Duplex echography as an adjuvant tool to clinical examination to detect early postoperative free flap vascular compromise

Ultrasound in Microsurgery: Current Applications and New Frontiers

Ultrasound has revolutionized reconstructive microsurgery, offering real-time imaging and enhanced precision allowing for preoperative flap planning, recipient vessel identification and selection, postoperative flap monitoring, and lymphatic surgery. This narrative review of the literature provides an updated evidence-based overlook on the current applications and emerging frontiers of ultrasound in microsurgery, focusing on free tissue transfer and lymphatic surgery. Color duplex ultrasound (CDU) plays a pivotal role in preoperative flap planning and design, providing real-time imaging that enables detailed perforator mapping, perforator suitability assessment, blood flow velocity measurement, and, ultimately, flap design optimization. Ultrasound also aids in recipient vessel selection by providing assessment of caliber, patency, location, and flow velocity of recipient vessels. Postoperatively, ultrasound enables real-time monitoring of flap perfusion, providing early detection of potential flap compromise and improved flap survival rates. In lymphatic surgery, ultra-high frequency ultrasound (UHFUS) offers precise mapping and evaluation of lymphatic vessels, improving efficacy and efficiency by targeting larger dilated vessels. Integrating ultrasound into reconstructive microsurgery represents a significant advancement in the utilization of imaging in the field. With growing accessibility of devices, improved training, and technological advancements, using ultrasound as a key imaging tool offers substantial potential for the evolution of reconstructive microsurgery.

Adjunctive technologies in postoperative free-flap monitoring: a systematic review

Patent microvascular anastomoses are essential for successful free tissue transfer. Early accurate detection of microvascular compromise is required for flap salvage. Adjunctive monitoring techniques, in addition to clinical examination, are increasingly used to detect flap compromise. This systematic review synthesized and appraised the literature to determine the efficacy of different postoperative monitoring technologies. Rates of flap takeback, salvage, failure, and mean time to detection of microvascular compromise were extracted, synthesized, and reviewed. Twenty-two studies were included, comprising 6370 flaps. One thousand three hundred and ninety-five flaps were monitored with Cook Swartz Doppler (21.83%), 1417 flaps with tissue oximetry (22.24%), 291 with laser Doppler (4.56%), 175 with duplex echography (2.74%), 210 with indocyanine green (ICG) fluorescence (3.30%), 196 with Synovis flow coupler (3.07%), and 81 (1.27%) with light spectroscopy. The overall true positive rate for microvascular compromise in taken back flaps was 70.18%. Cook Swartz Doppler (n = 1391) had a true positive rate of 80.17% and 83.63% salvage rate and was associated with an overall 2.60% rate of flap failure. Tissue oximetry (n = 1417) had a true positive rate of 74.76% and a salvage rate of 88.62%. Laser Doppler, duplex echography, light spectroscopy, and Synovis flow coupler demonstrated true positive rates between 69.4% and 100% with salvage rates between 64% and 100%. Cook Swartz Doppler and tissue oximetry are associated with prompt identification of microvascular compromise and return to theatre. Alternative modalities, including near-infrared spectroscopy, laser Doppler, and duplex echography, show promise. Further well-designed randomised controlled trials (RCTs) appraising head-to-head efficacy are required to comparatively assess adjunctive technologies.

A new protocol for improving immediate monitoring of skin-island free flap with near-infrared spectroscopy and ultrasound

BACKGROUND

Postoperative monitoring is essential for detecting early complications and improving the salvage rate of free flaps. We propose a new protocol for free flap monitoring based on the combination of near-infrared spectroscopy (NIRS) and ultrasound.

METHODS

All free flaps with a skin paddle were included and divided into two groups according to the immediate postoperative monitoring method used: ultrasound examination (control group) or those monitored using our protocol (study group). The number of surgical revisions, intraoperative findings, immediate flap failure, sensitivity, and specificity were compared between the two groups.

RESULTS

A total of 221 free flaps performed in 209 patients were included. The NIRS automatically detected vascular compromise in 21.8% of cases. A complication was confirmed in half of these cases by ultrasound examination, and surgical reintervention was indicated (10.9%), even in the absence of clinical changes in the skin paddle. In all the surgical revisions, the complication was confirmed, and there was no flap necrosis in the non-revised cases. The salvage rate for revised flaps and the flap survival rate were higher in the study group (salvage rate: 25% vs 72.7%; survival rate: 92.5% vs 97%). A sensitivity of 100% and a specificity of 100% were found for the combination of both monitoring methods.

CONCLUSION

The proposed protocol is a non-invasive and reliable method for early identification of postoperative complications of free flaps that allows higher rates of salvage rate and reduces the need for specific staff with continuous on-site presence for flap monitoring.

Using Duplex Ultrasound for Recipient Vessel Selection

INTRODUCTION

 Among the many factors involved in reconstructive microsurgery, identifying a good recipient vessel is one of the key elements leading to a successful result.

MATERIAL AND METHOD

 Multiple modalities have been used to identify recipient vessels from simple palpation of axial arteries to hand-held Doppler, duplex ultrasound, computed tomography angiograms, and other advanced techniques. Although these various modalities bring their own unique advantages, using the duplex ultrasound can provide far superior and real-time information based on the anatomy and physiology of the recipient vessel.

RESULT

 Duplex ultrasound is a valuable and powerful tool for reconstructive surgeons who are interested in performing microsurgery or supermicrosurgery.

CONCLUSION

 As we enter the era of individualized/customized reconstruction using superthin flaps, perforator-to-perforator anastomosis, and supermicrosurgery, understanding and becoming versatile with duplex ultrasound will be critical especially in choosing recipient vessels.

Applications of Ultrasound in the Postoperative Period: A Review

Background Recent advances in ultrasound technology have further increased its potential for routine use by plastic and reconstructive surgeons.

Methods An extensive literature review was performed to determine the most common applications of ultrasound in the postoperative care of plastic and reconstructive surgery patients.

Results In contrast with other available imaging modalities, ultrasound is cost-effective, rapid to obtain, eliminates the need for ionizing radiation or intravenous contrast, and has virtually no contraindications. In addition to its diagnostic capabilities, ultrasound can also be used to facilitate treatment of common postoperative concerns conveniently at the bedside or in an office setting.

Conclusion This article presents a review of the current applications of ultrasound imaging in the postoperative care of plastic and reconstructive surgery patients, including free flap monitoring following microsurgery, diagnosis and treatment of hematoma and seroma, including those associated with BIA-ALCL, and breast implant surveillance.