Introduction

Claudication is cramping or pain which can occur in the legs during exercise and is caused by a blockage or narrowing in the arteries. During physical activity, the muscles and tissues in the body require an increased supply of oxygen-rich blood in order for respiration to take place. Any blockages or narrowings in the arteries prevent the delivery of blood to these tissues, resulting in calf cramping. On resting the pain usually dissipates. Claudication is linked with peripheral artery disease (PAD), where plaque builds up in the arteries, restricting blood flow.¹ 

Early detection and treatment of claudication is essential, as the condition can worsen over time, and further problems can develop. If left untreated, arterial narrowings can develop into blockages, leading to reduced blood flow at rest, ongoing pain, and subsequently tissue death. 

This article will explore the topic of claudication, along with its causes and effects on daily life. Diagnosis and treatment options will be detailed, along with patient management and follow-up. 

Understanding claudication

Claudication can be caused by atherosclerosis, which is where plaque builds up in the walls of the arteries. Damage to the arterial wall can cause inflammation, and build-up of fats and cholesterol, which cause narrowings in the vessels. 

Risk factors for claudication include high blood pressure, high cholesterol, smoking history and diabetes.² Claudication can affect walking distance, which has an impact on daily life and the ability to carry out normal activities. 

Diagnosis of claudication

Diagnosis begins with the clinician taking a medical history from the patient, to find out about the smoking history, the presence of diabetes, and identifying other past problems such as heart attack, and stroke. On physical examination, the lower limbs may present with colour changes, such as turning pale or blue, hair loss, and wounds that are slow to heal.

Diagnostic tests

Diagnostic tests can also be used, an example of which is the ankle-brachial pressure index. This involves taking blood pressure from the brachial artery at the elbow and comparing this to the posterior tibial and anterior tibial artery pressure at the ankle. The pressure at the ankle is then divided by the pressure of the brachial, to give the value. If there are narrowings or blockages in the arteries, then the pressure at the ankle will be lower than the pressure at the arm, and the ABPI measurement will be less than 1.0. However, this test does not work well for diabetic patients, as hardening of the arteries means they cannot be compressed by the pressure cuff, leading to misleading results. 

Treadmill exercise testing is also useful, as the ABPI can be taken at rest, and then repeated after exercise. This will indicate the reduced amount of flow reaching the lower limb after exercise. 

Duplex ultrasound can help to pinpoint the exact location of blockages or narrowings in the arteries. In these scans a healthcare professional called a vascular scientist, or a sonographer, will use an ultrasound machine to assess the arteries throughout the leg, to listen to the blood flow and measure the speed of the blood at various points.³ 

Angiography can also be used and involves using X-rays, along with a contrast agent to assess the arteries to determine the location of blockages. 

Early diagnosis of arterial narrowings is essential in order to build a treatment plan tailored for the individual, and also to prevent further development of the arterial disease.

Treatment options for claudication

Lifestyle modifications

Lifestyle changes can include exercise programs.⁴ With regular exercise, the body can create other arteries, which can act as different pathways for the blood flow to reach the lower tissues when there is a blockage or narrowing. This is called ‘collateralisation’. 

Smoking cessation can be incredibly important to reduce the build-up of plaque in the arteries and stop inflammatory processes causing damage to the arteries. 

Dietary changes to reduce the levels of cholesterol in the blood can be useful for preventing arterial blockages. In overweight patients, losing weight can help with circulation.

Medications

Antiplatelet medication, such as aspirin, can be used to prevent the aggregation of platelets in the blood to prevent blood clotting. Thinner blood allows for the blood to pass through the arterial narrowings more easily and reduces the chance of plaque rupture. Antiplatelets reduce the chances of both stroke and heart attack. 

Statins are used to lower the cholesterol level in the blood. Cholesterol is produced in the liver, and an enzyme called HMG-CoA reductase aids its production.⁵ Statins inhibit this enzyme, to reduce the levels of low-density lipoprotein circulating in the blood. 

Vasodilators are also used in claudication, to dilate and widen the arteries and allow for higher blood flow to pass through. This works by reducing the resistance in the arteries and lowering blood pressure. 

Antihypertensive medications can also be used to lower blood pressure, aiming to reduce the damage to the blood vessels, which can lead to the development of atherosclerosis. 

Interventional procedures

Angioplasty is a minimally invasive surgical procedure where a wire is inserted into the narrowed artery with a balloon that is inflated. This widens the artery at the desired location, increasing the blood flow down the artery and removing the narrowing. Metallic stents can also be inserted into the arteries to hold them open and prevent repeated blockage. 

Surgical options

Other surgical options can include bypass surgery, where a section of the patient's own vein, or a graft is used to bypass the blocked region of the artery. 

Endarterectomy can also be used, which involves opening up the artery to remove plaque.

Novel therapies and emerging treatments

One novel therapy which can be used is gene therapy, which could aid in the growth of new arteries in areas with blockages or narrowings. Angiogenesis is the creation of new blood vessels, and in gene therapy, this can aid with angiogenesis by modifying the genetic material encoding the proteins involved. This can then work to promote blood flow in the affected limb and help with the recovery of tissues. 

Cell therapy is another emerging treatment for claudication, which involves transplanting cells responsible for angiogenesis into the patient, to encourage growth. 

Nanotherapy is where nanoparticles can be used to deliver drugs to a specific site in the body, for a targeted response. In the past, protein distribution and nucleic acids have been used to increase the effectiveness of PAD therapy. 

Other types of medication such as monoclonal antibodies can reduce the level of low-density lipoprotein in the blood, which can reduce the risk of cardiovascular events and increase blood flow through areas of narrowing.⁶  

Management and follow-up

Patients with claudication should have follow-up appointments to monitor treatment progress, check on medications, and determine if any further treatment will be needed, such as surgical intervention. Patients should be educated to understand the condition, and the impact that lifestyle modifications can have on symptoms and disease severity, such as increased exercise and stopping smoking. The whole multidisciplinary team of doctors, nurses, and other healthcare professionals need to work together to prevent claudication from developing further into rest pain and chronic limb ischaemia.  

Summary

In summary, claudication can be a debilitating condition caused by the build-up of plaque within arteries, leading to pain and cramping during exercise. Risk factors include diabetes, high cholesterol and high blood pressure, along with lifestyle factors such as smoking. Diagnosis can involve a physical examination, along with the use of diagnostic tests, such as ABPI, treadmill exercise testing, duplex ultrasound and angiography. 

Treatment for claudication can include lifestyle modifications, such as stopping smoking, diet changes, and participation in an exercise programme to develop collateral pathways. Medications also play an important role, such as antiplatelets, statins and vasodilators, to improve blood flow in the arteries. Surgical options can be useful in cases of severe disease when lifestyle changes are not enough to improve circulation. 

It is also important that patients are monitored throughout treatment to assess for changes or progression of symptoms. Early diagnosis and comprehensive treatment are essential to prevent the development of disease and to salvage the remaining arteries. Future treatment might focus on novel areas such as nanotechnology, cell therapy, or gene therapy. Also, new medications such as monoclonal antibodies.