Clinical distinction of acute and acute on chronic leg ischaemia. 
The importance of the distinction between acute embolic ischaemia and acute on chronic ischaemia caused by a thrombus superimposed on an arteriosclerotic stenoses has been emphasized during the recent years, as the differentiation should affect the choice of surgical treatment.  A retrospective attempt was made to differentiate between acute ischaemia (AI = embolism) and acute on chronic ischaemia (AOCI = thrombosis) of the leg by categorizing the patients according to the clinical characteristics they presented.  The material consisted of 194 ischaemic lower limbs of 189 patients who underwent a balloon-catheter thromboembolectomy because of sudden arterial occlusion.  The retrospective diagnosis of AI was made in 94 (48%) and AOCI in 69 (36%) cases.  The preoperative assessment could not be done in 43 (22%) patients by surgeon working at the emergency room.  The retrospective distinction was impossible in 31 (16%) patients.  The preoperative diagnosis was in better agreement with the retrospective category when AI, as opposed to AOCI, was the aetiology of occlusion (70% vs 46%).  The results of the present study emphasize the difficulties of clinical assessment.  These findings suggest a routine angiography as an evaluative tool in the planning of optimal management especially as most of the patients today can be treated simultaneously by thrombolysis.