Aneurysm of other precerebral arteries

This code represents a localized, abnormal dilation or ballooning of an artery that supplies blood to the brain, excluding the carotid and vertebral arteries. These precerebral arteries are located outside the brain itself but are crucial for cerebral circulation.

Use this code when documentation specifies an aneurysm of a precerebral artery other than the carotid or vertebral arteries, such as the subclavian, innominate, or common carotid artery (before its bifurcation). Supporting documentation should clearly identify the specific artery involved and confirm the presence of an aneurysm.

• Carefully review documentation to differentiate between an aneurysm and a dissection, as these are distinct conditions with different codes.
• Always confirm the specific artery involved to ensure it's not a carotid or vertebral artery aneurysm, which have their own dedicated codes.
• Be mindful of the "Excludes2" notes to avoid miscoding related conditions like carotid or vertebral artery aneurysms or dissections.