Neurosurgery Coding Alert

Question: Encounter notes indicate that the surgeon performed prolonged administration of drugs in two vascular territories for a patient with “Hypercoagulable state NOS.” How should I report this encounter, and what are the vascular territories?

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Answer: First, we’ll focus on coding the encounter; then read on for a breakdown of the vascular territories you’ll need to know.

On the claim, report:

• 61650 (Endovascular intracranial prolonged administration of pharmacologic agent(s) other than for thrombolysis, arterial, including catheter placement, diagnostic angiography, and imaging guidance; initial vascular territory) for the drug administration to the first vascular territory
• +61651 (Endovascular intracranial prolonged administration of pharmacologic agent(s) other than for thrombolysis, arterial, including catheter placement, diagnostic angiography, and imaging guidance; each additional vascular territory (List separately in addition to code for primary procedure)) for the drug administration to the second vascular territory
• D68.59 (Other primary thrombophilia) appended to 61650 and +61651 to represent the patient’s hypercoagulable state

Dx note: The notes mentioned “Hypercoagulable state NOS,” which is listed as a synonym under the

D68.59 banner. Other conditions that you’d code with D68.59 include:

• Antithrombin III deficiency
• Primary hypercoagulable state NEC
• Primary thrombophilia NEC
• Protein C deficiency
• Protein S deficiency
• Thrombophilia NOS

Vascular areas explained: According to CPT®, “For purposes of reporting services described by … 61650, +61651, the intracranial arteries are divided into three vascular territories”:

• Right carotid (anterior) circulation
• Left carotid (anterior) circulation
• Vertebro-basilar (posterior) circulation

Again, according to CPT^®, the vessels included for each vascular territory are (bold text added for emphasis):

• “Right carotid circulation: Intracranial portion of right internal carotid (includes clinoid and supraclinoid segments); branches of right internal carotid (anterior cerebral artery, middle cerebral artery, posterior communicating artery, etc.)
• “Left carotid circulation: Intracranial portion of left internal carotid (includes clinoid and supraclinoid segments); branches of left internal carotid (anterior cerebral artery, middle cerebral artery, posterior communicating artery, etc.)
• “Vertebro-basilar circulation: Intracranial portions of the left and right vertebral arteries; basilar artery (formed by the junction of the left and right vertebral); branches of the basilar artery (anterior inferior cerebellar artery, superior cerebellar artery, etc.).”