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The present study was undertaken to compare fluorometric documentation of fluorescein dye delivery with the standard means of determining the level at which an amputation should be performed in the dysvascular extremity. Thirty-nine patients underwent lower-extremity amputation at the level determined by the surgeon based upon physical examination, angiography, segmental pressure indices, and/or pulse volume recordings. In addition, fiberoptic fluorometry was performed preoperatively. After intravenous administration of sodium fluorescein (4-8 mg/kg), fluorometric readings were obtained by placing the fluorometer's light guide on 126 reading sites. Fluorometric findings were evaluated retrospectively, and therefore did not influence the surgeon's decision. Of the 39 amputations performed overall, only 26 healed. The accuracy of the standard criteria was lowest for the 20 below-ankle amputations, where only 12 cases healed. Alternatively, fluorometric indices separated healing from nonhealing sites in 36 of the 39 cases and in 18 of the 20 below-ankle amputations. Overall, healing sites averaged 94 percent of the fluorescence of the healthy reference area, while nonhealing sites averaged only 29 percent. We conclude that fluorometry should prove to be a valuable adjunct in the assessment of the dysvascular extremity. It uses a low dose of dye, is easy to perform, and is readily repeatable.

This retrospective study evaluated quantification of skin fluorescein delivery by fiberoptic fluorometry as a means of predicting the healing potential of an amputation site. Fluorometry uses a dual-channel fiberoptic light guide--one channel transmits blue light to excite the fluorescein in the skin under study, and the other transmits emitted fluorescence from the skin to a photomultiplier tube where it is measured. Ten minutes after intravenous administration of sodium fluorescein (4 to 8 mg/kg), fluorometric readings were obtained at more than 100 reading sites. In the 86 cases without preoperative cellulitis at the site of amputation, preoperative fluorometry clearly distinguished between healing and nonhealing sites. Healing sites averaged 79% of the fluorescence of a healthy reference area (dye fluorescence index [DFI] = 79), while failing sites averaged only 27% (p less than 0.01 by ANOVA). In all but one case where the DFI was greater than 42, the amputation healed. In all cases where the DFI was less than 38, the amputation failed. In general, uncertainty was limited to sites with values between these limits. The technique maintained its high accuracy in patients with diabetes and for distal amputations. However, it was not accurate at sites of active cellulitis (12 cases). There were no significant adverse effects from the slow injection of the low dose of fluorescein used for this technique. We conclude that fluorometry is an effective means of predicting healing in patients undergoing amputation.