Medical Laser Center Lübeck, 23562, Lübeck, Germany.
Department of Neurosurgery, University Medical Center Schleswig-Holstein, 23562, Lübeck, Germany.
Lasers Med Sci. 2023 Mar 27;38(1):94. doi: 10.1007/s10103-023-03747-9.
Due to wavelength-specific water absorption, infrared lasers like the thulium laser emitting at 1940 nm wavelength proved to be suitable for coagulation in neurosurgery. Commonly bipolar forceps used for intraoperative haemostasis can cause mechanical and thermal tissue damage, whilst thulium laser can provide a tissue-gentle haemostasis through non-contact coagulation. The aim of this work is a less-damaging blood vessel coagulation by pulsed thulium laser radiation in comparison to standard bipolar forceps haemostasis. Ex vivo porcine blood vessels in brain tissue (0.34 ± 0.20 mm diameter) were irradiated in non-contact with a thulium laser in pulsed mode (1940 nm wavelength, 15 W power, 100-500 ms pulse duration), with a CO gas flow provided simultaneously at the distal fibre tip (5 L/min). In comparison, a bipolar forceps was used at various power levels (20-60 W). Tissue coagulation and ablation were evaluated by white light images and vessel occlusion was visualised by optical coherence tomography (OCT) B-scans at a wavelength of 1060 nm. Coagulation efficiency was calculated by means of the quotient of the difference between the coagulation and ablation radius to the coagulation radius. Pulsed laser application achieved blood vessel occlusion rate of 92% at low pulse duration of 200 ms with no occurrence of ablation (coagulation efficiency 100%). Bipolar forceps showed an occlusion rate of 100%, however resulted in tissue ablation. Tissue ablation depth with laser application is limited to 40 μm and by a factor of 10 less traumatising than with bipolar forceps. Pulsed thulium laser radiation achieved blood vessel haemostasis up to 0.3 mm in diameter without tissue ablation and has proven to be a tissue-gentle method compared to bipolar forceps.
由于特定波长的水吸收，1940nm 波长的铥激光等红外激光已被证明可用于神经外科的凝固。通常用于术中止血的双极镊子会导致机械和热组织损伤，而铥激光可以通过非接触式凝固提供温和的组织止血效果。这项工作的目的是通过脉冲铥激光辐射对血管进行比标准双极镊子止血损伤更小的凝固。在非接触状态下，用脉冲模式的铥激光（1940nm 波长，15W 功率，100-500ms 脉冲持续时间）对离体猪脑组织中的血管（直径 0.34±0.20mm）进行照射，同时在远端光纤尖端提供 CO 气流（5L/min）。相比之下，使用双极镊子在不同功率水平（20-60W）下进行止血。用白光图像评估组织凝固和消融情况，并用 1060nm 波长的光学相干断层扫描（OCT）B 扫描观察血管闭塞情况。通过用凝固和消融半径之间的差值与凝固半径的商来计算凝固效率。在 200ms 的短脉冲持续时间下，脉冲激光应用可实现 92%的血管闭塞率，且没有发生消融（凝固效率 100%）。双极镊子的闭塞率为 100%，但会导致组织消融。激光应用的组织消融深度限制在 40μm 以内，与双极镊子相比，创伤性要小 10 倍。脉冲铥激光辐射可实现直径达 0.3mm 的血管止血，而不会发生组织消融，与双极镊子相比，已被证明是一种温和的组织止血方法。
