Perfuze has published final results from the 180-patient MARRS pivotal study showing that its Millipede88 Aspiration Catheter achieved successful reperfusion in 89% of acute ischemic stroke patients without rescue therapy, exceeding the study’s prespecified performance goal. Among patients with M1 middle cerebral artery occlusions where Millipede88 was used for the initial attempt, 75% achieved a high-quality first-pass reperfusion result, while overall device-delivery success reached 96%. The prospective study was conducted at 22 hospitals in the United States and Europe under a U.S. Food and Drug Administration Investigational Device Exemption and supported FDA 510(k) clearance of the catheter.
The results matter because mechanical thrombectomy is a race against irreversible brain injury. When a large cerebral artery is blocked by a clot, downstream brain tissue begins losing oxygen, and every additional attempt to retrieve the clot consumes time while potentially disturbing the vessel. A catheter capable of reaching the blockage and restoring strong blood flow on the first attempt can therefore be clinically valuable even if a second or third attempt could eventually achieve the same technical endpoint.
What is the Millipede88 aspiration catheter actually designed to do?
Mechanical thrombectomy removes large blood clots from brain arteries in selected patients with acute ischemic stroke. One approach uses a stent retriever that opens through the clot and pulls it out, while another places a large-bore aspiration catheter against the clot and uses suction to extract it. Many interventions combine techniques depending on clot location, vessel anatomy and physician preference.
Millipede88 is built around standalone direct aspiration using a 0.088-inch internal lumen, making it part of a newer generation of so-called super-bore aspiration catheters. Perfuze uses a corrugated catheter architecture rather than conventional braided or coiled construction, which the company says helps preserve internal lumen geometry and maintain aspiration force at the face of the clot.
Why does first-pass effect matter so much during a stroke?
Every additional thrombectomy attempt has potential consequences. Repeated manipulation can extend procedure time, fragment the clot, move embolic material into new territories or increase trauma to the vessel wall. Researchers therefore increasingly focus on first-pass effect, generally meaning near-complete or complete reperfusion after the first device attempt, because it captures procedural efficiency rather than simply whether blood flow was eventually restored.
In MARRS, Millipede88 achieved a 75% first-pass effect at the mTICI 2c-3 level among the specified M1 occlusion population. The study’s lead investigator described the independently adjudicated first-pass and reperfusion results as exceptionally strong compared with previously reported prospective thrombectomy datasets, although cross-trial comparisons should be interpreted cautiously because patient selection, clot anatomy and trial design can differ substantially between studies.
How many patients needed additional rescue devices?
Fewer than 8% of Millipede88 cases required rescue therapy, according to the final report. That suggests standalone aspiration was sufficient in the large majority of treated cases rather than routinely requiring an additional stent retriever or other thrombectomy device. Reducing the number of devices used during a procedure could potentially simplify workflow and affect procedural cost, although those economic benefits would need dedicated analysis rather than being assumed from the device count alone.
The system also achieved 96% delivery success, an important measure because a very large aspiration catheter provides little value if physicians cannot navigate it safely through tortuous vessels to reach the intracranial clot. The balance between lumen size and navigability has been one of the central engineering challenges in aspiration-catheter design, particularly as manufacturers attempt to bring larger inner diameters farther into cerebral circulation.
What did the study show about safety?
MARRS reported symptomatic intracranial hemorrhage in 2.3% of patients, with no vessel perforations and no serious adverse events attributed to the device. Imaging and safety endpoints were independently adjudicated, which strengthens confidence that outcomes were not determined solely by the manufacturer or treating physicians. The study was prospective and multicenter, although it used a single-arm design rather than randomizing patients directly against a competing catheter or stent-retriever strategy.
That lack of a randomized head-to-head comparator is important when interpreting claims about superiority. An 89% reperfusion rate and 75% first-pass effect can look extremely strong, but hospitals ultimately need to know whether those advantages persist against modern competitor devices in similar patients and operators. Comparative real-world studies may become increasingly important as the super-bore aspiration market grows.
Why are aspiration catheters becoming larger?
Suction force at the clot generally increases as catheter diameter increases, which gives engineers a straightforward reason to build larger lumens. The problem is that cerebral arteries are narrow and frequently tortuous, so increasing catheter size can make navigation harder and potentially increase the risk of vascular injury. The optimal system therefore needs to maximize clot-engagement area while remaining flexible and deliverable.
Perfuze argues that its Corrugated architecture helps solve this trade-off by supporting a large internal lumen without relying on conventional reinforcement designs. The Millipede88 has now moved beyond laboratory engineering into prospective pivotal data, which is a crucial transition for any neurovascular device attempting to change routine stroke practice.
Could better first-pass thrombectomy improve patients’ long-term recovery?
That is the clinically important question, and technical reperfusion does not automatically answer it. Restoring blood flow quickly is strongly associated with better stroke outcomes, but recovery also depends on how long the vessel was blocked before treatment, the amount of brain already irreversibly injured, collateral circulation, age, medical history and post-procedure complications. A technically excellent thrombectomy device cannot rescue tissue that died before the patient arrived.
Nevertheless, procedural efficiency matters because interventionists control what happens once the patient reaches the angiography suite. A device that restores near-complete blood flow during the first attempt can reduce one avoidable source of delay, potentially preserving brain tissue in patients who still have salvageable penumbra. Future comparative studies linking first-pass performance directly with 90-day functional outcomes will be particularly valuable.
Where does Millipede88 go after FDA clearance?
Perfuze is conducting a limited market release in selected U.S. comprehensive stroke centers before broader commercialization. This staged approach allows the company to build operator experience, gather real-world performance data and refine training before exposing the system to a much larger range of hospitals and anatomical challenges. The recently cleared Zipline Access Catheter can also be used as part of the company’s broader aspiration platform.
Commercial competition will be intense because stroke thrombectomy is already served by major neurovascular-device companies with established physician relationships and broad catheter portfolios. Perfuze therefore needs the MARRS results to translate into a practical advantage that interventionists can reproduce outside the trial environment. If first-pass performance remains high in routine use, the device could compete around a simple and compelling procedural goal: get the clot out cleanly on the first attempt.
