Laser Sealing and Cutting of Vascular Tissues

摘要 传统的手术中血管组织缝线结扎术费时费力。使用 基于能量的设备使血管和组织结扎能够更快、更有效地维持止血 在手术过程中，与标准缝合和机械夹相比，后者会将异物留在体内并破坏 该程序通过需要交换的票据。超声波(US)和射频(RF)能量- 基于设备的设备加快了一些劳动密集型外科手术的速度，包括肺叶切除术、肾切除术、 胃旁路、脾切除、甲状腺切除、子宫切除和结肠切除，节省了大量的成本。 然而，RF和US设备都有局限性，包括可能出现不希望的炭化和 不必要的大间接热损伤区，热扩散平均大于1毫米。一个 主要担心的是，当发生以下情况时，可能会对邻近的关键组织结构造成意外的热损害 在密闭的空间里进行精细的手术。此外，美国设备的活动下巴可以到达 应用过程中温度超过200摄氏度，可能需要超过20 S才能冷却到可用 在继续进行下一步应用之前，请注意温度的变化。射频有源爪上的最高温度 器件较低(&lt；100oC)，但观察到较大的散热。在过去的8年里，我们的实验室已经 正在开发一种使用红外(IR)激光进行血管密封的新方法。几个优势 基于激光的血管组织的封闭和切割与传统的超声和射频能量的比较 设备包括：(1)更快速地封切血管组织，封切时间短至1 S 每一个；(2)更多的能量定向沉积到组织中，侧枝热扩散小于1毫米；(3) 更坚固的容器密封，具有更高的破裂压力(高达1500毫米汞)；(4)能够 血管组织的光学封闭和切割，而不需要可展开的机械刀片来分割 组织密封件；(5)与超声波(~200℃)相比，下颌峰值温度(&lt；60 oC)更低，外形更安全 和射频(~100oC)装置；(6)大于5 mm的大血管的封堵。然而， 关于我们对激光-组织相互作用的基本理解，仍有几个基本问题 我们的方法的机制和可行性，才能在临床上采用。以下是具体目标 意在回答这些基本问题，从而有利于激光器参数的优化和器件的设计 用于血管组织的密封：(1)作为功能的血管的光学和热学性质测量 成分(胶原/弹性蛋白比率)、温度和压力；(2)腹腔镜的设计和测试 血管密封装置，集成光学诊断以确认血管关闭成功并避免 对邻近组织结构(如神经)的损害；(3)激光、超声和射频设备之间的直接比较 在活体急性猪模型中，确定封闭和切割时间，并量化侧枝热损伤。

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.