CUTANEOUS BLOOD-FLOW PATTERNS IN FREE FLAPS DETERMINED BY LASER-DOPPLER FLOWMETRY

Accurate monitoring of tissue perfusion in microvascular surgery is pa ramount to flap survival. Many methods have been proposed for monitori ng of flaps, but none have achieved widespread acceptance. The laser D oppler has been shown to be beneficial in monitoring flap perfusion. T rends have been noted in laser Doppler measurements over time in free TRAM, free latissimus dorsi, and free iliac-crest osteomyocutaneous fl aps. TRAM flaps demonstrated a slow increase in the laser Doppler inde x (LDI), with a peak increase in skin blood flow of over 600 percent a t 52 to 80 hr postoperatively (LDI 6.77 +/- 3.51), and then a gradual decline to previous baseline. Latissimus dorsi flaps also demonstrated a slow increase until about 80 hr postoperatively (LDI 9.8 +/- 10.65) , indicating an increase in skin blood flow of almost 900 percent. Ili ac-crest osteomyocutaneous free flaps had a slow increase in blood flo w until approximately 70 hr postoperatively, when the LDI (5.5) increa sed, representing an increase in skin blood flow of over 500 percent. These changes in skin blood flow over time, seen with continuous laser Doppler measurements, depict the dynamic nature of skin blood flow an d allow predictive patterns to be established, instead of single norma l values, by which to gauge adequate flap perfusion.