, effective, and clinically successful.
How debris is loaded, how securely it is held, and how reliably it can be retrieved through tortuous anatomy determines whether the system is safe and effective.
This article explores the mechanics behind debris capture and retrieval and highlight how Medical Murray’s experience with braided and laser-cut nitinol frames, polyurethane and ePTFE coverings, and complex catheter assemblies helps innovators bring reliable, commercial-ready devices to market.
Thrombus and Debris Loading: The First Critical Step
Debris loading into an embolic filter is primarily driven by flow dynamics. A filter must expand predictably, aperture precisely, and maintain tension across its mesh or polymer covering so debris enters the capture zone rather than accumulating along the frame. Consistent deployment of the nitinol structure (braided or laser-cut) is essential for smooth particle entry. Medical Murray works with multiple frame types to help achieve the opening symmetry and geometric repeatability required for consistent debris loading.
Loading for thrombectomy devices is more complex. Instead of passive flow, the device must engage thrombus of different ages and compositions. Acute red clots can be very different than chronic clots, and the loading mechanism must accommodate both types of clots without fragmenting material. This commonly requires tapered inflow sections, expandable baskets, or nitinol retrieval elements designed to conform to the different clot types. Our ability to build multi-layer catheter shafts, integrate expandable nitinol structures, and combine varying durometers within a single catheter-based system allows thrombectomy devices to load clot more predictably in real clinical conditions.
Retention and Release Risk: Keeping Debris Under Control
Once debris enters the device, the next question is whether it stays there. For embolic filters, retention depends heavily on pore geometry, mesh tension, and frame elasticity. The covering material (e.g. polyurethane or ePTFE) must be applied with consistency, so the device retains debris while still allowing flow. Even small inconsistencies in porosity or bonding can affect how debris behaves under pulsatile or reverse-flow conditions. Medical Murray’s precision processes for micro-hole creation and frame covering ensure uniformity across complex frame geometries, helping prevent unwanted debris extrusion or bypass.
Retention in thrombectomy devices requires more active engagement. The device must maintain its hold on the clot while being pulled through curves, branches, and varying vessel diameters. This often involves mechanical grip, polymer encapsulation, or suction forces. Smooth transitions into the retrieval sheath are especially important to avoid scraping, shearing, or clot fragmentation. Our engineering teams have experience with catheter systems that balance flexibility and pushability to make sure the retrieval elements maintain controlled engagement with the clot throughout withdrawal.
Retrieval Mechanics: Everything Must Work
Regardless of the device category, retrieval is the moment of most risk. A filter may have performed flawlessly during capture, but if it collapses inconsistently or sheds debris during withdrawal, the device fails its most important job. Predictable collapse behavior comes from the interplay of frame design, heat-set geometry, covering tension, and sheath interface. Medical Murray’s experience with both braided and laser-cut nitinol frames, and with covering these structures using polyurethane or ePTFE, has shown that retrieval performance is achieved through the way every component works together.
Thrombectomy retrieval adds even more variables. As a loaded device is pulled back through tortuous anatomy, forces surge and relax repeatedly. Without properly controlled shaft flexibility and collapse sequencing, the device may lose its grip, compress unpredictably, or fragment the clot. Our catheter assembly expertise (including braid- and coil-reinforced shafts, smooth tip transitions, and well-controlled marker placement) helps maintain stability and containment during real-world retrieval paths.
Materials, Manufacturing, and the Real Drivers of Performance
Behind the visible performance of an embolic filter or thrombectomy system is a series of decisive design and manufacturing details. The success of these devices relies heavily on the quality of the frame and its covering, and Medical Murray’s long history with both provides a significant advantage for customers.
We build braided nitinol baskets, laser-cut retrieval frames, and custom heat-set geometries that expand and collapse consistently across dozens of cycles. We also specialize in applying polyurethane and ePTFE coverings with laser drilled holes over these complex shapes, producing uniform porosity and strong frame-to-cover bonds even on delicate, multi-curved structures. These covering techniques are often a determining factor in whether a prototype advances into verification testing because they enable the pore control, elasticity, and collapse predictability required for safe device function.
Paired with our ability to build multi-durometer catheter shafts, integrate balloons, optics modules, or articulation, and assemble Class III systems with tight tolerance control, we’re able to support devices from early proof-of-concept prototypes through full-scale commercial manufacturing.
Testing and Validation: Proving What Matters
A device’s ability to load, retain, and retrieve debris is ultimately proven through testing. Medical Murray helps customers design test methods and build units for studies that evaluate:
- Particle capture and debris behavior under flow
- Retention during pulsatile or reverse-flow conditions
- Collapse forces and retrieval mechanics
- Fatigue and cycle performance of frames and coverings
- Behavior through simulated or anatomically representative pathways
Our teams frequently support rapid design iteration during these stages so that performance improvements can be incorporated quickly and verified under controlled conditions.
Ready to Advance Your Embolic Protection or Retrieval Device?
Although embolic filters and thrombectomy systems serve different clinical purposes, their engineering challenges converge where it matters most: smooth debris loading, secure retention, and reliable retrieval. These capabilities rely heavily on the quality of the frame, the precision of its covering, and the integration of those components into a catheter system that behaves predictably under clinical forces.
Medical Murray’s experience with braided and laser-cut nitinol frames, polyurethane and ePTFE coverings, and complex catheter assemblies positions us to support innovators developing next-generation embolic protection or clot-retrieval systems. From concept through verification, clinical builds, and full production, we help create devices that load safely, retain securely, and retrieve reliably.
If you’d like to discuss your next device or explore how our frame, covering, and catheter capabilities might support your program, we’d be glad to connect.