Laser Sealing and Cutting of Vascular Tissues

摘要 手术期间血管组织的常规缝合结扎是耗时且技术密集的。使用 基于能量的器械能够更快速、更有效地结扎血管和组织， 在手术过程中，标准缝线和机械夹会将异物留在体内， 通过交换工具的需要来完成程序。超声（US）和射频（RF）能量- 基于的装置加快了许多劳动密集型的外科手术，包括肺叶切除术，肾切除术， 胃分流术、脾切除术、甲状腺切除术、子宫切除术和结肠切除术，显著节省了费用。 然而，射频和超声器械都有局限性，包括可能出现不期望的炭化， 不必要的大的附带热损伤区，平均热扩散大于1 mm。 主要关注的是对邻近关键组织结构的意外热损伤的可能性， 在狭小的空间里进行精密的手术此外，US器械的活动钳口可以达到 温度超过200摄氏度，可能需要20秒以上的时间冷却到可用状态。 在进一步应用之前保持温度。RF活动钳口上的最高温度 器件的温度较低（< 100 oC），但观察到较大的热扩散。在过去的8年里，我们的实验室 一直在开发一种新的替代方法，使用红外（IR）激光器进行血管密封。几个优点 基于激光的血管组织凝闭和切割与基于传统US和RF能量的 器械包括：（1）更快速地凝闭和切割血管组织，凝闭和切割时间短至1 s （2）能量更直接地沉积到组织中，附带热扩散小于1 mm;（3） 更强的血管凝闭和更高的爆破压力（高达1500 mmHg）;（4）能够 血管组织的光学密封和切割而不需要可展开的机械刀片来平分 组织凝闭;（5）与超声波（~ 200 oC）相比，钳口峰值温度较低（< 60 oC），更安全 和射频（~ 100 oC）器械;（6）凝闭大于5 mm的大血管。然而， 关于我们对激光-组织相互作用的基本理解，仍然存在着几个基本问题 我们的方法的机制和可行性，然后才能在临床上采用。以下具体目标 本文旨在回答这些基本问题，从而促进激光器参数和器件设计的优化 用于血管组织的密封：（1）作为函数的血管的光学和热性质测量 组成（胶原/弹性蛋白比例）、温度和压力;（2）腹腔镜手术的设计和测试 血管闭合装置，集成光学诊断，用于确认血管闭合成功， 对邻近组织结构（例如神经）的损伤;（3）激光、超声和射频器械之间的直接比较 在体内急性猪模型中，确定凝闭和切割时间并量化附带热损伤。

Abstract Conventional suture ligation of vascular tissues during surgery is time consuming and skill intensive. Use of energy-based devices enables more rapid and efficient vessel and tissue ligation to maintain hemostasis during surgery than standard sutures and mechanical clips, which leave foreign objects in the body and disrupt the procedure through the need to exchange instruments. Ultrasonic (US) and radiofrequency (RF) energy- based devices expedite a number of labor-intensive surgical procedures, including lobectomy, nephrectomy, gastric bypass, splenectomy, thyroidectomy, hysterectomy, and colectomy, with significant cost savings. However, both RF and US devices have limitations, including potential for undesirable charring and unnecessarily large collateral thermal damage zones, with thermal spread averaging greater than 1 mm. A major concern is the possibility of unintended thermal damage to adjacent critical tissue structures when performing delicate procedures in confined spaces. Additionally, the active jaw of US devices can reach temperatures in excess of 200 oC during an application and can take greater than 20 s to cool to usable temperatures before proceeding with further applications. The maximum temperatures on the active jaw of RF devices are lower (< 100 oC), but larger thermal spread is observed. Over the past 8 years, our laboratory has been developing a novel alternative method using infrared (IR) lasers for vessel sealing. Several advantages of laser-based sealing and cutting of vascular tissues compared to conventional US and RF energy-based devices include: (1) More rapid sealing and cutting of vascular tissues with seal and cut times as short as 1 s each; (2) More directed deposition of energy into tissue with collateral thermal spread of less than 1 mm; (3) Stronger vessel seals with higher burst pressures (up to 1500 mmHg); (4) An integrated device capable of optical sealing and cutting of vascular tissues without the need for a deployable mechanical blade to bisect tissue seals; (5) Safer profile with lower jaw peak temperatures (< 60 oC) compared to ultrasound (~ 200 oC) and radiofrequency (~ 100 oC) devices; (6) Sealing of large blood vessels greater than 5 mm. However, several fundamental questions remain concerning our basic understanding of the laser-tissue interactions mechanism and feasibility of our method before it can be adopted in the clinic. The following specific aims intend to answer these basic questions, thus facilitating optimization of the laser parameters and device design for sealing of vascular tissues: (1) Optical and thermal property measurements of blood vessels as a function of composition (collagen/elastin ratio), temperature, and pressure; (2) Design and testing of laparoscopic vessel sealing device, integrating optical diagnostics for confirming successful vessel closure and avoiding damage to adjacent tissue structures (e.g. nerves); (3) Direct comparison between laser, US, and RF devices in an in vivo acute pig model, to determine sealing and cutting times and quantify collateral thermal damage.