马普外科手术中二氧化碳激光的仪器与技术.doc

INSTRUMENTATION AND TECHNIQUES FOR CARBON DIOXIDE LASERS IN EQUINE GENERAL SURGERY马普外科手术中二氧化碳激光的仪器与技术During the past 20 years the carbon dioxide laser has become an important surgical instrument in human and veterinary medicine. The unique properties of this laser make it the instrument of choice for precise incision and vaporization of tissue at the body surface with minimal hemorrhage and morbidity. Although a variety of wavelengths have become available for clinical use, the carbon dioxide laser remains the most commonly used wavelength in general surgery. This laser can be used to accomplish a variety of surgical procedures in horses.在过去20年的二氧化碳激光器已经成为人类医学和兽医学的重要的外科器械。这种激光器的独特性质，使得它成为在身体表面以最小的出血和发病率进行精确切割和组织的汽化的仪器。虽然各种波长的激光已变得可在临床上使用，但在一般手术中，二氧化碳激光器仍然是最常用的波长。该激光可以被用来完成各种马外科手术。CARBON DIOXIDE LASER INSTRUMENTATION二氧化碳激光仪器The unique property of any laser is its ability to generate a powerful form of electromagnetic energy or light that is monochromatic (one frequency or color), coherent (energy waves arc synchronized in time and space), and highly collimated (minimally divergent). These specific properties of laser light enable the surgeon to achieve tissue effects that are unique to the wavelength of the instrument.任何激光器的独特属性是它能够产生一个强有力的电磁能或单色光性（一个频率或颜色）的、一致性（能量波在时间上和空间同步）、和高准度性（最小发散）的光。激光的这些特定属性使外科医生能够做到切割不同组织使用特有的仪器波长的效果。The lasing medium for the carbon dioxide laser is a mixture of carbon dioxide, helium, and nitrogen gas that is either self-contained within the optical cavity (sealed-tube system) or vacuum pumped into the optical cavity from external cylinders (flowing gas system). High voltage DC electric current or radiofrequency waves are used to excite the gas medium, emitting a laser beam with a wavelength of 10.6 ixm. Although both systems produce reliable power for surgery, the flowing gas systems have a cleaner output in the supcrpulso mode, can generate higher powers, and are more stable and reliable at low powers.1 The laser beam is reflected along a series of mirrors within an articulated arm and is focused onto tissue through a lens in the handpiece (Fig. 1). Lenses with focal lengths of 50 and 125 mm produce focused spot sizes of approximately 0.1 to 0.2 mm, respectively. The carbon dioxide laser may also be used with an operating microscope or through rigid or flexible hollow waveguides. Lasers used for tissue welding applications are equipped with stable low-power regulation devices that assure a unifonn power output (maximum 10% variation) in the low power range that is required for coagulation of collagen.二氧化碳激光器的激光介质是两种包含的光纤管（密封管系统），或从外部泵入真空圆筒光学腔内（流过气体系统）在内的二氧化碳、氦气和氮气的混合物。高压直流电流或高频波用于激发气体介质，发射10.6m波长的激光束。虽然这两个系统都可以产生可靠的动力来进行手术，但流动气体系统在超脉冲模式可提供更清洁的输出，可以产生更高的功率，而且在低功率时更稳定可靠。激光束沿关节臂内的一系列反射镜反射，并通过在手持激光枪（图1）的透镜聚焦到组织上。透镜具有50和125毫米焦距，产生约0.1至0.2毫米尺寸的聚焦点。二氧化碳激光器，也可以使用与在手术显微镜或通过刚性或柔性的中空传到管。用于组织切割应用的激光器都配备有稳定的低功率调节装置，即保证均匀的功率输出（最大10的变化），是要求的凝集胶原的低功率范围。Figure 1. The Sharplan 1100 C02 Laser. (A) control panel, (B) articulating arm, (C) handpiece and lens, and (D) lasing cavity. (Courtesy of Mr. Avi Farbstein, Sharplan Lasers, Inc, Allendale, NJ.)图1. Sharplan1100二氧化碳激光器。（A）控制面板（B）关节臂，（C）手柄和镜头，（D）激光腔。 （提供者Mr. Avi Farbstein, Sharplan Lasers, Inc, Allendale, NJ.。）For most laser procedures, a routine surgical pack is used to support the laser as the principal means of dissection. A bowl of saline is used to keep tissues moist throughout the procedure and to remove char when required. Anodized or brushed surgical instruments reduce the danger of reflection burns to the patient and surgeon. However, routine stainless steel instruments can be used safely with the carbon dioxide laser, provided care is taken to avoid directing the laser beam onto the surface of these instruments. Optical backstops are focusing guides with right-angle blades at the tip that attach to the end of the laser handpiece . The tissue to be incised is isolated by placing the blade beneath it and lifting the handpiece to create tension. When the laser is activated, the tissue is divided and deeper structures are protected from the laser beam by the metal surface of the backstop. Quartz or metal laser rods are another effective means of backstopping the laser beam. They are similarly placed beneath target tissue through a small incision and are used to provide traction and countertraction at the site of the incision and to stop the laser beam as the dissection is advanced (Fig. 2). Whenever tissue is vaporized, a laser plume is generated that contains organic materials and water vapor. Evacuation of the laser plume is accomplished with a dedicated smoke evacuation system that includes a powerful rheostat-controlled vacuum motor, an in-line filter, and sterilized tubing that can be used in the operative field. A portable light source or head lamp is helpful to illuminate the field.对于大多数激光程序，一个常规的外科手术包是用来帮助激光设备的主要解剖手段。一瓶盐水是用来保持组织在整个过程中湿润，并在需要时消除焦糊的组织。电镀或拉丝手术器械要防止反射的危险，以避免灼伤病人和外科医生。不过，常规不锈钢器械可以安全地与二氧化碳激光器配合使用，只要小心地避免将激光束引导到这些仪器的表面上即可。光源在光纤导管与直角反光片聚焦在激光枪头的顶端。被切开的组织是激光枪的下面，并抬起手持设备使组织处于紧张状态。当激光被激活时，组织被分割，而且更深的组织结构通过逆止的金属表面上被保护免受激光束。石英或金属激光棒是“支助”激光束的另一种有效的手段。它们通过一个小切口被类似地放置靶组织下方，在切口的部位用来提供牵引力和组织张力，并作为夹层停止激光束前进（图2）。每当组织汽化，激光烟雾生成有机碳和水蒸汽。激光烟雾通过一专用排烟系统疏散，该系统包括一个强大变阻器控制的真空马达，一个管状过滤器，和一个可以在术野中使用的灭菌管。以及一个便携式光源或头灯有帮助的照明领域。The Swiftlase (Sharplan Lasers Inc, Allendale, N) is an innovative accessory device used with the carbon dioxide laser to enable application of a defocused, yet powerful spot size of energy to tissue for debridement or sanitization. It consists of a series of three motorized rotating mirrors within a housing that is placed between the handpiece and the articulating arm of the laser and a battery pack. When activated, the Swiftlase reflects the laser beam onto these moving mirrors to spread the light over a relatively wide area while maintaining a uniform and concentrated power density (Fig. 3).Swiftlease（Sharplan激光器公司，的Allendale，N）是使用二氧化碳激光器的创新附件装置，用于光源的散焦，而散焦较大的光源用于组织的清创或消毒。它由一系列内放置三个机动旋转反射镜的手持机器、激光的活动连接臂和电池组的的机械外壳组成。在激活时，该swiftlase反射激光束投射到这些可移动的镜子来传播光在相对宽的区域，而且保持统一和集中的功率密度（图3）。Flexible hollow waveguides are available for use with the carbon dioxide laser. The laser beam is reflected along the lining of these 1-m waveguides to emerge with a slightly diffused spot at the distal tip. Although these waveguides can be used for open general surgery, trans endoscopic use of these waveguides awaits development of protective layers to prevent leakage of the light beam within the biopsy channel, which could damage the fiberoptic bundles of the endoscope.柔性的中空波导可用于与二氧化碳激光器的使用。沿这些1-m的波导的内层反射的激光束在远端尖端出现轻微扩散光斑。虽然这些波导可以用于开放式普通外科，但反式内窥镜使用这些波导仍等待着防护层的开发,防止光束泄漏到手术通路内,这可能损坏内窥镜的纤维束。Figure 2. Placement of a laser rod beneath the skin to elevate the target tissue establishes traction and countertraction, as well as protects tissues deep to the target tissue from inadvertent damage.图2.放置在皮肤下的激光棒提升目标组织下方的激光棒提升组织的牵引力和组织张力。并保护深层目标组织的损伤。Rigid hollow waveguides and operating microscope attachments also direct the laser beam through a hollow tube onto target tissue through lens systems that are incorporated within the proximal segment of the va oguido. These dox ices are used commonly in human gynecologic and neurosurgical applications, but are not currently used in equine general surgery.刚性空心波导和手术显微镜装件也通过波导的近侧段内的方式并入透镜系统直接通过中空管的激光光束投影到目标组织。这些设备通常用于人类妇科和神经外科应用，但目前并不在马普外科中使用。PRINCIPLES AND TECHNIQUES OF LASER SURGERY 激光手术原理与技术Properties and Control of the Carbon Dioxide Laser二氧化碳激光的性能和控制The carbon dioxide laser emits light in the infrared portion of the electromagnetic spectrum and exerts a thermal effect on tissue. Optimal results of laser surgery are achieved by selective use of this wavelength to achieve specific surgical objectives. The carbon dioxide wavelength is absorbed almost exclusively by water at the point of contact, making this laser a precise cutting instrument. This wavelength is not transmitted through fluids and is absorbed uniformly by tissues independent of pigment.二氧化碳激光器在电磁频谱的红外部分发射光，并对组织产生热效应。激光手术的最佳效果是通过选择性地使用这个波长来实现特定的手术目标。二氧化碳波长在接触点几乎完全被水吸收，从而使该激光成为精确的切割器械。该波长不通过的流体传送，是通过均匀地组织独特的色素来吸收。The surgeon can adjust the power, focusing, and timing of laser emission. Power density is defined as the power (watts) of the laser beam divided by the area of the spot size on the tissue surface. The surgeon can increase the spot size by moving the handpiece further away from the target tissue and spreading the power over a larger area. Because the area of the spot size is an exponential function doubling the spot size reduces the power density by a factor of 4.外科医生可以调整功率，聚焦，以及激光发射的时长。功率密度被定义为激光束通过在组织表面上的光点大小的面积除以功率（瓦）。外科医生可以通过移动手持设备来远离目标组织和在变大的区域扩展功率来增加光斑尺寸。因为光斑尺寸的面积是一个指数函数(A = r2)，双倍增长光点尺寸会减少了4倍的功率密度。Temporal (pulse length) and mode (pulse cycle) controls of the laser also determine the amount and character of energy delivered to the tissue surface. The shutter system of the carbon dioxide laser provides great versatility, allowing operation in continuous mode, pulse mode, or super pulse mode. Continuous mode provides a uniform power output from the moment the laser is activated until the foot pedal is released, generating maximum power and thermal effect. Alternately, the shutter system of the laser can open and close the exit port to produce pulses of energy from 0.1 to 2.0 seconds. The surgeon may select an individual pulse or a series of pulses that continue as long as the foot pedal is depressed. Super pulse mode delivers pulses of up to 500 W for 50 to 200 microseconds at a repetition rate of 25 to 250 pulses per second. Because collateral thermal injury is dependent on both total energy applied to tissue and the time over which the energy is delivered, use of pulsed modes that provide time for tissue cooling between pulses provides for increased precision with minimal lateral injury and charring but less hemostasis. 时间(脉冲长度)和模式(脉冲周期) 控制的激光也确定输送到组织表面的量和能量的性质. 二氧化碳激光器的快门系统提供了很大的通用性，允许在连续模式下，脉冲模式，或超级脉冲模式操作。连续模式从激活发出激光到松开脚踏板提供了均匀的输出功率，产生最大功率和热效应。或者，激光的快门系统可以打开和关闭所说的开关，来产生0.1至2.0秒的能量脉冲。外科医生只要踩下脚踏板就可以可以选择单个脉冲或一系列继续的脉冲。超级脉冲模式以每秒25到250个脉冲的重复率提供50到200微秒高达500瓦的脉冲。因为附带的热损伤取决于施加于组织总能量和在其上的能量传递的时间，利用脉冲模式，提供了在脉冲时足够的冷却时间，带来最小的组织损伤和碳化，但是止血效果小。Tissue Effects of the Carbon Dioxide Laser二氧化碳激光对组织的影响When laser energy interacts with biologic tissues, it is either trans-mitted, reflected, scattered, or absorbed. The response of a particular tissue (such as skin or muscle) to carbon dioxide laser emission is a function of the properties of the carbon dioxide wavelength and that tissues cellular architecture and moisture content.当激光能量与生物组织相接触时，它会发生传输，反射，散射，或吸收。特定组织（如皮肤或肌肉）由该组织中的细胞结构和水分含量，在被二氧化碳激光发射二氧化碳波长的特殊的功能的响应。If tissue temperature is raised above 50, denaturation and coagulation of protein occurs. As tissue temperatures approach 100, further desiccation takes place. At or above 100C heating of intracellular water ruptures the cell membrane, causing vaporization of tissue. Laser incisions are characterized by zones of thermal injury, the size of which can be manipulated to achieve a desired clinical effect (Fig. 4). If a precise incision with minimal thermal effect is desired, the carbon dioxide laser may be adjusted to high power and super pulse mode with a rapid hand speed used to separate the tissue. If maximum coagulation is required, the laser is set for low power output and the laser beam is kept in contact with tissue for a longer period to slowly heat the tissue at greater depth. This causes a greater degree of thermal necrosis or ablation by conduction of heat into the surrounding tissue and provides excellent hemostasis by coagulating small blood vessels.如果组织的温度上升至50度，会发生蛋白的变形及凝固。随着组织温度接近100度，会发生进一步的脱水。细胞内水分上升到100度，会出现细胞的破裂，并引起组织汽化。激光切口的特点是手术区域的热损伤，这些区域，这些区域可根据临床要求所需操作来控制大小（图4）。理想情况下在最小的热效应下得到一个精确的气口，通过调整二氧化碳激光器以高功率和超脉冲模式来进行快速的组织分离。如果需要较大的血液凝结，应将激光设备设置在低功率输出，并且保持激光束与组织接触较长的时间，慢慢的持续的对组织加热。由热传导到周围组织会导致更高程度的热坏死或烧灼，以及通过凝固小血来管提供了非常好的止血效果。Although the hemostatic property of the carbon dioxide laser is well documented, controversy surrounds the claim of lymphatic sealing by lasers. Several authors state that lymphatic vessels are sealed by the carbon dioxide laser, but others report patent lymphatic channels. One study showed that technetium-labeled colloid placed in a wound migrated into regional lymph nodes from laser-induced wounds similar to the pattern seen with scalpel incisions.虽然二氧化碳激光器的止血性能是有根据的，但争议围绕激光器导致的淋巴密封。一些作者指出，二氧化碳激光器会封闭淋巴管，但是还有一些报道淋巴有独有的通道。一项研究表明，将锝标记的胶体放置在用激光切割的伤口上，自后可以看到标记物出现在手术切口及淋巴结的图像。The sealing of lymphatic vessels by the carbon dioxide laser may be a function of the mode and power applied to the tissues. Just as superpulse mode and high powers tend to create precise incisions with minimal hemostasis because of minimal transfer of heat to adjacent tissue, a similar effect on lymphatic vessels (negligible coagulation of lymphatic vessel margins) is reasonable to expect. In the authors clinical experience, the use of low powers and longer application times with continuous mode coagulates not only small blood vessels but also small lymphatic vessels.二氧化碳激光密封淋巴管由可能是由于施加到组织中的模式和功率的导致。正如超级脉冲模式和高功率模式，因为热最小转移到相邻组织，而易于产生精确的切口，且出血量少。淋巴管会出现类似的效果（淋巴管边缘可以忽略凝血）也是合理的。在笔者的临床经验，采用低功率和连续模式，使用更长的时间，不仅凝固小血管也凝固小淋巴管。Creating an Incision with the Carbon Dioxide Laser使用二氧化碳激光进行切口Incisions are made with the carbon dioxide laser using no-touch” technique. Tactile feedback is replaced by coordination of observed tissue effects with movement of the handpiece. The target tissue is placed under tension in a plane perpendicular to the length of the incision, and the laser beam is passed over the tissue with the beam in focus. Super pulse mode is used for skin incisions to minimize collateral thermal injury, whereas continuous mode is more efficient for dissection of muscle, fascia, and subcutaneous tissues. Effective traction and countertraction are critical for the creation of a clean incision with minimal collateral thermal injury. An assistant can provide this tension on the skin surface with fingers protected by moist gauze or by using small plexiglass squares arranged on either side of and parallel to the incision. The surgeon may also provide this traction by use of laser rods or with fingers kept distant from the point of laser emission. For deeper planes of dissection, mechanical retractors can be used to create tissue tension (Fig. 5).使用“无接触”技术的二氧化碳激光器进行切口。通过调试及运作手持器械来观察组织的形态来代替触觉的反馈。被激光和光束切割的组织在张力的作用下与切口的面相垂直。切开皮肤一般使用超脉冲模式，来尽可能减少附带的热损伤，而持续模式在切割肌肉、筋膜和清理皮下组织时更有效。有效的牵引力和张力是在最小热损伤情况下创造一个干净切口的关键。医师助理可以使用湿纱布保护组织或平行于切口的小有机玻璃块，在皮肤表面提供所需的张力。外科医生还可以使用激光棒或用手指牵引组织来保持与激光点的距离。用于解剖更深组织的支架和机械拉钩可以用来提供组织张力（图5）。Volume Ablation and Coagulation of Tissue组织的烧灼和组织凝结The carbon dioxide laser is the instrument of choice for precise vaporization of small or large lesions at the bodys surface. High power (60 to 100 W) with continuous or pulsed mode is used to remove tissue in layers until an endpoint is achieved. Because of the peak absorption of the wavelength by water, the effect is immediate, precise, and independent of tissue pigment. Tissue vaporizes into a smoke plume, and the degree of vaporization can be assessed immediately. This is referred to as the WYSIWYG effect (what you see is what you get). To achieve an even plane of tissue vaporization, a cross-hatched pattern is used with a defocused beam to minimize furrowing of the tissue. Use of the Swiftlase can also help to create even ablation or coagulation of the tissue surface.二氧化碳激光器是在精确汽化动物体表上或大或小的病变的首选仪器。以高功率（60至100瓦）连续或脉冲模式，可用于多层组织的切割，直到切割完成。因为波长被水和独特的组织色素吸收，其效果是即时的，明确的。组织汽化出现烟柱，并且可以立即对汽化程度进行评估。这被称为所见即所得的效果（你看到的就是你得到的）。实现组织表面的汽化，使用交叉线模式和散焦光束来最小化的切开组织。使用Swiftlase也可以帮助组织表面出现烧灼或凝固。Sanitizing the Operating Field手术区域的消毒One of the advantages of laser surgery is the antimicrobial effect of the heat generated by the laser beam. In vitro, low power radiation with carbon dioxide lasers is an effective means of sterilization of instruments contaminated with microorganisms. In another in vitro study, comparative bactericidal exposures for common pathogenic bacteria were determined using the carbon dioxide laser. At an energy density of 32 J/cm2, more than 90 of all bacteria were killed. No apparent difference existed in the susceptibility of particular bacteria to the killing effects of carbon dioxide radiation. This property of laser irradiation can be used to advantage in debridement and sanitization of contaminated wounds. For the uniform application of energy, a relatively large spot size (5 mm) should be used. To achieve an energy density of 32 J/cm2 with this spot size, 20 W of power are required for a total exposure time of 0.3 seconds.激光手术的优点之一是由激光束产生的热量具有抗微生物效果。在体外，用二氧化碳激光器的低功率辐射被微生物污染的器械，是一种有效的消毒手段。在另一个体外研究中，使用二氧化碳激光器进行了测定，比较辐射常见致病菌的杀菌效果。在32焦耳/平方厘米的能量密度下，90以上的细菌被杀死。二氧化碳辐射的杀菌作用，对于特定细菌不存在明显的敏感性差异。激光照射该特性可用于清创和污染伤口的消毒。能量是均匀放射的，使用时的光斑比较大（5毫米）的时候。该光点的能量密度能达到32焦耳/平方厘米，达到20瓦功率需要照射0.3秒。LASER SAFETY激光安全Laser safety requires an understanding of laser physics and instrumentation by all operative personnel. Operative laser safety includes eye protection, burn prevention, electric safety precautions, fire prevention, and smoke plume evacuation. Surgeons and technicians operating the laser must bo trained in laser safety protocol and one individual in the group should assume the responsibilities of a laser safety officer to ensure that proper safety protocol is observed at all times.激光的安全使用需要一个对激光的原理和仪器仪表等所有工作都了解的人员。手术激光的安全，包括保护眼睛、防止烧伤，用电的安全防范措施，防火，消散烟雾。外科医生和技术人员在操作激光前必须经过培训，安全使用激光的团队中应该有一个人担任激光安全负责人的职务，来确保在任何时间都遵守其安全使用规则。Preventing Uncontrolled Exposure to the Laser Beam意外暴露于激光光束的防范Protection of operative and clinic personnel includes use of safety glasses and warning signs and control of access to the operating room. For carbon dioxide laser surgery, the nominal hazard zone is a 1-m diameter sphere centered a