Limb Saving Treatment for Blocked Leg Arteries: In a significant development, a phase 3 randomized clinical trial (RCT) led by researchers from the University of New South Wales (UNSW) has unveiled a promising solution for patients suffering from blocked lower leg arteries. The new stent, named Esprit BTK, has demonstrated superior effectiveness compared to the current standard procedure. For those treated with Esprit BTK, the likelihood of maintaining an open blood vessel has increased, consequently reducing the need for limb amputation.
These groundbreaking findings from the clinical trial were recently published in the prestigious New England Journal of Medicine. Conjoint Associate Professor Ramon Varcoe, a key figure from UNSW Medicine & Health and the Prince of Wales Hospital, is the lead author of the study and one of the three principal investigators on a global scale.
A/Prof. Varcoe is optimistic that patients at the Prince of Wales Hospital may gain early access to Esprit BTK even before the device receives widespread approval from the Therapeutic Goods Administration (TGA) in Australia. This breakthrough has the potential to expand treatment options for individuals grappling with peripheral artery disease (PAD).
Peripheral artery disease (PAD) involves the accumulation of plaque in the peripheral arteries, which carry blood from the heart to the limbs. This process leads to the narrowing of peripheral arteries, ultimately resulting in chronic limb-threatening ischemia (CTLI) in severe cases. Patients with CTLI experience excruciating pain, gangrene, non-healing ulcers, and, in some cases, the grim possibility of limb amputation, with low survival rates.
A/Prof. Varcoe emphasizes the severity of the situation, stating, “The prognosis after amputation is worse than most cancers.” He, being a clinical academic and vascular surgeon, understands the critical need for effective solutions in this domain.
While there is no national data available for Australia, PAD is estimated to affect over 200 million people worldwide. Notably, according to the Australian Institute for Health and Welfare, PAD was the primary cause of almost 60,000 hospitalizations in 2020-21. It most commonly affects the lower limbs.
Presently, when PAD occurs in the blood vessels below the knee, the standard procedure involves balloon angioplasty, a method that has been in use since the 1950s. During this procedure, a miniature balloon is introduced into the blocked artery, inflated to widen the passage and increase blood flow. However, the current approach, balloon angioplasty, lacks mechanical scaffolding properties and often fails to keep the artery open for an extended duration.
Also Read: Mandurah Unites Against Lung Cancer: Shining Light in the Shadows
In many instances, following balloon angioplasty, the treated blood vessel tends to narrow again, and the balloon’s effect diminishes over time, causing the artery to become obstructed once more.
To address this issue, Conjoint Associate Professor Ramon Varcoe and his collaborators, in collaboration with US medical devices company Abbott, have developed Esprit BTK, a pioneering stent specifically designed for treating blocked arteries below the knee.
Esprit BTK acts as a mechanical scaffold, inserted into blocked lower leg arteries. This scaffold is constructed from poly-l-lactic acid, a material that safely dissolves within the body over a period of 18-24 months. This characteristic is advantageous as it only needs to keep the artery open for a limited time to restore blood flow and resolve the blockage. Furthermore, the scaffold is coated with everolimus, a drug that prevents the blood vessel from narrowing.
In A/Prof. Varcoe’s words, “The Esprit scaffold offers mechanical support to the newly opened artery, delivers a drug to the blood vessel wall that prevents re-narrowing, and subsequently dissolves, leaving behind no irritants to affect the blood vessel or induce scar tissue formation. It also ensures that no bridges are burned should the patient require bypass surgery in the future.”
A/Prof. Varcoe holds the distinction of being the first individual to implant the scaffold in a human and conducted the Phase 1 clinical trial with his colleagues before becoming one of the principal investigators for the advanced-stage clinical trials.
The Phase 3 RCT for Esprit BTK encompassed 261 patients globally with blocked lower leg arteries, who were at risk of needing limb amputation. These patients were divided into two groups, with one receiving balloon angioplasty and the other Esprit BTK treatment.
After one year following treatment, the researchers observed a significantly higher rate of success with Esprit BTK in keeping the artery open, a critical factor in preventing limb amputation. Approximately 75% of the patients in the Esprit BTK group achieved this favorable outcome, compared to 44% in the balloon angioplasty group. In terms of patient safety, there was little distinction between the two treatments, with serious adverse events occurring in 3% of patients in the balloon angioplasty group and 2% in the Esprit BTK group.
A/Prof. Varcoe reflects on this achievement, stating, “This marks the first positive RCT in this field, providing us with an effective tool to save limbs for patients who are often gravely ill.”
Following the triumph of the Phase 3 RCT, researchers and Abbott Laboratories are collaborating to make Esprit BTK accessible to patients across various countries. The journey begins with the submission of Esprit BTK for approval by the Food and Drug Administration (FDA) in the United States, with subsequent submissions planned for Europe, Japan, and Australia. Additionally, the researchers are navigating the TGA Authorized Prescriber Scheme to secure early access for patients at the Prince of Wales Hospital. This significant advancement promises hope for individuals grappling with blocked lower leg arteries and offers the prospect of a better quality of life.
Our Reader’s Queries
What is the best treatment for blocked arteries in the legs?
While maintaining a healthy diet and exercise routine can aid in preventing artery blockages, certain patients may need medical assistance to ensure proper blood flow. For those with PAD, angiography, angioplasty, and stenting are effective treatments that can save limbs.
What type of surgery would it be to unblock arteries in the legs?
Angioplasty is a medical procedure that aims to unblock narrowed or obstructed blood vessels that provide blood to your legs. The arteries can accumulate fatty deposits that hinder blood flow, leading to complications.
What surgery is done for poor circulation in legs?
Peripheral artery bypass surgery is a common procedure for those who suffer from inadequate blood flow to their legs. Roughly half of those affected opt for this surgery to improve their condition. While peripheral artery disease affects around 6.5 million Americans, there are alternative treatments available for those who do not choose to undergo this procedure.
How do you reverse peripheral artery disease in the legs?
While there is no known cure for peripheral arterial disease (PAD), there are ways to manage its symptoms. By making lifestyle changes and taking medication, you can reduce the impact of PAD on your daily life. Additionally, these treatments can lower your risk of developing other cardiovascular diseases, such as coronary heart disease and stroke. It’s important to take action and prioritize your health to prevent further complications.