你想象过一种这样的心脏支架吗？植入后过一段时间就能完全溶解，从而使得象继发凝血等副作用能够最大程度的减少；同时使得受累动脉的进一步手术变得更简单。事实上这样的支架已经在新西兰奥克兰市医院研发出来了。
心脏支架就是一种支架或网状物，其通常被植入阻塞或狭窄的动脉以保持动脉的开放。支架通常被用于心脏病发作的病人，他们常常有冠脉的阻塞，还用于心绞痛病人。目前，支架都由金属制成，植入以后终生存在。问题是，正因为他们象网筛，所以可在其上形成凝血并逐渐累积最终形成阻塞—这些阻塞在植入后多年内都可发生。这些阻塞叫做“晚期支架血栓形成”。
这一新的支架，叫做BVS依维莫司-洗脱支架（Bioabsorbable Vascular Solutions公司的产品），是由一种三年后就可消失的聚合物制成。该聚合物在体内的产物是乳酸，最终会分解成二氧化碳和水（通过三羧酸循环代谢掉）。
John Ormiston是该团队的领导者，他说：“你不会在受伤的胳膊痊愈以后还戴着那个铸型。同理，动脉复原后仍旧留着支架在原处也是毫无意义的。 我想，将来也许我们回顾起来十年前我们还在把金属块放入冠状动脉并让他们终生保持在那会觉得可笑。”
研究者说：新的支架有很多优点：
－更低的支架血栓发生率。
－使得进一步的动脉手术变得更简单。
－支架为非金属材料，CT和MRI影像更清晰。
－支架很柔韧，很适于植入动脉。
－它也是一个药物洗脱支架，这意味着它可以释放药物－其洗脱期大约是120天。
根据Ormiston博士的数据，该支架在30例单个、先天冠脉损伤的病人的临床实验中有很高的成功率。手术后30天的随访期间没有发生严重心脏意外。Ormiston博士工作在奥克兰的Green Lane and Mercy医院，他说在病人住院期间没有缺血导致的严重心脏意外事件发生，手术的成功率是100%。
Dissolving Heart Stent Created
Main Category: Cardiovascular / Cardiology News
Article Date: 11 Dec 2006 - 12:00pm (PST)
Imagine a heart stent which completely dissolves after a while, minimizing the risk of side-effects, such as secondary blood clots, while at the same time making it easier to perform further surgery on the affected artery. Such a stent has been developed at Auckland City Hospital, New Zealand.
A heart stent is a type of scaffold, or mesh, which is placed in a blocked/narrowed artery to keep it open. Stents are commonly used for heart attack patients, people with a clogged artery, as well as patients with angina. Currently, stents are made of metal and stay where they are placed, intact, for life. The problem is that because they are like a mesh, clogs can build up and created blockages - these blockages can occur many years after the stents were placed. These blockages are called 'late stent thrombosis'.
This novel stent, called the BVS everolimus-eluting stent (Bioabsorbable Vascular Solutions, Inc.), is made of a polymer that disappears after three years. The polymer turns into lactic acid. It eventually breaks down into carbon dioxide and water (metabolized through the Krebs cycle).
Dr John Ormiston, team leader, said "You wouldn't want to keep a cast on a broken arm after its mended. In the same way, there is no point keeping a stent in place after the artery has healed. I think we'll look back in 10 years' time and laugh at the idea of putting bits of metal into coronary arteries that stay there for ever."
The researchers say this new stent has many advantages:
-- Lower risk of late stent thrombosis
-- Easier to perform further surgeries on the artery
-- Clearer CT and MRI images because stents are not made of metal
-- As they are flexible, they fit more snugly inside the artery
It is also a drug eluting stent, meaning it releases a drug - its elution period is about 120 days.
The BVS stent had a high success rate in a trial with 30 patients who had single, de novo, native coronary artery lesions. - no major adverse cardiac events were reported during a 30-day follow-up, according to Dr. Ormiston, who works at the Green Lane and Mercy Hospital in Auckland, New Zealand. He said there were no cases of ischemia-driven major adverse cardiac events during the patients' stay in hospital. The procedural success rate was 100%.
"Bioabsorbable Coronary Stents Successfully and Safely Deployed"
Transcatheter Cardiovascular Therapeutics
Click here to view report online
"Auckland patients test meltaway heart device"
Mercy Angiography, New Zealand
Written by: Christian Nordqvist
Editor: Medical News Today
http://www.medicalnewstoday.com/healthnews.php?newsid=58669
编辑：蓝色幻想
