I74.11

Embolism and thrombosis of thoracic aorta

Embolism and thrombosis of the thoracic aorta (I74.11) is a critical vascular condition involving the occlusion of the thoracic segment of the aorta by a blood clot. This can occur either as a primary thrombus (thrombosis) forming directly on the aortic wall—often at the site of an atherosclerotic plaque or structural abnormality—or as an embolus originating from a proximal source, such as the heart or a more proximal aortic segment. The clinical danger of a thoracic aortic thrombus is twofold: it may cause localized flow obstruction, but more frequently, it serves as a source for distal arterial embolization. Fragments of the thrombus can break off and travel downstream, leading to devastating complications such as acute limb ischemia, mesenteric ischemia, renal infarction, or cerebrovascular accidents if the arch vessels are involved. Diagnosis typically requires high-resolution imaging such as Computed Tomography Angiography (CTA) or Transesophageal Echocardiography (TEE) to visualize the thrombus and assess its mobility and size.

Clinical Symptoms

  • Sudden, severe chest pain radiating to the back
  • Sharp interscapular pain
  • Acute onset of limb pain, pallor, or coldness
  • Paresthesia or numbness in the lower or upper extremities
  • Absent or diminished peripheral pulses (radial, femoral, or pedal)
  • Blue Toe Syndrome (localized digital cyanosis and livedo reticularis)
  • Acute abdominal pain (secondary to mesenteric embolization)
  • Neurological deficits, such as hemiparesis or visual changes
  • Hypertension secondary to renal artery involvement
  • Signs of systemic inflammatory response (if the thrombus is extensive)

Common Causes

  • Advanced atherosclerosis with ulcerated plaques
  • Thoracic aortic aneurysm (blood stasis within the dilated segment)
  • Aortic dissection (clot formation within the false or true lumen)
  • Hypercoagulable states (e.g., Protein C or S deficiency, Factor V Leiden)
  • Blunt chest trauma causing intimal injury
  • Iatrogenic injury from intra-aortic balloon pumps or catheterization
  • Infectious aortitis (mycotic thrombus)
  • Underlying malignancy leading to a prothrombotic state
  • Vasculitis (e.g., Takayasu arteritis or Giant cell arteritis)
  • Cardiac sources such as atrial fibrillation or prosthetic valve emboli

Documentation & Coding Tips

Distinguish between a primary thrombus and a secondary embolism to the thoracic aorta.

Example: Patient presents with acute onset chest pain. Transesophageal echocardiogram reveals a 2.5 cm mobile thrombus attached to the descending thoracic aortic wall, distinct from atherosclerotic plaques. Diagnosed with acute thrombosis of the thoracic aorta (I74.11). This represents a high-risk vascular event (HCC 108) requiring immediate anticoagulation with heparin infusion and surgical consultation for potential embolectomy.

Billing Focus: Documentation must specify the thoracic segment of the aorta to distinguish from abdominal or unspecified locations to ensure correct code I74.11 is used.

Document the specific segment of the thoracic aorta affected by the thrombus or embolism.

Example: Computed tomography angiography (CTA) demonstrates an intraluminal filling defect consistent with an embolism in the ascending thoracic aorta. No evidence of aortic dissection was noted. The finding is documented as an embolism of the ascending thoracic aorta (I74.11). Patient has a history of atrial fibrillation which is the likely source.

Billing Focus: Specificity of the thoracic segment (ascending, arch, or descending) supports the use of I74.11 rather than I74.10 (unspecified aorta).

Clearly state the clinical manifestations resulting from the aortic thrombosis, such as distal ischemia.

Example: A 72-year-old male with known mural thrombus of the thoracic aorta (I74.11) now presents with acute lower extremity ischemia in the right leg. The thoracic thrombus is identified as the source of the peripheral embolism. This acute exacerbation of chronic vascular disease requires intensive monitoring and contributes to the overall medical complexity.

Billing Focus: Linking the aortic condition to distal complications justifies higher-level E/M codes and supports medical necessity for imaging.

Differentiate between an acute thrombus and chronic mural thrombosis associated with atherosclerosis.

Example: Follow-up imaging shows a stable, non-occlusive mural thrombus of the thoracic aorta (I74.11) in a patient with advanced atherosclerosis of the aorta (I70.0). The documentation specifies both the chronic thrombus and the underlying atherosclerotic disease to provide a complete clinical picture of the patient's vascular health.

Billing Focus: Using both I74.11 and I70.0 when applicable ensures all chronic conditions are reported for comprehensive billing.

Include the plan for long-term anticoagulation or surgical intervention in the documentation.

Example: Patient diagnosed with embolism and thrombosis of the thoracic aorta (I74.11). Plan includes initiation of long-term warfarin therapy with a target INR of 2.0-3.0. Patient is scheduled for monthly monitoring of coagulation levels. This chronic management plan indicates the ongoing risk and the need for continuous medical supervision.

Billing Focus: Documenting the management plan supports the medical decision-making (MDM) component of E/M coding, particularly for high-risk medication management.

Relevant CPT Codes