The histological characteristics of peripheral obstructive arteriopathy (POA) in diabetic patients do not differ substantially from the arteriopathy of the non-diabetic population: patches of lipids and other substances restrict the diameter of the vein (Figure 25).
However the clinical characteristics are very different: in diabetic patients arteriopathy is more frequent, early, rapidly progressive, does not exclude women, even those of fertile age, affects both legs and mainly involves the arteries under the knee.
The latter is the most important characteristic in terms of treatment: the arteries of the leg and foot are smaller in gauge than the arteries of the thigh, which therefore makes it more difficult to treat them.
In addition, in diabetic patients the arteries are very often calcified, and total closure of the vein (occlusion) is often more common than partial closure, i.e. restriction (stenosis); there is often multiple occlusion and stenosis in the same artery (Figure 26).
A typical characteristic of the diabetic patient is often the lack of an earlier symptom of peripheral arteriopathy: "claudication".
Claudication is the pain which occurs in the calf or thigh after a certain number of steps have been taken
This pain stems from the fact that the arteries in the leg which receive less blood than they need, because they are stenotic or occluded, are not able to increase the blood flow required while the effort to walk is made.
The number of steps which can be taken before pain begins is extremely variable, it may be reduced to a few steps or exceed a hundred, and is closely linked to the seriousness of the arteriopathy.
Absence of claudication occurs in the diabetic patient on account of the concurrent presence of sensory neuropathy: the pain will be deadened or completely absent and the patient will not realise that they have an arteriopathy of the legs.
This means that an early, non-invasive diagnosis will not be so simple, with the risk that the first sign of peripheral arteriopathy will be an ulcer which fails to heal, or, in more serious cases, gangrene.
At international level the criteria for diagnosing chronic critical ischaemia have been re-established several times in the light of new information and new studies.
The most recent criteria are those of the TASC (TransAtlantic Inter-Society Consensus) published in January 2000 whose diagnostic criteria, explained in the table below, fully correspond to the clinical pictures found in every day clinical practice.

Table 1 - TASC criteria for chronic critical ischemia



In our case, we used several methods at the same time, when carrying out a diagnosis.
Above all the presence of peripheral pulses must be evaluated.
The absence of posterior tibial or pedal pulse ( Figure 27) means that more sophisticated diagnostic methods must be used.
A simple method is to determine pressure in the malleolus: today there are very practical portable Doppler instruments which facilitate the use of this method ( Figure 28).
If the ratio between the pressure on the ankle and the pressure on the arm is less than 0.9 (normal value between 0.9 and 1.3), it is very likely that peripheral arteriopathy is present, whose seriousness increases as the pressure ratio falls.
In this case it is necessary to carry out an echoDoppler to show the presence of stenosis or occlusion along the whole axis of the lower limb (Figure 29).
The parameter which may be the most important is transcutaneous oximetry, which, in simple terms, evaluates the quantity of oxygen which gets to the foot ( Figure 30).
On the basis of the results of all these examinations the decision about whether or not to carry out an arteriography is taken, as described in our protocol shown in the following table.

Table 2 - Diagnostic-therapeutic protocol for peripheral arteriopathy



In the presence of peripheral occlusive arteriopathy the only treatment which is really effective is re-vascularisation, i.e. restoring a flow of blood to the foot, which can be obtained using angioplasty or bypass.
When should revascularisation be carried out?
This is a critical point because it may involve an excess of indicators but above all to a lack of indications.
In our Centre the indications are very precise: in the case of claudication with a good free walking interval, certainly if greater than 200 metres, we prefer to treat the patient by instructing him or her to increase their physical exercise, to stop smoking if applicable, to use anti-aggregant and anti-dyslipidaemic drugs and by scheduling intense out-patient monitoring.
However, if the following are present:

• pain at rest
• ulcer or gangrene
• claudication < 50 m

we give an indication for revascularisation, starting with angioplasty (PTA: Percutaneous Transluminal Angioplasty) which is carried out at the same time as the arteriography.
The concept of angioplasty ( Figure 31 - Film Sequence "Angioplasty (PTA)") is exactly the same as cardiac angioplasty: arteriography is used to determine the exact location of the stenosis and occlusion and, in our Centre, dilation of the obstructing patches with a balloon is carried out at the same time as the angiographic study.
This procedure, which does not require any general anaesthesia and is not painful, is very effective with regard to ischaemic pain and the possibility of curing the ulcer but above all it allows the wound to heal if a surgical intervention needs to be carried out on the foot.
Complications are less frequent and serious in comparison with surgical procedures which require anaesthesia.
However even angioplasty is an "interventionist treatment" which may result in complications; the table below shows the complications which occurred in 993 patients who underwent this procedure in the period 1999-2003.

Table 3 - Complications and treatment in 993 subjects who underwent PTA

It is important to emphasise the fact that, in order to save the foot, it is necessary for a least one artery at its level to be opened (Figure 32) and it is completely useless to reopen an artery in the thigh leaving the arteries in the leg closed.
If angioplasty is not possible the possibility of a bypass will be evaluated ( Figure 33).
For many years it was thought that the distal surgical bypass, in the foot, was useless because it was bound to close at an early stage.
The results obtained in the 90’s in America and available today in Italy as well tell us that this technique produces satisfactory results, although it remains a technique which requires a great deal of professional skill.
The important thing when faced with an ulcer is not to underevaluate the presence of arteriopathy.
The risk is that of carrying out surgical interventions which, if undiagnosed peripheral arteriopathy is present and has not therefore been re-vascularised, result in the need for further interventions to the point of amputating the leg ( Figure 34).

Is revascularisation always necessary?
Our approach is that of re-vascularisation whenever pain or an ulcer is present.
However revascularisation is a procedure which is not exempt from risk, which is difficult for the patient and family members; it also has a high cost for the National Health Service.
In some cases we do not recommend re-vascularisation and recommend direct amputation.
In bed-ridden patients for whom saving the limb would not in any event be useful for walking, in that subjects who are not aware of their condition and who would not suffer psychologically from having a missing limb, we believe it is more useful to amputate directly rather than take the route of re-vascularisation and subsequent treatments.
However even in patients who are bedridden but who are aware and manifest intense psychological suffering when faced with major amputation, we are prepared to take the long route of re-vascularisation and subsequent treatments in order to avoid amputation.