Dec 2002 | Robert J. Allen, MD, Aldo Guerra, MD Scott K. Sullivan, MD
Journal of Reconstructive Microsurgery - Vol. 2 #19
Abstract
More women than ever before are undergoing mastectomies secondary to increased awareness and screening. This has also caused a corresponding increase in the number of breast reconstructions requested each year. The demand for improved results has fueled recent advances in new techniques. Aside from implant reconstruction, the methods now being employed are related to autogenous donations and reconstruction. Currently, the most commonly used techniques for autogenous breast reconstruction are the DIEP (deep inferior epigastric perforator) and TRAM (transverse rectus abdominis myocutaneous) flaps from the lower abdomen.
The anterolateral thigh flap is a type of perforator flap usually described for use in head and neck reconstruction. The authors have discovered this flap's utility as an alternative in autogenous breast reconstruction when the abdomen is not available as a donor site. A review of the literature reveals a dearth of experience in using the anterolateral thigh flap for breast reconstruction. The artide reviews the literature with regard to current uses of the anterolateral thigh flap, and then reports three case studies which highlight the thigh flap as an excellent alternative for breast reconstruction in selected patients.
KEYWORDS: Autogenous breast reconstruction, thigh flap, perforator flap
With mammography screening guidelines to include women aged 40 years and above, more women are undergoing rnastectomies than ever before. After these procedures, women often choose to undergo breast reconstruction partly for restoration of their self-images. The need for better results and muscle-sparing alternatives for autogenous reconstruction have fueled research and the development of newer techniques. Through its evolution, breast reconstruction has come to include several modalities. Most familiar are those modalities dealing with silicone and, currently, saline implants. The latter are advantageous because they are simple to insert and relatively safe. However, they appear less natural than the normal breast, and often result in capsular contraction. After 4 years, the incident or capsular contraction is at least 30 percent, and increases in subsequent years. Additionally, implants tend to become more expensive than other techniques over several years. This is usually due to the need for removal of implants or capsulectomy secondary to contractures.
Because of the disadvantages of implant reconstruction, and the advantages of muscle-sparing techniques using perforator flaps, better results for patients have evolved over the last decade. This is clearly advantageous for women, because they are now provided with several alternatives in the type of reconstruction they prefer. With the disadvantages stated above, research and development have now encouraged newer micro- vascular techniques, including the perforator flaps and the free TRAM flaps.
Autogenous breast reconstruction is useful in areas where implant-based reconstruction is lacking. Silicone shell implants, by definition, cause capsular contracture. Additionally, muscle, fat, and skin without implants create a more natural feeling breast.3 Common to all autogenous breast reconstruction is the much longer initial surgical procedure. An added disadvantage with TRAM flaps is the morbidity associated with abdominal hernias and restricted range of motion.4
Anterolateral Thigh Flap
Perforator artery flaps are being performed in increasing numbers. Koshima and Soeda5 first described parauxnbilical perforator flaps in 1989. This technique involves the harvesting of free flaps based on dissection of the myocutaneous perforators, using fat and skin alone, while avoiding the use of muscle that can result in functional deficits. These perforator and muscle-sparing flaps can be based on the deep inferior epigastric perforator (DIEP), the superficial inferior epigastric artery (SIEA), the thorncodorsal artery perforator (T-DAP), or the superior gluteal artery perforator (S-GAP).6 Allen and Treece7 first introduced perforator flaps for breast reconstruction. Over 1000 perforator flaps for breast reconstruction have been successfully performed at the Louisiana State University Health Sciences Center since 1992. Based on our experience, there were fewer donor-site complications with the perforator flaps, especially complications involving abdominal hernias, bulges, and muscle weakness, when compared to the TRAM flaps.
The authors' most recent technique in breast reconstruction involves the use of the anterolateral thigh flap when abdominal tissue is not available. The thigh flap is not necessarily better or more advantageous than other types of perfurator flaps, but provides an additional donor site when traditional donor Sites are not available. Although there is some variation, the anterolateral thigh flap is usually based on the descending branch of the lateral circumflex femoral artery.89 This flap was first reported by Baekin 1983, and soon after by Song et al. in 1984. The flap has a long vascular pedicle, moderate thickness, and a large cutaneous area. The donor site can be closed primarily or covered with a split- thickness skin graft.
Prior to its recent use in breast reconstruction, the thigh flap has been used for other types of reconstruction. Specifically, the anterolateral free flap has been used for coverage and reconstruction of the lower eyelid after excision of malignant melanoma, full thickness defects of the mandible or cheek,'3 and for pharyngoesophageal defects after radical resection of malignancy). The above procedures were all free flaps, but the anterolateral thigh flap can also be used as a pedicled flap. This was done for coverage of defects resulting from resection of abdominal tumors that extended to the anterior abdominal wall.'5 The anterolateral thigh flap has also been combined with a vascularized fibula graft for two patients with wide through-and-through oromandibular defects, as described by Koshima et al.16
Anatomy
In most cases, the descending branch of the lateral circumflex femoral artery (LCFA) supplies the anterolatcmi thigh flap. A Doppler probe can delineate the surface projection of the perforating artery from the LCFA. This area of projection is estimated to be at the midpoint of a line linking the anterior superior iliac spine and the superolateral border of the patella. The descending branch runs downward through the intermuscular space between the rectus femons and the vastus lateralis, and terminates in the vastus lateralis muscle near the knee joint. The cutaneous branches supply the skin overlying the vastus lateralis.
The cutaneous branches are classified into four types by Luo et al. First are the musculocutaneous perforators that penetrate the vastus lateralis muscle. These are the most common types. Second are the septocutaneous peforators that run between the rectus femoris and the vastus lateralis before entering the skin. Third, there are the direct cutaneous branches that arise from the transverse branch of the LCFA and pass through the fascia lata. Finally, there are the tiny cutaneous branches found on the surface of the vastus lateralis. If a sensate flap is desired, the lateral femoral cutaneous nerve (L2-3) must be included with the harvested flap. The largest branch of this nerve traverses downward along the previously mentioned line that extends from the antenor superior iliac spine down to the lateral border of the patella.
Anatomic Variations of the Pedicle
The major advantage of the thigh flap can also be its major disadvantage. While the length of the vascular pedicle can be helpful, it also has a great deal of vanation in its course along the thigh. In a 13-patient series reported by Koshima et al.~ in 1989, two vascular patterns of the septocutaneous perforator are described. In type 1, the septocutaneous perforator derives from the descending branch of the lateral circumflex femoral artery. However, only 3 of 13 patients demonstrated this type. In type 2, the septocutaneous perforators emerge directly from the profnnda femoris and not the LCFA. Five cases of 13 were of the type 2 variation. The five remaining cases were not included in either type because no septocutaneous perforating artery could be found,
References