Improving the Accuracy of Easily Accessible 5-MHz Handheld Doppler Examination in Perforator Flap Planning

Abstract

Sir:FigurePreoperative handheld Doppler examination has been applied widely in planning perforator flap surgery because of its moderate cost, noninvasive nature, and simplicity.1 Ideally, an 8- or 10-MHz handheld Doppler probe is suitable for this purpose.2 The 5-MHz handheld Doppler probe is a more easily accessible choice because it can be found in several departments of every hospital; however, it has a higher tissue penetration depth. It is a fact that a 5-MHz handheld Doppler probe does not distinguish perforating vessels from main axial vessels and can create false-positive localization of perforators when the axial vessels run very superficially.3 In the pediatric population and slim adults, the source arteries lie too close to the skin. The purpose of our study was to demonstrate a practical way of using 5-MHz handheld Doppler examination in perforator flap planning in children, in thin adults, and in extremities. Institutional review board approval was obtained before our examination procedures began. Lateral circumflex femoral artery perforator flap planning was performed on either of the thighs of six pediatric volunteers. The mean age of the patients was 11 years (range, 8 to 14 years) and all were in the healthy range in terms of body mass index. Vessel signals were sought using a handheld Doppler device (Huntleigh Multi Dopplex MD 1; Huntleigh Health Care Ltd., Cardiff, United Kingdom) with a 5-MHz probe. In all volunteers, the signals of the perforators and the source artery were mixed up, all over the course of the descending branch of the lateral circumflex femoral artery. (See Video, Supplemental Digital Content 1, which demonstrates the clutter of signals, https://links.lww.com/PRS/A640.) As the proposed supplementary procedure, an inflatable toy balloon filled with water is used as a distance protector between the skin and the handheld Doppler probe. Ultrasound gel is applied both on the skin-balloon interface and on the balloon-probe interface. At the beginning, to detect a clear signal, the probe is pushed through the balloon toward the marked point of possible perforator sites, close to the vessels (Fig. 1, above). After acquisition of the signal, the probe is moved away from the skin slowly, maintaining the contact with the balloon until the signal becomes significantly weakened and hardly heard (Fig. 1, below). At that height, if no signals are detected around this premarked possible point of perforator, that point is regarded as a probable perforator site. (See Video, Supplemental Digital Content 2, which briefly demonstrates the barely heard signals isolated on a premarked possible point of perforator, https://links.lww.com/PRS/A641.)Fig. 1: (Above) The probe is embedded in the water-filled toy balloon and directed toward one of the premarked possible perforator positive points. This way, it is approximated to the skin to find the vessel signals more easily. (Below) The probe is elevated until the sound becomes significantly weakened, and this final distance is protected.Video 1: Supplemental Digital Content 1 demonstrates the clutter of signals, https://links.lww.com/PRS/A640.Video 2: Supplemental Digital Content 2 briefly demonstrates the barely heard signals isolated on a premarked possible point of perforator, https://links.lww.com/PRS/A641.In all six volunteers, the technique worked properly and probable perforator signals could be differentiated from the underlying source artery signals. In two of these volunteers, a radiologist checked probable perforator sites by color Doppler ultrasound imaging, and these points were found to include subcutaneous perforator vessels. The balloon verification increases the specificity and preserves the sensitivity and thus increases the overall accuracy of the 5-MHz handheld Doppler examination. Thus, it seems to be feasible for a perforator flap surgeon, who is in a period of abstinence from technology (as occurs sometimes in appointments to peripheral hospitals), to use a borrowed 5-MHz handheld Doppler device with simple balloon verification in preoperative planning. It may also be useful in verification of the perforator points detected by an 8-MHz handheld Doppler device. Emre Hocaoğlu, M.D. Hüseyin Elbey, M.D. Department of Plastic Reconstructive and Aesthetic Surgery Artur Salmaslıoğlu, M.D. Department of Radiodiagnostics Metin Erer, M.D. Department of Plastic Reconstructive and Aesthetic Surgery, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey The preliminary work of this study was presented as an oral presentation at the Fifth National Congress of the Turkish Society of Reconstructive Microsurgeons, in Bodrum, Turkey, December 15 through 17, 2011. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article.