Radiology Coding Alert

Answer: With regard to your first question, it's important to realize that while you're still dealing with a nephrostomy tube change, the fact that the previous tube has been dislodged may significantly increase the difficulty of the service. Sometimes coders underestimate the potential complexity of this procedure, and sometimes radiologists fail to document the full extent of their efforts.

While the tract may be relatively easier to negotiate in some patients, in other patients the tract may be tortuous and irregular even in longstanding drainages. If certain initial steps are not performed and the tract is damaged, it may be impossible to renegotiate, thereby forcing the physician to start from scratch with an entirely new tube placement.

Therefore, the additional steps that are required should be well-documented and coded. The first step required in replacing a dislodged nephrostomy tube (or virtually any dislodged nonvascular drainage or infusion tube) is the performance of a sonogram followed by careful renegotiation of the tract under imaging guidance. Use codes 20501* (Injection of sinus tract; diagnostic [sinogram]) and 76080 (Radiologic examination, abscess, fistula or sinus tract study, radiological supervision and interpretation). These codes would be assigned when there is a separately identifiable diagnostic study performed, but would not be billed if a minimal evaluation was performed as part of the tube replacement service.

Once the tract is negotiated with a catheter and guidewire combination, the guidewire may be used to exchange the diagnostic sonogram catheter for a new nephrostomy tube. If the tract has closed down, it may also be necessary to redilate the tract prior to nephrostomy tube placement.

Assuming that aforementioned technique is used and described in the procedural report, you should bill first for the sinogram (20501 and 76080) and thereafter for the exchange codes 50398* (Change of nephrostomy or pyelostomy tube) and 75984 (Change of percutaneous tube or drainage catheter with contrast monitoring [e.g., gastrointestinal system, genitourinary system, abscess], radiological supervision and interpretation).

In general, you only want to restrict your use of 50395 to the following conditions:
1. The nephrostomy tract is dilated prior to percutaneous stone removal or other large-bore procedure, such as percutaneous nephroscopy in the procedure suite or operating room; or,
2. A ureteric stricture is dilated. The tract dilation is needed to allow introduction of the stone-removal equipment or nephroscope in the first case, and the ureter is dilated to treat the patient's underlying stricture in the second case.