CPT® Code 93898

1. Indications

The procedure coded as CPT® 93898 is indicated for the detection of venous-arterial shunts, particularly in patients who may be experiencing cryptogenic acute ischemic strokes. This condition is characterized by strokes of unknown origin, which can be particularly prevalent in individuals younger than 55 years of age. The presence of a right-to-left shunt, often through a patent foramen ovale, can lead to the passage of emboli from the venous system directly into the arterial circulation, potentially resulting in ischemic events. Therefore, this procedure is crucial for identifying such shunts in patients presenting with unexplained strokes.

2. Procedure

The procedure begins with the intravenous administration of agitated saline, which serves as a contrast agent to enhance the visualization of blood flow during the transcranial Doppler study. Following the injection, a handheld Doppler probe is positioned over the patient's skull to monitor the intracranial arteries continuously. This monitoring is crucial as it allows for real-time assessment of blood flow dynamics. The Doppler system captures both sound and visual images of the blood flow, which are recorded on a designated computer system. The physician then reviews the acquired Doppler spectral waveforms, focusing on key parameters such as flow direction, velocity, and pulsatility index values. This analysis includes waveforms obtained before, during, and after the agitated saline injection. The physician is tasked with identifying any high-intensity transient embolic signals, which are critical for diagnosing the presence of a shunt. These signals must be differentiated from artifacts that may arise during the procedure. The total number of post-injection embolic signals is counted, and any notable patterns, such as a "shower" or "curtain" appearance of these signals, are documented. Additionally, the specific vessel segments where these signals occur are noted, along with the timing of their appearance following the intravenous injection. Finally, the physician compiles a comprehensive written report detailing the findings and interpretations of the procedure.

3. Post-Procedure

After the completion of the venous-arterial shunt detection procedure, the physician is responsible for thoroughly reviewing the recorded data and interpreting the results. This includes analyzing the Doppler spectral waveforms and documenting any significant findings related to the presence of embolic signals. The physician will provide a written report that details the findings, including the total number of embolic signals detected, their characteristics, and any relevant observations regarding the timing and location of these signals. The report serves as a critical component for further clinical decision-making and may guide subsequent management strategies for the patient. Additionally, patients may be monitored for any immediate post-procedural effects, although specific post-procedure care instructions are not detailed in the provided data.