These images illustrate efforts to save a limb from amputation, or, at least delay the event, when the limb is threatened by severe diabetic angiopathy and a non-healing ulcer. 
 
Neuropathy and vasculopathy due to diabetes substantially contribute to limb loss all over the world, which in turn reduces an amputee’s longevity. Revascularization of chronic total occlusions (CTOs) or severe but non-occlusive arterial disease of the lower extremities has revolutionized the management of the diabetic foot and primary care givers and podiatrists commonly seek out vascular specialists skilled in endovascular treatment of such flow impediments when confronted with patients on the verge of losing their limbs to them. Even if limb amputation is unavoidable, such interventions may limit the extent of amputation.
 
The images in the top panel illustrate multicentric moderate and severe (>50%) narrowings of the proximal left common femoral artery (LCFA) – not shown – and the superficial femoral artery and a focal critical stenosis of the proximal left tibioperoneal trunk in an elderly diabetic man with a chronic ulcer of his left foot. Notice that the critical tibioperoneal stenosis limits blood flow into the patient’s only named branch of his left popliteal artery, the peroneal artery, which is the principal path of blood inflow to the foot. Note, too, the severity of the lack of perfusion of the foot as shown by the “whiteness” of the patient’s hind foot.
 
It was , therefore, helpful to the patient that I eliminate as much of the upstream disease as was feasible and dilate the critical stenosis of the left tibioperoneal trunk. Thus, balloon angioplasty was applied to the common femoral obstruction and the tibioperoneal trunk stenosis and a stent-graft was used to exclude from the circulation all the superficial femoral arterial disease. The bottom panel of images shows the immediate outcome of these interventions. The ulcer eventually healed.

Smoking, dyslipidemias (disorders of lipids such as hypercholesterolemia), hypertension, and diabetes, individually and severally, may narrow or occlude arteries in all parts of the body.

Amongst arteries that may suffer are the ones that carry blood from the abdominal aorta (the large artery that carries blood from the heart across the abdomen towards the lower limbs) through the pelvis (the waist area) into the lower limbs, called the iliac arteries. If the narrowing of the vessel lumen is significant or the occlusion total, symptoms like claudication (pain during ambulation), paraesthesia, numbness, and erectile dysfunction may develop and bring a patient to medical attention. (Arterial stenoses usually cause symptoms (see above) when they reduce the diameter of affected vessels by more than 50%, corresponding to loss of 75% of their surface area.)

The images below illustrate percutaneous stenting of stenosis of the distal proximal and the mid left common iliac artery, without disease of the left external iliac artery in one of my patients who presented with left calf claudication. CTA of his abdominal aorta and arterial duplex ultrasound of his lower limbs ( images not shown) revealed left iliac  stenosis, confirmed by the digital subtraction angiographic images in the first row. He did well following stenting of the diseased artery.  Iliac arterial stenting stays open for nearly as long as surgical revascularization and at much less the morbidity and cost of the latter.

The blue toe syndrome results when the arterial supply to a digit of the foot is acutely interrupted. Since digital arteries are end arteries and the interruption sudden, the affected toe quickly develops ischemia, which manifests as acute pain and discoloration. Often the obstructing agent is a fragment of clot dislodged off diseased segments of the upstream arterial tree – the heart, the aorta, the iliacs, or the femoropopliteal segment. The primary disease may be luminal thrombosis or thrombus in an aneurysmal sac or a left heart chamber. Occasionally, usually in the setting of endovascular interventions, it may be a cholesterol crystal broken off a mural plaque, a more obstinate problem to treat than embolized blood clot. It is reasonable, therefore, in the patient with the blue toe syndrome that the care giver investigates their arterial paths from the heart to the toes and consider as well the possibility of a hypercoagulable state.

I present here a young woman whose primary care physician referred to me because of acute pain in her left great toe that was associated with discoloration. Her left common femoral pulse was diminished on examination and its waveform abnormal on arterial Doppler sonography. The image to the far left of the reader shows a focal filling defect of the distal left common iliac artery with sharp margins between its upper and distal surfaces and the vessel lumen, a calcified plaque from which a small embolus may have arisen. The rest of her angiography was normal. The middle image shows the deployment of a short balloon-expandable stent across the filling defect, while the image to the reader’s right is the post-intervention study that shows restoration of normal blood flow through the left iliac channel. Her symptoms resolved and she returned to her primary care provider on aspirin, Plavix, and advice to quite smoking, while pursuing hypercoagulability workup with him.