I74.09

Embolism and thrombosis of other parts of abdominal aorta

I74.09 represents a critical vascular condition involving the occlusion of the abdominal aorta in segments other than the bifurcation (saddle embolus). This code specifically identifies acute or chronic blockages resulting from a dislodged blood clot (embolism) or a clot formed in situ (thrombosis) within the suprarenal or infrarenal segments of the abdominal aorta. Such occlusions are medical emergencies as they can lead to catastrophic ischemia of the lower extremities, kidneys, or mesenteric organs depending on the precise anatomical location of the thrombus. Clinical management often requires immediate surgical or endovascular intervention to restore perfusion and prevent tissue necrosis, limb loss, or multi-organ failure.

Clinical Symptoms

Sudden, severe pain in the abdomen or lower back
Acute limb ischemia (pain, pallor, pulselessness, paresthesia, paralysis, poikilothermia)
Bilateral lower extremity weakness or numbness
Decreased or absent femoral and distal pulses
Signs of bowel ischemia (severe abdominal pain out of proportion to exam findings)
Oliguria or anuria if renal artery ostia are involved
Hypertension secondary to renal hypoperfusion
Mottling of the skin on the lower trunk and legs

Common Causes

Advanced atherosclerosis with plaque rupture
Cardiac-origin emboli (atrial fibrillation, mural thrombi following myocardial infarction)
Aortic aneurysm with mural thrombus formation
Hypercoagulable states (Protein C/S deficiency, Factor V Leiden, malignancy)
Complications from vascular procedures or catheterization
Blunt or penetrating abdominal trauma
Aortic dissection extending into the abdominal segment
Prosthetic heart valves or vascular grafts

Documentation & Coding Tips

Distinguish between saddle and non-saddle emboli for precise coding. Code I74.09 applies only to non-saddle emboli or thrombi of the abdominal aorta. Specify the exact anatomical location, such as suprarenal or infrarenal, to support clinical necessity for interventions.

Example: 68-year-old male with history of atrial fibrillation presents with acute onset bilateral lower extremity pain and coolness. CT angiography confirms a non-saddle acute thrombus of the infrarenal abdominal aorta extending to the bifurcation. Findings are consistent with I74.09. Documentation of comorbidities including paroxysmal atrial fibrillation and hypertension increases the risk adjustment factor for this encounter.

Billing Focus: Identify the thrombus as non-saddle and specify the infrarenal location to justify high-complexity imaging and surgical consultation.

Document the acuity of the thrombosis or embolism clearly. Acute events typically require emergent intervention and qualify for higher-level E/M services compared to chronic, stable mural thrombi found incidentally.

Example: Patient with established peripheral artery disease presents with worsening claudication. Duplex ultrasound reveals a chronic, partially occluding thrombus of the distal abdominal aorta, coded as I74.09. There are no signs of acute limb-threatening ischemia. Continued management with dual antiplatelet therapy and statin. Documentation of chronic status ensures appropriate longitudinal risk scoring.

Billing Focus: Differentiate between acute and chronic presentation to justify the intensity of the diagnostic workup.

Explicitly state the presence or absence of underlying aortic aneurysms. If the thrombus is associated with an abdominal aortic aneurysm (AAA), the aneurysm code may take precedence or be used concurrently depending on the focus of treatment.

Example: Incidental finding of a 4.5 cm infrarenal abdominal aortic aneurysm with an eccentric mural thrombus not causing significant luminal narrowing. Code I71.40 for the aneurysm and I74.09 for the mural thrombus. Clinical plan involves 6-month surveillance via CTA and optimization of cardiovascular risk factors.

Billing Focus: Concurrent coding of both the aneurysm and the thrombus provides a more complete picture of the patient's vascular pathology.

Detail the clinical manifestations of the embolism, such as the status of distal pulses, skin temperature, and motor/sensory function. This clinical evidence supports the diagnosis of I74.09 in the absence of a saddle embolus.

Example: Evaluation for acute limb ischemia. Physical exam shows absent popliteal and pedal pulses bilaterally, but femoral pulses remain palpable. CTA reveals acute thrombosis of the abdominal aorta just proximal to the bifurcation but not straddling the bifurcation (non-saddle). I74.09 is the primary diagnosis. Patient is admitted for emergent heparinization and vascular surgery evaluation.

Billing Focus: Physical exam findings of pulse deficits must correlate with the anatomical site of the aortic thrombus documented in the imaging report.

Document the underlying cause of the thrombosis whenever possible. Identifying whether the thrombus is due to atherosclerosis, a hypercoagulable state, or a proximal embolic source (like the heart) affects the long-term management and risk adjustment.

Example: Patient diagnosed with acute non-saddle abdominal aortic thrombosis (I74.09). Workup suggests the source is a mural thrombus from a recently diagnosed myocardial infarction (I21.19). Treatment includes anticoagulation and cardiology follow-up. Documenting the cardiac source adds specificity to the clinical picture and impacts HCC 122 (Circulatory System).

Billing Focus: Etiological specificity (e.g., secondary to atherosclerosis vs. cardiac embolus) supports the necessity of multi-specialty care.

Relevant CPT Codes

99214 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a moderate level of medical decision making. When using total time on the date of the encounter for code selection, 30 through 39 minutes of total time is spent.
Patients with I74.09 often have multiple comorbidities and require moderate MDM to manage anticoagulation and monitor for progression.
99204 - Office or other outpatient visit for the evaluation and management of a new patient, which requires a moderate level of medical decision making. When using total time on the date of the encounter for code selection, 45 through 59 minutes of total time is spent.
The complexity of diagnosing the cause and determining the risk of embolism in a new patient constitutes moderate MDM.
99215 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a high level of medical decision making. When using total time on the date of the encounter for code selection, 40 through 54 minutes of total time is spent.
High MDM is required when a patient has a threatened limb or complex anticoagulation needs in the setting of multiple comorbidities.
34201 - Embolectomy or thrombectomy, with or without catheter; aortoiliac artery, by abdominal incision
Direct procedural treatment for acute I74.09 when catheter-based methods are insufficient.
37184 - Primary percutaneous transluminal mechanical thrombectomy, arterial, inclusive of all imaging guidance and intraprocedural pharmacological thrombolytic injection(s); initial vessel
Modern first-line treatment for many cases of acute abdominal aortic thrombosis.
74175 - Computed tomographic angiography, abdomen and pelvis, with contrast material(s), including noncontrast images, if performed, and image postprocessing
CTA is the gold standard for identifying the location and extent of I74.09.
37221 - Revascularization, endovascular, open or percutaneous, iliac artery, unilateral, with transluminal stent placement(s), includes angioplasty within the same vessel, when performed
Often performed in conjunction with aortic thrombectomy to secure the distal outflow.
75625 - Aortography, abdominal, by serialography, radiological supervision and interpretation
Used during interventional procedures to guide thrombectomy and confirm restoration of flow.
34802 - Endovascular repair of infrarenal abdominal aortic aneurysm or dissection; using modular bifurcated prosthesis (two docking limbs)
Relevant if I74.09 is secondary to an aneurysm requiring exclusion.
93922 - Limited bilateral noninvasive physiologic studies of upper or lower extremity arteries
Used to assess the hemodynamic impact of the aortic thrombus on distal perfusion.