Ultrasound thrombolysis in stent thrombosis

Abstract

Recent refinement in stent implantation technique and peri-procedural pharmacological treatment has lowered the incidence of stent thrombosis significantly. Still, all stent thromboses are associated with major adverse events. In previous studies it has been suggested that intravascular ultrasound fibrinolysis is safe and effective. In this report, ultrasound successfully reperfused thrombotically occluded stents. These observations suggest that ultrasound may dissolve occlusive platelet-rich thrombus effectively and safely. Cathet. Cardiovasc. Intervent. 51:332-334, 2000.

Acoustic communication for medical nanorobots

“…Static fluid pressures of 42 Pa can initiate major changes in the endothelial cells in the arteries [36] and 300 Pa osmotic pressure produces enough tension, ≈ 2 × 10 −3 N/m, to rupture eukaryotic cell membranes [68], but to date all mechanical cell stimulation experiments have been conducted at low frequencies (< 100 Hz) [28]. Given the relative safety of procedures associated with intravascular ultrasound [9,37,41,69,76,95,101] with its low complication rate using frequencies as high as 10-20 MHz [37,95,101], it seems improbable that MHz acoustic waves of the intensities that might be employed by medical nanorobots for communication will damage the endothelial vascular walls. Interestingly, relatively high-intensity intravascular ultrasound has been used to dissolve occlusive platelet-rich thrombi safely and effectively in myocardial infarctions [41] and in restenosed stents [76].…”

“…Given the relative safety of procedures associated with intravascular ultrasound [9,37,41,69,76,95,101] with its low complication rate using frequencies as high as 10-20 MHz [37,95,101], it seems improbable that MHz acoustic waves of the intensities that might be employed by medical nanorobots for communication will damage the endothelial vascular walls. Interestingly, relatively high-intensity intravascular ultrasound has been used to dissolve occlusive platelet-rich thrombi safely and effectively in myocardial infarctions [41] and in restenosed stents [76].…”