What is the root operation called for removing a Staghorn calculus through a percutaneous nephrostomy tube after prior lithotripsy?

The correct root operation for removing a Staghorn calculus through a percutaneous nephrostomy tube is extirpation. This procedure involves the complete removal of a solid matter, which in this case is the Staghorn calculus, from a body part. The definition of extirpation in this context specifically refers to the act of taking out or eliminating the calculus that has formed within the renal system.

In contrast, the other options do not accurately describe the procedure in this scenario. Resection generally refers to the removal of a portion of an organ or tissue but does not apply here since the focus is on removing an obstructive calculus rather than part of an organ. Destruction indicates the process of destroying or eliminating but does not involve physically removing the material (like a calculus) from the body, which is key for this case. Excision is typically used for procedures involving cutting and removing tissue but does not capture the nature of completely eliminating a calculi mass as extirpation does. Thus, extirpation is the most precise term for the action performed in this procedure.