Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research University, Paris, France.
Theraclion, Malakoff, France.
Int J Hyperthermia. 2020;37(1):231-244. doi: 10.1080/02656736.2020.1734672.
Varicose veins are a common pathology that can be treated by endovenous thermal procedures like radiofrequency ablation (RFA). Such catheter-based techniques consist in raising the temperature of the vein wall to 70 to 120 °C to induce vein wall coagulation. Although effective, this treatment option is not suited for all types of veins and can be technically challenging. In this study, we used High-Intensity Focused Ultrasound (HIFU) as a non-invasive thermal ablation procedure to treat varicose veins and we assessed the long-term efficacy and safety of the procedure in a sheep model. experiments were first conducted on two saphenous veins to measure the temperature rise induced at the vein wall during HIFU ablation and were compared with reported RFA-induced thermal rise. Thermocouples were inserted to perform 20 measurements during 8-s ultrasound pulses at 3 MHz. Eighteen saphenous veins of nine anesthetized sheep (2-2.5 % Isoflurane) were then exposed to similar pulses (85 W acoustic, 8 s). After treatments, animals recovered from anesthesia and were followed up 30, 60 and 90 days post-treatment ( = 3 animals per group). At the end of the follow-up, vein segments and perivenous tissues were harvested and histologically examined. Temperatures induced by HIFU pulses were found to be comparable to reported RFA treatments. Likewise, histological findings were similar to the ones reported after RFA and laser-based coagulation necrosis of the vein wall, thrombotic occlusions and vein wall fibrosis. These results support strongly the effectiveness and safety of HIFU for ablating non-invasively veins.
静脉曲张是一种常见的病症，可以通过静脉内热疗方法如射频消融（RFA）来治疗。这种基于导管的技术包括将静脉壁的温度升高到 70 到 120°C，以诱导静脉壁的凝固。虽然这种治疗方法有效，但并不适合所有类型的静脉，并且在技术上具有挑战性。在本研究中，我们使用高强度聚焦超声（HIFU）作为一种非侵入性的热消融程序来治疗静脉曲张，并在绵羊模型中评估了该程序的长期疗效和安全性。首先在两条隐静脉上进行实验，以测量 HIFU 消融过程中静脉壁的温升，并与报道的 RFA 诱导的热升进行比较。热电偶被插入以在 3 MHz 的 8 秒超声脉冲期间进行 20 次测量。然后，将 9 只麻醉绵羊（2-2.5%异氟烷）的 18 条隐静脉暴露于类似的脉冲（85 W 声能，8 秒）。治疗后，动物从麻醉中恢复并在治疗后 30、60 和 90 天进行随访（每组 3 只动物）。在随访结束时，采集静脉段和静脉周围组织进行组织学检查。HIFU 脉冲诱导的温度与报道的 RFA 治疗相当。同样，组织学发现与 RFA 和激光基凝固后静脉壁坏死、血栓闭塞和静脉壁纤维化的报告相似。这些结果强烈支持 HIFU 用于非侵入性消融静脉的有效性和安全性。
