Anesthesia Coding Alert

CPT codes for endovascular repair of abdominal aortic aneurysm (AAA) were a welcome addition in 2001. But two years later, coders are still often confused about which anesthesia code best represents the procedure.

AAA endovascular repair is an alternative to more invasive treatments of the problem. It involves placing a stent graft within the lumen of the aorta and usually the iliac(s). The surgeon uses fluoroscopic guidance to thread the graft through the femoral artery to the surgical site. The procedure is performed under epidural or general anesthesia or monitored anesthesia care (MAC), depending on the situation.


"Many of these cases are done under epidural anesthesia," says Mary Klein, CPC, an anesthesia coding specialist with Panhandle Medical Services in Pensacola, Fla. "The patient's overall state of health (comorbidities) sometimes might dictate using general anesthesia. Sedation may also be used in conjunction with the epidural to increase the patient's comfort.


" Whichever type of anesthesia the provider uses, codes remain the same except in states that require you to add MAC modifiers when appropriate (-QS, Monitored anesthesia care service; -G8, Monitored anesthesia care [MAC] for deep complex, complicated, or markedly invasive surgical procedure; and -G9, Monitored anesthesia care for patient who has history of severe cardio-pulmonary condition). You don't report the MAC modifier, however, if the epidural is the mode of anesthesia and the provider uses sedation to increase the patient's comfort, Klein says.

The primary surgical code for AAAendovascular repair is CPT 34800 (Endovascular repair of infrarenal abdominal aortic aneurysm or dissection; using aorto-aortic tube prosthesis). This describes placement of a single tube, but many surgeons use a bifurcated, or split, tube that extends two limbs into the iliac arteries to ensure more complete coverage of the aneurysm. You should report this type of prosthesis with 34802 ( using modular bifurcated prosthesis [one docking limb]) or 34804 ( using unibody bifurcated prosthesis).

The primary cross-code for anesthesia during the procedure is 00770 (Anesthesia for all procedures on major abdominal blood vessels), but coders have differing opinions about its appropriateness. More confusion arises because of alternative cross-codes or varying combinations of primary and secondary cross-codes in different resources.                                  

For example, older editions of the ASACrosswalk list 01933 (Anesthesia for therapeutic interventional radiologic procedures involving the venous/lymphatic system [not to include access to the central circulation]; intracranial) as the primary cross-code for 34800, then 00770.

Klein disagrees with using 01933 for the procedure, stating that surgical code 34800 and related codes 34802 and 34804 now all correspond to anesthesia code 01926 (Anesthesia for therapeutic interventional radiologic procedures involving the arterial system; intracranial, intracardiac, or aortic). "Code 01933 also specifies only the intracranial venous system now," she adds. "That isn't appropriate for this procedure since the aorta is an artery and the repair is arterial, not venous (as described by 01933)."                                                                                  

"Any CPT code that specifies 'endovascular'in the descriptor and is for an intracranial, intracardiac or aortic procedure should cross to 01926 unless another higher-base procedure was performed at the same time," Klein adds. "All of the endovascular procedures now fall under the Radiological Procedures section of the CPT anesthesia codes (01905-01933)."                                                           

But some coders argue that 00770 is more appropriate, on the grounds that it better reflects "repair" procedures as described by codes 34800-34804 and because 01926's descriptor does not specify "endovascular." Coders in this camp acknowledge that procedures falling under code 01926 can lead to repair, but they stress the "therapeutic" portion of the descriptor instead and say the procedure deserves the higher-value anesthesia code (which is 00770 with 15 units versus 10 units for 01926).

Klein disagrees, maintaining that the anesthesiologist's work during an endovascular AAA repair is less intense than for an open repair under general anesthesia. The surgeon clamps the aorta during an open AAArepair, which can cause the patient's blood pressure to rise because of the acute increase in afterload. The anesthesiologist may need to use drugs such as nitroglycerine to keep the blood pressure normal and to decrease the cardiac stress of the procedure. The anesthesiologist also performs preparations for unclamping to regulate a possible drop in blood pressure once the aorta is unclamped and blood begins to flow in the ischemic lower extremities. The anesthesiologist will usually have to treat this, then bring the patient out from under the anesthetic once he or she has stabilized.                                                                          

"Endovascular repairs usually don't require this major interruption of blood flow and don't disturb the abdominal organs like an open procedure can do," Klein explains. "You get fewer units for 01926, but it still has a higher base value than most anesthesia procedures. The additional units for code 00770 are certainly justified for an open procedure, but not for an endovascular repair."

Most patients go into surgery, undergo the repair and recover with no real surprises. But how should you code for cases that begin as endovascular repair and become more complicated?

One such scenario is when the surgeon performs other procedures during the session to ensure that everything is taken care of, such as completing an incidental hernia repair. But Susan L. Turney, MD, FACP, medical director of reimbursement for the Marshfield Clinic in Marshfield, Wis., says this doesn't change coding from an anesthesia perspective. As in any case when multiple procedures are performed, you code by the procedure with the highest base value and bill for the anesthesiologist's total amount of time spent on the procedure.

The coding challenge lies in reporting things correctly when the endovascular repair unexpectedly becomes an open procedure. For example, the case becomes an emergency open procedure if the aorta or iliac arteries rupture while the surgeon is placing the endovascular prosthesis. Turney and Klein agree that the anesthesiologist should report 00770 in that case what Klein refers to as the "open code" plus total time and any billable monitoring lines (arterial lines, central venous line, Swan-Ganz). (You can also bill these lines if the anesthesiologist inserts them during a routine endograft, if they are medically necessary.)                                                                                                    

 In addition, you may want to add diagnosis codes such as V64.1 (Surgical or other procedure not carried out because of contraindication) or V64.4 (Laparoscopic surgical procedure converted to open procedure) to more fully describe the situation.

Terminology in the operative report can help point you in the right coding direction, such as whether the surgeon used an open or percutaneous approach. "Sometimes coders get confused because the surgeon opens the femoral arteries in order to deliver the prosthesis to the aorta," Klein explains. "But this is still considered a percutaneous approach. Atrue open procedure involves an abdominal incision and all that that entails."

Anesthesia coding will become trickier as surgery becomes more technical and endovascular and laparo-scopic surgical approaches continue to grow.

"The new endovascular procedures and the older open procedures are very different from each other, so it's important to understand what's involved with each approach and why the associated anesthesia codes have different base values," Klein notes.

Learn the key elements of AAA repairs at your hospital to help you code them correctly. Klein says anesthesiologists use epidural anesthesia for the endovascular procedure at her hospital and general anesthesia for open cases, but that may not be true everywhere. Look for clues in the operative report such as the use of fluoroscopy (which is unnecessary for open cases), whether the surgeon crossclamped the aorta, or whether an invasive radiologist became involved in the case to help you know which technique was used.

If you're still unsure of how to code a particular case after reviewing the records, check with the anesthesiologist. He or she can help you with the case in question and can explain the rationale behind selecting 00770 or 01926 as the most appropriate code.