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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.

Fiberoptic perfusion fluorometry and assessment of ultimate viability were used to analyze the tolerance to warm ischemia of rat vascular island skin flaps. Both acute flaps and flaps raised 24 hours previously and then reraised were subjected to 0 (control), 6, 8, 10, and 12 hours of vascular pedicle clamping. Following clamp release, serial fluorometry documented the progressive delay in effective reflow resulting from extended periods of ischemia. Fluorometry, furthermore , suggested that flaps constructed 24 hours previously had an improved hemodynamic status with a significantly reduced period of poor reflow following clamp release. The improved hemodynamics were associated with increased viability, confirming the increased tolerance of 24-hour-old flaps to warm ischemia.

Improved accuracy and objectivity in the evaluation of intestinal viability has been reported by some investigators using Doppler ultrasound, and more recently laser Doppler velocimetry and perfusion fluorometry. To compare the sensitivity and clinical applicability of these techniques, intestinal viability was evaluated by each method in nine 15- to 50-cm loops of small bowel prepared by division of the mesenteric vasculature in five anesthetized dogs. The sensitivity of Doppler ultrasound was 86%, of laser Doppler flow velocity 85%, of laser Doppler index 94%, and of perfusion fluorometry 95%. Though the sensitivity of Doppler ultrasound is significantly less than that of laser Doppler and perfusion fluorometry, this is not unexpected since the latter two techniques are more quantitative than Doppler ultrasound. Clinically, Doppler ultrasound compares favorably with laser Doppler and perfusion fluorometry, and its low cost and simplicity suggest its adjunctive use in the operative setting.

The present study evaluated the ability of DHV-PGE2ME, a topically effective 16-vinyl prostaglandin E2 analogue, to improve the tolerance of skin flaps to a period of ischemia. DHV-PGE2ME and placebo were applied to bilateral island flaps on 70 anesthetized rats; then the vascular pedicle of each flap was clamped for 10 hours. Treated flaps evidenced significantly better reperfusion, as documented by quantification of fluorescein dye delivery at 90 minutes after clamp release, and they had significantly greater ultimate viability (p less than 0.05, by ANOVA). While less than 3 percent of untreated flaps survived, those treated with 1.75 and 17.5 microgram/cm2 of drug evidenced 76 and 86 percent survival, respectively. Treatment of a given flap did not affect its contralateral mate, since there was no evidence of a systemic effect. Especially since its effect can be limited to the site of application, DHV-PGE2ME should be valuable for the treatment of compromised perfusion in a variety of settings.

The effects of intravenous nitroglycerin infusion on experimental skin flap survival and fluorescein dye kinetics were studied in animals. Perfusion fluorometry was utilized to examine changes in flap hemodynamics and viability. An improvement in skin flap survival was found in the nitroglycerin-infused animals, whether the nitroglycerin was initiated 30 minutes before or 30 minutes after flap elevation. Dye elimination in the flap appeared to be significantly improved with the drug therapy, indicating an improvement in flap blood flow with nitroglycerin.