Use of intraoperative fluorescein dye for prediction of flap viability

Introduction: 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 the viability of a flap, both intraoperatively and postoperatively. The ideal method must be simple, accurate, reproducible, and safe. Aim: The aim of this study was to study the role of fluorescein dye in the prediction of intraoperative flap viability as compared to clinical assessment for the same. Materials and methods: Thirty patients undergoing flap coverage for various defects were evaluated. Flaps were elevated and evaluated clinically for viability. Intravenous fluorescein was injected 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 were made. No surgical intervention was done till post-operative day 5. Results: The area of viable flap as determined using intraoperative fluorescein dye administration corresponded to surviving flap area on post-operative day 5 in 27 of the 30 cases studied, giving a 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. Conclusions: Accurate assessment of flap viability is an area of constant research. The use of intraoperative fluorescein dye for the 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 was prone to underpredict the area of viable flap tissue. The dye can be used to corroborate the clinical assessment of viable flap tissue when used intraoperatively. The dye was found to be safe and easy to use.