Muscle-Sparing and Free TRAM Flap Breast Reconstruction

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CHAPTER 8 Muscle-Sparing and Free TRAM Flap Breast Reconstruction

Joseph J. Disa, Andrea L. Pusic, Toni Zhong

Summary/Key Points

1. The choice of which technique of transverse rectus abdominis myocutaneous (TRAM) flap to use is based on the physical characteristics of the patient as assessed both preoperatively and intraoperatively. The physical examination is generally most helpful in arriving at the decision between a pedicled or a free TRAM flap preoperatively, while the decision to use a free TRAM or muscle-sparing (MS) TRAM or deep inferior epigastric artery perforator (DIEP) flap is made intraoperatively based on individual anatomical variations.

2. For most breast shapes, a contralateral free or MS TRAM anastomosed to the internal mammary vessels or an ipsilateral free or MS TRAM anastomosed to the thoracodorsal vessels allows for a vertical flap inset, which best recreates the naturally ptotic appearing breast.

3. Before committing to free muscle transfer by transection of the superior aspect of rectus muscle, the recipient vessels must be completely dissected to ensure usability of both the vein and artery.

4. When performing a muscle-sparing TRAM, the medial anterior rectus sheath incision is made first and intramuscular dissection is carried inferiorly while visualizing the medial branch of the pedicle to ensure that it is retained with the flap. The superior border of the anterior rectus sheath incision is then made and the muscle is transected. At this point, the underside of the rectus muscle is inspected to directly visualize both the medial and lateral branches of the deep inferior epigastric vessels. This way, the lateral fascial incision can be safely made at a location lateral to the lateral branch of the pedicle such that both branches of the pedicle are harvested with the flap.

5. When insetting the TRAM flap, the first tacking suture is placed at the most superomedial position followed by the placement of tacking sutures along the sternal border and then superior border of the mastectomy space to ensure adequate superomedial volume of the reconstructed breast. Superolaterally, the TRAM flap is tacked to the remaining soft tissue anterior to the axillary fold to avoid an unsightly dysjunction between the axilla and breast. Proper positioning and shaping of the flap at the initial stage is the key to obtaining optimal breast aesthetics and minimizing the need for future revisions.

Introduction

Breast reconstruction with autologous tissue can generally achieve more durable and natural results than with the use of implants alone.¹ When well designed and executed, the TRAM flap offers the advantage of being able to provide large soft tissue volume. In large breasted women undergoing unilateral reconstruction, this technique offers improved aesthetics over implant reconstruction (Fig. 8.1). In addition, complete restoration of the breast mound is often possible in a single stage. Of all the available donor sites for autologous breast reconstruction, the TRAM flap in both pedicled and free form is the most frequently used method.² The evolution of the TRAM flap, from pedicled, to free TRAM, to muscle-sparing (MS) free TRAM, to perforator flap (DIEP) has occurred in an attempt to reduce the morbidity that results from the loss of the rectus muscle and anterior sheath associated with the pedicled TRAM flap.

Fig. 8.1 Postoperative photos of a large breasted patient who has undergone left sided mastectomy with immediate reconstruction using a MS-TRAM. Note the large soft tissue volume of reconstruction on the left side to match the native breast. A Frontal view. B Right oblique view. C Left oblique view.

The free TRAM flap is based upon the dominant deep inferior epigastric vascular pedicle which permits transfer of a larger volume of abdominal tissue than with the use of pedicled TRAM flaps. The muscle-sparing TRAM flap is a modification of the free TRAM flap which limits the amount of rectus muscle and anterior sheath harvested to only those encompassing the medial and lateral rows of musculocutaneous perforating vessels. The theoretical advantage of the muscle-sparing TRAM is the ability to minimize the violation of the abdominal wall integrity while ensuring equal blood supply to the flap as compared to a free TRAM flap. A more comprehensive understanding of the evolution of the MS TRAM to the DIEP flap is reflected in the classification of muscle-sparing TRAM described by Nahabedien ³ (Table 8.1). The DIEP flap is the most refined form of MS TRAM in which no muscle or anterior rectus fascia is harvested with the abdominal flap.

Table 8.1 Classification of MS free TRAM

Muscle-sparing technique	Definition (rectus abdominis)
MS0	Full width, partial length harvested
MS1	Preservation of lateral segment
MS2	Preservation of medial and lateral segments
MS3 (DIEP)	Preservation of entire muscle

From Nahabedian MY, Momen B, Galdino G, Manson PN. Breast reconstruction with the free TRAM or DIEP flap: patient selection, choice of flap, and outcome. Plast Reconstr Surg 2002;110(2):466.

Indications and Contraindications

Indications

A free or MS TRAM represents an excellent reconstructive option for women undergoing either immediate or delayed breast reconstruction who possess an adequate amount of abdominal fat to achieve the desired breast volume. Moreover, free TRAM or MS TRAM flaps are preferred over pedicled TRAM flaps in the immediate breast reconstruction setting because there is less risk of fat necrosis or partial flap loss in the breast flap. The more dominant blood supply to the free TRAM or MS TRAM can help minimize the problems with wound healing that can lead to delays in the delivery of adjuvant therapy as seen with pedicled TRAMs.⁴ While obesity and tobacco smoking are two relative contraindications to performing a pedicled TRAM flap, in these high risk patients who either require or strongly desire autologous tissue reconstruction, they generally have a lower complication rate in both the breast and abdomen following a free TRAM or MS TRAM flap.²^,⁴ This is felt to be due to a more robust blood supply to the breast and less surgical insult to the abdominal wall integrity. Lastly, in a large-breasted patient who does not desire a reduction on the contralateral side, a free TRAM or MS TRAM will more reliably transfer a large amount of abdominal tissue onto the chest wall than a pedicled TRAM flap (Box 8.1).

Contraindications

Absolute contraindications to free TRAM or MS TRAM include:

1. Any previous abdominal surgeries that may have transected the inferior epigastric blood supply to the flap.

2. Previous abdominal surgeries that have disrupted the system of periumbilical perforators to the cutaneous portion of the TRAM flap.

3. Lack of recipient vessel availability.

4. Lack of redundant lower abdominal tissue.

Abdominal incisions that should arouse suspicion include those used for inguinal hernia repair and paramedian scars. Conversely, common scars that generally do not preclude the use of free TRAM flaps are lower transverse incisions such as a Pfannensteil incision or midline incisions. The potential lack of recipient vessels should be suspected in patients with both a heavily dissected axilla and radiation to both the chest wall and axilla. Other relative contraindications to free TRAM flaps include patients who are medically unfit, patients with a grave prognosis, and previous liposuction to the abdomen (Box 8.1).

Patient Selection

The choice of which technique of TRAM flap to use is based on the physical characteristics of the patient assessed both preoperative and intraoperatively. An algorithm to aid the decision-making process is outlined in Figure 8.2. Generally, whether the patient is a good candidate for pedicled versus free TRAM can be determined preoperatively based on the physical examination. On the other hand, the decision to use a free TRAM or MS TRAM or DIEP flap is made intraoperatively based on individual anatomical variations.

Fig. 8.2 Algorithm for procedure and patient selection.

The role of rectus abdominis muscle within the abdominal flap is to carry and protect the epigastric vascular system.⁵ The muscle itself is not felt to contribute to volume, shape, or vascularity of the reconstructed breast. MS TRAM minimizes the amount of rectus abdominis muscle and anterior rectus sheath harvested, and thus lessens the insult to the abdominal wall. Though comparative studies examining the incidence of hernias and bulges following pedicled TRAM, free TRAM, and DIEP flaps have shown mixed results, evaluations of abdominal strength have demonstrated that free TRAM is superior to pedicled TRAM, and DIEP flap may be further superior to the free TRAM.⁶^–⁹ More recently, Nahabedian et al observed a significantly higher incidence of lower abdominal bulges in bilateral breast reconstruction in the non-muscle-sparing than muscle-sparing group.⁵

The patient characteristics noted preoperatively are as follows:

1. Breast size and volume. When the desired reconstructed breast volume is in excess of 1000 g, then free TRAM or MS TRAM flap is the technique of choice. Pedicled TRAM flaps are most reliable when the transferred abdominal flap is small in volume and based largely around Zones I and II. Although DIEP flaps based on one or two perforators have been demonstrated to provide adequate perfusion, its usefulness for large volume reconstructions has not been rigorously established.³

2. Abdominal pannus. While a small to moderate pannus is ideal for a pedicled TRAM flap, a pannus that is any larger harbors significant risk for wound partial flap loss and significant fat necrosis in the breast.⁴ Free TRAM or MS TRAM can more safely address this issue because the blood supply is based on the more dominant deep inferior epigastric pedicle.

3. Smokers. Although TRAM reconstructions are strongly discouraged in active smokers, free TRAM or MS TRAM is preferred over pedicled TRAM flaps in those who require or strongly request autologous breast reconstruction. The free TRAM flap captures more periumbilical perforators and minimizes the morbidity related to tobacco use in both the breast and abdomen.

The anatomical flap characteristics noted intraoperatively are as follows:

The decision between performing a MS TRAM versus DIEP is made at the level of the anterior rectus sheath.

1. Caliber of perforators to the skin. Most authorities in this field agree that if an arterial perforator is greater than 1.5 mm in diameter with a palpable pulse and a visible vein, then a DIEP flap can be attempted safely.^3,^7,¹⁰ If none of the aforementioned criteria are met, then a MS-TRAM is preferred.

2. Number of perforators to the skin. In some patients, there are a large number of perforators in both the medial and lateral rows, but no single dominant perforator. In these patients, a MS-TRAM is preferred over a DIEP flap. The average number of medial and lateral row perforators encountered in a free TRAM is usually three to four per row.¹¹

3. Location of perforators to the skin. If two dominant perforators equal in caliber are present and are located adjacent to each other within the same row (i.e., both are in the medial row or both are in the lateral row), then the possibility of performing a DIEP flap based on both perforators is explored. If two dominant perforators equal in caliber are present but are located either in different rows or far apart from each other, then the decision between using a MS TRAM or a DIEP flap is based on the caliber of the perforators. If both perforators are less than 1.5 mm, then a MS TRAM is performed. A DIEP flap is attempted if the perforators are greater than 1.5 mm in diameter. In the latter scenario, the DIEP flap will be based on the perforator that is most caudal, such that the length of intramuscular dissection of the perforator to the main pedicle is minimized.

Operative Technique

Marking

The patient is marked in an upright as well as supine position.

Breast marking

The inframammary line is an important landmark to be noted preoperatively. In the immediate reconstruction setting, the marked or stapled inframammary line is a helpful guide to define the lower limit of the mastectomy for the breast surgeon. In the delayed setting, the previous inframammary line is determined from the opposite breast and reproduced on the ipsilateral side.

For a patient undergoing skin-sparing mastectomy with a small or moderate sized breast, a simple elliptical or circular excision is marked over the central mound of the breast which includes the nipple–areolar complex (NAC). This allows closure of the reconstructed TRAM flap skin to the mastectomy skin either in an elliptical pattern or as a circular purse-string pattern to create a template for the future NAC (Figs 8.3 and 8.4). For a patient with large breasts or breasts with grade III ptosis, a Wise type pattern skin reduction can be used in the involved breast (Fig. 8.5). For patients with existing grade II ptosis in the involved breast who wish a future mastopexy on the opposite breast, a vertical mastopexy skin excision pattern can be applied.

Fig. 8.3 A Preoperative photo. B Postoperative photo following skin-sparing mastectomy with elliptical pattern and MS TRAM reconstruction.

Fig. 8.4 A Preoperative photo. B Postoperative photo following skin-sparing mastectomy with periareolar circular pattern and MS TRAM reconstruction.

Fig. 8.5 A Preoperative photo showing left breast following a lumpectomy. B Postoperative photo showing left sided mastectomy using a Wise pattern reduction with MS TRAM reconstruction. A nipple areolar reconstruction has been performed on the left breast mound. Wise pattern reduction was performed on the right breast.

Abdominal marking

The transverse skin island of the TRAM flap is marked over the lower abdomen encompassing the lower abdominal redundant soft tissues. The superior incision lies just above the level of the umbilicus in order to capture as many periumbilical perforators as possible into the flap (Fig. 8.6). Ideally, the height of the abdominal flap should be equal or greater than the breast width of the mastectomy specimen (Fig. 8.7). This is because during the flap inset, the TRAM flap is inset vertically on the chest as to create the most natural ptotic shape for the reconstructed breast. In designing the inferior incision, care is taken to mark it at a location such that the abdomen can be closed with minimal tension. As well, the inferior incision is designed such that it is hidden in the natural suprapubic crease to camouflage its appearance. Lastly, the inferior incision should not be within the pubic hair-bearing region, as this may lead to problems with delayed wound healing. A midline mark is made just above the umbilicus and on the pubic region. These marks help place the midline of the upper abdominal flap to the midline of the pubic area when closing the abdominal donor site.

Fig. 8.6 Photo of the abdominal markings of a free TRAM flap.

Fig. 8.7 Abdominal markings are designed such that the height of TRAM flap is equal to or greater than the width of the breast on the involved side.

Positioning

Once the patient is brought into the operating room, bilateral intermittent compression devices are placed on the lower extremities and compression is started before general anesthesia is induced. For most patients, no invasive monitoring devices are required.

After induction of anesthesia, a urinary catheter is inserted to monitor fluid status throughout the procedure. On the involved side, the arm is prepped and draped free, and placed on a well padded arm-board that can be removed during the microsurgical portion of the procedure. The uninvolved arm is well padded and secured along the patient’s side. A warming blanket is placed over the pelvis and legs and a safety strap is secured over the thighs.

Surgical approaches

The free TRAM and MS TRAM technique

For both immediate and delayed reconstruction, a two-team approach is employed whenever possible. In the immediate setting, the mastectomy is performed at the same time as the flap harvest in the abdomen. In the delayed setting, mastectomy flap elevation and recipient vessel exposure are performed concomitantly with flap elevation.

When the internal mammary vessels are selected as the recipient vessels, the contralateral rectus muscle is preferred as the donor muscle. In the setting of an immediate reconstruction where thoracodorsal vessels are already or easily exposed, the ipsilateral rectus muscle is preferred as the donor muscle. The exception to this guideline occurs when confronted with breasts that are wide and transversely oriented. In these cases, an ipsilateral rectus muscle is chosen for internal mammary vessel anastomosis, and a contralateral rectus muscle is chosen for thoracodorsal vessel anastomosis to facilitate a horizontal flap inset.

1 Flap harvest

The upper TRAM skin island is incised and an upper abdominal flap is elevated superficial to the anterior rectus sheath up to the costal margins laterally and xiphoid sternum centrally. A slight superior bevel is emphasized in incising the subcutaneous tissue of the upper skin island such that more sub-Scarpal fat is retained with the TRAM flap to ensure adequate volume of the reconstructed breast. In addition, this beveling technique allows closure of the thicker upper abdominal flap to the thinner lower pubic flap without an unsightly step-off. Care is taken to limit the upper abdominal flap dissection laterally to preserve the remaining blood supply.

An incision is then made around the umbilicus using a #11-blade. We prefer to retain ample fat around the umbilical stalk to ensure viability of the umbilicus. A 2-0 silk suture is placed routinely at the 12 o’clock position of the umbilicus to prevent unintentional twisting of the umbilicus when it is later retrieved and sutured to its new position on the abdominal wall.

Before the lower skin island incision is made, the OR bed is flexed and the upper abdominal flap is brought down to the lower incision marking to ensure tension-free closure. After incising the lower skin island flap, care is taken not to undermine inferiorly in the subcutaneous tissue. Problems with persistent pubic region edema and an unsightly pubic symphysis bulge can be minimized in this manner.

For either unilateral or bilateral breast reconstructions, the skin island of the flap is elevated from lateral to medial until the lateral row of perforators is seen to arise from the anterior rectus sheath. To fully visualize the perforators, the plane of the dissection must be immediately anterior to the rectus sheath, such that the perforators are not accidentally divided within the substance of the flap. Low cautery setting must be maintained during this portion of the procedure to prevent accidental heat injury to the perforators. Caution must be applied to cases where a midline rectus diastasis is present such that the lateral row perforators come into view earlier than anticipated. In the case of a bilateral reconstruction, the midline of the flap is incised down to the linea alba. Both sides of the flap can then be elevated from a medial to lateral direction until the medial row perforators are encountered.

At this point, the perforators are visualized carefully under loupe magnification and palpated for pulsations to decide between performing a MS TRAM versus a DIEP flap (see Fig. 8.2). Before committing to free muscle transfer or transecting the superior aspect of the rectus muscle, recipient vessels must be completely dissected to ensure usability of both a vein and an artery.

In the case of a unilateral breast reconstruction, once the laterality of the MS TRAM has been decided, then the opposite flap can be rapidly elevated from the anterior rectus sheath. This dissection slows down once the linea alba is crossed, and coagulation is turned down in intensity when the dissection approaches the ipsilateral medial row of perforators.

Dissection of the thoracodorsal vessel

In the setting of immediate reconstruction, the recipient thoracodorsal vessels are usually well exposed following axillary dissection, and if kept free from injury and spasm, they are the best choice for recipient vessels.¹⁵ If a skin-sparing mastectomy is performed through a small periareolar incision, then a separate incision in the axillary dome is necessary for dissection of the thoracodorsal vessels (Fig. 8.11). For delayed reconstructions, many surgeons avoid dissecting in the previously radiated or dissected axilla. This exploratory process is inherently difficult when the thoracodorsal vessels are encased in scar and the vessels are often too fibrosed to be used safely after significant wasted time and effort.

Fig. 8.11 A Photo of skin-sparing mastectomy (SSM) incision with separate incision for dissection of thoracodorsal vessels. B Following SSM and thoracodorsal vessel dissection.

When the thoracodorsal vessels are not readily exposed from an axillary lymph node dissection, they can be found in a plane deep to the axillary fat. The arm should be positioned at 90° of abduction from the chest. The vessels can be readily identified once the envelope of axillary fat has been opened. It is important to keep in mind that at this level, the thoracodorsal vessels are in the apex of the axilla, rather than immediately adjacent to the chest wall. Once the thoracodorsal vessels are identified, they are exposed from their axillary location to the serratus anterior branch. The authors prefer to divide the thoracodorsal vessels just proximal to the serratus branch allowing the distal portion of the vessels to be brought out of the axilla and into the operative field.

3 Anastomosis

Once the flap has been divided from its pedicle, it is wrapped and protected in a moist sponge with the pedicle free and dangling from it. A weight is obtained from the flap to aid in matching the mastectomy specimen in the case of immediate reconstruction.

Setup for anastomosing to the internal mammary vessels

The flap is rotated 180° and set down on the chest in a horizontal fashion such that the pedicle is exiting from the superior border of the flap and the umbilical defect of the flap is at the inferior border of the flap (Fig. 8.12). This orientation of the flap allows for microanastomosis between the donor and recipient vessels to take place without twisting or kinking. Once the position of the flap is set, the sponge containing the flap is stapled to the chest skin to stabilize the flap during the anastomosis.

Fig. 8.12 Drawing of TRAM flap inset for mastectomy defect using internal mammary recipient vessels.

A For a right mastectomy defect, a left free TRAM or MS TRAM is harvested. Flap is rotated 180° and temporarily affixed to the chest during anastomosis. Following completion of the anastomosis, the flap is then rotated clockwise 90° and inset in this vertical position on the chest.B For a left mastectomy defect, a right free TRAM or MS TRAM is harvested. Flap is rotated 180° and temporarily affixed to the chest during anastomosis. Following completion of the anastomosis, the flap is then rotated counterclockwise 90° and inset in this vertical position on the chest.

Setup for anastomosing to the thoracodorsal vessels

The flap is rotated 90° and set down on the chest in a vertical orientation such that the ipsilateral tip of the flap is directed at the clavicle and the contralateral tip of the flap is directed at the feet (Fig. 8.13). The pedicle exits obliquely from the flap and reaches the thoracodorsal vessels with a gentle curve. The flap is similarly secured to the chest skin as described above.

Fig. 8.13 Drawing of TRAM flap inset for mastectomy defect using thoracodorsal recipient vessels.

A For a right mastectomy defect, a right free TRAM or MS TRAM is harvested. Flap is rotated 90° clockwise for anastomosis and inset in this vertical position.B For a left mastectomy defect, a left free TRAM or MS TRAM is harvested. Flap is rotated 90° counterclockwise for anastomosis and inset in this vertical position.

Microanastomosis

Final clearance of the recipient and donor vessels is performed under the microscope. Care is taken to either bipolar or clip any side branches arising from the recipient vessels. In the case of dissecting the internal mammary artery, aggressive clearance of adventitia is not recommended as the intima of this vessel is extremely delicate and can be easily traumatized by traction. The recipient vessels are marked on their superficial surface prior to their division. Both the recipient and donor vessels are flushed well with heparinized Ringer’s lactate solution to remove any pre-existing clots within the lumen. They are gently dilated to achieve maximum lumen diameter.

Arterial anastomosis is routinely performed first using 9-0 nylon. This can be done in an interrupted or running fashion. When using a running suture, it is essential to have a proficient assistant who can provide traction on the suture to act as a stay suture. Venous anastomosis is performed using a microvascular coupling device. Average coupler sizes that are employed are between 2.5 and 3 mm. In our experience, the venous coupler significantly reduces the time needed for the venous anastomosis and helps to stent open the venous anastomosis.

4 Abdominal wall closure

After revascularization is completed, the flap tissue is temporarily placed inside the mastectomy pocket and secured with 2-0 Vicryl sutures and skin staples. Attention is then turned to closure of the abdominal wall. It is important to close the abdomen prior to insetting the flap in the breast. Depending on the tension that exists in the abdominal closure, the level of the inframammary fold (IMF) will alter and thereby change the shape of the reconstructed breast.

In a unilateral MS TRAM, the fascial defect is always closed primarily using interrupted 0-Ethibond sutures at 2 cm intervals and over-sewn with 2-0 running PDS suture (Fig. 8.14). Emphasis is made on closing both leaflets of the anterior rectus sheath, as this has been shown to reduce bulge rates.⁹ A contralateral plication of the anterior abdominal sheath is performed in selected cases to centralize the umbilicus and give balance to the abdominal wall closure.

Fig. 8.14 Photo demonstrating fascial repair following harvest of a left sided MS TRAM.

In some cases of bilateral MS- or free TRAMs, a small mesh inlay may be necessary. The fascial defect is repaired with a soft polypropylene inlay mesh using interrupted 0 polypropylene sutures. The size of the mesh is tailored to exactly replace the amount of fascia harvested with the flap (Fig. 8.15). The patient is then put into a semi-fowler’s position to take the tension off the abdominal skin during skin closure. The upper abdominal skin flap is advanced and sutured to the lower abdominal flap using multi-layered closure over two closed suction drains. A new umbilical opening is made using a small vertical elliptical excision on the abdominal wall and the umbilicus is retrieved and closed at its new position. In a younger and thinner patient, creation of some superior hooding of the umbilicus is advantageous. With the abdomen closed, the patient can now be placed in an upright position in the bed and flap inset can take place.

Fig. 8.15 Photo demonstrating bilateral polypropylene mesh inlays for repair of fascial defects following a bilateral free TRAM harvest.

5 Flap inset

The first step of flap inset is to inspect the anastomosis and ensure that the pedicle is in a position free of twisting, kinking or tension. Flap inset then takes place with the patient in an upright position in the bed. Whether in the case of a delayed or immediate reconstruction, we routinely recreate the fold using 0 silk sutures when the IMF has been violated.

Once the mastectomy pocket is adequately developed, the TRAM flap can be tacked in place to shape the breast mound. The TRAM flap that is anastomosed to the internal mammary vessels must now be rotated another 90° such that Zone III is now directed at the clavicle and Zone IV is directed at the feet (Fig. 8.12) When the pedicle is anastomosed to the thoracodorsal vessels, the flap has already assumed a vertical position on the chest, therefore no additional flap rotation is necessary for the final inset (Fig. 8.13). In a unilateral breast inset, the corner of Zone III is trimmed and then tucked under the superior mastectomy flap to add superior pole fullness and minimize any superior hollowing. Zone IV is completely amputated and Zone II is trimmed to match the volume of the reconstructed breast to the opposite breast (Fig. 8.16).

Fig. 8.16 Drawing demonstrating the vertical inset of the flap within the mastectomy defect. Zone III is trimmed to form a rounded edge and Zone IV is completely amputated from the flap and discarded.

Tacking sutures are then used to secure the flap to the chest wall with interrupted 2-0 Vicryl sutures. When insetting the TRAM flap, the first and most important tacking suture is at the most superomedial aspect of the breast mound (Fig. 8.17). Tacking sutures are then placed along the sternal border to ensure a medial flap inset position, and these are followed by superior tacking sutures to create an upper breast pole. Superolaterally, the TRAM flap should be sutured to the remaining soft tissues anterior to the axillary fold to avoid an unsightly dysjunction between the axilla and breast. These insetting sutures are important to obtain and maintain breast mound shape. Over-zealous use of these shaping sutures, however, must be avoided as fat necrosis can result beneath these sutures. Controlling the lateral aspect of the TRAM flap can help to increase breast projection by the use of sutures to effectively roll the lateral TRAM tissue under itself (Fig. 8.18). The inferior pole of the breast is simply folded and tucked above the recreated IMF to create a natural ptotic breast.

Fig. 8.17 Drawing of the key tacking sutures between the TRAM flap and pectoralis fascia.

Fig. 8.18 Intraoperative photo of the final TRAM inset illustrating the importance of controlling the lateral aspect of the breast to increase projection.

Once the tacking sutures are in place, the mastectomy skin envelope is draped over the TRAM flap and tailor tacked with temporary staples to address the breast skin envelope. In immediate breast reconstructions this step is relatively straightforward as the skin envelope is supple and in ample supply. Once viability of the mastectomy flaps is assessed, most of the TRAM skin island can be de-epithelialized and buried under the mastectomy flaps. Any questionable areas of vascularity on the mastectomy flap must be removed. Furthermore, in the initial postoperative period as the flap swells, it may exert pressure on mastectomy flap to cause further compromise of the mastectomy flaps.

In the setting of delayed reconstruction, particularly with radiation-induced changes present, the skin envelope can be very poor in quality and relatively inelastic. We address this by replacing the inelastic and damaged skin flaps with as much TRAM skin island as possible (Fig. 8.19). In order to adequately fit the TRAM flap under a tight upper mastectomy skin flap, several vertical-releasing incisions can be used in the superior mastectomy flap to release the constriction band in the junction between the mastectomy flap and TRAM flap. When relaxing incisions are not made at the time of the primary surgery, the tight band between the mastectomy flap and TRAM flap does not settle or become subtle over time (Fig. 8.20).

Fig. 8.19 A Preoperative photo of a patient presenting for a delayed TRAM reconstruction. B Postoperative photo following MS TRAM reconstruction. Note the entire radiated lower mastectomy was excised and replaced with healthy TRAM skin.

Fig. 8.20 Photo demonstrating the constriction band in junction between superior mastectomy flap and TRAM flap. This deformity did not settle in time as seen in this photo taken months after the primary reconstruction. This would have been better treated with vertical releasing incisions between the tight mastectomy flap and TRAM skin island.

A drain is always placed in the inferolateral aspect of the breast in its most dependent position. A hand-held Doppler is used to find and mark an arterial signal on the exposed TRAM skin island that is routinely used for postoperative monitoring. Xeroform gauze (Sherwood Medical, St. Louis, MO) is loosely laid over the incisions and no constricting bandages are placed on the patient.

Summary of the operative steps for unilateral MS TRAM

1 MS TRAM harvest

1. Upper abdominal flap is elevated to xiphoid sternum centrally and costal margins laterally.

2. Lower abdominal incision is only made after tension-free closure is confirmed with OR bed flexed.

3. TRAM skin flap is elevated from lateral to medial to isolate the lateral row perforators.

4. Once recipient vessels are dissected, then the use of either a contralateral TRAM for IMA or ipsilateral TRAM for TD anastomosis can be determined.

5. Skin island contralateral to the pedicled side is rapidly elevated off the anterior rectus sheath to the midline.

6. Medial row perforators are isolated on the side that the TRAM is based.

7. The decision is made on the use of either MS TRAM or DIEP flap (see section on Patient Selection).

8. The dominant perforators to retain with flap are identified and fascial incision bordering these perforators is marked.

9. Medial anterior rectus sheath incision is made first followed by intramuscular dissection to visualize the medial branch of pedicle and retain it with the flap.

10. Rectus muscle is divided at the superior border of the flap.

11. Once lateral branch of pedicle is visualized on undersurface of the muscle, lateral rectus sheath incision is made and intramuscular dissection is performed just lateral to the lateral branch.

12. Rectus muscle is elevated from posterior rectus sheath in a cephalic to caudal direction leaving a strip of muscle medially and laterally.

13. The deep inferior epigastric pedicle is identified beneath the transversalis fascia and dissection is carried directly on the pedicle.

14. Pedicle is traced into the pelvis until sufficient pedicle length is achieved or until deep inferior epigastric vein reaches adequate caliber.

15. Pedicle is only divided once recipient vessels are completely prepared.

2 Recipient vessel dissection

1. If TD vessels are chosen, then vessels are prepared from the serratus anterior branch to at least 5 cm proximal of this point to allow vessel mobilization.

2. If IM vessels are chosen, the pectoralis muscle flap is elevated from the third rib and a small piece of the third rib costal cartilage is removed. IM vessels are prepared through the entire rib interspace.

3 Vessel anastomosis

1. For anastomosis to the IM vessels, the flap is rotated 180° such that the pedicle is exiting from the superior border of the flap and aligned with the recipient vessels free of twist or kink.

2. For anastomosis to the TD vessels, the flap is rotated 90° such that the pedicle is exiting from the lateral aspect of the flap.

3. Flap is secured to the chest with staples during the microanastomosis.

4. Arterial anastomosis is performed first using 9-0 Nylon.

5. Venous anastomosis is then performed using the largest microvascular coupler that it can accommodate.

4 Abdomen closure

1. For a unilateral MS TRAM flap harvest, anterior rectus fascia is closed primarily using 0-Ethibond sutures and a running 2-0 PDS suture.

2. Contralateral plication of the anterior rectus sheath is performed if umbilicus centralization is necessary.

3. Patient is placed in a semi-Fowler position while the abdominal skin closure is performed using a multi-layered closure technique.

5 Breast inset

1. Surgical anastomosis is inspected to ensure that the pedicle remains in a position free of twisting, kinking or tension.

2. Flap insetting takes place with the patient sitting in an upright position.

3. IMF is assessed and reinforced if violated by the mastectomy.

4. For anastomosis to the IM vessels, a final 90° rotation is necessary for the flap to assume a vertical position on the chest.

5. For anastomosis to the TD vessels, flap has already assumed a vertical position and no further rotation is necessary.

6. The first tacking suture is placed between the flap and the most superomedial point of the mastectomy space. This is followed by tacking sutures along the sternal border and then along the superior border to facilitate a flap inset that is adequately medial and superior.

7. Zone 4 of the flap is completely amputated and Zone III is trimmed to match the volume of the contralateral breast.

8. Mastectomy flaps are inspected and trimmed back to healthy edges.

9. Mastectomy skin envelope is tailor tacked closed and evaluated for its vascularity.

10. Buried portion of the TRAM flap is de-epithelialized. Skin island of the flap is closed to the mastectomy skin.

11. Skin perforators on the TRAM skin paddle are localized using a hand-held Doppler and marked.

Pitfalls and How to Correct

Case I: Vessel thrombosis

As alluded to earlier under the Operative Technique section, the following are three common mistakes that can lead to vessel thrombosis.

1. One of the most common technical errors leading to thrombosis in the deep inferior epigastric artery is over-zealous traction of the pedicle during its dissection within the depth of the pelvis. In this scenario, arterial thrombosis will occur within the donor arterial lumen despite a patent arterial microanastomosis. An extremely important step to prevent intimal damage to the pedicle is to avoid excess traction on the pedicle during its dissection. The primary surgeon must be acutely aware of the amount of traction applied on the pedicle at all times and frequently check the pedicle for a palpable pulse. Loss of the pulse during pedicle dissection may indicate an intimal injury.

2. A common reason for delayed arterial or venous thrombosis is unintentional twisting or kinking of the vessels (Fig. 8.21). Therefore it is routine at our institution to mark both the superficial surface of both the donor and recipient vessels before they are divided. Prior to performing any vessel anastomosis, vessel orientation is confirmed to ensure that the vessels are lying with the marked side up on both sides of the microvascular double clamps. During venous coupling, the surgeon must be diligent in making certain that the veins are aligned properly on both sides of the coupler.

3. When preparing the IM vessels for microanastomosis, the surgeon must be judicious with the dissection of these vessels. IMA thrombosis can easily result from inadvertent intimal damage sustained during the vessel dissection process. Aggressive clearance of adventitia from the IMA is not recommended. The intima of this vessel is extremely delicate and tears can easily result from traction.

Fig. 8.21 A Photo of delayed venous thrombosis of the flap. B Flap was removed intraoperatively and found to be non-salvageable. C Venous thrombosis.

Case II: Medial and superior hollowness of the reconstructed breast

When preparing the mastectomy pocket prior to inset of the TRAM, the inframammary fold must be inspected. If it has been violated, the fold must be recreated using permanent sutures. An IMF that is obliterated or poorly defined is unsightly and unnatural in its appearance (Fig. 8.22). It is advisable to create the IMF in the primary setting rather than during revisions.

Fig. 8.22 A Frontal view of a patient with a poorly defined medial IMF. B After revision procedure during which the medial IMF was reinforced with permanent sutures.

During the inset of the TRAM, a common mistake is failure to secure the TRAM flap sufficiently superior and medial within the mastectomy defect. Figure 8.23 illustrates a suboptimal aesthetic result of a TRAM reconstructed breast. The patient is dissatisfied with the medial and superior hollowness of the breast (Fig. 8.23).

Fig. 8.23 Photo of a patient with medial and superior hollowness of the reconstructed breast.

A Frontal view demonstrating the superior hollowness of the breast. B Left oblique view showing inadequate flap volume underneath the medial mastectomy flap. C Right oblique view showing an excess volume of flap laterally.

To avoid this pitfall, the first and most important tacking suture is at the most superior-medial pole of the breast mound (see Fig. 8.17). The most difficult revisions of the reconstructed breast mound involve transposing the entire breast mound more medially and superiorly. Therefore this key suture must place the TRAM flap in the mastectomy pocket that is adequately medial and superior from the onset. The next tacking sutures that follow are along the sternal border to ensure a medial flap inset position to provide medial breast volume and desirable cleavage. Superior tacking sutures are then placed with attention directed at creating upper pole fullness that may appear slightly exaggerated at the time of the OR. Superolaterally, the TRAM flap is tacked to the remaining soft tissue anterior to the axillary fold. As all autologous tissue reconstructed breasts descend over time, if this step is not performed, an unsightly disjunction will appear between the axilla and breast (Fig. 8.24).