In the winter 2011 issue of Clinical Examples in Radiology Newsletter (volume 7, issue 1, page 4), the American Medical Association provided the following guideline. (Also see note below if you have purchased MedLearns 2011 Instructional Coding Guide for Lower Extremity Interventions.)

The common tibial-peroneal trunk is considered to be part of the tibial-peroneal territory, and is not considered a separate fourth vessel for CPT reporting purposes. For instance, if lesions in the common tibial-peroneal trunk are treated in conjunction with lesions in the posterior-tibial artery, a single code would be reported. If, however, the anterior tibial artery and the common tibial-peroneal trunk are treated, it is appropriate to report a primary and an add-on code, as the anterior-tibial artery is not a vessel that rises from the tibial-peroneal trunk.

Therefore, per these clarifying instructions, when both the AT and common TPT are treated at the same session by angioplasty, it would be appropriate to assign both the primary procedure code (37228) and the each additional vessel code (37232).

Note: This new AMA guidance replaces the answer we provided in question 4, page 46, of our 2011 Instructional Coding Guide for Lower Extremity Interventions. Please delete the answer we provided, which was appropriate at the time of publication, and follow the above guideline.