Technical Aspects of High-Resolution Color-Coded Duplex Sonography for the Design of Perforator Flaps

Abstract

Background Technical aspects are of utmost significance for an efficient execution in designing perforator flaps with high-resolution color-coded Duplex sonography (CCDS). The following study evaluates decisive factors for a successful microvessel examination conducted by the microsurgeon. Methods Technical knowledge presented in this study was based on a series of more than 200 perforator flaps planned with CCDS. Flap reconstructions were performed at the University Hospital Regensburg, Germany, from July 2013 to January 2021. Standard high-resolution ultrasound (US) devices with linear multifrequency transducers of 4 to 18 MHz were used. Modes and device settings were evaluated regarding applicability by microsurgeons. Key steps for safe perforator identification and further optional steps for additional assessment should be discriminated. Results Different US modes including brightness mode (B-mode), color flow (CF), power Doppler (PD), pulse wave (PW), and blood flow (B-Flow) were used. Transducers from 15 MHz and up were favorable to detect microvessels. Knobology of a standard US device regarding buttons, switches, and specific onscreen options with relevance for perforator mapping was subcategorized in four different groups. For qualitative and quantitative evaluation of microvessels, different US modes were tested with respect to their usefulness.Vital elements of the CCDS exam are disaggregated into three key steps for safe perforator identification and three optional steps for further perforator characterization. A standardized protocol for the CCDS exams was applied. Downregulation of pulse-repetition frequency/scale to adapt device sensitivity to slow-flow velocities represented the most important criterion to visualize microvessels.Qualitative microvessel evaluation was performed in B-mode, CCDS, PD mode, and B-Flow mode. Quantitative assessment was executed using PW-mode and CCDS measuring the microvessels' diameter (mm) and flow characteristics. Quantitative information may be obtained using PW-mode and the distance-measuring tool in CF-mode. Conclusion Technical aspects with respect to proper device trimming and application decisively impact CCDS-guided perforator vessel identification and evaluation.

Comparative Study of Small Vessel (under 0.8 mm) Anastomosed Free Flap and Larger Vessel (over 0.8 mm) Anastomosed Free Flap: Does Supermicrosurgery Provide Sufficient Blood Flow to the Free Flap?

“…9-11 Among these modalities, color doppler ultrasound has become popular due to its advantages, including a real time imaging, fast and noninvasive procedures, and possibility of performing flowmetry of the pedicle. 12,13 The average flow volume of the flap pedicle was 6.8 mL/min, and the average flow volume per 100 g of the flap was 5.5 mL/min/100 g. The measurements of blood flow volume per 100 g of the flap were higher in this study than in previous reports for muscle or largevolume fasciocutaneous flaps. 14 The main reason for the difference could be the difference in This article is protected by copyright.…”

“…9 10 11 Among these modalities, color Doppler ultrasound has become popular due to its advantages, including real-time imaging, fast and noninvasive procedures, and possibility of performing flowmetry of the pedicle. 12 13…”

Stable Arterial Perforators Mapping in Lower Leg Using Color-Coded Doppler Sonography, Acoustic Doppler, and Thermal Imaging Camera in Patients Undergoing Digital Subtraction Angiography

“…CCDS has become a highly valuable imaging tool for identifying micro vessels with a high sensitivity. [16][17][18][19] Plastic surgeons commonly use CCDS for perforator mapping and flap planning in their daily practice. The confirmed perforators identified by acoustic doppler were examined twice.…”

The Thoracodorsal Artery Perforator Flap: A Powerful Tool in Breast Reconstruction

“…Several iterations of the latest versions offer imaging with high frequency (15 to 20 MHz), which gives exceptional clarity to even small perforators (<1 mm). 11 Use of this information could give real meaning to the phrase “careful surgical planning.” Ultrasound may be the “modern-day stethoscope” for the microsurgeon, and with the assistance of this technology, success as reported in this study will become routine. 12…”