Ask Dr. Z

Please help. I'm really hoping this isn't an unlisted code and that there is a CPT code that accurately represents the below procedure, but every one I come across involves graft stent placement. Code 33877 would be perfect, I think, except for the no graft placement issue. Is there a code I'm missing, or is this unlisted code 37799?

"Patient had percutaneous endovascular repair of dissecting descending thoracic aorta, which came off just below the pre-existing stent graft placed five years prior for descending thoracic aorta traumatic injury. They successfully excluded the aneurysm, but one week later CT scan showed persistence of large aneurysm, which was causing mass effect on esophagus and left heart. Patient was taken to OR for open exposure of the aneurysm and repair with decompression of aneurysm sac. Cardiologist performed left posterolateral thoracotomy. Vascular surgeon opened aneurysm sac and removed the thrombus. TEE showed sac was totally decompressed, and sac was closed over the previously placed stent graft and aortic wall repaired with suture."