There is provided an improved graft for treatment of diseased, typically aneurysmal, tissue of the ascending aorta and aortic arch. The graft described is based on the "Elephant Trunk" graft which requires a two-stage procedure for completion of treatment. The modified graft includes a series of markers to allow visualisation of the distal end of the graft, irrespective of the requirements to trim the distal end of the graft to match the patient's anatomy. The markers are typically radio-opaque allowing visualisation by X-ray.