A Simple Method of Intraoperative Identification of a Reliable Perforator while Dissecting an Anterolateral Thigh Flap

Anterolateral thigh (ALT) flap is currently the workhorse flap in many centers as it provides variable reconstructive options. ALT flap can be raised subfascially or suprafascially based on the requirement. The localization of a reliable perforator is a key step during the flap elevation.[1] ALT perforator at the deep fascia level can be divided into three groups: thin (<0.5 mm), medium (0.5–1 mm), and thick (>1 mm). Earlier, 1-mm perforator was considered to be a reliable perforator.[2] But recent literature shows that a perforator of equal to or more than 0.5 mm can be considered reliable, and a flap can be safely raised on it,[3] whereas in the case if it's <0.5 mm, at least two perforators should be included in the flap.[4]

Various imaging methods have been described to localize these perforators preoperatively. Color-coded Doppler sonography is an efficient method to localize the course of the perforator and measure its size. Availability of this device in the operation theater and familiarity of the surgeon with its working are a prerequisite. Computed tomography angiography, magnetic resonance angiography, and digital subtraction angiography are more accurate but cumbersome investigations. They are also quite expensive and thus not routinely used. Hand-held unidirectional pencil Doppler is still the most commonly used technique to localize perforators. However, it does not provide any knowledge about the perforator size.[5]

Despite preoperative marking of these perforators by hand-held Doppler, choosing a sizable perforator can be challenging in the absence of a measuring tool, especially for Young Plastic surgeons at the beginning of their career.

In our center, we follow a simple method to select a sizable perforator. Disposable needles are used for comparing and assessing the size of perforator by keeping them adjacent to it. These needles come with a standard diameter and are readily available in the theater setting. We use 24-gauze (purple hub) and 20-gauze (yellow hub) needles with a standard diameter of 0.55 and 0.90 mm, respectively (Hindustan Syringes & Medical Devices Ltd) ([Fig. 1]). The following table based on the above knowledge is then applied ([Table 1]).

Table 1 Implication of the use of needle for sizing of perforator

Size of the perforators	Implication
All perforators are <0.55 mm (purple needle).	At least two perforators are included in the flap.
Perforator size is between 0.55 mm (purple needle) and 0.90 mm (yellow needle).	One perforator is enough. In case of more perforators, prefer a perforator with a shorter course to the main vessel.
Perforator with size >0.90 mm (yellow needle).	One perforator is enough, and the flap can be safely raised on that.

Fig. 1 Photo showing sizing of perforator by disposable needles. (A) Descending branch of lateral circumflex artery. (B) Flap perforator.

Same concept can be applied in other perforator flaps as well where the reliable perforator size has been defined in literature. This method may be subjective, but it is a simple, quick, and cost-effective method of choosing a sizable perforator especially in resource-limited settings. Also, it acts as a very basic tool for trainees and relatively newer reconstructive surgeons which makes ALT flap harvest quite straightforward.

Publication History

Received: 22 June 2021

Accepted: 06 July 2021

Article published online:
07 September 2021

• References

• 1 Seth AK, Iorio ML. Super-thin and suprafascial anterolateral thigh perforator flaps for extremity reconstruction. J Reconstr Microsurg 2017; 33 (07) 466-473
• 2 Yu P. Characteristics of the anterolateral thigh flap in a Western population and its application in head and neck reconstruction. Head Neck 2004; 26 (09) 759-769
• 3 Sun JM, Chew KY, Wong CH, Goh TLH. Vascular anatomy of the anteromedial thigh flap. JPRAS Open 2017; 13: 113-125 DOI: 10.1016/j.jpra.2017.05.008.
• 4 Zapata-Ospina A, Chen J, Tee R, Jeng S-F, Karki B, Shih H-S. Harvesting the anterolateral thigh flap with non-sizable perforators. J Plast Reconstr Aesthet Surg 2021; 74 (05) 1022-1030
• 5 Zhao Z, Yang J, Wang B. et al. Clinical application of preoperative imaging evaluation in the anterolateral thigh flap transplantation: comparison of computed tomography angiography, digital subtract angiography and magnetic resonance angiography. Zhonghua Zheng Xing Wai Ke Za Zhi 2015; 31 (03) 172-175