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Hello, my name is Daniel Riding and I am a member of the Glasgow University Radiology Society today, I'm going to be talking about peripheral vascular disease and in particular, we're going to focus on the points that are relevant to the MLA content map. So, what I'm going to do is I'm going to introduce a case and then I'm going to talk about the pathophysiology diagnosis and management of PVD and then we will come back to the case at the end. So we have a 70 year old male who presents to his GP with a several month history of cramping pain in his calves. When walking, this could be caused by a number of different diseases. He could have peripheral arterial disease, he could have spinal stenosis, a herniated lumbar disc, hip arthritis or a symptomatic Baker's cyst PVD can present in a number of different ways. Chronic limb ischemia describes varying severities of symptoms. And this correlates to varying severity of stenoses in vessels themselves. And it can be classified using the Fontaine classification. Grade one is asymptomatic stenoses. Grade two is intermittent claudication and this is classically crampy, calf pain elicited by exercise and then relieved by rest. Grade three is rest pain and that is pain regardless of activity. Grade four is tissue loss that is ulcers and gangrene, critical limb ischemia is a term to be aware of. And this is a more severe form of chronic limb ischemia. It can be defined in three ways as tissue loss. Hence why it's grade four on the Fontaine classification, it could be defined as rest pain lasting for more than two weeks and requiring opiate analgesia to relieve. And it can also be defined as an ankle brachial pressure index of less than 0.5. And I'll talk about the ankle brachial pressure index. Later on in the presentation, acute limb ischemia is where there is a sudden cessation of perfusion of a limb. And this can be remembered using the six ps. The symptoms will be pulselessness, pallor, paresthesia, pain, paralysis or weakness and the perishing called limb. Another presentation of PVD is ulceration and I'll talk about that more in the next slide. So venous ulcers tend to be shallow with flat margins. They release neck date and have a sloppy base with granulation tissue. These are caused by an inflammatory process, secondary to venous insufficiency, the skin around the venous ulceration will be thickened and fibrosed eczematous and itchy likely with edema and hemosiderin staining. And unless there is underlying arterial disease, these patients will usually have a normal capillary refill time. Classically, these ulcers appear at the medium male ius. And this is because this is the location of the distal great saf vein, arterial ulcers. On the other hand, are punched out, they are deeper. They have an irregular shape and they have necrotic tissue and minimal exudate is released. The skin in these patients will be thin and shiny with reduced hair growth. It may be cool and the limb may become white with pallor. When you elevate the legs, they will probably also have weak pulses and an increased capillary refill time. These also form pressure points on the toes and feet and may form at sites of trauma. For example, the lateral malleolus and tibial area. If people knock their legs against objects such as table legs or chairs. The pathophysiology of pad is the arteries, supplying limbs and periphery are narrowed which causes reduced blood flow and hypoxia. In less severe disease, the metabolic needs of the tissues may be met at rest. But when these needs increase during exercise, they cause hypoxia and pain. The mechanism most commonly is atherosclerosis. The more rarely it can be vasculitis. Complications include septic, gangrene, critical or acute limb ischemia, reduced mobility, amputation and death modifiable risk factors include smoking, hypertension, hyperlipidemia, obesity or physical inactivity and diabetes. Non modifiable risk factors include a family history, increasing age and being male. Ok. So peripheral vascular disease can be diagnosed correctly and what patients will likely present with is a classical history of pain. With arterial disease or maybe a history of, of varicose veins and increased abdominal pressure with venous insufficiency. They likely also have risk factors which need to be asked about. On physical examination. You may well see skin changes and not sensation changes and maybe ulcers. And you may also feel weakened peripheral pulses and then increased capillary refill time. A couple of tests that you can do to quantify the severity of peripheral arterial disease include the ankle brachial pressure index. Now, this is where you measure the BP at the ankle and at the upper limb. And you compare the two by dividing the ankle systolic BP by the brachial systolic BP. And this will give you a number and if it's between 0.9 and 1.2 that's normal. If it's less than 0.9 then that means they do have peripheral arterial disease. If it's above 1.2 then that indicates that the ankle vessels have become calcified and this is usually due to diabetes or end stage renal failure. Buerger's test is where you ask the patient to lie down and then you will lift their limbs up in the air to about 45 degrees for between one and two minutes. And this is to see if the limbs go pale. What you'll want to do is you'll want to see at what angle the limbs go pale because that will indicate how well perfused the limbs are against the force of gravity. And if it's only a small angle as in less than 20 degrees off the bed, then that indicates more severe arterial disease to finish the test. After lifting the limbs up, you will then ask the patient to lie their legs over the side of the bed while sitting up. And this is to encourage blood flow back into the legs. What you will likely to see in peripheral arterial disease is the limbs will go blue and then they will go red with reactive hyperemia. The first of imaging you'd like to do in pa is an ultrasound with duplex and Doppler. And this will allow you to uh quantify the rate of blood flow and also to make a note of where the stenoses are throughout the limbs. Another test you can do is CTA that is computerized tomography, angiography and that's what you can see in images amb on this slide. An alternative to this is Mra Magnetic resonance angiography. The gold standard for imaging vessels is digital subtraction angiography and that is what you can see in images C and D on the right. This is part this imaging will be done as part of an endovascular procedure. And what will happen is dye will be injected directly into the vessels. And at the same time, interventional radiologists will be looking to see where the dye goes on X ray fluoroscopy. So they can see where the blood is flowing in real time, different presentations of PVD are managed differently. So, acute limb ischemia is an acute presentation where patients are critically unwell, they will likely need resuscitation and very quick imaging. If not going straight to the theater to have their limbs revascularized as quickly as possible. And the aim is to have this done in under six hours, which much, much increases the chance of successful revascularization of the limbs, intermittent claudication, chronic and critical limb ischemia. Their management depends on the severity of symptoms and what the imaging shows. And I'll talk a bit more about that in the next slide. In terms of managing ulcers, arterial ulcers will only really recover if you revascularize the limb and the bride and necrotic tissue that is formed there. Venous ulcers can be treated with compression bandages. And what this does is it squashes the pathologically dilated veins and forces blood to flow through competent veins to reduce the sort of stasis of blood in these pathological veins and prevent the propagation of the inflammatory process that has caused the ulcers to form. Risk factor. Modification is very important both before and after interventions, smoking is a huge risk factor and can result in stenoses reoccurring much more quickly if the patient continues to smoke. After intervention, ex exercise is important. It's also important to control hypercholesteremia with statins to control hypertension with antihypertensives and to prevent, to reduce the risk of clots with anti clot drugs such as aspirin and CGL. You also want to ensure that you control the patient's diabetes as best as you can. In terms of interventional management. Endovascular management includes angioplasty and stenting angioplasty is where you pass a balloon on the end of a tube into a vessel. Expand the balloon to try and stretch the obstruction out and increase the blood flow through the blood vessel. You can also put a stent on a balloon and leave that in place. The pros of this is that it's minimally invasive. You use local anesthetic and it can be done as a day case. The downsides are that it's not definitive and some patients may require repeated interventions to resolve their symptoms. It is also less effective at treating lung occlusions and you don't want to stent across the popliteal artery because the stent can kink and bend as the knee flexor. Also angioplasty is less good at treating distal disease. Surgical management options include endarterectomy. This is where you open an artery and remove the atherosclerosis that is inside and then sew it back up. Arterial bypass grafts. This is where you use a vessel graft from other parts of the body or you can use prosthetic grafts and you bypass the narrowed artery entirely. You can also amputate necrotic tissue if certain parts of limbs or toes have died already or are unsalvageable. The pros of surgical management include the fact that you can treat very long occlusions. You can often treat po or death or disease. Definitively, the downsides are that it's very invasive. There is a risk of infection in grafts and general anesthetics are unsuitable for some people. So to continue the case, the patient gives a history that they can walk a predictable distance before the pain comes on and the pain is relieved quickly with rest. They have a past medical history of diabetes, hypertension and coronary artery disease. And they also have a 60 pack year smoking history on examination. Their lower limbs are cold. They've lost hair and they have decreased posterior tibialis and dorsalis pedis pulses bilaterally, their sensation however, is intact and their burger is positive at 45 degrees. You do a BP and it's quite high. You also do an ankle brachial pressure index and find that it's 0.8. So that just puts them in the category of peripheral arterial disease because it's less than 0.9. On further investigations, we find that on duplex, ultrasound and MRA there is a stenosis of the femoral popliteal arteries bilaterally and this helps the the clinicians to make a definitive diagnosis of chronic limb ischemia. So to summarize, we have covered the following presentations from the MLA curriculum, cold, pale, painful, pulseless leg and foot limb claudication, limb weakness, skin ulcers and gangrene. We've talked about the pathophysiology usually caused by atherosclerosis, reducing blood flow. We talked about risk factors which include cardiovascular risk factors such as being male and being of increasing age. We talked about the diagnosis which may make clinically but also supported through ultrasound CT and Mra. And we discussed management options including conservative endovascular and surgical management. Thank you very much.
