UNDERSTANDING THE BASICS OF NEUROINTERVENTION RADIOLOGY
Neurointervention is a medical field that involves minimally invasive procedures to diagnose and treat conditions affecting the blood vessels in the brain and spinal cord. Interventional radiology is a broader specialty that uses image-guided techniques to perform various procedures throughout the body. In the context of neurointervention, interventional radiologists use advanced imaging technologies to navigate catheters and devices through blood vessels to treat conditions like aneurysms, arteriovenous malformations (AVMs), and strokes. These procedures often offer less risk and quicker recovery compared to traditional open surgeries.
CNS Vascular Supply
The vascular supply of the central nervous system (CNS) is crucial for delivering oxygen and nutrients to the brain and spinal cord. It consists of two main circulatory systems: the anterior circulation and the posterior circulation.
- Anterior Circulation: The anterior circulation supplies blood to the front two-thirds of the cerebral hemispheres and several deep brain structures. It is primarily facilitated by two major arteries:
a. Internal Carotid Arteries (ICAs): The ICAs arise from the common carotid arteries in the neck and enter the skull through the carotid canals. Inside the cranium, they divide into two main branches: the Middle Cerebral Artery (MCA) and the Anterior Cerebral Artery (ACA). The MCA supplies lateral areas of the cerebral hemispheres, while the ACA provides blood to the medial aspects of the frontal and parietal lobes.
- Posterior Circulation: The posterior circulation supplies blood to the posterior part of the cerebral hemispheres, the brainstem, and the cerebellum. It is mainly facilitated by two major arteries:
a. Vertebral Arteries: The vertebral arteries arise from the subclavian arteries and travel up through the vertebrae in the neck to enter the skull through the foramen magnum. Inside the skull, they merge to form the Basilar Artery.
b. Basilar Artery: The basilar artery is formed by the union of the two vertebral arteries. It supplies blood to the brainstem and cerebellum and gives rise to several important branches, including the Posterior Cerebral Arteries (PCAs).
Branches of the posterior circulation include:
- Posterior Cerebral Arteries (PCAs): These supply the posterior part of the cerebral hemispheres, including the occipital lobes.
- Superior Cerebellar Arteries (SCAs) and Anterior Inferior Cerebellar Arteries (AICAs): These arteries provide blood to the cerebellum.
- Pontine Arteries: These supply the pons, a vital part of the brainstem.
The Circle of Willis: The Circle of Willis is an important circulatory structure at the base of the brain, formed by the joining of the anterior and posterior circulations. It provides collateral circulation, allowing blood flow to be maintained even if one of the major arteries is compromised.
In summary, the vascular supply of the CNS is a complex network of arteries that ensures a continuous and adequate blood supply to sustain the functions of the brain and spinal cord. Any disruptions or blockages in these arteries can lead to severe neurological consequences.
Intervention Radiology In Non-traumatic Subarachnoid Hemorrhage
Interventional radiology plays a crucial role in the diagnosis and treatment of non-traumatic subarachnoid hemorrhage, particularly in cases of ruptured berry aneurysms and arteriovenous malformation (AVM).
- Diagnosis:
- Angiography: Interventional radiologists use digital subtraction angiography (DSA) to visualize the blood vessels in the brain. This technique helps identify the location and characteristics of aneurysms or AVMs responsible for the hemorrhage.
- Cerebral angiogram: It provides detailed images of the cerebral vasculature and allows the radiologist to identify abnormal blood vessels or aneurysms.
- Treatment:
- Endovascular coiling: For berry aneurysms, interventional radiologists can use a minimally invasive approach called endovascular coiling. They insert a catheter into the blood vessels and place tiny platinum coils within the aneurysm. The coils promote blood clotting and prevent further bleeding.
- AVM embolization: In the case of AVMs, interventional radiologists can use embolization, wherein they introduce embolic agents through a catheter to block the abnormal vessels, reducing the risk of bleeding.
- Balloon-assisted coiling: For complex aneurysms, a balloon may be used along with the coils to stabilize the catheter and facilitate efficient coiling.
Interventional radiology offers many benefits, including less invasive procedures, shorter recovery times, and reduced risk of complications compared to traditional open surgeries. However, it’s essential to note that the suitability of these procedures depends on the individual patient’s condition and the expertise of the interventional radiology team. Close collaboration with other medical specialists, such as neurosurgeons and neurologists, is crucial for optimal patient outcomes.
Interventional radiology in Acute Stroke
Interventional radiology plays a crucial role in the treatment of acute ischemic stroke by employing two main procedures: thrombolysis and thrombectomy.
- Thrombolysis: Thrombolysis, also known as intravenous (IV) tissue plasminogen activator (tPA) therapy, involves the administration of a clot-dissolving medication directly into the bloodstream. The drug targets the blood clot causing the ischemic stroke and helps to break it down, restoring blood flow to the affected area of the brain. This treatment is most effective when administered within the first few hours of stroke onset, ideally within 4.5 hours, to minimize brain damage.
- Thrombectomy: Thrombectomy is a minimally invasive procedure that involves the removal of the blood clot causing the stroke using specialized devices. This procedure is typically performed using endovascular techniques, where a catheter is threaded through the blood vessels to the site of the clot. The clot is then physically removed, allowing blood flow to be restored promptly. Thrombectomy has proven to be highly effective in cases where thrombolysis alone may not be sufficient, and it can extend the treatment window beyond the initial 4.5 hours.
Both thrombolysis and thrombectomy are time-sensitive treatments, and their success rates are significantly higher when performed early after the onset of symptoms. These interventional radiology procedures have revolutionized the management of acute ischemic stroke, providing improved outcomes and reducing long-term disability for many patients. However, it’s essential to note that not all patients are eligible for these treatments, and individualized assessment and care are necessary to determine the most appropriate approach for each case.
NONVASCULAR INTERVENTIONAL RADIOLOGY
You May Also Like
SUBSISTENCE AND COMMERCIAL AGRICULTURE
THIGH MUSCLES, FEMORAL TRIANGLE AND SUBSARTORIAL CANAL
