Large and small artery occlusion in diabetics and nondiabetics with severe vascular disease.

Casts were made of the vascular lumen of 20 successive extremities amputated for gangrene. Half of the patients were diabetic. All nondiabetics had arteriosclerotic vascular disease plus acute occlusion. Only one diabetic had an acute episode. There was no significant difference in age, blood pressure, or digital blood flow between the two groups. Diabetics had somewhat greater occlusion of the calf vessels and less occlusion in the foot than nondiabetics; the overall extent of large artery occlusion was equal in the two groups. There was no increase in small vessel occlusion with diabetes. Small vessel occlusions were present in all areas of muscle and skin examined. The findings indicate that: (1) very extensive occlusion must be present to result in necrosis; (2) in nondiabetics, amputation was required only when sudden occlusion was superimposed on previous occlusive disease; (3) both large and small vessels are occluded to about the same extent in diabetics and nondiabetics when amputation is required, and (4) either diabetes or sudden occlusion in conjunction with chronic vascular disease can result in insufficient collateral flow and subsequent death of tissues.