Artery of Adamkiewicz
The Artery of Adamkiewicz, also known as the great anterior radiculomedullary artery, is the largest and most significant segmental medullary artery supplying the spinal cord. It plays a critical role in providing blood flow to the lower two-thirds of the spinal cord, particularly the lumbar and sacral regions.
Anatomy and Origin
- Origin: Typically arises from a posterior branch of an intercostal artery (usually between T9 and T12 levels) or from a lumbar artery.
- Side Predominance: In about 75% of individuals, it originates on the left side.
- Course: After its origin, it enters the vertebral canal through an intervertebral foramen and ascends to join the anterior spinal artery.
- Variation: The exact level of origin can vary significantly, ranging from T5 to L2.
Physiological Significance
- Blood Supply: Supplies the anterior two-thirds of the spinal cord, including the anterior horn cells and corticospinal tracts.
- Function: Essential for motor function, as it nourishes motor neurons responsible for movement.
Clinical Relevance
- Spinal Cord Ischemia: Damage or occlusion can lead to anterior spinal artery syndrome, resulting in paralysis and loss of pain and temperature sensation below the lesion.
- Surgical Considerations: Critical during surgeries involving the aorta (e.g., aneurysm repair) to prevent inadvertent injury that could cause paraplegia.
- Imaging: Preoperative identification via spinal angiography or magnetic resonance angiography (MRA) is recommended.
Pathophysiology
- Vulnerability: Due to its significant contribution to spinal cord perfusion, it's susceptible to ischemia during systemic hypotension or aortic pathology.
- Anterior Spinal Artery Syndrome: Characterized by motor paralysis and dissociated sensory loss (pain and temperature), with preserved dorsal column functions (proprioception and vibration).
Diagnostic and Imaging Techniques
- Magnetic Resonance Angiography (MRA): Non-invasive method to visualize the artery's course and origin.
- Computed Tomography Angiography (CTA): Provides high-resolution images but involves radiation exposure.
- Digital Subtraction Angiography (DSA): Gold standard for detailed vascular mapping but is invasive.
Surgical Implications
- Aortic Aneurysm Repair: Identification and preservation are crucial to prevent postoperative neurological deficits.
- Spinal Cord Protection Strategies: Techniques like hypothermia, cerebrospinal fluid drainage, and maintaining adequate perfusion pressure are employed.
Recent Advances
- Endovascular Techniques: Minimally invasive approaches reduce the risk of disrupting the artery.
- Neuromonitoring: Intraoperative monitoring of spinal cord function helps detect ischemia early.