Anesthesia Coding Alert

Until the release of CPT 2001, endovascular repairs for abdominal aortic aneurysm (AAA) were billed with the unlisted-procedure code 37799 (unlisted procedure, vascular surgery), because there were no specific codes for these procedures. Now that unique codes are in place, such as 34800 (endovascular repair of infrarenal abdominal aortic aneurysm or dissection; using aorto-aortic tube prosthesis), 34802 (... using modular bifurcated prosthesis [one docking limb]) and 34804 (... using unibody bifurcated prosthesis), anesthesiology coders must know how to bill for associated anesthesia service in both routine and unusual circumstances.
 
As an alternative to more invasive methods, endovascular repair of AAA involves placing a stent graft within the lumen of the aorta and usually the iliac(s). Under fluoroscopic guidance, the graft is threaded through the femoral artery to the surgical site. These procedures can be done under epidural anesthesia, as well as under monitored anesthesia care (MAC) and general anesthesia. Mary Klein, coding specialist with Panhandle Medical Services of Pensacola, Fla., says, "The anesthesiologist places the arterial and central venous lines, and monitors the patient throughout the case. Usually the surgical team comprises a vascular surgeon and a radiologist. The anesthesiologist is considered ancillary to the procedure and not a member of the surgical team, so you would not append a co-surgery modifier to the procedure code to bill the anesthesiologist's services."

 
During endovascular repair, the surgeon might perform additional procedures to complete the treatment successfully, such as an artery occlusion to block a stenosed iliac artery to prevent retrograde blood flow into the aorta. In turn, this procedure requires the surgeon to place a femoral-femoral prosthetic bypass graft to maintain blood flow into the affected leg. Theresa Ruiz-Law, director of managed care and reimbursement with the American Association of Nurse Anesthetists in Chicago, says, "Under Medicare payment policies, the anesthesiologist can only bill for the procedure with the highest base value, plus the total time of the procedure. The associated procedures would be considered as add-ons to the primary surgical code, with no corresponding anesthesia codes. In this scenario, therefore, the anesthesiologist bills 34800 to indicate the primary procedure, and CPT anesthesia code CPT 00770 (anesthesia for all procedures on major abdominal blood vessels).
 
"Some coders might use CPT 00880 (anesthesia for procedures on major lower abdominal vessels; not otherwise specified) rather than 00770 to indicate anesthesia for AAA repairs involving lower abdominal incisions," notes Barbara Johnson, CPC, MPC, professional coder at Loma Linda University Anesthesiology Medical Group Inc. of Loma Linda, Calif.
 
"For billing other payers, check with your carries to determine how they want you to bill anesthesia services performed with multiple surgical procedures," Ruiz-Law says.

 
AAAs can be performed in a cath lab or special-procedure room. In the event of complications, an operating room must be available so the surgeon can switch to an open procedure. If the endovascular method is abandoned, Klein offers three options for coding the anesthesiologist's services:

 
1. The surgeon decides to continue the graft placement as an open procedure, and the anesthesiologist remains with the patient during the trip to the operating room. In this case, bill the open procedure (such as 35082 -- direct repair of aneurysm ... for ruptured aneurysm, abdominal aorta) plus the total time spent -- from the start of the endovascular procedure to the end of the open procedure -- with CPT anesthesia code 00770 (and its 15 associated base units plus total time spent). This assumes the anesthesiologist was in constant attendance.

 
2. The endovascular repair is halted, and the patient is scheduled for an open procedure later the same day. The anesthesiologist (but not the surgeon) can bill it as a separate procedure, using the appropriate surgical code and 00770. "In Florida, our Medicare carrier requires appending modifier -59 (distinct procedural service) to the second procedure to indicate that the surgeries were separate. Both cases must also be submitted on paper claims, with copies of both anesthesia records indicating the stop/start times of each," Klein says. 

 
3. The endovascular repair is abandoned, and the patient is scheduled for an open procedure on another day. The anesthesiologist bills both surgeries as regular anesthesia -- with no modifier. The claims must show different dates of service, and, because anesthesia has no global period, both procedures should be reimbursed.

 
Klein states that, at this time, there is no difference in the anesthesia reimbursement between endovascular repair and an open one. "The ASA crosswalk shows the same anesthesia code of 00770 for both approaches. There is a proposed code of 01933 (anesthesia for interventional radiologic procedures involving the arterial system; intracranial, intracardiac, or aortic) that has not been accepted by CMS (formerly HCFA) and does not appear in the CPT 2001. If you tried to file a claim with 01933 now, it would be denied as an invalid or unrecognized procedure code, regardless of the insurance carrier."
 
Klein suggests that coders take special care with endovascular cases that go to open procedures. "You might also consider adding modifier -22 (unusual procedural service) for an endo-to-open situation if the case lasted more than six hours or if there was a significant gap between the same-day surgeries and the anesthesiologist stayed with the patient, charting vital signs, while the operating room and/or surgical team was being readied. In these circumstances, you might need to send documentation showing the reason for the extended anesthesia time." 
 
Postsurgical problems (such as a leak in the graft) are possible, and the patient must be returned to surgery for an open procedure. In these cases, Klein says that the same day/different day coding scenarios defined above (items 2 and 3) would apply. "Attach modifier -59 (and possibly -22) to the second surgery if the patient is returned to surgery the same day; if post-op surgery occurs on a different day, no modifier is necessary."

 
Medicare Part B guidelines require that the surgeon who performs AAA repair submit hard-copy claims along with operative notes and medical records, including radiology and anesthesia reports. For the anesthesiologist's services, Klein says that her local Medicare carrier in Florida prefers to receive claims electronically, but there are exceptions. "For straightforward cases with no complications, we send it electronically with no documentation. For two cases the same day, we have to send them on paper with copies of the anesthesia record. We have rarely had to get the surgeon's post-op report to send with our anesthesia claim, although it wouldn't hurt to include it if it is easily obtainable." Both Klein and Ruiz-Law strongly recommend that coders investigate their local Medicare and private carriers' preferences regarding claims submission and what documentation they require for processing the claim.