Using Colour Doppler Ultrasound for Flap Planning in the Hand and Upper Extremity.

Conventional techniques for planning perforator flaps rely on anatomical landmarks and handheld Doppler. Handheld Doppler can be unreliable in localising perforators, with false positive signals from the axial vessel or perforators that terminate in the muscle. Additionally, the loudness of the audible signal on Doppler does not correlate with the presence or size of the perforator. Advanced imaging modalities offer a more accurate tool for preoperative perforator mapping. These include ultrasound, computed tomography angiography (CTA) and magnetic resonance angiography (MRA). Colour Doppler ultrasound (CDU) is available in most operating rooms, with the advantages of no added cost, lack of radiation and no requirement for intravenous contrast. Location and characteristics of perforators can be accurately mapped preoperatively, allowing for rapid and efficient flap harvest. Additionally, accurate preoperative perforator localisation with CDU allows elevation of thin and superthin flaps, which allow a better 'like-for-like' reconstruction in the hand and upper extremity. In this article, the technique of CDU for flap planning is discussed together with illustrative cases. Level of Evidence: Level V (Therapeutic).