Thrombectomy


Mechanical thrombectomy, or simply thrombectomy, is the interventional procedure of removing a blood clot from a blood vessel. It is commonly performed in the cerebral arteries. The effectiveness of thrombectomy was confirmed in several randomised clinical trials conducted at University at Buffalo and elsewhere by a team of researchers including Elad Levy.

Applications in brain

Ischemic stroke represents the fifth most common cause of death in the western world and the number one cause of long-term disability. Until recent times, systemic intravenous fibrinolysis was the only evidence-based therapy for patients with acute onset of stroke due to large vessel occlusion.
In 2015, the results of five trials from different countries were published in the New England Journal of Medicine, demonstrating the safety and efficacy of mechanical thrombectomy with stent-retrievers in improving outcomes and reducing mortality for patients who present within 6 hours from their time last known well. It is now a widespread procedure performed in most primary, thrombectomy capable, or comprehensive stroke centers across the globe.
In 2018 the DAWN and DEFUSE-3 trails were published. These trials showed that mechanical thrombectomy is a safe and effective treatment for individuals who have an acute ischemic stroke out to 24 hours of symptom onset.

Stent-retriever thrombectomy

The procedure can be performed with general anesthesia or under conscious sedation in an angiographic room. A system of coaxial catheters is pushed inside the arterial circulation, usually through a percutaneous access to the right femoral artery. A microcatheter is finally positioned beyond the occluded segment and a stent-retriever is deployed to catch the thrombus; finally, the stent is pulled out from the artery, usually under continuous aspiration in the larger catheters.

Direct aspiration

A different technique for mechanical thrombectomy in the brain is direct aspiration. It is performed by pushing a large soft aspiration catheter into the occluded vessel and applying direct aspiration to retrieve the thrombus; it can be combined with the stent-retriever technique to achieve higher recanalization rates, but the complexity of the procedure increases.
Direct aspiration, has not been studied as thoroughly as stent-retriever thrombectomy, but it is still widely performed because of its relative simplicity and low cost.