Proebstle T M, Lehr H A, Kargl A, Espinola-Klein C, Rother W, Bethge S, Knop J
Department of Dermatology, University of Mainz, Germany.
J Vasc Surg. 2002 Apr;35(4):729-36. doi: 10.1067/mva.2002.121132.
Despite a rapid spread of the technique, very little is known about the laser-tissue interaction in endovenous laser treatment (EVLT). We evaluated EVLT of the incompetent greater saphenous vein (GSV) for efficacy, treatment-related adverse effects, and putative mechanisms of action.
Twenty-six patients with 31 limbs of clinical stages C(2-6), E(P), A(S,P), P(R) with incompetent GSV proven by means of duplex scanning were selected for EVLT in an outpatient setting. A 600-microm fiber was entered into the GSV via an 18-gauge needle below the knee and proceeded to the saphenofemoral junction (SFJ). After infiltration of tumescent local anesthesia, multiple laser pulses of 15 J energy and a wavelength of 940 nm were administered along the vein in a standardized fashion. D-dimers were determined in peripheral blood samples 30 minutes after completion of EVLT in 16 patients and on postoperative day 1 in 20 patients. One GSV that was surgically removed after EVLT was examined by means of histopathology. Additionally, an experimental in vitro set-up was constructed as a means of investigating the mechanism of laser action within a blood-filled tube.
A median of 80 laser pulses (range, 22-116 laser pulses) were applied along the treated veins. On days 1, 7, and 28, all limbs except one (97%) showed a thrombotically occluded GSV. In one patient, the vessel showed incomplete occlusion. The distance of the proximal end of the thrombus to the SFJ was a median 1.1 cm (range, 0.2-5.9 cm) in the remaining patients. Adverse effects in all 26 patients were ecchymoses and palpable induration along the thrombotically occluded GSV that lasted for 2 to 3 weeks. In two limbs (6%), thrombophlebitis of a varicose tributary required oral treatment with diclofenac. D-dimers in peripheral blood were tested with normal results in 14 of 16 patients 30 minutes after completion of the procedure and elevated results in 7 of 20 patients at day 1 after EVLT. However, an increase of D-dimers from day 0 to day 1 was observed in 15 of the 16 patients undergoing tests 30 minutes after EVLT and on day 1. The 940-nm laser was demonstrated by means of in vitro experiments and the histopathological examination of one explanted GSV to act by means of indirect heat damage of the inner vein wall.
EVLT of the GSV with a 940-nm diode laser is effective in inducing thrombotic vessel occlusion and is associated with only minor adverse effects. Laser-induced indirect local heat injury of the inner vein wall by steam bubbles originating from boiling blood is proposed as the pathophysiological mechanism of action of EVLT.
尽管该技术迅速普及，但对于静脉腔内激光治疗（EVLT）中激光与组织的相互作用却知之甚少。我们评估了大隐静脉功能不全患者行EVLT的疗效、治疗相关不良反应及可能的作用机制。
选取26例患者的31条肢体，临床分期为C（2 - 6）、E（P）、A（S，P）、P（R），经双功超声扫描证实大隐静脉功能不全，在门诊行EVLT。通过18号穿刺针在膝下将一根600微米的光纤插入大隐静脉，并推进至隐股交界处（SFJ）。在肿胀局麻浸润后，沿静脉以标准化方式给予多个能量为15焦耳、波长为940纳米的激光脉冲。16例患者在EVLT完成后30分钟、20例患者在术后第1天采集外周血样本检测D - 二聚体。对1例EVLT后手术切除的大隐静脉进行组织病理学检查。此外，构建了一个体外实验装置，以研究激光在充满血液的血管内的作用机制。
沿治疗静脉平均施加80个激光脉冲（范围为22 - 116个激光脉冲）。在第1、7和28天除1条肢体（97%）外，所有肢体的大隐静脉均出现血栓闭塞。1例患者血管显示不完全闭塞。其余患者血栓近端至SFJ的距离中位数为1.1厘米（范围为0.2 - 5.9厘米）。所有26例患者的不良反应为沿血栓闭塞的大隐静脉出现瘀斑和可触及的硬结，持续2至3周。2条肢体（6%）出现曲张属支血栓性静脉炎，需口服双氯芬酸治疗。16例患者中14例在手术完成后30分钟外周血D - 二聚体检测结果正常，20例患者中7例在EVLT术后第1天结果升高。然而，在EVLT后30分钟及术后第1天接受检测的16例患者中，15例患者的D - 二聚体从第0天到第1天出现升高。通过体外实验及对1条切除的大隐静脉的组织病理学检查证明，940纳米激光通过间接热损伤静脉内壁发挥作用。
使用940纳米二极管激光行大隐静脉EVLT可有效诱导血管血栓形成闭塞，且仅伴有轻微不良反应。提出由沸腾血液产生的蒸汽泡导致静脉内壁激光诱导的间接局部热损伤是EVLT的病理生理作用机制。
