ONE of our male patients with an abdominal aortic aneurysm treated by excision, endarterectomy, and insertion of a freeze-dried homograft died two and a half years later from coronary thrombosis. We have been unable to find any reference in the literature these areas were not affected by the freeze-drying process which was used to preserve the graft.Externally at autopsy the graft appeared like a new vessel, and the area of the aorta which had been endarterectomized looked very much healthier than FIG. r7r.-The post-mortem specimen showing the satisfactory result 21 years after the replacement of the distal portion and bifurcation of the aorta by a homograft. ( x 2.)to a patient surviving more than one year after the insertion of a similar graft.At operation, failure to wash out any soft clot before the end of the grafting procedure delayed restoration of the peripheral pulses, but probably had no permanent ill effects. During the period of survival we were able to watch the change in the patient's peripheral pulses as he developed intermittent claudication; finally we have detailed histological studies of his vessels and of the graft.Areas of atheroma were present in the graft when it was taken from a man aged 39, and apparently FIG. 17z.--Distal portion of graft showing the lines of anastomosis in the common iliac arteries (A). The plaques of atheroma (6) which are present in the graft are not so severe as those in the patient's arteries. ( x 4.)