Color flow ultrasound for delineating microsurgical vessels: a clinical and experimental study.

There is a need in plastic and reconstructive surgery for a method of monitoring flaps and replants pre- and postoperatively. This study evaluates color flow Doppler done as a monitoring technique for microvascular vessels. The capability of color flow ultrasound to monitor venous and arterial insufficiency and occlusion was studied by means of an experimental system in the Yucatan miniature swine model. A circulatory circuit in line with a magnetic flow probe is created. Measurements are made on the isolated hind limb of the animal. Color flow ultrasound is demonstrated to be a technique that is sensitive to venous and arterial insufficiency at flow rates as low as 3.0 ml/min. Characteristic waveform patterns are shown to predict arterial and venous insufficiency before they actually progress to occlusion. A clinical series of 25 postoperative patients is presented, consisting of volunteer studies as well as pre- and postoperative examinations of free flaps and replantations. Color flow ultrasound is shown to visualize a spectrum of pre- and postoperative microvascular conduits encountered in plastic and reconstructive surgery.