Endovascular surgery is a form of minimally invasive surgery that was designed to remove blocks in major blood vessels using balloons and stents.
Basic technique involves the introduction of a catheter percutaneously into a large blood vessel. Typically the blood vessel chosen is the femoral artery or brachial artery at the elbow. A needle is inserted into the artery and a wire is passed inside. A small catheter is passed over the wire and negotiated to the artery to be studied. Radio-opaque dye is injected through the catheter and the artery can be seen on live X-ray or fluoroscopy. As the dye courses through the blood vessels, characteristic images showing the vessel lumen, blocks and the circulation beyond the block can be seen. This serves as a road map to plan further treatment.
In recent years, however, the development of intravascular balloons and stents have allowed for new therapies as alternatives to traditional surgeries such as arterial bypass surgery and aneurysm repair. Stents are composed of fine wire materials such as nitinol, that can be inserted through a thin catheter and expanded into a predetermined shape once they are guided into place.
In balloon angioplasty the balloon is positioned across the block or narrowed artery and dilated. This causes the plaque (Fatty material deposited in the wall) to get compressed and the arterial wall is stretched. Majority of the blocks to the limb vessels can be opened by balloon angioplasty. In some cases, the block is hard and the artery collapses again after the balloon is removed. In these cases, a metal mesh(stent) is kept inside to prevent the wall from collapsing again. Recently a stent is also covered with a thin fabric so that a smooth lining can be achieved for the arterial wall. These stent grafts are used for treating aneurysms (abnormal dilatation of the artery).
Nowadays angioplasty is offered as the treatment of choice for treating limb ischemia.
