[Procedures in critical ischemia of the legs in non-emergency situations].
Our experience with 91 operated cases in 84 patients (47 men, 37 women) relates essentially to arterial diseases resulting from overloading and diabetic arteriopathy. Diagnosis of critical ischemia is easy in clinical conditions, but it is advisable to rely on universally recognized hemodynamic standards to define this condition. Ankle pressure should be less than 400 mmHg and the Doppler trace flat or barely perceptible. Patients in our series had a mean ankle pressure of 32.4 mmHg. Local examination can determine the extent of gangrene, whereas general examination detects numerous, often associated defects diabetes, coronary artery disease, rhythm disorders, arterial hypertension, etc. As far as possible, these defects are to be corrected before surgery. X-ray examination (M. Kasbarian) is frequently done in conjunction with conventional aorto-arteriography and digital angiography. The later technique allows arteries to be visualized which are not seen with the conventional technique. The x-ray examination will indicate whether revascularization is feasible, although it cannot show whether it will be efficient. In our series, opacification of the plantar arches was predictive neither of success nor failure. But do tests exist which can predict the success of a revascularization attempt? It would be necessary to be able to estimate ankle pressure after the operation, and several methods have tried to do this. TcPO2 would seem to be a good examination. The possibilities of nuclear magnetic resonance are being studied, and the results thus far are promising. Preoperative explorations are carried out in a different situation. Arteriography performed in the operating room is a simple act which can reveal a usable downstream bed not indicated in preoperative X-rays, although it provides no hemodynamic data. Measurement of peripheral resistances would appear to be a very good predictive examination. Flow measurements by infusion or electronic flowmeter also seem to be predictive for bypass results. Unfortunately, these measurements are at present not widely performed and the critical threshold is assessed differently. Given the difficulty of correctly estimating the value of these numerous methods, many surgeons, ourselves included, have chosen to revascularize patients whenever the upstream bed as evaluated by X-ray indicates the presence of at least one viable artery.