Neurosurgery Coding Alert

Question: My neurosurgeon had to return a patient to the OR for a repair of the dura to arrest a cerebrospinal fluid (CSF) leak in the anterior cranial fossa 40 days following a skull base surgery. I am fairly confident that 61618 is the correct code for this procedure. However, my colleague is pretty sure we need to append a modifier to the code, but we are not sure which is the appropriate modifier. Can you please help us?

Maine Subscriber

Answer: You are correct by choosing code 61618 (Secondary repair of dura for cerebrospinal fluid leak, anterior, middle or posterior cranial fossa following surgery of the skull base; by free tissue graft (eg, pericranium, fascia, tensor fascia lata, adipose tissue, homologous or synthetic grafts)) for this procedure.

Your colleague is also correct. You need to append modifier 78 (Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period) to code 61618.

When it comes to modifier 78, you can always ask yourself three questions about whether you should append it to your procedure code. If the answer to all of these questions is “yes,” you may be able to appropriately append modifier 78.

Question 1: Is the subsequent procedure related to the initial surgery? You should only append modifier 78 if your surgeon undertook the subsequent surgery due to complications from an initial surgery. Our answer is “yes” here because your surgeon performed the subsequent surgery, the secondary repair of the dura for a CSF, because of complications from the initial surgery, the skull base surgery.

Question 2: Does the procedure fall within a global period? To correctly append modifier 78, the subsequent surgery must occur during the 90-day global period of the initial surgery. For this example, the surgeon performed the subsequent surgery 40 days after the initial surgery, so the answer to this question is “yes.”

Question 3: Did the physician perform the procedure in the OR? To correctly append modifier 78, the subsequent surgery requires a return trip to the OR. In your case, your surgeon took the patient back to the OR to treat a complication of the original skull base procedure, so you can answer “yes.” In contrast, if the service was performed in the office such as over-sewing a wound to treat drainage, you would not report a procedure code, and modifier 78 would not apply.