Drug coated balloon
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor-In-Chief: Parth Vikram Singh, MBBS[2]
Overview
In cardiology, a drug-coated balloon (DCB) is a semi-compliant balloon coated with a lipophilic matrix containing a high concentration of antiproliferative drug, which enables rapid uptake during inflation and sustained release into narrowed coronary arteries to prevent neointimal hyperplasia, offering an advantage over drug-eluting stents (DES) by delivering more drug directly to the vessel wall without leaving a permanent implant.
Heart attacks, or myocardial infarctions, are a leading cause of death and disability, occurring when part of the heart muscle dies due to reduced blood flow. This usually happens at sites where coronary arteries are narrowed by fat, cholesterol, and inflammation. Plaque buildup injures the vessel wall, leading to further growth and cholesterol accumulation. When plaques rupture, they release substances that trigger clot formation, potentially blocking the artery or causing an embolism downstream. Early restoration of blood flow can prevent permanent damage, and timely intervention may help prevent heart attacks altogether. Percutaneous coronary intervention (PCI) using drug-eluting stents (DES) is the most frequently employed revascularization method for individuals with coronary artery disease (CAD). [1,2] While drug-eluting stents (DES) offer immediate, reliable results and reduce major cardiac events, their universal use poses challenges, including impaired vessel remodeling, a 2% annual rise in adverse events (especially with longer stents or in diabetics), technical difficulties in re-intervention, risks from poor deployment, and the complex management of in-stent restenosis, prompting growing interest in drug-coated balloon (DCB) angioplasty as an alternative for select patients. [4-7]
Drug-coated balloons (DCBs) deliver uniform antiproliferative medication without leaving behind a permanent implant, offering a “cage-free” treatment approach. This may promote faster vessel healing, maintain natural vessel structure and function, and encourage favorable vessel remodeling. DCB angioplasty is especially beneficial in certain situations, such as: (1) in-stent restenosis (ISR), (2) small-caliber arteries, (3) lengthy lesions, (4) side branches at bifurcations, (5) diffuse disease in distal vessels following reopening of chronic total occlusions, and (6) other patient-specific factors that may favor the use of DCBs include a high risk of bleeding, presence of diabetes, or treatment in the setting of acute coronary syndromes (ACS).
DCB safety and efficacy depend on the specific device used, and consistent application of proper lesion preparation is crucial to achieving favorable outcomes. Ongoing randomized controlled trials will help clarify the most effective role of these emerging devices as alternatives in the treatment of coronary artery disease.
Structure
DCBs are semicompliant balloons coated with a lipophilic matrix containing an antiproliferative drug and excipient, and they carry a higher concentration of drug on their surface compared to drug-eluting stents (DES). [8] In the absence of a polymer, DCBs require technology that ensures rapid drug uptake during balloon inflation and prolonged release into the vessel wall to prevent neointimal hyperplasia, with the specific drugs and excipients used playing a critical role, explaining the lack of a class effect due to the differing pharmacokinetic properties across devices.[9]
Paclitaxel, the most commonly used antiproliferative agent in DCB due to its lipophilic nature and effective cellular uptake, inhibits neointimal formation by irreversibly binding to the β-tubulin subunit, preventing microtubule disassembly and halting smooth muscle cell proliferation, migration, and extracellular matrix production. Unlike paclitaxel, sirolimus, the most widely used limus-based agent in DES, is a cytostatic drug with a broad therapeutic window that inhibits vascular smooth muscle cell proliferation by forming a complex that reversibly blocks the mammalian target of rapamycin (mTOR),[10] and despite its lower lipophilicity, its proven safety and efficacy have driven the development of sirolimus-based DCBs and other analogues currently under preclinical investigation.
Initial concerns about paclitaxel-related toxicity and increased mortality with DCB use in peripheral artery disease have largely been resolved, with no evidence of excess mortality or coronary artery aneurysm formation reported following paclitaxel DCB treatment for coronary artery disease.[11,12]
The concept of achieving a sustained biological effect from brief drug contact was first demonstrated with a paclitaxel-coated DCB using iopromide as an excipient, leading to the realization that both the active drug and suitable excipients are essential for effective drug delivery, while factors like coating morphology, drug transfer, tissue retention, and particle loss influence the safety and efficacy profiles of different coating formulations and dosages. [7,10,13-15] Crystalline formulations of paclitaxel and sirolimus DCBs show greater efficacy, stability, and drug retention compared to their amorphous counterparts, though they may generate more downstream particulates after angioplasty; [16] despite concerns about potential slow-flow or periprocedural myocardial infarction, no adverse impact on clinical safety has been observed to date.
Placement
Lesion Preparation: Effective lesion preparation is essential for successful DCB angioplasty, as uniform drug delivery relies on optimal vessel wall contact. Intravascular imaging can guide assessment of plaque burden, vessel size, and lumen gain, particularly in ISR or diffuse disease. [76] While specific imaging-based procedural criteria are lacking, IVUS has shown promise in high bleeding risk patients. Predilation with noncompliant balloons (1:1 ratio) and full expansion in two views is standard. In cases of recoil or calcification, scoring/cutting balloons or high-pressure noncompliant balloons should be considered, with undersizing used to reduce
complication risks. Resistant lesions may require super high-pressure inflation, lithotripsy, or atherectomy. Although these strategies
aim to improve drug diffusion, their direct benefit remains unproven. [77] In ISR, scoring or cutting balloons are preferred over noncompliant
ones, [78] and balloon upsizing may be needed in underexpanded stents.
Result Assessment: Proper lesion preparation—with residual stenosis ≤30%—is associated with fewer adverse events. [6,79,80] Procedural success includes the absence of ischemic symptoms, ECG changes, or persistent contrast retention, worsening vessel narrowing, significant dissection impairing flow, or TIMI flow grade below 3. A distal coronary/aortic pressure ratio >0.90 may indicates favorable outcome in coronary dissections. [59] Bail-out stenting should be used for unstable results, with reported rates between 5–15% in de novo lesions. [3,60,61,81] A hybrid strategy (proximal DES + distal DCB) is also an option for long lesions.
DCB Application: DCBs should match artery diameter (1:1) and extend 2 mm beyond the prepared segment at each end. Balloons should be inflated at nominal pressure for 60–90 seconds. The outcome should be evaluated using the same criteria as after lesion preparation, with further lesion modification, repeat DCB angioplasty, or stent placement performed if necessary.
Follow-Up: Postprocedure care is similar to stenting, with possible same-day discharge if stable after 4 hours. Overnight observation may be warranted in complex cases like triple vessel disease or 3 or more lesions treated, bifurcation disease or chronic total occlusion lesions. While DAPT duration is still under investigation, a minimum of 30 days is suggested, with single antiplatelet therapy considered for those at high bleeding risk. [82] Further research is needed to refine follow-up strategies.
Current devices
A range of drug-coated balloons (DCBs) are currently either commercially available or under clinical investigation, with various technologies and drug-excipient combinations tailored to optimize antiproliferative efficacy and vascular healing. Among sirolimus-based DCBs, the Selution balloon, developed by MedAlliance (Mont-sur-Rolle, Switzerland), utilizes a dose of 1 µg/mm² of sirolimus embedded in microreservoirs within a biodegradable polymer matrix. It is CE marked for clinical use. Similarly, MagicTouch, developed by Concept Medical Research (Gujarat, India), delivers sirolimus at a dose of 1.3 µg/mm² using phospholipids as both drug carrier and excipient, and has also obtained CE marking. The SeQuent Please SCB, from B. Braun Melsungen (Berlin, Germany), employs crystalline sirolimus at a dose of 4 µg/mm² to maximize stability and retention; this product has received both CE marking and PMDA approval in Japan.
Paclitaxel-based DCBs also remain widely utilized. The SeQuent Please Neo, another product from B. Braun Melsungen, delivers paclitaxel at a dose of 3 µg/mm² using iopromide (a contrast medium) as the excipient and has received CE marking. Restore, developed by Cardionovum (Bonn, Germany), uses a shellac-based varnish excipient in its amorphous form to deliver paclitaxel at the same 3 µg/mm² dose and is CE marked. Biotronik’s Pantera Lux, from Bülach, Switzerland, uses butyryl-tri-hexyl citrate, a plasticizer, as the excipient with a paclitaxel dose of 3 µg/mm² and is CE approved. Medtronic’s Prevail balloon (Dublin, Ireland) incorporates urea, an endogenous metabolite, as the excipient for paclitaxel delivery at 3.5 µg/mm², and is also CE marked. The Elutax SV, manufactured by Aachen Resonance (Aachen, Germany), uses dextrane—a complex, branched glucan in its amorphous form—as an excipient to deliver paclitaxel at 2.2 µg/mm². This device holds both CE and PMDA approvals. Finally, Agent, a paclitaxel-coated balloon produced by Boston Scientific (Marlborough, Massachusetts), uses acetyl tributyl citrate as a plasticizer-based excipient and delivers paclitaxel at a concentration of 2 µg/mm². Notably, Agent is among the few DCBs to have achieved both CE and FDA approvals, reflecting its broad international regulatory acceptance.
History
The treatment of coronary artery disease has evolved significantly over the past few decades. Initially, open-heart surgery, specifically coronary artery bypass grafting (CABG), was the standard approach, using segments of veins or arteries from elsewhere in the body to reroute blood around blocked coronary arteries. A major shift occurred in 1977 when Andreas Grüntzig introduced percutaneous transluminal coronary angioplasty (PTCA), a minimally invasive technique using a balloon-tipped catheter to compress and disrupt plaque buildup inside coronary vessels. [87]
As interventional tools and techniques advanced, the use of PTCA increased rapidly through the 1980s. However, it faced challenges such as high restenosis rates (up to 30–40% within six months) and the occasional need for emergency bypass surgery. The introduction of stents in the mid-1980s, pioneered by Puel and Sigwart, provided a way to keep the artery open after balloon angioplasty. [b] Bare-metal stents (BMS) soon gave way to drug-eluting stents (DES) in the early 2000s, which release antiproliferative drugs to suppress neointimal hyperplasia and lower restenosis risk. Trials like those involving sirolimus- and paclitaxel-eluting stents (Cypher and Taxus) marked major milestones, and DES quickly became the dominant percutaneous coronary intervention (PCI) strategy.[88,89]
Despite these advances, DES are not without limitations. The permanent metal scaffold may interfere with natural vessel physiology and healing, and concerns remain over late stent thrombosis, neoatherosclerosis, and prolonged dual antiplatelet therapy—especially in patients with small vessels, bifurcations, or high bleeding risk. These limitations reignited interest in a strategy that would “leave nothing behind,” leading to the development of Drug-Coated Balloons (DCBs).
DCBs emerged in the early 2000s as a novel approach to deliver antiproliferative medication directly to the vessel wall without leaving a permanent implant. While they do not provide structural support like stents, DCBs rely on adequate lesion preparation to ensure optimal drug uptake and therapeutic effect. [90]
The technology was initially developed to address in-stent restenosis (ISR)—a recurrent challenge even with DES. Early studies such as the PACCOCATH and PEPCAD trials demonstrated that DCBs were superior to plain balloon angioplasty for ISR, with comparable outcomes to repeat stenting in some cases. [91,92] Consequently, DCBs became a recommended treatment for ISR and were widely adopted in Europe and other regions.
Since the introduction of coronary DCBs over 15 years ago, the technology has seen increasing global clinical adoption. Although ISR remains the only approved indication for DCB angioplasty in North America, experience with newer devices and growing evidence in the treatment of de novo lesions have led to varied adoption across regions. The ratio of DCB-to-DES PCI procedures currently ranges from 1:20 in Europe to 1:10 in the Asia Pacific, and as high as 1:4 in Japan. [17] This reflects not only regional practice patterns but also differences in regulatory approval, operator experience, and available devices. In the United States, the Agent DCB (Boston Scientific) became the first commercially approved DCB, marking a key milestone. Moreover, the acquisition of MedAlliance by Cordis and the ongoing SELUTION DeNovo trial, which evaluates sirolimus DCBs in de novo coronary lesions, may further expand the use of DCBs if trial outcomes are favorable. [18]
Today, DCBs represent a growing paradigm shift toward minimalistic, biologically guided coronary interventions. As technology matures and ongoing randomized controlled trials expand the evidence base, DCBs are poised to play an increasingly prominent role in the treatment of CAD—offering effective revascularization without the long-term risks of permanent implants.
Drug-coated balloon versus plain balloon, and drug-eluting stent
DCB significantly reduces the primary composite endpoint and TLR compared to PB, with a notable difference in the primary endpoint when compared to PB (p<0.001), but there was no significant difference in the major secondary safety endpoint, cardiac death, or MI when compared to PB or DES. (83)
| Outcome Measure | Plain Balloon (PB) | Drug-Coated Balloon (DCB) | Drug-Eluting Stent (DES) | P-Value (DCB vs PES) | P-Value (DCB vs PB) |
| Primary composite endpoint (CD, TV-MI, TLT, TLR) | 72.00% | 55.90% | 62.40% | 0.61 | <0.001 |
| Major secondary safety (CD, TV-MI, TLT) | 34.10% | 34.00% | 40.00% | 0.708 | 0.943 |
| Target lesion revascularization (TLR) | 58.00% | 43.90% | 38.60% | 0.282 | <0.001 |
| Death (All-cause) | 38.70% | 35.70% | 47.20% | 0.153 | 0.145 |
| Cardiac death (CD) | 32.60% | 28.60% | 37.80% | 0.403 | 0.324 |
| Myocardial infarction (MI) | 6.60% | 9.80% | 5.30% | 0.634 | 0.555 |
| Target vessel MI (TV-MI) | 4.70% | 6.80% | 2.60% | 0.661 | 0.576 |
| Target lesion thrombosis (TLT) | 1.90% | 2.20% | 1.60% | 0.943 | 0.990 |
Uses
Coronary Artery ISR: The strongest evidence supporting DCB use in PCI comes from in-stent restenosis (ISR),[1] where multiple randomized clinical trials have consistently demonstrated superior angiographic, and more recently, clinical outcomes with paclitaxel-based DCBs compared to balloon angioplasty in both BMS and DES ISR, [19-22] culminating in FDA approval of the AGENT DCB (Boston Scientific) for ISR treatment. [23]
Paclitaxel-coated DCBs have demonstrated angiographic noninferiority to DES in both BMS and DES-related ISR. [24,25]
Some experts advocate for using DCB as the initial treatment for the first occurrence of ISR, reserving DES implantation for potential future recurrences. This approach is especially appealing in cases of BMS-related ISR, small vessel involvement, the presence of multiple prior stent layers, or when important side branches originate from the restenotic segment. [8,34] Conversely, in DES-related ISR involving large vessels where adding another stent layer has minimal impact, repeat DES placement may be more appropriate.
Small Vessels: In de novo small-vessel coronary artery disease (≤2.75 mm), DCBs have shown promising results as an alternative to DES, [42] offering the advantage of no permanent implant and reduced late lumen loss. Five RCTs comparing various paclitaxel-based DCBs with DES demonstrated comparable clinical outcomes, with some DCBs showing noninferiority in major adverse cardiac events (MACE) up to 5 years. [43-52] While results varied across devices, partly due to differences in drug formulation and lesion preparation, DCBs generally offered similar net lumen gain despite higher percentage diameter stenosis. [53] Based on current evidence, a DCB-first strategy may be reasonable in small-vessel disease, reserving DES for suboptimal outcomes or recurrence.
Long Lesions: Emerging observational data suggest that DCB angioplasty is a promising option for long coronary lesions, especially in complex anatomies with severe tortuosity, multiple side branches, or cases where future bypass surgery (e.g., involving the LAD) remains an option. [8,18,57] A hybrid approach, using DES proximally and DCB distally, can help minimize total stent length.
Recent cohort studies, primarily involving sirolimus DCBs, have supported the effectiveness of this strategy, showing favorable outcomes in large vessels (≥3.0 mm) and long lesions, with up to 80% treated using a DCB-only approach. [58-61] In an all-comer registry, target lesion revascularization was just 1.4% at 12 months, [62] and one study in LAD PCI reported an 80% reduction in target lesion failure with the hybrid DCB-DES strategy versus DES-only. [61] Similar benefits have been observed in multivessel disease. [63] Ongoing RCTs aim to confirm whether limiting DES use improves long-term outcomes by reducing stent-related complications. [18]
Complex Lesions: Indications for DCB angioplasty are emerging in complex and diffuse coronary disease, driven by the goal of simplifying treatment and preserving natural vessel remodeling.
Bifurcation lesions, involved in ~20% of PCI cases, pose procedural challenges and carry higher risks of adverse events. DCB use in side branches, alongside provisional DES in the main vessel, can promote favorable remodeling while avoiding dual stenting. Small observational studies using DCBs like Restore and Magic Touch have shown promising 1-year results. [64-66]
In Chronic Total Occlusions, DCBs may help limit extensive stenting by being used alone or in hybrid approaches, where DES is reserved for the occluded segment and DCBs treat the distal, often small and remodeled vessels. This can help avoid stent undersizing and support vessel healing. [69] Two recent prospective registries have shown that DCB strategies in CTOs are safe, reduce stent length, and may lower 1-year event rates compared to DES alone. [70] Randomized trials are underway to validate these findings.
Other Uses: DCB angioplasty is particularly appealing in several clinical scenarios: (1) patients at high bleeding risk, (2) those with diabetes, due to a higher risk of restenosis and small vessel disease, and (3) acute coronary syndromes (ACS), where vessel sizing may be inaccurate during the acute phase.
Expert consensus recommends a short duration of dual antiplatelet therapy (DAPT, typically 4 weeks for stable de novo lesions, [6,71] and potentially just 2 weeks in very high bleeding risk patients, due to the absence of a permanent implant. DCBs may also be safe with single antiplatelet therapy, [62] although data on interactions with antithrombotics and differences between DCB types remain limited.
In diabetic patients, DCBs have demonstrated lower rates of restenosis and late lumen loss compared to DES, with consistent performance across various formulations. [72,73,49] Similarly, in ACS, DCBs reduce the risk of stent undersizing and have shown noninferiority to DES in both NSTEMI and STEMI settings, with comparable long-term outcomes. [50, 74] Some studies even suggest lower rates of cardiac death and MI with DCB in ACS involving small vessels. [75]
Ongoing randomized trials continue to investigate the long-term safety and efficacy of DCBs in these high-risk populations.
Current research
Over the past decade (2014–2024), numerous randomized controlled trials (RCTs) have evaluated drug-coated balloon (DCB) angioplasty in both de novo coronary artery disease (CAD) and in-stent restenosis (ISR), consistently demonstrating promising results. In de novo CAD, studies such as BELLO [44], and BASKET-SMALL 2 [45] have assessed paclitaxel-based DCBs, most notably SeQuent Please and IN.PACT Falcon, against drug-eluting stents (DES) and bare-metal stents (BMS). These trials, with sample sizes ranging from 40 to over 750 patients, examined endpoints including late lumen loss (LLL), target lesion revascularization (TLR), and major adverse cardiac events (MACE), with follow-up extending up to 60 months. Minimum DAPT durations varied from 1 to 12 months. The data consistently demonstrated the noninferiority of DCBs in selected patients, especially those with small-vessel disease, and supported their role in reducing overall stent burden. More recent trials such as PICCOLETO II [47], PEPCAD [40], and TRANSFORM-I [57] have further expanded the evidence base for DCB use in more complex and acute clinical settings.
In the United States, DCB use received a major boost with the commercial approval of the Agent DCB (Boston Scientific), the first of its kind in the country. The AGENT IDE trial [23], demonstrating lower target lesion failure (TLF) rates compared to plain balloon angioplasty in ISR, supported this regulatory milestone. Ongoing trials, such as the SELUTION DeNovo study [18], may further accelerate DCB adoption, particularly following the acquisition of MedAlliance by Cordis, and if results are positive, may expand the market penetration of sirolimus-based DCB technologies.
For ISR, paclitaxel-based DCBs have been the standard, evaluated in landmark trials such as RIBS V [36], PEPCAD China ISR [40], and RESTORE ISR [46]. These trials showed comparable outcomes between DCB and DES in terms of angiographic parameters like LLL and clinical endpoints, and also highlighted DCBs' advantage of reducing the need for additional stent layers. Recent innovation in ISR management has centered on newer-generation sirolimus-based DCBs. Notably, the Virtue balloon (Caliber Therapeutics) which uses a porous balloon to deliver a nanoencapsulated liquid formulation of sirolimus, was the first of its class tested in ISR, demonstrating in-segment LLL at six months comparable to that of paclitaxel DCBs [29]. Further evidence comes from a pooled analysis of two RCTs investigating crystalline sirolimus DCBs [30], and a large observational cohort evaluating a sirolimus-phospholipid nanocarrier DCB [31,32], all of which reported encouraging medium-term outcomes. A noninferiority trial is currently underway comparing a biolimus A9-coated DCB with a standard paclitaxel DCB in ISR treatment [33].
Multiple cohort and registry studies, including those with predominantly sirolimus-based DCBs, have reinforced these findings. Notably, trials such as FIM LIMUS DCB [61] and AGENT IDE [61] demonstrate that DCBs can be safe and effective in complex ISR presentations, including those with multiple prior stent layers, small vessels, and bifurcation disease. Moreover, the advantage of shorter required durations of DAPT makes DCBs particularly attractive in patients at high bleeding risk [6,71].
In parallel, several ongoing RCTs are exploring novel DCB applications in both de novo CAD and ISR. These include the SELUTION 4 trial [ClinicalTrials.gov: NCT05946629], TRANSFORM II [NCT04893291], and REVERSE [NCT05846893], which target small vessels, native CAD, and large-vessel disease respectively. Trials such as Hybrid DEB [NCT05731687] investigate bifurcation treatment strategies, while others like AGENT Japan SV [NCT04058990] and PREPARE-NSE [NCT03817801] assess alternative preparation techniques or short-duration DAPT strategies in high-risk populations. Notably, studies such as MAGICAL-SV [NCT06271590] and MAGICAL ISR [NCT05908331] will further define the role of sirolimus-coated MagicTouch balloons in both de novo and restenotic lesions.
In the ISR domain, pivotal trials including ISAR-DESIRE 5 [NCT05544864] and SELUTION4ISR [NCT04280029] are evaluating DCB strategies in relation to neointimal morphology and DES comparators. These trials assess modern endpoints such as MACE, TLF, and angiographic restenosis, and are critical for shaping future guideline recommendations.
Together, this expanding body of evidence highlights a growing shift toward personalized, lesion-specific PCI strategies, with DCBs playing an increasingly central role—particularly in patients with small vessels, ISR, high bleeding risk, and complex coronary anatomies. The next wave of RCT outcomes will be instrumental in validating these approaches and driving broader clinical adoption.
Complications
In recent years, drug-coated balloons have emerged as a compelling alternative to stents in selected percutaneous coronary interventions (PCI). However, DCBs are not without limitations, and as relatively newer technology, long-term comparative data—especially beyond 5 to 10 years—are still evolving.
Risks Related to Balloon Angioplasty: As with any PCI procedure, DCB use involves cardiac catheterization, which carries procedural risks. Contrast agents used for angiography can provoke severe allergic reactions, and vascular access sites may develop hematomas or pseudoaneurysms post-procedure.
Dissections and Recoil: Unlike stents, DCBs do not provide mechanical scaffolding. As a result, balloon angioplasty may lead to vessel recoil or dissection, particularly if lesion preparation is suboptimal. While many dissections heal without clinical consequence, flow-limiting dissections may require “bail-out” stenting, somewhat defeating the purpose of using a DCB. [84]
Restenosis and Drug Uptake: The primary mechanism of DCBs is local drug delivery, typically paclitaxel or sirolimus, to inhibit neointimal proliferation. Restenosis after DCB treatment is generally lower than with plain balloon angioplasty and comparable to drug-eluting stents in some studies, particularly in ISR. However, adequate lesion preparation is crucial to optimize drug absorption and ensure even contact with the vessel wall.
Allergic Reactions and Safety Signals: While rare, hypersensitivity to the antiproliferative drug or excipients on the balloon surface can occur. Severe allergic reactions are infrequent but possible, and vigilance is necessary, especially in patients with known sensitivities. [85,86]
Controversy
As initial enthusiasm for drug-coated balloons (DCBs) has grown, concerns have emerged about their expanding use beyond well-studied indications. While DCBs are well-established for in-stent restenosis, their application in de novo coronary disease remains less well-validated. This findings highlight the need for careful patient and lesion selection, as well as further randomized trials to define appropriate boundaries for DCB use.
References
Further reading
- Fischetti, Mark (2006). "Vascular Stents: Expanding Use". Scientific American: 94. Unknown parameter
|month=ignored (help) (layperson overview, subscription required) - Serruys, Patrick W. (2006-02-02). "Coronary-Artery Stents". New England Journal of Medicine. 354 (5): 483–495. Unknown parameter
|coauthors=ignored (help) (journal review article, subscription required)
External links
 |
Wikimedia Commons has media related to Stent. |