Results of amputation for gangrene in diabetic and non-diabetic patients. Selection of amputation level using photoelectric measurements of skin-perfusion pressure.

Evaluation was done of 235 patients who had had 273 primary amputations for gangrene. Measurements of local skin-perfusion pressure or systolic blood pressure were made in 222 limbs (188 patients). For the other fifty-one limbs, for which no measurements of pressure were available, the surgeon elected to perform an above-the-knee amputation in nine of seventeen diabetic limbs and a below-the-knee amputation in eight. An above-the-knee amputation was selected by the surgeon for thirty-two of thirty-four non-diabetic limbs and a below-the-knee amputation, for two for which no measurements of pressure were available. Local skin-perfusion pressure was measured distal to the knee before amputation, using a standardized photoelectric technique in 203 limbs and systolic blood-pressure measurements in nineteen. Skin-perfusion pressure was also measured above the knee in seventy-six of the 222 limbs in which a pressure was determined below the knee. These measurements were made available to the surgeon for use as an adjuvant guide to clinical assessment in selecting the appropriate level of amputation. Seventy-four patients (ninety-two amputations) had diabetes and 114 patients (130 amputations) did not. The limbs of the diabetic patients had a significantly higher skin-perfusion pressure at the below-the-knee level (p less than 0.001) than did those of the non-diabetic patients. The ratios of below-the-knee to above-the-knee amputations for the diabetic and non-diabetic patients were 3.8 to one and 1.3 to one (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)