Pectoralis major

The pectoralis major muscle originates from the medial clavicle and lateral sternum and inserts on the humerus (Fig. 57.1). The major blood supply is thoracoacromial artery in addition to the intercostal perforators. The medial and lateral anterior thoracic nerves provide innervation for the muscle. The action of the pectoralis major is to flex, adduct, and rotate the arm medially. This muscle becomes important when additional soft tissue coverage is needed for an implant both in an aesthetic as well as a reconstructive setting.

Fig. 57.1 Anatomy of chest wall musculature.

Serratus anterior

The serratus anterior muscle runs along the anterolateral chest wall. Its origin is the outer surface of the upper borders of the first through eighth ribs and inserts on the deep surface of the scapula (see Fig. 57.1). Its vascular supply is derived equally from the lateral thoracic artery and branches from the thoracodorsal artery. The long thoracic nerve serves to innervate the serratus anterior, which acts to rotate the scapula, raising the point of the shoulder and drawing the scapula forward toward the body. To completely cover the implant with muscle in reconstructive surgery, often the serratus anterior must be elevated sharply to obtain the necessary coverage.

Latissimus dorsi

The latissimus dorsi muscle, which is a mirror image of the pectoralis major, arises from the lower thoracic vertebrae, the lumbar and sacral spinal processes, and the iliac crest. Its large, flat muscle belly converges into a flat tendon that inserts into the lesser tubercle of the humerus. The thoracodorsal artery provides the dominant vascular supply to the flap (Fig. 57.2). The subscapular artery originates from the axillary artery, gives off the circumflex scapular artery, and terminates in the thoracodorsal artery. This vessel, located in the posterior aspect of the axilla, gives off one or two serratus branches before entering the anterior undersurface of the latissimus dorsi muscle. The thoracodorsal artery is accompanied on its course by the thoracodorsal nerve and veins. The structures can be injured during an aggressive axillary dissection and therefore assessment of the pedicle in these patients is important in the preoperative planning.

Fig. 57.2 The blood supply to the latissimus dorsi muscle.

Rectus abdominus

The paired rectus abdominis muscles originate from the cartilage of the sixth, seventh, and eighth ribs and insert into the pubic tubercle and pubic crest (Fig. 57.3). The blood supply comes from the superior epigastric artery above and deep inferior epigastric artery below (Fig. 57.4). Within the muscle these main vascular sources may not have direct anastomoses with each other under normal physiologic conditions. Although the deep inferior epigastric system has been shown to be the primary vascular pedicle for this skin territory, the superior epigastric artery and vein are able to carry the lower abdominal soft tissue and comprise the vascular basis for the transverse rectus abdominis flap (Fig. 57.5). Additional blood supply is from the posterior perforating vessels accompanying the eighth through twelfth sensory and motor nerves. The musculocutaneous perforators that supply the flap are centered in the perumbilical area and emerge through the medial half of the rectus muscle to supply the subdermal plexus superficial to it (Fig. 57.6). Patient selection is important for this operation. Patients with an obese, pendulous abdominal panniculus, diabetics, and smokers carry a much higher risk of flap loss.

Fig. 57.3 Anatomy of the rectus sheath above and below the arcuate line.

Fig. 57.4 Vascular anatomy of superior and inferior deep epigastric artery and venae comitantes below the skin island.

Fig. 57.5 Vascular anatomy of the deep epigastric system.

Fig. 57.6 Circulatory zones of the TRAM flap.

Expander/implant reconstruction

Simple placement of an implant beneath the soft tissues of the chest can provide a breast mound of acceptable shape and volume in women with small to moderate sized breasts. By placement of the implant beneath the muscles of the chest wall, an additional layer of healthy tissue is interposed between implant and the mastectomy flaps. This serves to soften the contours of the reconstructed breast and decrease the incidence of complications. When planning a submuscular reconstruction, the inframammary fold on the contralateral side is marked and the mark is transposed to the side of the reconstruction. A second mark is made approximately 2 cm below the first mark, which becomes the lower extent of the pocket dissection. If the submuscular pocket is not made lower initially, the implant generally ends up too high. A true submuscular pocket consists of pocket being dissected deep to the pectoralis major, serratus anterior laterally to the level of the anterior axillary line and the rectus abdominis fascia (Fig. 57.7).

Fig. 57.7 Expander-implant reconstruction. A, Markings. Determine inframammary line at time of mastectomy or, in delayed reconstruction, on the basis of the opposite inframammary position. B, Expose superficial surface of pectoralis major muscle. C, Release pectoralis major muscle from origin at inframammary line or sixth intercostal space and along sternum from fourth to sixth intercostal spaces. D, After a subpectoral space is prepared for expander insertion, rotate pectoralis major muscle laterally to the anterior axillary line.

When the total muscle coverage of the prosthesis is not possible, the use of allogenic tissue supplements avoids the problems of autogenous tissue coverage and provides camouflage, thus decreasing rippling, reinforcing the capsulectomy or capsulotomy, and increasing soft tissue padding (Fig. 57.8).

Fig. 57.8 Complete device coverage with pectoralis major and acellular dermal matrix (ADM).

The use of acellular dermal matrix (ADM) in breast reconstruction is of particular interest to plastic surgeons, especially in patients at high-risk for post-mastectomy complications. The rising demand has spurred tremendous growth in the number of available ADMs. Published research regarding the use and efficacy of acellular dermal matrices in immediate breast reconstruction is growing but hasn’t kept pace with the market explosion. The many features and indications of all ADMs can confound the decision making process for surgeons who want to incorporate ADMs in their treatment armamentarium. From our extensive experience using multiple products it has become clear to us that the use of ADM in breast reconstruction has several advantages. There is less rippling due to additional soft tissue coverage that is achieved with ADMs. In addition, a controlled pocket can be created with complete device coverage and full control of the inframammary fold position. From our revisionary breast surgery data we have found that ADMs play an important role in the management of capsular contracture. Changing the implant interface environment is going to be one of the critical points in ameliorating capsular contracture.

Following complete coverage of expander with ADM or autologous tissue, intra-operative fill is enough to flatten the base of the expander, remove any wrinkles, and in general gain as much ground as possible without putting undue pressure on skin flaps or wound closure. Isotonic saline is used to fill the expander (Fig. 57.9). Percutaneous expansion is begun one to two weeks postoperatively or as soon as wound appears ready. Expansion can be done every week based on tissue and patient tolerance. Although there is a variation in injecting volumes, the average is around 50–100 mL per expansion. The expander is usually filled to a volume 10%–30% greater than that which seems necessary. The total expansion time is usually a period of 2–6 months. Recently we have started utilizing the use of botulism toxin to paralyze the pectoralis major to decrease pain and facilitate expansion. This study is currently in progress and we are seeing early encouraging results with decrease visits to the office, less narcotic use and enhanced expansion in a period of 4–8 weeks.

Fig. 57.9 A, Place expander beneath pectoralis major muscle flap with inferior edge of expander located at inframammary line. Suture lateral edge of pectoralis major flap at anterior axillary line. B, Expander is generally inflated with 50 to 100 mL of saline before insertion. A closed suction drain is generally inserted through the lateral chest wall incision. Note that total muscle coverage is not provided by this technique. The inferior central skin envelope is directly over the expander. If skin viability is questionable, do not release inferior pectoralis muscle or add rectus abdominis-external oblique segmental flap. C, Lateral view demonstrates position of expander with relationship to inframammary line. D, Expander port patency is checked after skin closure to ensure that the port is accessible and patent.

Significant technical advances have been made in the expansion devices since their introduction. Shaped expanders create a more anatomic breast mound than a round device and to some degree, minimize the upper chest deformity during expansion. The silicone texturing of tissue expanders may prevent two of the biggest problems with expansion; formation of contractile capsule around expander causing expander displacement and need to create an inframammary fold. Formation of capsular contracture causes pain and limits the level of expansion leading to chest wall concavity upon removal and capsulectomy. The volume of the expander is related to the patient’s overall size and size of the opposite breast and it is best selected by the base width of chest wall rather than selecting a device based on volume.

Surgeons differ in their preference of prostheses for breast reconstruction. The options include silicone gel versus saline implants with either smooth or textured surfaces. Recent advances in prosthesis design have resulted in anatomically shaped textured devices that provide significant improvements in overall breast shape. All anatomical implants are textured. Anatomical devices filled with saline or less highly cohesive silicone gel, when held in place through texturing, suffer from upper pole collapse, resulting in a loss of benefit of the anatomical shape and a likelihood of upper pole rippling. The form stable highly cohesive gel anatomical implants provide an anatomical option with a filler material that maintains its shape in an upright position. The use of cohesive gel implants outside of the United States has changed the reconstructive era. In an attempt to find an implant that could adapt to a variety of chest dimensions and breast shapes, these implants were first introduced into Europe in 1993. Based on previous work by Tebbetts and Maxwell on biodimensional principles of breast surgery, the 3 × 3 cohesive gel matrix was introduced in 1997. The matrix has undergone modifications and being currently reviewed by the F.D.A. for approval in the U.S. Cohesive gel implants have the potential for providing a natural breast shape, minimizing the risk of postoperative rippling, and providing a greater degree of safety should the implant lose its integrity. We believe that this implant will add an additional option to the plastic surgeon’s armamentarium, striving to achieve natural aesthetic breast shapes both in reconstructive and aesthetic procedures.

Autogenous reconstruction

This category of reconstruction has become sophisticated over the last 20 years with the introduction of the perforator flaps by Allen. Microvascular breast reconstruction has served as a backup procedure for more difficult or unusual situations. Sine the introduction of the perforator flaps however, surgeons are starting to offer them as the primary procedure. The technical details of each procedure are beyond the scope of this chapter and recommend referral to a microsurgical textbook.

The pedicled and free TRAM flaps have the tremendous theoretical advantage of creating a breast mound composed of autogenous tissue without the need of prostheses and producing an abdominal lipectomy in the donor area (Fig. 57.10). Its disadvantage is that it is an operation of greater magnitude with a longer postoperative recuperation time than other techniques.

Fig. 57.10 Standard single-pedicle TRAM flap utilizing the muscle contralateral to the mastectomy defect. Only that portion of the muscle noted is raised with the flap.

The procedure is begun in the supine position and measurement of the tissue deficits and necessary flap dimensions are helpful. The inferior abdominal incision is made and carried to the level of rectus fascia. An incision in the anterior rectus sheath (on the side of the flap) is made and the deep inferior epigastric vessels are identified and tied off near their origin (in case need for conversion to free flap or supercharging). Whether a contralateral or ipsilateral flap is chosen, this is left to the surgeon’s preference and the patients underlying surgical history. The upper incision of the transverse skin island is made, and the upper abdominal panniculus is elevated above the costochondral cartilages (Fig. 57.11). The arterialized side of the flap is then elevated to halfway across the anterior rectus fascia. The muscle is then identified through the fascial incision and divided and care is again taken to preserve length on the deep inferior epigastric vessels. A sterile Doppler is then utilized to determine the location of the superior epigastric blood vessels along the deep surface of the rectus muscle. The lateral 40% or more of the rectus muscle and fascia can be preserved as well as a portion medial to the umbilicus. The lateral muscle slip may remain innervated. After incision around the umbilical stalk, the remaining central portion of the rectus abdominis muscle with its overlying fascia is delivered from the sheath to allow the flap to be suspended on its superior epigastric blood supply. Some surgeons prefer to remove the entire muscle. The chest skin flaps are elevated to create and adequate pocket and a connecting wide tunnel is made medially with the abdominal dissection over the sternum. The flap is carefully passed through this tunnel to the chest wall (Fig. 57.12). Care is taken to avoid any undue tension or torque on the vascular pedicle. Abdominal reconstruction can be accomplished by primary closure of the remaining medial anterior rectus muscle and sheath to the remaining lateral muscle and sheath. Additional options for reconstruction of the abdomen may be with marlex or praline mesh or acellular human dermis as either onlay or inlay depending on the condition of the fascia and whether additional reinforcements are necessary. The table is then flexed and procedure is completed as in abdominal lipectomy.

Fig. 57.11 The rectus muscle is split longitudinally, including only the muscle that carries the medial and lateral perforator rows in the TRAM flap.

Fig. 57.12 Vertical orientation for breast mount contouring using a contralateral single-muscle TRAM flap: applies to single- or double-pedicle flaps.

The latissimus dorsi musculocutaneous flap has provided a consistently reliable method of breast reconstruction. Its main advantage is its ability to supply additional vascularized muscle and skin to breast mound in a predictable fashion during a single operative procedure. Its disadvantages include the creation of new chest scars plus a back donor scar and the fact that the transfer of autogenous tissue from the back does not eliminate the need for in an implant. Generally even with the extended latissimus dorsi flap an implant is necessary for final symmetry. We believe that the benefit of this flap is mainly to enhance any implant reconstruction by changing the entire quality of pocket, whether it is due to radiation damage, surgical damage, or the paucity of tissue. This adds the additional vascularized tissue that is needed for an improved reconstruction. Generally we do not consider the latissimus dorsi musculocutaneous flap (extended) as a primary option for autogenous reconstruction. In order for a patient to have enough soft tissue form the donor site adequate for the reconstruction, this equates to higher BMI patient group, which could result in higher complication rates of donor sites.

After preoperative markings in the upright position the procedure is begun with the patient in the lateral decubitus position. The flap is elevated from distal to proximal. The latissimus dorsi tendinous insertion into the humerus can be left or severed (Fig. 57.13). A tunnel is made across the apex of the axilla to pass the flap from the back to the front. Drains are inserted in the back and after donor site closure the patient is turned to the supine position. A subpectoral pocket is then created and the flap is redraped in the desired position. The upper latissimus muscle is sutured to the lower pectoralis major muscle (Fig. 57.14). The skin island is carefully tailored and the inframammary fold formed by suturing it in position (Fig. 57.15). An appropriately sized implant, expander-implant, or expander is selected and placed submuscular followed by suction drains.

Fig. 57.13 Technique for latissimus dorsi musculocutaneous flap. A, Elevation of the latissimus dorsi musculocutaneous; Patient positioned in lateral decubitus position. Posterior chest (flap donor site) and anterior chest (breast mound reconstruction site) are included in the operative field. B, Incision around skin island allows dissection to expose anterior surface of latissimus dorsi muscle. C, Latissimus dorsi fibers of origin from lumbosacral fascia and vertebrae are divided. D, Deep surface of muscle is exposed. Care is taken to avoid flap dissection deep to the serratus anterior muscle. The latissimus muscle is separated from the underlying serratus anterior, with dissection starting posterior where the muscle plane is easily identified. E, Final mobilization of the latissimus dorsi muscle is separation from congenital adhesions with adjacent musculature at the anterior axillary line. F, Proximal dissection toward latissimus dorsi insertion required for identification and preservation of the thoracodorsal artery, veins, and nerve. A lighted retractor allows visualization of the pedicle while dissection is performed to muscle insertion. G, Complete elevation of the latissimus dorsi muscle with skin island. Thoracodorsal branch to serratus can generally be left intact. H, Incision is made adjacent to inframammary line, and remaining skin envelope and pectoralis muscle are elevated together. A tunnel is made in the superior axilla, and the flap is transposed to the anterior chest. The donor site is closed, and the patient is ready for repositioning in the supine position for flap inset.

Fig. 57.14 Latissimus dorsi musculocutaneous flap inset for delayed breast reconstruction. A, Patient is reprepared and draped in supine position. Flap is placed in axilla while recipient site is prepared. B, Inset of latissimus dorsi musculocutaneous flap for delayed breast reconstruction. Skin envelope is elevated with underlying pectoralis major muscle. Care is required to preserve vascular connection between skin envelope and pectoralis muscle. If the pectoralis muscle is absent (radical mastectomy), skin is elevated from ribs and costal muscles. C, Pocket is formed between pectoralis major muscle and chest wall. Pectoralis major fibers of origin are divided along the inframammary line and at the sternal edge between fourth and sixth intercostal spaces. D, Latissimus dorsi skin island is placed over defect. The patient is placed in the sitting position for final inset of the flap and selection of appropriately sized implant. Implant sizer is beneath latissimus muscle inferiorly and pectoralis major muscle superiorly. E, Lateral mastectomy scar is released and skin island inset to provide inferior skin envelope. The permanent implant is selected on the basis of the sizer and placed in a pocket beneath the pectoralis and latissimus dorsi muscles. F, Release of lateral mastectomy scar will allow skin envelope to drape and demonstrate slight ptosis. G, After release of mastectomy scar laterally, skin island is inset. The distal skin envelope below the mastectomy scar is resected if adequate skin envelope is provided by latissimus skin island. H, Permanent implant is positioned behind latissimus and pectoralis muscles. Superior edge of latissimus muscle is loosely sutured to edge of pectoralis muscle. I, Permanent implant size should be selected on the basis of symmetry to contralateral breast. If the skin envelope appears inadequate despite addition of latissimus dorsi skin island, a tissue expander should be selected with plans to expand the region.

Fig. 57.15 Transposition of flap. The expander pocket is created by anchoring to the latissimus flap.

In the recent surge of conservation therapy, immediate autogenous reconstruction in these patients has increased. In a patient with mammary ptosis, a skin envelope reduction can be performed during lumpectomy and skin flaps closed in the usual inverted T-configuration. The knowledge of several reduction mammaplasty techniques is advantageous, since based on the location of the mass an appropriate pedicle can be designed to preserve the nipple–areolar complex.

Fig. 57.16 NAC A, preoperative view of 36-year-old female following modified radical mastectomy. B, Postoperative view, following left reconstruction with expander and subsequent expansion. C, Final postoperative view, following left silicone implant placement/NAC reconstruction and right augmentation with silicone implant.