Ask Dr. Z

"No pulse in the right hepatic artery. Gastroduodenal artery clamped, aneurysm was entered, resection of aneurysmal tissue was performed. Saphenous vein was harvested and then anastomosed to the gastroduodenal artery in a reverse fashion. I then redirected my attention to the left hepatic artery. I extended the arteriotomy approximately 1/2 cm to widen the artery. I then fashioned the vein graft to fit this arteriotomy. A functional end-to-end anastomosis between the vein graft and the left hepatic artery was performed."  It has been suggested that I code this with code 35121; however, in my opinion, this is should be coded with an unlisted code 37799, as this was a hepatic artery - gastroduodenal bypass (no current CPT code for this procedure) and not a repair of an hepatic artery aneurysm. It is my understanding that code 35121 is for repair of aneurysm with graft insertion, not an actual bypass. Please advise which would be the more appropriate coding and the rationale behind your opinion.