Chronic embolism and thrombosis of left iliac vein

This code signifies a persistent blockage of the left iliac vein due to a blood clot, which may be either an embolus (a clot that traveled from elsewhere) or a thrombus (a clot that formed in situ). This chronic obstruction can lead to impaired venous return from the left lower extremity and pelvis.

Apply this code when documentation clearly indicates a long-standing or recurrent thrombotic event affecting the left iliac vein. This is typically supported by imaging studies (e.g., venography, duplex ultrasound, CT venogram) confirming chronic occlusion or significant stenosis, and clinical signs/symptoms consistent with chronic venous insufficiency in the left leg.

• Differentiate between acute (I82.422) and chronic (I82.522) conditions; documentation must specify chronicity.
• Ensure the laterality is explicitly stated as "left" in the medical record.
• Code any associated complications, such as post-thrombotic syndrome (I87.0-) or venous ulcer (I83.0-, I83.2-), separately.