A modified scintigraphic technique for amputation level selection in diabetics

A modified 123I-antipyrine cutaneous washout technique for the selection of amputation levels is described. The modifications imply a reduction of time needed for the examination by simultaneous recordings on different levels, and a better patient acceptance by reducing inconvenience. Furthermore, both skin perfusion pressure (SPP) and skin blood flow (SBF) are determined from each clearance curve. In a prospective study among 26 diabetic patients presenting with ulcers or gangrene of the foot, both SPP and SBF were determined preoperatively on the selected level of surgery and on adjacent amputation sites. These 26 patients underwent 12 minor foot amputations and 17 major lower limb amputations. Two of these amputations failed to heal. SBF values appeared indicative for the degree of peripheral vascular disease, as low SBF values were found with low SPP values. SPP determinations revealed good predictive values: all surgical procedures healed when SPP greater than 20 mmHg, but 2 out of 3 failed when SPP less than 20 mmHg. If SPP values would have been decisive, the amputation would have been converted to a lower level in 6 out of 17 cases. This modified scintigraphic technique provides accurate objective information for amputation level selection.