Aneurysm of vertebral artery

This code signifies an abnormal, localized dilation or ballooning of the vertebral artery, a major blood vessel in the neck that supplies blood to the brain. This weakening of the arterial wall can be congenital or acquired and may lead to rupture or compression of surrounding structures.

Use this code when documentation explicitly states a diagnosis of an aneurysm of the vertebral artery. This typically follows imaging studies such as CT angiography, MRA, or conventional angiography confirming the presence and location of the aneurysm.

• Differentiate from dissection of the vertebral artery (I77.74), which is an excluded condition.
• Ensure the documentation specifies "aneurysm" and not just "dilation" unless further clarified as an aneurysm.
• Code any associated neurological symptoms or complications separately, such as subarachnoid hemorrhage if rupture has occurred.