Improved knowledge of abdominal wall anatomy and blood supply has allowed for the development of abdominal wall–based flaps for breast reconstruction. The paired rectus abdominis muscles run in parallel on either side of the abdominal midline. This muscle has two main blood supplies or dominant “vascular pedicles”: superiorly from the superior epigastric artery/vein and inferiorly from the deep inferior epigastric artery/vein (DIEA/V).
With anatomical studies elaborating on the blood supply to this area, the lower abdomen has become the most common donor site. The flaps utilize the transverse portion of lower abdominal wall skin and soft tissue. In many patients there is sufficient volume of skin and fat to reconstruct one or both breasts. The flaps are raised above the abdominal muscular fascia from lateral to medial, and include the skin and full-thickness subcutaneous fat tissues. Once the border of the rectus muscle is reached, further dissection depends on the vascular anatomy and type of flap being harvested. Unilateral or bilateral reconstruction can be performed since the blood supply for each half of the abdomen is separate and distinct.
The transverse rectus abdominis myocutaneous (TRAM) flap was originally described as a pedicled flap based upon the superior epigastric vessels.11 The pedicled TRAM flap typically requires dissection of the entire rectus muscle off of its attachments to the pubic bone. Modifications in this technique are attempts to leave some of the rectus muscle in place; however, extensive dissection of the muscle is still required in a pedicled TRAM flap.
The main drawback is the sacrifice of the entire rectus muscle. The loss of the rectus muscle from the abdomen leads to abdominal wall weakness that can affect a woman's ability to perform strenuous physical activity, including exercise. In addition, the superior epigastric vessels contribute to a lesser extent to the blood supply of the lower abdomen; hence, the pedicled TRAM flap has a higher rate of partial flap necrosis and fat necrosis. It is the authors’ preference that a pedicled TRAM flap rarely be performed and only when microsurgery is not an option.
With advancements in microsurgical techniques, the free TRAM flap has become more commonly performed.12 The DIEAs/Vs provide a greater blood supply to the lower abdominal skin and fat, and consequently, there are less problems with partial flap necrosis and fat necrosis. The DIEAs/Vs are divided, the entire tissue is moved to the chest, and then the blood vessels are reconnected to local recipient blood vessels. As with the pedicled TRAM flap, the entire rectus muscle is harvested along with the overlying lower abdominal skin and subcutaneous tissues. With this technique, there is still the risk of developing postoperative hernias and bulges.
As a natural evolution in operative technique, surgeons sought to minimize sacrifice of the rectus abdominis muscle, but still are able to transfer the same amount of abdominal tissue. The DIEA/V commonly divides into medial and lateral branches before entering the rectus muscle. These branches give rise to a medial and lateral row of perforating blood vessels (aka “perforators”) that then supply the overlying skin and fat. Therefore, it is technically possible to harvest only a small cuff of rectus muscle that surrounds the chosen perforating vessels in order to harvest the lower abdominal flap. The benefit is that it spares a portion of the rectus abdominis muscle and, therefore, is meant to preserve as much abdominal wall strength and minimize the risk of hernia or bulging.13
Taken one step further, surgeons sought to leave the entire rectus abdominis muscle in the abdomen and harvest only the skin, fat, and perforating blood vessels.14 The same skin area is excised and utilized for the breast reconstruction as previously described (Figs. 155-1 and 155-2). When units of tissue are harvested solely with the perforating vessels leaving the entire muscle behind, they are termed “perforator flaps.” The flap is elevated suprafascial, beginning laterally. Perforating vessels from the deep inferior epigastric vessels are identified as they enter the flap (Fig. 155-3). These perforating vessels are then dissected toward the deep inferior epigastric vessels through their intramuscular course (Fig. 155-4). Once the vascular pedicle has been isolated, the flap is ready for transplant to the chest (Fig. 155-5). The deep inferior epigastric perforator (DIEP) flap allows for harvest of the lower abdominal skin and fat while leaving all of the rectus abdominis muscle in the abdomen (Figs. 155-6 and 155-7).
Preoperative pictures before bilateral mastectomy and immediate breast reconstruction with DIEP flaps: anterior view (A) and lateral view (B).
Preoperative markings indicating the size of skin flap for bilateral DIEP flaps.
Schematic showing isolation of the perforating vessels for the DIEP flap.
Schematic showing longitudinal splitting of the rectus abdominis muscle.
Schematic showing completion of the flap dissection.
A. Intraoperative view of the lower abdominal skin raised superiorly before splitting the skin into two flaps, individually based on the deep inferior epigastric vessels. B. View of the conjoined DIEP flaps before division, while the vessels are still attached. Notice the opened abdominal wall fascia and rectus abdominis muscles. Bilateral isolated vascular pedicles are shown with the perforators entering the flap on each side. With this type of flap, no rectus muscle is removed.
A. Intraoperative view of the DIEP flap isolated for a unilateral reconstruction. B. Intraoperative view of the corresponding abdominal donor site before primary repair.
With an increase in knowledge of perforator perfusion and improvement in dissection techniques, the DIEP flap has been shown to be a safe option that can provide excellent reconstructive results and have lower abdominal wall morbidity than the muscle-sparing TRAM, free TRAM, and certainly pedicled TRAM flaps (Fig. 155-8). While the deep inferior epigastric artery can routinely perfuse the flap, the accompanying vein may not always allow for adequate drainage. Dominant venous drainage systems based upon the superficial epigastric vein has been shown to be occasionally present requiring its use during surgery.15 Furthermore, studies have shown that DIEP flaps tend to have a higher rate of fat necrosis than muscle-sparing TRAM flaps, which is likely explained by the fact that muscle-sparing techniques preserve a greater number of perforators and hence greater blood supply to the tissues.16 Surgeon experience and technical expertise strongly correlate with success in performing perforator flaps. Careful patient selection and thorough understanding of vascular anatomy are critically important. Patients should understand that a DIEP flap is not applicable to everyone.
Postoperative pictures after immediate bilateral breast reconstruction with DIEP flaps and nipple-areolar reconstruction: anterior view (A) and lateral view (B).
SUPERFICIAL INFERIOR EPIGASTRIC ARTERY
The superficial inferior epigastric artery (SIEA) can also be used for supplying the lower abdominal tissue for breast reconstruction.17 It does not “perforate” through a muscle and therefore should not be considered a type of perforator flap. The superficial inferior epigastric vein (SIEV) originates from the common femoral vein and needs to be included with the flap for venous outflow drainage. Since the SIEA/V vessels do not run through the rectus muscle, no fascial incisions or muscular dissection is required for harvesting of this flap. Hence, no muscle weakness is expected from this procedure and the resultant abdomen is comparable to a cosmetic abdominoplasty or “tummy tuck.” However, the SIEA has been shown in cadaveric studies to not always be present, and even when it is there, it may be too small to be used for microsurgery.18 In contrast, the SIEV is fairly consistently present, and the authors will routinely include this as part of the flap harvest as a backup for venous outflow drainage even when a DIEP flap or muscle-sparing TRAM flap is performed.
While the described abdominal-based breast reconstruction options remain the most common, there are still indications for other donor sites. Patients with insufficient abdominal tissue, history of prior abdominal surgeries including abdominoplasty or liposuction, or extensive abdominal scarring may still be candidates for autologous reconstruction. Patient preference and surgeon experience are key factors in deciding the recommended donor site location.
GLUTEAL FLAPS (SGAP, IGAP)
Another source of tissue is the upper and lower buttocks. Development of the superior gluteal artery perforator (SGAP) and inferior gluteal artery perforator (IGAP) flap has a similar, parallel history as the DIEP flap. Originally described as using the superior gluteal muscle for the reconstruction, refinements in techniques allowed for the use of gluteal artery perforator flaps to transfer the gluteal skin and fat tissue without sacrificing the underlying muscle.19,20 The perforating vessels enter the flap along a line connecting the posterior superior iliac spine and the greater trochanter (Fig. 155-9). For unilateral reconstruction, the patient can be placed in the lateral decubitus position in the operating room using a bean bag. With thoughtful patient positioning, it is possible to work both on the breast/chest and buttock at the same time. For bilateral reconstructions, mastectomies are performed and then followed by harvesting gluteal flaps in the prone position. The repositioning and inability to perform simultaneous flap harvest, especially in bilateral surgeries, add considerable time to these procedures.
Schematic showing location of SGAP flap markings.
The authors prefer the use of the SGAP over the IGAP for several reasons. The SGAP results in a donor scar very similar to what is performed for a cosmetic “buttock lift” and can be tailored along the natural upper buttock and lower back crease when designed appropriately. Some surgeons prefer a more obliquely oriented scar in an attempt to capture more fat; however, the resultant donor site tends to flatten the buttock and produce a less natural appearance. Therefore, it is the authors’ preference to perform a more transversely oriented scar (Figs. 155-10 and 155-11). In contrast, the harvest of the IGAP flap often involves dissection around the sciatic nerve, which risks potential injury and chronic neuropathic conditions, such as pain, neuroma, and sensitivity. Furthermore, the donor site scar of the IGAP is directly in the lower buttock crease, which can be painful when sitting and also flattens the lower buttock in a rather unnatural fashion. As no muscle is taken with this technique, patients are not expected to have any problems with abdominal wall weakness long-term. The buttock flap may be somewhat firmer than abdominal fat; hence, this can make shaping the flap more challenging in terms of breast reconstruction. In general, gluteal flaps may appear more rectangular than round. The gluteal flaps are less commonly performed for breast reconstruction and can be technically more challenging for inexperienced microsurgeons.
A. Preoperative picture of patient presenting for immediate breast reconstruction following a right mastectomy with a left SGAP flap. The left breast was reconstructed in a delayed fashion with the contralateral right SGAP flap. B. Markings of right SGAP flap. The elliptical markings represent the skin excised for the breast reconstruction. The circles represent the area of the perforators penetrating through the underlying gluteus muscles.
A. Postoperative picture following staged bilateral breast reconstruction with SGAP flaps. B. The scar is beneath the panty line and the patient has had the benefit of a buttock's lift. This patient has yet to undergo nipple-areolar reconstruction.
TRANSVERSE UPPER GRACILIS
The transverse upper gracilis (TUG) flap is another option that utilizes the skin and subcutaneous tissues of the proximal medial thigh.21,22 The inner thigh can have a significant amount of subcutaneous tissue to allow for breast reconstruction in the appropriately selected patient. Evaluation includes a pinch test to determine the approximate volume available in the upper inner thigh. This flap tends to have a fairly consistent blood supply. The TUG flap is supplied by the medial circumflex femoral vessels, which itself originates from the profunda femoris vessels. Once it enters the muscle, there are perforating vessels that travel through the gracilis to supply the overlying skin and subcutaneous tissue. Conveniently enough, the blood supply runs favorably in a transverse direction rather than a longitudinal direction, which allows for a transversely oriented skin paddle to be harvested with the flap (Fig. 155-12). After flap harvest, the donor site can be closed primarily such that the resultant scar lies just beneath the groin crease and can be concealed with shorts (Figs. 155-13 and 155-14).
Schematic showing location of TUG flap and required shaping “coning” for breast reconstruction.
A. Preoperative picture before bilateral mastectomy followed by immediate bilateral TUG flap reconstruction. B. Preoperative markings mark the ribs medially with the internal mammary vessels running beneath. The midline and inframammary folds are also always marked. C. Preoperative markings for bilateral TUG flap. The flaps were created in the same dimensions (green marking is the area excised with gracilis muscle beneath).
A. Postoperative picture following immediate bilateral breast reconstruction with TUG flaps. Nipple-areolar reconstruction with tattooing has been completed. B. The donor site scars are located in the upper medial thigh area and are easily concealable.
In the authors’ experience, the TUG flap is reserved for patients who are not candidates for abdominal tissue flaps and who have a sufficient volume of tissue of the inner thighs on pinch test.
The latissimus dorsi muscle is most commonly used to reconstruct a breast when combined with an implant (Figs. 155-15 and 155-16). Given the proximity of the latissimus dorsi muscle, this flap can be transposed with an overlying skin paddle from the back to the breast region as a pedicled flap without having to divide the blood vessels and hence obviates the need for microsurgery techniques. In general, the volume of the tissue from the latissimus flap is not sufficient to reconstruct a full breast, which explains why it is often combined with an implant or tissue expander. An “extended” latissimus flap has been described that involves harvesting a broad area of subcutaneous tissue overlying the entire latissimus and hence can provide a greater volume of tissue that can be used to recreate a full breast in select patients without the need for implants.23,24 However, with this technique there may be significant donor site morbidity. Specifically, there may be a cosmetically noticeable donor site contour deformity compared to the opposite side, and also an increased risk of seroma. In addition, loss of the latissimus muscle, which is involved in upper extremity motion, internal rotation, and adduction, can cause unwanted upper extremity weakness in physically active patients.25
A. Preoperative picture before delayed left breast with a reconstruction with pedicled latissimus dorsi flap and implant placement. The patient has a history of left chest wall radiation. B. The elliptical skin area marked will be transferred along with the underlying muscle to cover the implant.
A. Postoperative picture after left breast reconstruction with pedicled latissimus dorsi flap and implant (silicone moderate profile, 339cc implant). Nipple-areola reconstruction with tattooing has also been performed. Contralateral augmentation mastopexy has also been completed (silicone low profile, 120cc implant). B. The back donor site scar lies beneath the bra line when placed in the transverse orientation.
Other areas of the body have been described as being used for breast reconstruction, but are used less frequently.26-32 However, in select patients, these alternative options could produce an aesthetically pleasing breast reconstruction.