Studies in the development of a novel side-branch stent

新型侧枝支架的研制

• 批准号: MR/L00514X/1
• 负责人: Anthony Gershlick
• 金额: $ 75.51万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FL00514X%2F1
• 关键词: Studies; development; novel; side; branch

Coronary artery disease is common. It occurs due to build-up of fatty deposits in the wall of the coronary arteries which supply blood to the heart muscle. This results in inadequate blood supply and therefore insufficient oxygen getting to the heart muscle causing cramp like sensation in the chest - angina. The commonest way of treating this is with stents; small wire mesh devices that keep the artery open. 4 million stents are placed in patients worldwide each year. In about 15% of patients the narrowings occur at a branch point which may then require the deployment of 2 stents at that point -one in the main artery and a second one abutting it in the side branch. If the angle between the main branch and the side branch is narrow (ie less than 90 degrees) and as stents have square ends, accommodating the angle between the main branch and the side branch is impossible - there is either a gap or an overlap, both of which can cause problems. A gap will result incomplete coverage of the disease while overlap of stents canresult in re-narrowing of the blood vessel and sometimes can lead to clot forming at this point, which can in turn lead to blocking of the artery and hence lead to a heart attack. The aim of this project is to develop a novel stent that can be placed in the side branch (with a specially designed end that can be modified by a balloon in the main branch) but without the side branch stent collapsing into the side branch artery lumen and obstructing blood flow. A second standard stent could then be placed in the main artery. We have worked extensively with a prototype design company (Protomed, Marseilles) to produce such a stent. Preliminary work involved computer modelling, simulation experiment, and computer assessment to see how a proposed stent design would behave when it is deployed in the artery. Using this method, stent designs with good mechanical properties (virtual radial strength, deliverability and recoil) were refined and 2 early prototypes were produced and tested in videoed side branch models to see how they performed. The prototypes were also placed in 2 pigs and the results assessed with a special X ray technique- micro CT. This work showed that the concept of producing a stent with a modifiable end was viable, however these experiments also showed that modifications are required to produce stents that completely cover the vessel side branch with good mechanical properties.The proposed research will take this preliminary work forward. We have liaised with our collaborators at Protomed Labs to determine how the initial designs to the modifiable end of the stent need to be changed to overcome some of the problems seen within the initial prototypes. We will then test these new designs virtually using computer modelling, to see how the stents would behave when they are deployed at various angles. This is an important stage, as any problems will require further modifications to the design and retesting. We will then laser-cut the stents from cobalt chromium and test these by deploying them within silicone models of bifurcations (2 models representing different angles). The deployment of the stent will be filmed and analysed to see how the modifiable end of the stent behaved. We will look to ensure that none of the stent struts impinge into the lumen of the bifurcation model. Mechanical properties of the stent will also be assessed. Any problems with be addressed with further design modification. Once the prototypes are successful, we will test them again in pigs to see how they perform in actual blood vessel branch points, and also in 28 day experiments which will give important information regarding the degree of healing around the stent, and to ensure no early complications of such a stent arise, such as formation of blood clot around the stent. The aim of this research is to produce a stent that can be used safely, effectively and with ease to treat this difficult aspect of coronary disease.

冠状动脉疾病很常见。这是由于为心肌提供血液的冠状动脉壁上脂肪堆积所致。这会导致血液供应不足，从而导致进入心脏肌肉的氧气不足，导致胸痛痉挛般的感觉。最常见的治疗方法是支架，也就是保持动脉通畅的小金属丝网装置。全世界每年有400万个支架植入患者体内。在大约15%的患者中，狭窄发生在一个分支点，这可能需要在该点放置两个支架-一个在主动脉，另一个在侧支。如果主支和侧支之间的角度很窄(即小于90度)，并且支架的末端是方形的，则不可能调节主支和侧支之间的角度--要么有间隙，要么有重叠，这两种情况都会造成问题。缝隙会导致疾病的不完全覆盖，而支架的重叠可能会导致血管再次狭窄，有时会导致在这一点上形成血栓，这反过来可能导致动脉堵塞，从而导致心脏病发作。该项目的目的是开发一种新型支架，该支架可以放置在侧支(有一个特殊设计的末端，可以通过主支中的球囊进行修改)，而不会使侧支支架塌陷到侧支动脉管腔内，从而阻碍血流。然后可以在主动脉内放置第二个标准支架。我们已经与一家原型设计公司(马赛Protomed)进行了广泛的合作，以生产这样的支架。初步工作包括计算机建模、模拟实验和计算机评估，以了解拟议的支架设计在部署到动脉中时会有什么表现。利用这种方法，改进了具有良好力学性能(虚拟径向强度、可交付性和反冲)的支架设计，并制作了2个早期原型，并在视频侧支模型中进行测试，以了解它们的表现。原型也被放置在2头猪身上，结果用一种特殊的X射线技术-微型CT进行评估。这项工作表明，制造末端可修改的支架的概念是可行的，但这些实验也表明，需要进行修改才能生产出完全覆盖血管侧支的支架，并具有良好的机械性能。我们已经与Protomed Labs的合作者联系，以确定需要如何更改支架可修改端的初始设计，以克服初始原型中看到的一些问题。然后，我们将使用计算机建模来虚拟测试这些新设计，以查看支架在不同角度展开时的表现。这是一个重要的阶段，因为任何问题都需要对设计和重新测试进行进一步的修改。然后，我们将激光切割钴铬支架，并将它们部署在硅胶分叉模型中进行测试(两个模型代表不同的角度)。支架的展开将被拍摄和分析，以了解支架的可修改端的行为。我们将确保支架支柱不会撞击分叉模型的管腔。支架的机械性能也将得到评估。任何问题都将通过进一步的设计修改来解决。一旦原型成功，我们将在猪身上再次测试它们，看看它们在实际血管分支点上的表现如何，还将在28天的实验中提供有关支架周围愈合程度的重要信息，并确保此类支架不会出现早期并发症，如支架周围形成血栓。这项研究的目的是生产一种可以安全、有效和轻松地使用的支架，以治疗这一棘手的冠状动脉疾病。

项目成果

Pre-Clinical studies in a novel side-branch stent

新型侧枝支架的临床前研究

• 发表时间: 2017
• 期刊: Heart
• 影响因子: 5.7
• 作者: Banning A S

5 Developing a novel stent concept in the management of bifurcation disease

5 开发治疗分叉疾病的新型支架概念

• DOI: 10.1136/heartjnl-2016-309588.5
• 发表时间: 2016
• 期刊: Heart
• 影响因子: 5.7
• 作者: Banning A

DEVELOPMENT OF A NOVEL SIDE-BRANCH STENT: IN-VITRO STUDY

新型侧枝支架的开发：体外研究

• DOI: 10.1016/s0735-1097(17)34454-6
• 发表时间: 2017
• 期刊: Journal of the American College of Cardiology
• 影响因子: 24
• 作者: Banning A