Improved Location Technology of Perforators of Anterolateral Thigh Flap for Chinese Patients

Abstract

Background The anterolateral thigh (ALT) flap has been widely used in reconstruction of soft tissue defects. The anatomic variations of perforators increase the difficulties of flap elevation. The ABC system has been described for locating the most common three perforators in Western populations. Less evidence has been found regarding whether it is suitable for Chinese population. The purpose of this study is to explore the improvement of preoperative location technology and flap design for Chinese people.

Methods Detection for perforator signals on the bilateral thigh surface was perfromed on 50 Chinese adults using handheld Doppler. Define the A-P line as the line between the anterior superior iliac spin (ASIS) and the superolateral corner of the patella (P). We defined a coordinate system on the thigh surface to record the data of each signal point. The A-P line was y-axis in this coordinate system, and the midpoint of the line was the zero point. The data of these signals were recorded in the form of coordinates. Statistics and mathematic methods were used to analyze the regularity of signal distribution and the correlation between body mass index (BMI) and signal distribution. The findings were applied in five patients who underwent the ALT flap transplantation to confirm its clinical value.

Results The results showed that most of the signals appeared near the A-P line. Most signals were located 1 cm lateral (mean 0.5 cm lateral) to the A-P line. The mean vertical distance between perforator B and perforators A and C was 4 cm . More perforator signals were detected at the two horizontal level (as shown in the picture above) than other horizontal levels. The rate of accurate preoperative detection was 40% (6 of 15 perforators) and the error rate was 20% (3 of 15 perforators). The mean deviation was 1.34 cm, which is acceptable for clinical application. The mean vertical distance between perforator B and perforators A and C in clinical study (4.81 cm) corresponded to the finding of the Doppler study (4.2 cm), whereas the mean distance between perforators and the A-P line (1.57 cm) was more than the Doppler finding (0.48 cm).

Conclusion The A-P line is still a reliable guiding line for Doppler detection and flap design. The ABC system is suitable for the Chinese population but must be adjusted: perforator B is marked first at the midpoint and 0.5 cm lateral to the A-P line and perforators A and C are marked 4 cm distal and proximal to perforator B, respectively. In designing the flap, the region 3 cm around point B and the region between the two horizontal planes at point B and 4 cm lower should both be contained into the flap, no matter what the finding of Doppler detection is.

Keywords

anterolateral thigh flap - handheld Doppler - perforator location - preoperative flap design - clinical application

Note

The authors Hong Zhou and Qian Tan have contributed equally to this work

• References

• 1 Song YG, Chen GZ, Song YL. The free thigh flap: a new free flap concept based on the septocutaneous artery. Br J Plast Surg 1984; 37 (2) 149-159
• 2 Zhou G, Qiao Q, Chen GY, Ling YC, Swift R. Clinical experience and surgical anatomy of 32 free anterolateral thigh flap transplantations. Br J Plast Surg 1991; 44 (2) 91-96
• 3 Koshima I, Nanba Y, Tsutsui T, Takahashi Y. New anterolateral thigh perforator flap with a short pedicle for reconstruction of defects in the upper extremities. Ann Plast Surg 2003; 51 (1) 30-36
• 4 Wei FC, Mardini S. Free-style free flaps. Plast Reconstr Surg 2004; 114 (4) 910-916
• 5 Yu P. Characteristics of the anterolateral thigh flap in a Western population and its application in head and neck reconstruction. Head Neck 2004; 26 (9) 759-769
• 6 Yu P, Youssef A. Efficacy of the handheld Doppler in preoperative identification of the cutaneous perforators in the anterolateral thigh flap. Plast Reconstr Surg 2006; 118 (4) 928-933 , discussion 934–935
• 7 Wei FC, Jain V, Celik N, Chen HC, Chuang DC, Lin CH. Have we found an ideal soft-tissue flap? An experience with 672 anterolateral thigh flaps. Plast Reconstr Surg 2002; 109 (7) 2219-2226 , discussion 2227–2230
• 8 Saint-Cyr M, Schaverien M, Wong C , et al. The extended anterolateral thigh flap: anatomical basis and clinical experience. Plast Reconstr Surg 2009; 123 (4) 1245-1255
• 9 Patel RS, Higgins KM, Enepekides DJ , et al. Clinical utility of colour flow Doppler ultrasonography in planning anterolateral thigh flap harvest. J. Otolaryngol Head Neck Surg 2010; 39 (5) 566-571
• 10 Ribuffo D, Atzeni M, Saba L, Milia A, Guerra M, Mallarini G. Angio computed tomography preoperative evaluation for anterolateral thigh flap harvesting. Ann Plast Surg 2009; 62 (4) 368-371
• 11 Fukaya E, Grossman RF, Saloner D, Leon P, Nozaki M, Mathes SJ. Magnetic resonance angiography for free fibula flap transfer. J Reconstr Microsurg 2007; 23 (4) 205-211