Intraoperative Angiography Using Laser-Assisted Indocyanine Green Imaging to Map Perfusion of Forehead Flaps

Figure 1. Preoperative real-time laser-assisted angiogram of the patient's forehead prior to flap elevation and transfer. The white arrows delineate the scar across the superior aspect of the forehead. The scar is dark in appearance, indicating an absence of detectable flow across the scar on the angiogram. “Fixed baseline: 15” represents the background fluorescence value; fps, frames per second.

Figure 2. Immediately following flap transfer, the white arrows identify demarcation of healthy, perfused tissue (bright) and poorly perfused tissue (dark). The marked difference in perfusion occurs distal to the scar depicted in Figure 1. This area appeared clinically well perfused intraoperatively following flap transfer as well as in the postanesthesia care unit. “Fixed baseline: 15” represents the background fluorescence value; fps, frames per second.

Figure 3. A, One-week postoperative visit demonstrating epidermolysis along the distal aspect of the flap corresponding to the poorly perfused area on the intraoperative angiogram. B, Base view at the 1-week postoperative visit demonstrating the extent of epidermolysis that occurred distal to the preoperative forehead scar.

Figure 4. Postoperative visits. A, One-month postoperative visit. The wound continues to heal by second intention with conservative wound care (ie; emollients). B, Five-month postoperative visit. The wound has healed without significant loss of flap contour. C, Base view at the 5-month postoperative visit.

Figure 5. Demonstration of intraoperative laser-assisted Indocyanine green angiography at 15 (A), 30 (B), 45 (C), and 60 (D) seconds. Bright areas indicate well-perfused tissue. The dark areas at the junction of the flap and recipient bed represent sutures. “Fixed baseline: 15” represents the background fluorescence value; fps, frames per second.

Figure 6. One-week postoperative visit. Laser-assisted Indocyanine green angiography was performed at 15 (A), 30 (B), 45 (C), and 60 (D) seconds. The pedicle remained clamped throughout the imaging. Bright areas indicate well perfused tissue. SPY-Q software was used to color map at each time interval. In these images, increased intensity indicates areas of increased perfusion. Note the increase in flow at the distal aspect of the flap with increases in time (white arrows). This flow is independent of any blood flow from the pedicle which remains dark while clamped throughout testing. “Fixed baseline: 15” represents the background fluorescence value; fps, frames per second.