Dissection of other precerebral arteries

This code represents a tear in the inner lining of an artery that supplies blood to the brain, excluding the carotid and vertebral arteries. This tear allows blood to flow between the layers of the arterial wall, forming a false lumen and potentially compromising blood flow. It is a serious condition that can lead to stroke or other neurological deficits.

Use this code for documented dissections affecting precerebral arteries such as the subclavian, innominate (brachiocephalic), or common carotid artery (before its bifurcation), when the specific artery is not otherwise classified. Documentation should clearly state "dissection" and specify an artery other than the carotid or vertebral.

• Carefully review documentation to ensure the dissection is not of the carotid (I77.71) or vertebral (I77.74) arteries, as these have specific codes.
• Distinguish dissection from aneurysm; this code is for dissection, not an aneurysm of these arteries (I72.5).
• Always sequence this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if it is a co-morbidity impacting care.