Unsp injury of unsp innominate or subclavian artery, sequela

This code signifies a long-term complication or residual effect stemming from an injury to an unspecified innominate (brachiocephalic) or subclavian artery. The original injury itself is not specified, nor is the laterality of the affected vessel. This indicates a chronic or late-stage issue rather than an acute event.

Use this code when documenting a sequela, such as an aneurysm, stenosis, or chronic dissection, that is a direct result of a past, unspecified injury to either the innominate or subclavian artery. This applies when the initial injury's details (e.g., type, specific vessel) are no longer available or were never precisely documented. It is appropriate for follow-up encounters addressing these persistent complications.

• Always sequence this code after the code for the specific sequela (e.g., I71.2 for dissecting aneurysm of subclavian artery).
• Avoid using this code for acute injuries; instead, use the acute injury codes from the S25 category.
• Ensure documentation clearly links the current condition to a past injury, even if the injury itself is unspecified.