What is the difference between CPT code 93458 and 93459?

CPT code 93458 refers to the insertion of a probe through the esophagus to measure pressure and identify changes in the esophagus. This procedure is typically used to diagnose conditions such as gastroesophageal reflux disease (GERD) or achalasia. CPT code 93459, on the other hand, is used to describe the insertion of a probe through the esophagus, stomach, and small intestine to measure pressure and identify changes in these organs. This procedure is typically used to diagnose conditions such as motility disorders or reflux. In summary, the main difference between CPT code 93458 and 93459 is the extent of the procedure and the areas of the digestive tract that are evaluated.