As free transfer of these workhorse flaps becomes routine, attention can focus on refining the quality of the reconstruction. One major aesthetic consideration is optimal contour match[19]. In patients with excess subcutaneous tissue in the back, free latissumus dorsi musculocutaneous flap may be too bulky when transferred to the lower extremity, especially on the lower-leg or foot. To reduce the receipt bulkiness and obviate the need for a skin graft on the donor site, free latissimus dorsi muscle flap with skin graft cover was proposed[20], but this procedure was restricted in yellow race owing to obvious scar formation.
Following the introduction of thoracodorsal artery perforator flap by Angrigiani et al, it attracted great interest of plastic surgeon and many articles have been published on the thoracodorsal artery perforator flap[21-28]. After abroad applications of the flaps, some distinct disadvantages appeared, including that the dominant large muscle perforators are often absent in actual surgery and the variable location and tedious dissection of the perforators prolong the surgery[7-12]. Therefore, Schwabegger et al introduced a muscle-sparing technique to harvest a latissimus dorsi myocutaneous flap, with the advantage of leaving intact innervation and function of the remaining latissimus dorsi muscle and increasing the reliability of the vascular pedicle[13].
In this series of seventeen patients, we present not only the muscle-sparing technique, but also another design refinement technique of latissimus dorsi musculocutaneous flap based on perforator flap conception. According to the territory of latissimus dorsi musculocutaneous flap[13,28], we designed forward the skin paddle, extended about 3-5 cm to the anterior edge of the latissimus dorsi muscle, in which anterior underlying muscle and main perforator was included. If necessary, an underlying latissimus dorsi muscle flap for soft tissue augmentation was dissected. Since the skin paddle is harvested anteriorly on the lateral thoracic region, where it is thinner than that of the back/shoulder, and the much less tissue provided, its reliable vascular supply, together with its limited donor-site morbidity make it a useful alternative free flap. Moreover, infected bone often exposed in the center of wound and needed a well-vascularized muscle for wound coverage to control low-grade infection, and the muscle tissue will shrink nicely with time, further debulking for contour improvement often may not be necessary.
However, a reliable perforator with visible pulsation cannot be identified in some clinical procedure, and only small invisible perforators exist around the hilus portion and the lateral border of the latissimus dorsi muscle and cannot be dissected into the muscle as they are generally very small to dissect. The surgical plan should be revised, and the flap was elevated to include the proximal level of the lateral branch with a small amount of the lateral border of the muscle (3–4 cm in width). This revision accords with recent report by Koshima et al[7].
Furthermore, helcosis of unstable scar in the heel and toe regions often require flap reconstruction. Under such conditions, since the two defective areas were at a distance of one foot, we separated the skin paddle with the latissimus dorsi muscle flap to resurface the two defective areas. The muscle-sparing latissimus dorsi musculocutaneous flap repaired the heel defect, and skin grafted on the latissimus dorsi muscle flap nourished by the lateral branches to resurface the toe defect. To decrease the risk of vascular impairment, we did not completely separate the muscle portion and cutaneous part to form a chimera thoracodorsal artery perforator flap described above[29-30]. The flap used in this study is not a true chimeric flap, but an intermediate form between musculocutaneous and chimeric flaps, and the good contour reconstruction has been obtained after a simple two-stage plastic operation in two clinical cases, as shown in this series. Therefore, the cautious method may be a useful option for the reconstruction of heel and toe defects, particularly when used by surgeons less experienced in perforator flap procedures.
In conclusion, we would like to advocate the compatible use of such latissimus dorsi musculocutaneous flaps based on the thoracodorsal artery perforator system, mainly due to the much less tissue which allows the reconstruction of some different defects, and also because of the limited donor-site morbidity. The flap procedure is safe and easy to perform. Moreover, the flap provides sufficient flexibility, even though it has less independent flap mobility than the chimeric flap. Therefore, the flap may be a convenient and reliable alternative for the wound reconstructions of the lower extremities.
