Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Biodegradable Magnesium Stents For Coronary Arteries

01.06.2007
Biodegradable magnesium stents have been developed to treat blockages in coronary arteries which can degrade within four months and achieve the same results as conventional stents, conclude authors of an Article published in this week’s edition of The Lancet.

But both the Article and an accompanying Comment warn longer term follow-up of the patients fitted with biodegradable stents is needed.

Coronary stents improve immediate and late results of balloon angioplasty by closing up dissections and preventing collapse of the arterial walls.

Professor Raimund Erbel, Department of Cardiology, West German Heart Centre Essen, Germany, and colleagues successfully implanted 71 of the biodegradable magnesium stents in 63 patients in their study – the PROGRESS-AMS clinical trial.

The researchers found that after 12 months, the stents were safe, with no incidence of stent thrombosis (clotting within the stent), heart attack or death in any of the patients. They found that the diameter of the blood vessel within the stent (in-stent acute gain) increased by an average of 1.41mm. Whilst the stent struts disappear over time, ultrasound confirms they remain present but have been absorbed into the vessel walls, with the space left behind “filled in.”

The magnesium is eventually replaced by calcium and phosphorous through the body’s natural processes.

However the trial also showed that angiographic restenosis (re-blocking of the artery) occurred in 47.5% of patients who received the biodegradable stents, and 27% needed target lesion vascularisation within 12 months due to recurrent ischaemia (lack of blood flow to the tissues).

The authors say: “This study showed that absorbable magnesium stents can be delivered and expanded at high pressure in artherosclerotic coronary arteries, providing good mechanical scaffolding and achieving a lumen enlargement similar to the immediate lumen gain obtained with conventional metallic stents.”

The Article says the new biodegradable stents overcome the limitations of conventional permanent stents – namely that they can cause thrombosis many months after implantation – and thus regular dual antiplatelet drug treatment such as aspirin and clopidogrel are required to prevent this occurring in patients with conventional stents fitted.

And drug-eluting stents have limitations because despite being able to achieve significant decreases in angiographic restenosis, they can cause hypersensitivity reactions and late-stent thrombosis, possibly because the drugs eluted hinder re-endothelialisation (re-lining of the inside wall of the artery) of stent struts. Biodegradable stents avoid this problem.

The authors caution that studies with more patients and longer term follow-up are required to confirm the safety of biodegradable magnesium stents.

They say: “For a new product such as absorbable metal stents, four months of angiographical study and 12 months clinical follow-up might be insufficient to capture all the potential late events and complications.”

They conclude: “This study shows that biodegradable magnesium stents can achieve an immediate angiographic result similar to the result of other metal stents and can be safely degraded after four months. Modifications of stent characteristics with prolonged degradation and drug elution are currently in development.”

In an accompanying comment, Dr John Ormiston and Dr Mark Webster, Mercy Angiography and Auckland City Hospital, Auckland, New Zealand, say: “Bioabsorbable stents are in an early stage of development but hold considerable promise for overcoming many of the limitations of permanent metallic implants.”

They add: “The initial patients treated with these devices will need to be followed up closely and for a long time. Whether bioabsorbable stents signal the threshold of a new era for percutaneous coronary intervention is yet to unfold.”

Tony Kirby | alfa
Further information:
http://www.thelancet.com
http://www.thelancet.com/webfiles/images/clusters/thelancet/press_office/Scaffolding.pdf

More articles from Medical Engineering:

nachricht New insight into the brain’s hidden depths: Jena scientists develop minimally-invasive endoscope
27.11.2018 | Leibniz-Institut für Photonische Technologien e. V.

nachricht New China and US studies back use of pulse oximeters for assessing blood pressure
21.11.2018 | University of British Columbia

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Physicists found a correlation between the structure and magnetic properties of ceramics

18.12.2018 | Physics and Astronomy

Unique insights into an exotic matter state

18.12.2018 | Physics and Astronomy

Physicists studied the influence of magnetic field on thin film structures

18.12.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>