Ask Dr. Z

I need clarification on when to use code 35091 versus 33877. My surgeon describes open suprarenal aneurysm repair by retroperoneal approach through a flank incision made from the 9th interspace to just caudal to the umbilicus. He describes exposure of the visceral aorta to the abdominal iliac bifurcation. The aneurysm sac is opened from the bifurcation to the juxtarenal. A Dacron tube graft is anastomosed proximally to the aorta and distally at the aortic bifurcation. My surgeon says this is enough to code as an thoracoabdominal aneurysm repair (33877). I disagree; I say that the descending aorta would need to be involved in the exposure and aneurysm resection to report code 33877. Is my surgeon correct?