Deepali N. Tukaye, MBBS, PhD, FSCAI; Monica Wright, MHA, CPC, CPMA, CPCO
Pulmonary embolism is defined as thrombotic occlusion of the pulmonary arterial tree – main, right, and left branches and segmental branches. Thrombotic occlusion of the pulmonary arterial system causes a mechanical barrier to return of blood flow through the lungs to the left side of the heart, preventing adequate oxygenation of the blood and causing hypoxia with or without increasing strain on right side of the heart.
Percutaneous pulmonary arterial thrombectomy procedures are performed using a transvenous approach to access the pulmonary arterial system. These procedures are considered arterial procedures because the service is performed in the pulmonary artery(ies).
The procedure for mechanical pulmonary thromboembolectomy starts with a venous access but ultimately is a complex procedure that involves positioning large-bore catheters and delivery of thrombolytics into the pulmonary arterial system. This requires skillful manipulation of these catheters from the veins into pulmonary arterial system via the right atrium and ventricle across the tricuspid valve. This carries inherent risk of right atrial or ventricular puncture/rupture, cardiac tamponade, and damage to tricuspid valve, which could potentially cause severe tricuspid regurgitation requiring surgical management.
Contrary to the venous system, the pulmonary arterial tree is a higher-pressure system. Procedural complications are associated with higher risk of massive and fatal hemorrhage. Acquiring these procedural skills involves fair amount of supervised training during fellowship and continued CME after.
Given that the mechanical embolectomy is being performed in an arterial system, it would be appropriate to report CPT® 37184, Primary percutaneous transluminal mechanical thrombectomy, noncoronary, non-intracranial, arterial or arterial bypass graft, including fluoroscopic guidance and intraprocedural pharmacological thrombolytic injection(s); initial vessel and CPT® 37185, Primary percutaneous transluminal mechanical thrombectomy, noncoronary, non-intracranial, arterial or arterial bypass graft, including fluoroscopic guidance and intraprocedural pharmacological thrombolytic injection(s); second and all subsequent vessel(s) within the same vascular family (List separately in addition to code for primary mechanical thrombectomy procedure).
Diagnosis selection is also important for billing pulmonary arterial thrombectomy procedures. While the I26.0X series is the most specific, it would be inappropriate to limit mechanical pulmonary embolectomy to patients with significant hemodynamic compromise alone as this usually constitutes massive pulmonary embolism. A large majority patients experience hypoxia requiring supplemental oxygenation without significant hemodynamic collapse significantly affecting quality of life without immediate or incident cardiopulmonary collapse (sub massive pulmonary embolism- has high 30d-1yr mortality rate up to 25%). These patients, if not treated with mechanical embolectomy, have prolonged hospital/intensive care stays and most of the time require home oxygen for extended periods of time. Also, mechanical embolectomy can also be utilized in patients with non-thrombotic embolism e.g., septic embolism, especially if they are deemed poor surgical candidates.
In contrast, CPT® 37187 Percutaneous transluminal mechanical thrombectomy, vein(s), including intraprocedural pharmacological thrombolytic injections and fluoroscopic guidance, and CPT® 37188 Percutaneous transluminal mechanical thrombectomy, vein(s), including intraprocedural pharmacological thrombolytic injections and fluoroscopic guidance, repeat treatment on subsequent day during course of thrombolytic therapy are more appropriately used for procedures performed in the low-pressure venous system such as upper and lower extremity veins, superior or inferior vena cave; Any venous system before it drains into the right atrium. The mechanical removal of a venous thrombus does not involve navigation through the heart. Often the approach to a venous thrombus is direct and may involve minimal catheter manipulation. Additionally, the venous system is a low-pressure system. For that reason, complications are better tolerated because there is less bleeding. It would be inappropriate to utilize venous embolectomy CPT® codes 37187-37188 for management of pulmonary arterial embolism.