Patients suffering from arteriosclerotic obliterating disease of the lower limbs that present with symptoms of rest pain, ulcers or more or less severe gangrene are considered as candidates for revascularization operation. Apart from the possible non relevance of individual symptoms, in some instances the revascularization operation is indicated solely on the basis of the angiographic evidence. Ascending thrombosis of the abdominal aorta, double or triple blocks, stenosis of the collateral circulation and, broadly speaking, any other situation that suggests a possible superimposition of an episode of acute ischaemia due to thrombosis in a condition of chronic obliterating arteriopathy are considered as absolute indication for revascularization operation. Patients whose conditions are not listed above are considered as stage II and indication for operation in this case is not absolute but relative or "luxury" since its purpose is only to improve the quality of life. The importance of the symptoms must be considered along with other factors, including the personal, social, working, sporting and psychological needs of the specific individual apart from the absence of general risks related to the patient's condition. The vascular surgeon's expertise is obviously fundamental in exactly evaluating the arteriography and in understanding the precise anatomic picture that varies in every single case: in fact, since the operation is optional and not a necessity, correction of the arterial lesions in only advisable when it is possible to carry out and operation that is broadly risk free and with good short and long term results, with reference to the patient's life expectancy.