Use of intra operative fluorescein dye for prediction of flap viability.

Background: A successful flap is dependent on its vascularity. During dissection, flap viability may become compromised due to inadequate perfusion from the vascular pedicle(s) on which the flap is based. Various methods have been proposed to determine viability of a flap both, intraoperatively and postoperatively. The ideal method must be simple, accurate, reproducible and safe. The purpose of this study was to study the role of fluorescein dye for prediction of flap viability.Materials & Methods: Thirty patients undergoing flap coverage for various defects were evaluated. Flaps were elevated and evaluated clinically for viability. Intravenous fluorescein was injected into the patients prior to flap inset and its course through the flap was monitored under ultraviolet light. Fluorescent areas were marked intraoperatively (size and location documented). Areas of viable flaps were documented on post-operative day 5 and comparisons made.

Result: The area of viable flap as determined using intra operative fluorescein dye administration corresponded to surviving flap area on post-operative day 5, in 27 of the 30 cases studied, giving positive predictive value of 90%. Overall, the dye had an accuracy of 99.03% compared to intraoperative clinical flap assessment accuracy of 95.70%. Marginal necrosis was seen in 16.6 % of all cases. No allergic reaction to the dye was observed.

Conclusion: - Accurate assessment of flap viability is an area of constant research. Use of intraoperative fluorescein dye for prediction of flap viability has an accuracy of 99.03% compared to intraoperative clinical flap assessment accuracy of 95.70%. In a few cases, the dye is prone to underpredict the area of viable flap tissue. The dye can be used to corroborate clinical asessment of viable flap tissue when used intraoperatively. The dye was found to be safe and easy to use.