Extracorporeal Treatment with High Intensity Focused Ultrasound of an Incompetent Perforating Vein in a Patient with Active Venous Ulcers

Abstract

Introduction Endovenous techniques such as ultrasound guided foam sclerotherapy, thermal methods, or glues are generally recommended to occlude incompetent veins. However, these methods can be technically challenging and risky for patients with severe atrophic skin disorders like lipodermatosclerosis or atrophie blanche. High intensity focused ultrasound (HIFU), which has been shown to coagulate and occlude veins successfully, may offer an alternative method. This case report details ultrasound guided HIFU to occlude non-invasively a refluxing perforator vein causing active ulcers. Report A 95 year old man presented to the Institute for Functional Phlebology (Melk, Austria) with painful recurrent ulcers in his left medial calf. His limb was scored C2,3,4a, b,6, Ep, Ap, Pr,18 according to the Clinical, Etiology, Anatomic, Pathophysiology (CEAP) classification. Lower limb ultrasound revealed a refluxing posterior tibial perforating vein, measuring 2.7 mm in diameter at the level of the fascia. Extracorporeal HIFU pulses were delivered to this vein with the Sonovein device (Theraclion, Malakoff, France). Sonication was applied for eight seconds at a mean acoustic power of 80 W. The patient was followed up for three months post-treatment and occlusion was evaluated by duplex ultrasound. There were no complications during treatment or follow up. Three months after the treatment, reflux was abolished and the two initially active ulcers had healed. Discussion Although this is an early report, this study shows that HIFU can be successful in ablation of incompetent perforator veins in the treatment of venous leg ulcers.

Review of Robot-Assisted HIFU Therapy

“…Due to the significant advantages of extracorporeal treatments, HIFU has gained significant popularity, enabling its use in several different clinical applications. These include: (i) treatment of tumors of the liver, kidney, brain, bone, prostate, breast, uterine fibroids, and more, (ii) aortic stenosis [ 19 ], (iii) varicose veins [ 20 ], (iv) essential tremor in Parkinson’s disease [ 5 ], and more. These treatments often enable outpatient procedures without the administration of general anesthesia [ 26 ], reducing complications and the risk of infection associated with hospital stays.…”

“…HIFU is an appealing non-invasive option to treat varicose veins, providing an outpatient procedure under local anesthetic [ 62 ]. The 3.0 MHz treatment head of the Sonovein system is equipped with a cooling and coupling kit and includes a linear ultrasound probe that is confocally mounted, as shown in Figure 10 [ 20 ]. Initial positioning is performed manually by the physician and ultrasound imaging is used for vein localization.…”

“…The robotic positioning system precisely moves toward target areas and treatment sites selected by the physician. The robotic positioning system allows for treatment 2 mm away from the femoral junction with a focal spot width of 0.5 mm [ 20 ].…”

“…Conversely, highly reflective structures, such as bone and gas, results in an acoustic impedance mismatch between the structure and the transducer, causing skin burns from the reflected ultrasound waves [ 12 ]. Further, HIFU efficacy is subject to focal positioning accuracy, with some applications requiring sub-millimeter focal accuracy (e.g., calcified aortic valves, as seen with the Valvosoft system, and the closing of varicose veins with the Sonovein System) [ 19 , 20 ]. These requirements have motivated physicians and engineers to incorporate novel technologies to improve treatment outcomes.…”

Growth and Collapse of an Isolated Bubble Driven by a Single Negative Histotripsy Cycle in Agarose Gel: Stress, Strain, and Strain Rate Fields

“…targeted drug delivery, thermal or mechanical ablation), and the relative safety of ultrasound waves as a delivery mechanism (e.g., compared to ionizing radiation which is dangerous and inherently damaging to tissues [10]). Indeed, HIFU therapies, through their various mechanisms of action, have been demonstrated effective in pre-clinical and/or clinical settings for treating pathologies ranging from varicose veins [11], [12], uterine fibroids [5], and essential tremor [13], to kidney-and gallstones [14], [15], to stroke [16] and various cancers [17].…”