Schematic diagram of an atherosclerotic plaque. The build-up of the lesion can eventually lead to arterial obstruction that limits blood flow, or alternatively can rupture causing catastrophic thrombosis in the coronary arteries
.Atherosclerosis (AS), a chronic arterial disease, is one of the major causes of morbidity and mortality worldwide. Several treatments have been demonstrated to be effective in treating AS; however, the mortality rate due to AS remains high. Sonodynamic therapy (SDT) is a promising new treatment using low-intensity ultrasound in combination with sonosensitizers. Although SDT was developed from photodynamic therapy (PDT), it has a stronger tissue-penetrating capability and exhibits a more focused effect on the target lesional site requiring treatment. Furthermore, SDT has been demonstrated to suppress the formation of atheromatous plaques, and it can increase plaque stability both in vitro and in vivo.
Atherosclerosis progresses through degeneration of the inner lumen of the vessel and with rupture and clot formation is the underlying mechanism for the majority of sudden cardiac deaths, particularly in young men. "vulnerable plaque" is used to identify all thrombosis-prone plaques and plaques with a high probability of undergoing rapid progression.
SPDT for cardiovascular disease. SPDT may show promise in cardiovascular medicine for the treatment of atherosclerosis . Atherothrombotic cardiovascular disease is a diffuse condition involving the coronary arteries, carotid arteries, aorta and peripheral arteries.
Human vascular system. Atherosclerosis is a systemic disease affecting the whole body and causing major diseases. Red color indicates arterial vessels, and blue the venous circulation. Claudication indicates pain arising due to deprivation of the muscles of blood flow by vascular blockages, usually in the legs.
However, the pathology of the disease and clinical consequences vary in different anatomical locations. In patients with atherothrombotic disease, myocardial ischemia or infarction causes as much as 70% of deaths.
The main lesion in atherosclerotic disease is called an atherothrombotic plaque
Photoangioplasty is a term for the combination of intravenous injection (IV) of PS followed by delivery of intravascular light by a fiber optic catheter introduced into a blood vessel and then advanced to the lesion. This is used for the direct application of light.
Experience with photoangioplasty in intermittent claudication with peripheral arterial atherosclerosis suggests that the therapy is well tolerated and has the capacity to invoke a therapeutic response in these patients. In 90% of vessels treated, intravascular ultrasonography confirmed measurable improvement in the lumen cross-sectional area after photoangioplasty. percutaneous coronary intervention and stent deployment. The therapeutic changes were achieved without documented adverse vascular responses or any treatment-limiting phototoxicity.
With SPDT it may be possible to increase circulation without invasive angioplasty and if this range of benefits extends to the coronary arteries it may well be an acceptable or even preferred treatment for narrowing of the coronary arteries, making the hugely invasive and costly coronary bypass operations obsolete.