Step by Step Guide to Ultrasound-Based Design of Alt Flaps by the Microsurgeon – Basic and Advanced Applications and Device Settings

Abstract Background The anterolateral thigh (ALT) perforator flap is a popular reconstructive tissue transfer. Consistent with the “hot/cold zone” concept for rapid dissection and thin flap harvest, reliable pre-operative perforator mapping is mandatory. Color coded duplex sonography (CCDS) has been shown to have the highest pooled sensitivity and positive predictive value to identify ALT perforating vessels. By reviewing this guide, the reader should learn: 1. Probe selection, basic/advanced device settings 2. Interpreting tissue morphology 3. Structured mapping approach 3. Pedicle position planning 4. Safe flap design 5. Assess subcutaneous course and flap's thickness for subfascial/epifascial/suprafascial harvest 6. Implement perforators identified into a tailor-made flap design including chimeric flaps. Methods Experiences with ultrasound-guided flap design gained from 125 ALT perforator flap free tissue transfers performed in two reconstructive centers was the basis of our guide. Our structured method comprises standardized markings, patient positioning, and simple ergonomics. Basic and advanced CCDS settings, selection, and conventional probe guidance are outlined for the microsurgeon. Results Linear multifrequency probes (6-15 MHz) were used. Best preset programs were breast, thyroid and vascular. Favorable device properties are Depth focused to 2-5 cm, Pulse repetition frequency (PRF/Scale) set low to 0.5-20 Hz /0.5-10 cm/s, Color gain high, Wall filter (WF) low/off ( Conclusion CCDS is a powerful tool for preoperative perforator mapping in perforator flaps such as the ALT.