• Primary amputation is indicated in the case of life-threatening infection or extensive necrosis of the foot. PAD is a risk factor for amputation [51] and [80] and needs to be diagnosed early in order to be able to take all of the therapeutic measures necessary to avoid it as soon as possible. In the case of a foot ulcer in a diabetic patient with PAD, it is MAPK inhibitor first necessary to evaluate the usefulness of revascularisation and then choose the method of revascularisation on the basis of the following clinical criteria: the healing potential of the ulcer; the local condition of the foot and its residual function after

the healing process; the condition of the vascular tree; and finally the general condition of the patient. Healing potential refers to the real possibility of healing on the basis of foot perfusion. Transcutaneous oximetry and evaluating the pressure of the toe may be helpful because, in addition to stenoses and obstructions, they can determine whether distal blood flow is sufficient to guarantee tissue healing. According selleck to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC

II) document [81], foot lesions generally heal if toe pressure is >50 mm Hg and TcPO2 >50 mm Hg, whereas healing is a remote possibility if both are <30 mm Hg. However, it must be pointed out that TASC II does not specifically refer to diabetics but also includes the non-diabetic population. In a critical review the of TcPO2 levels, Faglia considers values of <34 mm Hg an absolute indication for revascularisation, with an 85% probability of amputation in the case of no revascularisation; values of 34–40 mm Hg represent a less impelling indication for revascularisation,

but there is still a considerable probability of amputation (about 20%). In the case of values of >40 mm Hg, revascularisation can be considered if the tissue loss is significant and there is a need to accelerate healing, or in the presence of osteomyelitis for which conservative treatment is preferred [82]. In any case, once a perfusion deficit has been identified, revascularisation should always be considered. [83]. Another possible situation is one in which the limb is apparently perfused (TcPO2 >40 mm Hg or toe pressure >50 mm Hg) but, despite optimal local treatment, the lesion shows no signs of healing. After having excluded general negative factors such as malnutrition or underlying osteomyelitis, it is necessary to consider the possibility that the non-invasive evaluations have overestimated peripheral perfusion and that there may be undetected ischaemia. In the presence of an ulcer that does not evolve positively within 4–6 weeks, an ischaemic component should always be suspected.