Reflow Medical’s Retrievable Coronary Drug‑Eluting Stent Shows Early Promise in In‑Stent Restenosis

Reflow Medical is pitching a different take on the coronary drug-eluting stent: a temporary, retrievable scaffold that delivers sirolimus to a coronary lesion and is then removed, leaving no permanent metal behind. Early six month data from a first in human trial look encouraging. This concept touches on several tough problems in heart care ranging from recurring narrowing inside stents to the downsides of leaving metal in arteries long term. If the device can safely open the artery, deliver drug to stop scar tissue and then be pulled out, it could change how we think about stents. Reflow’s Spur Elute system, currently being tested in patients with in-stent restenosis (ISR), is designed to do exactly that.

Why It Matters

CAD remains one of the most common reasons for illnesses and mortality. For example, in the US alone, one in every 20 people has been diagnosed with some kind of CAD that causes deaths numbering in the hundred thousand every year. The invention of drug-eluting stents (DES) marked a breakthrough in the field because it reduced by many times the risk of restenosis compared to bare metal stents. Restenosis with first generation stents reached up to 20–30% whereas now the rate is reduced to several percentage points with modern DES. However, the use of metallic stents poses its own difficulties. Metallic components may cause irritation of the arterial walls, chronic inflammation and even late complications such as stent fracture and thrombosis after a number of years. A retrievable approach aims to keep the best of both worlds: mechanical opening of the artery plus targeted drug therapy but without the long-term implant. In practice, the Spur Elute device deploys like a tiny stent (with expandable spikes and a balloon) to open the vessel and press a drug-coated surface against the wall. The unique spikes create tiny channels so the sirolimus drug can penetrate the tissue more effectively. After a set time, the system is fully collapsed and removed through the catheter, leaving nothing behind. This concept is appealing because it could deliver a higher dose of drug more precisely than a balloon alone, and it holds the artery open while the drug takes effect. Similar ideas have shown promise in peripheral arteries (Reflow already has an approved retrievable stent for some leg vessels), suggesting the approach can work. For patients and doctors, the idea is intuitive: treat the blockage well, then let the artery heal naturally without a permanent scaffold. But caution is warranted. So far, data on this device are very early. First in human studies (like the small DEEPER CORONARY trial) are mainly about feasibility and safety. They aren’t proof that the retrievable stent will beat current best treatments in the long run. For example, Reflow’s own report showed that in 9 patients treated for ISR, 100% were free of major adverse cardiac events at six months a great start, but in only nine patients. Specialists will want to see larger studies and head-to-head comparisons before changing practice. In other words, early human data suggest the idea can work, but we still need to know if it truly improves outcomes or just adds complexity. Clinicians and researchers will be asking: Does the artery stay open without more narrowing? Are there unseen risks when pulling the device out? How does it compare with other ISR treatments? Those answers require more research and time.

Who It Affects

Patients with coronary artery disease stand to benefit the most if this device works as hoped. In particular, people with in-stent restenosis have limited options today. ISR means a stent has already been placed, and now scar tissue has built up inside it again. The usual fix might be another drug-eluting stent or a drug-coated balloon, but each time you add metal the vessel gets more rigid and future options get harder. Delivering a potent dose of sirolimus and then removing the implant could avoid piling on more metal. Young patients are another key group. A 40-year-old getting a stent today could need heart procedures for decades; not leaving permanent metal might preserve their future treatment choices. Also, any patient who may eventually need bypass surgery could benefit from “sterile” arteries – after all, it’s easier for a surgeon to work on a clean vessel rather than one caged in metal. For interventional cardiologists, the new stent means learning new tricks. Implanting the device is similar to a standard PCI up to a point, but then doctors must retrieve it safely. That means they need to master collapsing the scaffold and pulling it out without hurting the artery. It likely requires a precise technique and backup plans in case of problems. Imaging will be important: doctors may use intravascular ultrasound (IVUS) or optical coherence tomography (OCT) to check that the device is well-apposed, that drug has reached the wall, and that the artery looks healthy before removal. Cath labs will need to develop new protocols – for example, training nurses and techs on the procedure and monitoring patients after retrieval. In early use, this device might be handled by specialized teams who treat complex cases. Over time, as experience grows, more cardiologists might adopt it into practice. Hospitals and payers will also feel the impact. A new class of stent means new costs and logistics. Hospitals must decide if the potential long-term benefits are worth the higher short-term expense of training and stocking a novel device. If avoiding a second stent or future complications saves money down the line, the investment could pay off. But insurers and Medicare will be cautious: they will demand strong evidence before reimbursing widely. Reimbursement typically requires clear proof that a new device improves outcomes or reduces costs. Health systems will weigh the device cost against the potential of fewer repeat procedures or hospital readmissions. If studies show that patients do better or need fewer follow-up interventions, payers may become supportive. Until then, coverage might be limited to research settings or select cases. Finally, manufacturers and distributors need to prepare – launching a whole new device category requires new supplier contracts, inventory plans, and quality controls.

What Changes

Procedural workflow. Using a retrievable stent changes the cath lab procedure. Clinicians will still perform a standard angioplasty sequence – wiring the lesion, predilation, etc. Then they deploy the retrievable device, wait the required time to allow drug transfer, and then collapse and remove it. That removal step is new. It requires careful handling and perhaps imaging to ensure a clean pull-out. Operators will need training on exactly how long to leave the device in place, how to confirm full drug delivery, and how to fold the device for extraction. There may be new checklists (for example, ensuring no wires are trapped) to prevent complications. In practice, cases might take a bit longer at first, and support staff will need to be on board. Over time, these steps would become routine, just as putting in the first-ever drug-eluting stents required a short learning curve two decades ago.

Training and follow-up. Doctors and care teams will develop new protocols around this device. Patient selection guidelines will have to be written: who is an ideal candidate and who should avoid it. There will be new steps for patient education – explaining that the stent is temporary and what patients should expect. Follow-up care may include more frequent check-ups or imaging to verify vessel healing after device removal. Cardiologists might collaborate more with imaging specialists to interpret post-procedure scans. Nursing staff will also need instruction on how to observe patients after this specific procedure. In short, adding this tool means creating a mini-specialty within interventional cardiology, at least during the early adoption phase.

Evidence and reimbursement. The biggest bottleneck is evidence. Large trials will be needed to prove that the retrievable stent has lasting benefits. Insurers will want randomized data showing that it is at least as good as current treatments (like a new DES or a drug-coated balloon) and ideally superior in some way (for example, fewer repeat stenting procedures). They will also look at economics: does the higher per-device cost save money later by preventing heart attacks or bypass surgery? Companies now collect long-term follow-up data on outcomes and costs to build a case. Guideline committees will also want durable results – not just 6-month outcomes, but data at 1, 3, and 5 years to see if the vessel stays open. Until such evidence is available, most systems will likely use the device only under research protocols or in very selected patients. Over time, strong trial results could pave the way for insurance coverage and guideline endorsements.

Unanswered technical questions. Certain practical concerns must be addressed. For example, what happens when you pull out the scaffold? Could it scrape or injure the vessel lining? If tiny bits of tissue come off, could that cause a clot? So far, early results suggest safe removal, but each patient is different and bigger studies will reveal rarer risks. Another question is drug dosing: the system uses a special sirolimus formulation to ensure enough drug stays in the artery wall after a short exposure. Whether that is as effective as a permanent drug-eluting stent’s months-long release remains to be seen. We also don’t know how the artery remodels over time without a supporting scaffold. Does it stay open on its own or does it slowly narrow again? If narrowing returns after removal, what is the plan – add a permanent stent, repeat the procedure, or move to surgery? Doctors will have to consider these scenarios.

Adoption timeline. This device will probably start in high-volume academic centers that run clinical trials. Early adopters are likely to be experts in complex coronary interventions who treat tough ISR cases. As these experts report on technique and outcomes in journals and conferences, other cardiologists will gain confidence. Over a few years, as data builds and marketing educates the community, use may spread more widely. Realistically, community hospitals and smaller practices will lag until the technology is proven and reimbursement is sorted out. Initially, the system might be priced as a premium product; however, if it avoids future costly procedures, its economic value could become clearer.

Equity and access. There’s also an equity angle. High-tech devices risk widening the gap in care if only available at top centers or to patients with good insurance. It will be important for manufacturers to train a broad base of doctors and for payers to consider fair coverage, so that disadvantaged patients aren’t left out. Plans might be needed to ensure rural or low-income patients can get this option, perhaps through programs or pilot projects. The technology relies on good follow-up, so patients without stable housing or access to care could be at a disadvantage. Planners should keep these issues in mind to prevent inadvertent bias in who benefits.

Looking ahead. In summary, the retrievable coronary stent is a promising idea that addresses a real need. In-stent restenosis is a difficult problem, and giving the artery a high dose of drug and then removing the scaffold could solve it without caging the vessel in more metal. Early human data (even though small) have shown impressive safety signals and symptom improvements in the handful of patients treated. The core question now is whether this approach can maintain those results at scale and over time. If future studies confirm that vessel patency holds and patients do well, this could become a valuable new tool alongside drug-coated balloons and permanent stents.

References

1. American Heart Association. 2025 Heart Disease and Stroke Statistics Update Fact Sheet (At-a-Glance). American Heart Association; 2025. Available from: https://www.heart.org/en/-/media/PHD-Files-2/Science-News/2/2025-Heart-and-Stroke-Stat-Update/2025-Statistics-At-A-Glance.pdf?sc\_lang=en [\[heart.org\]](https://www.heart.org/en/-/media/PHD-Files-2/Science-News/2/2025-Heart-and-Stroke-Stat-Update/2025-Statistics-At-A-Glance.pdf?sc_lang=en)
2. Donisan T, Madanat L, Balanescu DV, Mertens A, Dixon S. Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge. Current Cardiology Reviews. 2023;19(3):E030123212355. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC10280993/ [\[pmc.ncbi.nlm.nih.gov\]](https://pmc.ncbi.nlm.nih.gov/articles/PMC10280993/)
3. ClinicalTrials.gov. Pilot Study of the Drug-eluting Coronary Spur StEnt as a Primary trEatment for In-stent Restenosis of the CORONARY Arteries (DEEPER CORONARY) (NCT06117150). U.S. National Library of Medicine; 2025. Available from: https://clinicaltrials.gov/study/NCT06117150 [\[clinicaltrials.gov\]](https://clinicaltrials.gov/study/NCT06117150?rank=1)
4. Reflow Medical, Inc. Reflow Medical Reports Six-Month Results from DEEPER CORONARY Study of Spur® Elute Stent. Reflow Medical; 2026. Available from: https://www.reflowmedical.com/reflow-medical-reports-six-month-results-from-deeper-coronary-study-of-spur-elute-stent/ [\[reflowmedical.com\]](https://www.reflowmedical.com/reflow-medical-reports-six-month-results-from-deeper-coronary-study-of-spur-elute-stent/)