冠状动脉旋磨技术(Rotational atherectomy)始于20世纪80年代,早期由DavidAuth发明,1988年初次用于患者的治疗[1]。在一些特殊病变如严重钙化病变,旋磨技术几乎是经皮冠状动脉介入手术(PCI)顺利完成不可缺少的一种技术。冠状动脉旋磨术采用呈橄榄型的带有钻石颗粒旋磨头,根据“差异切割” 或“选择性切割”的原理消除软性、纤维化及钙化的所有形态学斑块;形成一个光滑的内腔通道,消除或减少血管壁的气压性创伤;最小化血管壁的伸展和弹性回缩[2]。对于一些严重狭窄伴重度钙化或纤维化的病变,球囊可能无法通过或病变难以扩张开,不仅即刻效果不理想,远期再狭窄率也较高。冠状动脉旋磨术用物理的方法将动脉硬化斑块祛除,以提高即刻效果,并有可能降低远期再狭窄率,是临床上较为有用的介入治疗手段。本文主要介绍冠状动脉旋磨技术的基本设备、器材、操作流程、护理常规、并发症防治以及相关的临床循证医学证据。1 冠状动脉旋磨术的设备和器材冠状动脉旋磨术的设备和器械包括固定的硬件设备及旋磨导管/导丝等(图1)。1.1 操纵控制台也称主机,是旋磨术所需的总体控制设备,可驱动旋磨导管、监测和控制旋磨头的转速,为术者提供旋磨头工作状态的信息。1.2 推进器与操纵控制台相连接,驱动和控制旋磨导管及旋磨头的移动。它主要由5部分组成:(1)旋磨头控制(移动)手柄:用于控制旋磨头的进退;(2)光纤转速连接缆线;(3)压缩气体连接软管;(4)灌注孔:用于连接冲洗液;(4)导丝制动器:防止导丝的旋转和移动,在旋磨过程中保证导丝位置固定不变。推进器需与旋磨导管相连。脚踏控制板通过控制操纵器气压涡轮的启动与关闭来控制旋磨头的旋转与停止。在脚踏板的右侧有dynaglide开关,当dynaglide处于启动状态时,旋磨头以50 000~90 000rpm低速旋转,用于前进或后退旋磨导管。1.4 高压气体罐为旋磨头提供持续旋转的气体动力旋磨术中所需的气体为压缩空气或氮气,装于专用的耐高压瓶中。压力气体罐调节装置应具备范围在90~110磅每平方英寸的压力调节范围以及最小140L/min的调节能力。1.5 旋磨导管包括旋磨头、导管及鞘管组成。旋磨头呈橄榄型,远端部分带有20~30μm大小的钻石颗粒。旋磨头与柔软的螺旋型的导管体部(驱动轴)相连接,导管的中心腔为0.010英寸,可通过旋磨导丝。在导管的外部为4F(1.4mm)聚四氟乙烯材料的外鞘管,此鞘管具有多种作用:(1)可避免旋磨术驱动轴导管对血管的损伤,起到保护血管壁的作用;(2)在旋磨时可通过外鞘管输注旋磨“鸡尾酒”冲洗液(成分见后述),减小摩擦损伤和热损伤,并预防旋磨中的冠脉痉挛和无再流;(3)可随时将研磨下来的微粒冲掉,以免造成微血管的栓塞和无再流发生。1.6 旋磨导丝为不锈钢材料构成,长度325cm,导丝主干直径为0.009英寸,而呈螺旋型缠绕的尖端柔软部分的直径为0.014英寸。 柔软型旋磨导丝具有良好的可控性和柔软性,但支撑能力较差。而超支撑型旋磨导丝的体部具有较好的支撑力。2 冠状动脉旋磨术的适应证和禁忌证2.1 冠状动脉旋磨术的适应证[3]主要是适合严重钙化病变和严重纤维化病变。2.2 旋磨的禁忌证2.2.1 严重成角的钙化病变;2.2.2 非钙化病变。3 冠状动脉旋磨术的操作流程3.1 病人的准备同常规PCI术的术前准备。3.1.1 术前一日及术日晨给予阿司匹林300mg。因患者在旋磨术后可能需要联合使用支架,应在术前开始给患者加服抗血小板制剂氯吡格雷(用法与支架术相同)。3.1.2 为减少冠脉痉挛等并发症,可在术前须给予钙拮抗剂。3.1.3 可适当地补充液体,保证有效和足够的血容量,以避免术中使用血管扩张剂时发生低血压并发症。3.2 旋磨设备连接和体外测试3.2.1 设备连接在体外将旋磨机与高压氮气筒及控制器相连接,并调整气体压力,以选择适当的转速。从包装内取出推进器,分别连接光纤转速连接缆线、压缩气体连接口、加压灌注液袋,并将旋磨头调节钮固定在距末端2cm 处。然后将导丝通过旋磨头前端的小孔逆行插入旋磨导管内直至尾端(旋磨头距Y型连接器数厘米),并在距旋磨推进器末端数厘米的地方用导丝夹将导丝固定。3.2.2 体外测试开启操纵控制台的开关。测试并调节旋磨头的转速,一般直径≤2.0mm的旋磨头,转速可调节在180 000~200 000rpm,直径≥2.15mm 的旋磨头转速应稍慢,在160 000~180 000rpm左右。3.3 器械准备3.3.1 引导导管的选择冠状动脉旋磨术所选用的引导导管的系列与常规PCI术相似,保证导管足够的支撑力和与冠状动脉开口的同轴性,并根据所需旋磨头的大小选择内腔足够大的引导导管。一般情况下直径≤1.5mm的旋磨头可选择6F的指引导管,1.5~2.15mm的旋磨头需选择7F指引导管,2.15~2.5mm的旋磨头则需要8F的指引导管,理论上是管腔足够大,但实际工作中应尽量避免大旋磨头的旋磨手术。3.3.2 导引钢丝的选择旋磨导丝为专用导丝,别无选择。与其他介入治疗方法(球囊或支架术) 所用导丝不同,它的直径为0.009英寸,长度为325cm,为单根不锈钢丝构成,导丝的尖端(末梢)为呈弹簧状缠绕的铂金构成,这种结构一方面可减少对血管的损伤,另一方面可增加导丝在X光下的可见性。3.3.3 旋磨头的选择旋磨头的大小直接影响旋磨术的效果和并发症率。选用原则应从小的旋磨头开始(burr/artery为 0.5~0.6),通常由1.25mm开始,酌情增大旋磨头,最大比例为0.7~0.8,这样可减少微栓塞和内膜撕裂、急性闭塞等并发症。在选择旋磨头大小的时候应考虑到患者血管的直径、病变的形态、远端血管床情况、左心室功能及其他血管的状态。在下列情况应从小的旋磨头开始:小血管或分叉病变、病变成角较大、严重的钙化病变、完全闭塞病变、长节段病变及导丝发生偏移时。一般选择的第一个旋磨头应较最终所需旋磨头小0.5mm。应特别注意的是,严重迂曲、成角病变以及病变仅位于血管弧度内缘的极度弯曲病变均不能旋磨,≥2.15mm的旋磨头的旋磨应格外小心。3.3.4 术中用药和保驾措施(1)术中用药:与普通球囊扩张相似,手术开始时给予肝素10000u,以后每小时追加1000~2000u,维持ACT>350秒。联合血小板GPⅡb/Ⅲa受体拮抗剂时,应该适当减少肝素用量。在旋磨前/后酌情给予硝酸甘油50~200μg预防或治疗冠脉痉挛等并发症。(2)旋磨“鸡尾酒”冲洗液(加压灌注液袋)的准备:在500ml生理盐水中加入肝素5,000 单位、硝酸甘油2mg、异搏定2.5mg,在旋磨时持续经冠状动脉加压滴注,以减少缓慢血流和无血流现象的发生[4]。(3)预置临时起搏导管:如果病变在优势型右冠状动脉,优势型左回旋支或前降支开口,以及使用2.25mm以上的旋磨头时易发生心动过缓和传导阻滞,应预置临时起搏导管。心动过缓通常发生在旋磨头向前推进时,一般在旋磨停止后5~60秒或咳嗽后可恢复。(4)其他:对左心室功能明显减退或病变血管供血范围大的患者施行旋磨术时,为保证血流动力学的稳定性可考虑行主动脉内气囊反搏泵(IABP)。3.4 手术过程3.4.1 将A型或C型旋磨导引钢丝沿导引导管插过冠状动脉狭窄处并到达血管的远端。将旋磨导管沿导引钢丝缓慢低速(60 000~80 000rpm)前送至狭窄近端,然后将旋磨机马达开至高速(1.7×104一2.0×104r/mln),并缓慢推送推进器上的旋磨头调整钮。同时在推进器的灌注管内输入肝素生理盐水,以减少驱动杆与特氟隆reflon鞘之间的摩擦力,并冷却驱动杆和旋磨头。 旋磨头不能推送过快,以免转速下降过多,磨屑过大发生远端栓塞导致无再流;同时也不要时间太长,以免损伤动脉管壁。当旋磨头多次通过狭窄部位后,根据具体情况决定是否增大旋磨头旋磨。3.4.2 退出旋磨导管旋磨结束后,以低速转动退出旋磨头导管。再次造影,满意后可行PTCA+支架术。3.4.3 操作时注意事项(1)冠状动脉内斑块旋磨术时,必须选择适当规格的旋磨头,遵循从小到大递增原则。文献报 道选用旋磨头直径为血管内径的75%~85%。这种选择常常凭经验,在严重狭窄或(和)钙化或 (和)长管状狭窄者,冠状动脉内斑块旋磨术时,旋磨头直径应从小到大递增。(2)与普通PTCA 相比,冠状动脉内斑块旋磨术时更强调导引钢丝尽量送至血管远端,特别是导引钢丝硬段必须跨越狭窄段,方能保证高速转动的旋磨头沿导引钢丝推进时的稳定性。控制适宜的旋磨头推进速度,一般宜0.5mm/s;并采取"啄食样"推进;(3)控制适宜的负载转速,力求保持在比空载转速减少10%的小范围内变动。必须避免在13×104r/min时工作。低速旋磨会造成碎屑粗大,栓塞远端血管。(4)同一冠状动脉病变部位一般旋磨2~3次,直到旋磨头试探管腔时,转速和声调已接近空载状态。表明管腔已被扩大到与旋磨头直径一致,即将旋磨头撤至病变近端。(5)常规附加PTCA+支架治疗,以求获得理想的管腔增大疗效。图2为阜外医院一例成功的前降支旋磨术病例。3.5 术后护理3.5.1 术后除认真做好冠心病介入治疗后的常规护理外,还应特别注意观察血压、心电图、心肌酶以及病人的症状变化。3.5.2 生命体征的观察 术后立即测心率、呼吸、血压、体温并记录,1 2 h内测量上述指标,1次/h,12 h后改为1次/4 h。若无心力衰竭时,应鼓励病人多饮水,以 促进造影剂的排出,减轻肾脏损害。同时,注意观察尿量、颜色及性质,记录出入液量3 d 。3.5.3 心电监护 术后常规进监护病房监护72 h,以便及时发现心律 失常,及时处理。每小时记录1份12导联心电图。3.5.4 穿刺局部护理 动脉鞘管于术后拔出,拔管后,穿刺部位由操作人员戴无菌手套用手加压止血。术中由于应用肝素抗凝剂不利于止血,压迫止血时间应延长。砂袋加压时,应随时注意砂袋的压迫着力点,随时注意出血情况。密切观察足背动脉搏动及该肢体皮肤颜色、温度、活动情况。嘱病人或家属在病人打喷嚏或咳嗽时,用手按压 砂袋,对穿刺部位施加压力,以免突发血压增高引起穿刺部位出血。如发生出血要重新加压止血,并更换敷料。术后卧床休息72 h,若出现并发症,可适当延长。3.5.5 预防感染及血栓形成 常规手术前后应用抗生素预防感染。术后预防血栓形成,可用低分子肝素3 天,并严密观察有无脑血管意外及出血性病变的征象。4 并发症的预防及处理研究显示冠状动脉旋磨术与PTCA术的并发症发生率相似,包括死亡0.9%, Q波心肌梗死1.3%,急诊CABG1.9%[5]。常见并发症及处理如下:4.1 冠状动脉痉挛是冠状动脉旋磨术的常见并发症,主要以预防为主。通常常规术前给患者口服钙拮抗剂,旋磨时从较小的旋磨头开始,旋磨头与血管的比例≤0.75,每次旋磨的时间不宜过长,一般应短于30秒。其次旋磨前及每次旋磨后酌情冠状动脉内给予硝酸甘油50~200μg,在加压灌注液袋的生理盐水中加入维拉帕米及/或硝酸甘油。最后如硝酸甘油不能缓解冠状动脉血管痉挛,必要时可经静脉或冠脉给予维拉帕米或硫氮唑酮,但需要密切注意患者的血压及心率,避免发生低血压及心动过缓。4.2 心动过缓和房室传导阻滞当右冠和回旋支优势时,发生心动过缓的几率比其他血管要高。用大的磨头治疗前降支的开口或近端可能会发生房室传导阻滞(AVB)。防治措施:患者需要治疗右冠,回旋支是优势血管及LAD的近端治疗,预防性安置临时起博器;咳嗽、阿托品静脉给药增加心率和修正房室传导阻滞(AVB)。4.3 慢血流/无再流旋磨治疗的患者发生慢流和无再流的比率是5%。关键在预防。首选要维持合适的灌注压力,给予硝酸甘油或其他扩血管药物(如腺苷、维拉帕米),尽量减少造影剂用量等。血液动力学不稳定时,尽早置入IABP。对于复杂的血管和病变用磨头消融时掌握合适的旋磨时间。4.4 冠状动脉夹层旋磨治疗的患者造影可见的撕裂的发生比例近10%。主要原因是非钙化病变和磨头过大。应尽快植入支架治疗。4.5 冠状动脉急性闭塞急性闭塞不常见,产生原因是冠脉痉孪或慢血流/无再流。可按常规处理。4.6 血压过低可能有以下因素引起:药物,情绪紧张,机械因素,不合适的补液,心动过缓。 血压过低的治疗以增加液体的输入提供合适的体液和给予多巴安治疗为主,必要时置入IABP。4.7 冠状动脉穿孔是严重的致死性血管并发症,应尽快处理。常见原因包括:磨头尺寸过大,指引导丝的偏离,严重的成角弯曲病变,不合适的手法等。处理方法:退出磨头,送入球囊封堵,尽快植入带膜支架。如果心包填塞发生,需要进行心包穿刺术和外科急诊手术。5总结冠状动脉旋磨术已经在临床应用了20年。随着冠状动脉介入治疗的适应证不断拓展,复杂多支病变、CTO病变、左主干病变、分叉病变的介入治疗逐渐成为大型冠状动脉介入治疗中心的常规工作[6-10]。冠状动脉旋磨术在这些复杂伴严重钙化病变中的应用将会不断拓展其适应证,发挥其独特的治疗作用。
A Visual Guide to Understanding Stroke 看图了解中风 What Is a Stroke? Stroke is a medical emergency and the third leading cause of death in the U.S. It occurs when a blood vessel in the brain bursts or, more commonly, when a blockage develops. Without treatment, cells in the brain quickly begin to die. The result can be serious disability or death. If a loved one is having stroke symptoms, seek emergency medical attention without delay.Stroke Symptoms Signs of a stroke may include:· Sudden numbness or weakness of the body, especially on one side. · Sudden vision changes in one or both eyes. · Sudden, severe headache with unknown cause. · Sudden problems with dizziness, walking, or balance. · Sudden confusion, difficulty speaking or understanding others.Call 911 immediately if you notice any of these symptoms.Stroke Test: Talk, Wave, Smile The F.A.S.T. test helps spot symptoms. It stands for:Face. Ask for a smile. Does one side droop?Arms. When raised, does one side drift down?Speech. Can the person repeat a simple sentence? Does he or she have trouble or slur (含糊的) words?Time. Time is critical. Call 911 immediately if any symptoms are present.Stroke: Time = Brain Damage Every second counts when seeking treatment for a stroke. When deprived 剥夺 of oxygen, brain cells begin dying within minutes. There are clot-busting drugs that can curb brain damage, but they have to be used within three hours of the initial stroke symptoms. Once brain tissue has died, the body parts controlled by that area won't work properly. This is why stroke is a top cause of long-term disability.Diagnosing a Stroke When someone with stroke symptoms arrives in the ER, the first step is to determine which type of stroke is occurring. There are two main types, and they are not treated the same way. A CT scan can (唉~~貌似对全部病人“做个核磁吧?”可能跟早期卒中单元有关,早期CT还是很有鉴别作用的) help doctors determine whether the symptoms are coming from a blocked blood vessel or a bleeding one. Additional tests may also be used to find the location of a blood clot or bleeding within the brain.Ischemic Stroke The most common type of stroke is known as an ischemic stroke. Nearly nine out of 10 strokes fall into this category. The culprit is a blood clot that obstructs a blood vessel inside the brain. The clot may develop on the spot or travel through the blood from elsewhere in the body.Hemorrhagic Stroke Hemorrhagic strokes are less common but far more likely to be fatal. They occur when a weakened blood vessel in the brain bursts. The result is bleeding inside the brain that can be difficult to stop.“Mini-Stroke” (TIA) A transient ischemic attack, often called a "mini-stroke," is more like a close call (千钧一发?). Blood flow is temporarily impaired to part of the brain, causing symptoms similar to an actual stroke. When the blood flows again, the symptoms disappear. A TIA is a warning sign that a stroke may happen soon. It’s critical to see your doctor if you think you've had a TIA. There are therapies to reduce the risk of stroke.What Causes a Stroke A common cause of stroke is atherosclerosis -- hardening of the arteries. Plaque 斑块 made of fat, cholesterol, calcium, and other substances builds up in the arteries, leaving less space for blood to flow. A blood clot may lodge in this narrow space and cause an ischemic stroke. Atherosclerosis also makes it easier for a clot to form. Hemorrhagic strokes often result from uncontrolled high blood pressure that causes a weakened artery to burst.Risk Factors: Chronic Conditions Certain chronic conditions increase your risk of stroke. These include:· High blood pressure · High cholesterol · Diabetes · ObesityTaking steps to control these conditions may reduce your risk.Risk Factors: Behaviors Certain behaviors also increase the risk of stroke:· Smoking · Getting too little exercise · Heavy use of alcoholRisk Factors: Diet A poor diet may increase the risk for stroke in a few significant ways. Eating too much fat and cholesterol can lead to arteries that are narrowed by plaque. Too much salt may contribute to high blood pressure. And too many calories can lead to obesity. A diet high in fruits, vegetables, whole grains, and fish may help lower stroke risk.Risk Factors You Can't Control Some stroke risk factors are beyond your control, such as getting older or having a family history of strokes. Gender plays a role, too, with men being more likely to have a stroke. However, more stroke deaths occur in women. Finally, race is an important risk factor. African-Americans, Native Americans, and Alaskan Natives are at greater risk compared to people of other ethnicities 种源特点.Stroke: Emergency Treatment For an ischemic stroke, emergency treatment focuses on medicine to restore blood flow. A clot-busting medication is highly effective at dissolving clots and minimizing long-term damage, but it must be given within three hours of the onset of symptoms. Hemorrhagic strokes are more difficult to manage. Treatment usually involves attempting to control high blood pressure, bleeding, and brain swelling.Stroke: Long-Term Damage Whether a stroke causes long-term damage depends on its severity and how quickly treatment stabilizes the brain. The type of damage depends on where in the brain the stroke occurs. Common problems after a stroke include numbness in the arms or legs, difficulty walking, vision problems, trouble swallowing, and problems with speech and comprehension. These problems can be permanent, but many people regain most of their abilities.Stroke Rehab 恢复 : Speech Therapy Rehabilitation is the centerpiece of the stroke recovery process. It helps patients regain lost skills and learn to compensate for damage that can't be undone. The goal is to help restore as much independence as possible. For people who have trouble speaking, speech and language therapy is essential. A speech therapist can also help patients who have trouble swallowing.(!!!表示压力很大)Stroke Rehab: Physical Therapy Muscle weakness, as well as balance problems, are very common after a stroke. This can interfere with walking and other daily activities. Physical therapy is an effective way to regain strength, balance, and coordination. For fine motor skills, such as using a knife and fork, writing, and buttoning a shirt, occupational therapy can help.Stroke Rehab: Talk Therapy It's common for stroke survivors and their loved ones to experience a wide range of intense emotions, such as fear, anger, worry, and grief. A psychologist or mental health counselor can provide strategies for coping with these emotions. A therapist can also watch for signs of depression, which frequently strikes people who are recovering from a stroke.Stroke Prevention: Lifestyle People who have had a stroke or TIA can take steps to prevent a recurrence:· Quit smoking. · Exercise and maintain a healthy weight. · Limit alcohol and salt intake. · Eat a healthier diet with more veggies, fish, and whole grains.Stroke Prevention: Medications For people with a high risk of stroke, doctors often recommend medications to lower this risk. Anti-platelet medicines, including aspirin, keep platelets in the blood from sticking together and forming clots. Anti-clotting drugs, such as warfarin, may be needed to help ward off stroke in some patients. Finally, if you have high blood pressure, your doctor will prescribe medication to lower it.Stroke Prevention: Surgery In some cases, a stroke results from a narrowed carotid artery -- the blood vessels that travel up each side of the neck to bring blood to the brain. People who have had a mild stroke or TIA due to this problem may benefit from surgery known as carotid endarterectomy颈动脉内膜切除术. This procedure removes plaque from the lining of the carotid arteries and can prevent additional strokes.Stroke Prevention: Balloon and Stent Doctors can also treat a clogged carotid artery without major surgery in some cases. The procedure, called angioplasty, involves temporarily inserting a catheter into the artery and inflating a tiny balloon to widen the area that is narrowed by plaque. A metal tube, called a stent, can be inserted and left in place to keep the artery open.Life After a Stroke More than half of people who have a stroke regain the ability to take care of themselves. Those who get clot-busting drugs soon enough may recover completely. And those who experience disability can often learn to function independently through therapy. While the risk of a second stroke is higher at first, this risk drops off over time.