Imaging for thinned perforator flap harvest: current status and future perspectives

Abstract

With advances in anatomical knowledge and technology, increased interest has been directed towards reconstruction with enhanced aesthetic and functional outcomes. A myriad of thinned perforator flap harvest approaches have been developed for this purpose; however, concerns about jeopardizing their vascularity remain. To ensure optimum reconstructive outcome without hampering the flap’s microcirculation, it is important to make good use of the existing advanced imaging modalities that can provide clear visualization of perforator branches, particularly in the adipose layer, and an accurate assessment of flap perfusion. Therefore, this review will highlight the imaging modalities that have been utilized for harvesting a thinned perforator flap from these two perspectives, along with future insights into creating both functionally and aesthetically satisfying, yet simultaneously safe, thinned perforator flaps for the best reconstructive outcomes for patients.

Precision of Dynamic Infrared Thermography in Anterolateral Thigh Flap Planning: Identification of the Perforator Fascia Passage

“…10 14 20 When choosing CTA, that some authors consider to be the gold standard, the inevitable radiation exposure needs to be considered. 21 Both CTA and MRA are resource consuming and may not be easily available. Furthermore, as for conventional angiography, they need invasive contrast media application and therefore entail the risk of anaphylaxis and further adverse effects.…”

“…10,22 Indocyanine green (ICG) fluorescence depends on intravenous application of indocyanine green with the risk of allergic reactions and requires special equipment for ICG visualization. 10 Handheld Doppler and CDU are affordable, portable, noninvasive, and easy to implement in daily clinic routine, 21 while CDU tops handheld Doppler in terms of accuracy. 23,24 However, CDU requires expertise and regular use to provide reliable guidance and the interexaminer variability limits its application.…”

Preoperative perforator localization in anterolateral thigh free flap using acoustic doppler and computed tomography angiography

“…CTA had a sensitivity of 90.4% in a meta‐analysis 21 . However, it is not conducted in real‐time and has disadvantages such as contrast medium allergy, potential carcinogenic effects due to radiation exposure, and its time consuming nature 11 . Catheter angiography using indocyanine, indocyanine green angiography, also showed perforator localization of nearly 100%, and it has the advantage of perforator mapping and perfusion in real time, but it is expensive and invasive 11,22 .…”

“…In addition, blood vessels in the muscle can also be detected because the 8 MHz transducer usually used in ALTF has a penetration depth of 3.5 cm 7,24 . However, if the perforator is located deep within the tissue, the course of blood vessel can be meandering 11 . To reduce the sensitivity of AD to deep blood vessels, Mun et al suggested that it is possible to distinguish whether a perforator is a perforator or not by the change in sound when the transducer is compressed 25 .…”

“…In addition, it is difficult to track the actual course of the perforator by an AD. CT angiography (CTA) has also been used to assess the anatomical details of blood vessels 11 . Preoperative CTA can be used to detect atherosclerotic disease, anomaly and the approximate course of the perforator.…”