Vascular (blood vessel) disorders treated by general surgery include varicose veins, blockages and narrowings in the arteries or abnormal swellings of the arteries (aneurysm). The most common of these conditions facing the general surgeon is varicose veins. This occurs when veins in the legs and thighs become enlarged and twisted. This is often caused by the failure of the one-way valve system in the veins, in which case it can be treated surgically by removing the segments of veins containing the malfunctioning valves as well as those veins which are significantly dilated.