Fig. 3.

Animal study protocol. (a and b) After isolating the flap and securing the optical probes, we conducted two different studies on each of four animals: (1) (c and d) arterial occlusion study and (2) (e and f) anastomosis study. (a) The surgeon elevated a latissimus dorsi myocutaneous flap with a single artery and vein serving as the sole supply and drain channels for the flap. (b) The skin optical patch was fixed onto the skin side of the flap for one- and two-channel DCS measurements. The DCS muscle probe was sutured on the muscle side of the flap. (c) The Hoffman clamp incrementally occluded the supplying artery to simulate vascular compromise while sequential data acquisition of DCS and DRS was performed for all the flap sites. (d) The opening distance of the Hoffman clamp as a function of time, in minutes. (e) The vessels were transected (left) and reconnected (right) via anastomosis to simulate free flap transfer. (f) Protocol for long-term monitoring after anastomosis.