Endovascular techniques were originally pioneered for diagnostic purposes by radiologists. Basic techniques involve the introduction of a catheter percutaneously into a large blood vessel (Seldinger technique). Typically the blood vessel chosen is the femoral artery or a vein found near the groin. Access to the femoral artery for example, is required for coronary, carotid, and cerebral angiographic procedures. The catheter is injected with a radio-opaque dye that can be seen on live X-ray or fluoroscopy. As the dye courses through the blood vessels, characteristic images are seen by experienced viewers and can assist in the diagnosis of diseases such as atherosclerosis, vascular trauma, or aneurysms.
In recent years, however, the development of intravascular balloons, stents and coils have allowed for new therapies as alternatives to traditional surgeries such as Coronary artery bypass surgery (CABG), carotid endarterectomy and aneurysm clipping. Stents and coils are composed of fine wire materials such as platinum, that can be inserted through a thin catheter and expanded into a predetermined shape once they are guided into place.
Endovascular surgery is performed by radiologists, neurologists, neurosurgeons, cardiologists, cardiothoracic surgeons, and vascular surgeons. The field is rapidly growing as its minimally invasive techniques would seem to offer a lower risk of complications compared to traditional highly invasive surgeries. However, as shown by the Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial, the complication rates for some endovascular procedures surpass those present after “aggressive medical management” (i.e., management without surgery). In the case of SAMMPRIS, the technique in question was intracranial arterial stenting with the use of the Wingspan stent system, with some resulting complications possibly due to “the fact that stenting of the intracranial vasculature is technically more challenging” than stenting of vessels elsewhere. Other trials examining the comparative effectiveness of endovascular procedures include the Carotid Revascularization Endarterectomy versus Stent Trial (CREST), and International Subarachnoid Aneurysm Trial (ISAT), among others