Latissimus Dorsi Flap Breast Reconstruction

Key Words

Latissimus dorsi flap, breast reconstruction, progressive tension sutures, quilting sutures, fat compartments, high BMI, breast cancer, fat grafting, seroma formation

Introduction

The latissimus dorsi (LD) flap is a reliable option for primary autologous breast reconstruction and for salvage of failed prior breast reconstruction because of its robust perfusion, consistent vascular anatomy, and concealable donor site scar. However, the traditional LD flap is limited by its volume, and often requires augmentation with either an implant, additional autologous tissue flaps, or fat grafting to obtain the desired shape and volume.

Hokin et al, first described the use of an extended LD (ELD) flap, which incorporated lumbar fat to increase flap volume. In an attempt to avoid using a breast implant, modifications of the ELD by harvesting the entire LD muscle, lumbar fascia, and a large skin paddle have been performed. However, it has been associated with increased morbidity, with risks of wound breakdown, skin necrosis, seroma formation, and significant contour deformities of the back.

Advancements in surgical techniques with the use of progressive tension sutures, quilting sutures, and fibrin sealants to obliterate potential space at the LD and ELD donor sites have decreased rates of seroma formation. ( and demonstrate progressive tension sutures and quilting sutures technique. demonstrates the obliteration of empty space after performing quilting sutures at the donor site). Furthermore, a greater appreciation of the different fat compartments in the back has limited fat harvest to the thoracolumbar and lumbar compartments, thereby optimizing the contour of the back after flap harvest. The selective harvest of these fat compartments provides the patient with an ideal “hourglass” figure, while avoiding the disfigurement associated with parascapular fat harvest, and the fat necrosis with harvest of the distal suprailiac fat. The most versatile tool in volume augmentation and for the correction of contour deformities has been the incorporation of fat grafting of the mastectomy site and the LD flap. Fat grafting can be performed at the time of LD breast reconstruction or as an adjunct procedure during secondary breast reconstruction revision. ( demonstrates intraoperative fat grafting of the LD flap.) Other modifications of the LD flap for breast reconstruction include the endoscopically harvested LD, muscle-sparing LD, and the thoracodorsal artery perforator flap (TDAP).

Indications and Contraindications

The LD flap with fat grafting or with an implant can be an excellent choice for primary reconstruction or for salvage of a previously failed reconstruction.

Please see Box 8.1 for inclusion criteria regarding use of LD flaps for breast reconstruction. We prefer to use the LD flap in combination with fat grafting (without implants) in patients with the following characteristics:

1.

Patient not a candidate for free flap–based breast reconstruction
2.

Previous radiation therapy (XRT)
3.

High BMI (BMI >35–40 kg/m ²) patients
4.

Co-morbidities which preclude long surgical procedures
5.

Conversion of implant-based reconstruction in non–free flap candidates.

Larger breasts can be reconstructed with the augmentation of the LD flap or by harvesting an ELD. The ability to perform fat grafting at the initial reconstruction can help avoid the use of an implant, keeping the reconstruction entirely autologous. The robust vascularity of the flap introduces healthy soft tissue in previously irradiated areas, and can provide excellent soft tissue coverage for implants. There are very few contraindications for the flap, which include:

1.

Previous history of posterolateral thoracotomy
2.

Previous injury to the thoracodorsal pedicle and nerve
3.

Inadequate soft tissue volume at the donor sites (including LD donor site and fat graft donor site).

Box 8.1

Inclusion Criteria for LD-Based Breast Reconstruction

•

Inadequate abdominal soft tissue (skin and fat).
•

Prior abdominal surgery with contraindication for abdominal-based reconstruction (abdominoplasty or previous abdominal-based reconstruction).
•

Medical co-morbidities with “high risk” of complications with prolonged surgical procedures, including personal history of pulmonary embolism or deep vein thrombosis with positive thrombophilia screen.
•

Patient with small to moderate breast volume with standard LD.
•

Patient with large breast volume in high-BMI patients with ELD and fat grafting.
•

Patient’s personal preference.
•

Prior radiation therapy for breast conservation therapy and not candidate for a free flap.

Preoperative Evaluation

Patient History

During the preoperative consultation, the patient’s medical history is critically evaluated for their surgical candidacy. This should always include documentation of surgical history, history of nicotine use, cardiopulmonary health status, personal and family history of coagulopathy, therapeutic use of antiplatelet or anticoagulation therapy, history of general anesthesia associated complications, and body mass index (BMI). A complete breast history should be obtained, including prior breast surgeries (aesthetic and reconstructive), planned tumor extirpation method (nipple-sparing vs skin-sparing vs simple mastectomy), prior or planned axillary lymph node dissection, and plan for adjuvant therapies. Women undergoing delayed breast reconstruction are considered better surgical candidates as they have completed all planned adjuvant therapy, have been disease-free for a period of time, and are at a lower risk for infection, hematoma, and mastectomy skin flap necrosis.

Physical Examination

A thorough physical examination involves evaluating the involved breasts for surgical scars, presence or absence of the nipple–areola complex, radiation-related skin changes and surrounding tissue quality, and relative symmetry with the contralateral breast. The abdomen, flanks and lower extremities should be examined as possible donor sites for free tissue transfer or fat grafting. The soft tissue of the back is evaluated with a “pinch” test to determine the amount of tissue which can be safely harvested without undue tension on donor-site closure ( Fig. 8.1 ). The thoracolumbar and lumbar fat compartments are readily identified by having the patient flex in the ipsilateral direction to create the natural intercompartmental creases ( Fig. 8.2 ). A pinch test can identify the most natural crease for the skin paddle design along the ipsilateral back. The orientation of the skin paddle is designed as needed to match the soft tissue deficit at the mastectomy site. A horizontal skin paddle designed at the low or mid-back results in a well-positioned final scar, hidden within the bra line, and has the highest reported patient satisfaction ( Fig. 8.3 ). Positioning the skin paddle main axis along a natural tissue crease in the back (usually horizontal or horizontal–oblique) will not only allow for a larger skin paddle harvest, but will also facilitate closure.

The functionality and anterior border of the LD muscle is verified by forceful adduction of the arm against the examiner’s hand. This maneuver demonstrates the integrity of function of the LD, and helps identify the anterior border of the muscle. Digital palpation can identify the anterior groove or border of the LD muscle, and the true anterior border of the LD muscle is usually marked 1–2 cm anterior to the palpated groove. The patient should be informed that muscle harvest can occasionally result in weakness with pulling and overhead activities, which might require postoperative physical therapy to help strengthen the shoulder muscles and to improve the range of motion.

Surgical Anatomy

The LD muscle is a Mathes and Nahai type V muscle with a dominant thoracodorsal (TD) artery and secondary segmental blood supply from lateral perforators of the lumbar arteries, and from medial perforators of the intercostal arteries. The pedicle is approximately 8 cm long and with a 2–3-mm arterial diameter. The artery bifurcates into the descending and transverse branches, approximately 5 cm inferior to the posterior axillary line. The descending branch is the dominant branch of the thoracodorsal artery and has larger perforators than the transverse branch, and is the pedicle for the muscle-sparing LD flap ( Fig. 8.4 ).

The four major fat compartments of the back are the parascapular, thoracolumbar, lumbar, and suprailiac fat compartments ( Fig. 8.5 : 2, 3, 4, and 5, respectively). The parascapular fat compartment is superficial to the scapula, and extends inferiorly to the level of T5. This compartment is left intact to avoid postoperative contour deformities. The entire thoracolumbar and lumbar fat compartments are harvested for breast reconstruction with an extended latissimus dorsi flap. The thoracolumbar fat compartment is immediately inferior to the parascapular compartment, and lies between T7 and T10 medially, and the inframammary fold laterally. The lumbar fat compartment is inferior to the thoracolumbar fat compartment and lies between T11 and L4 medially, and to the superior border of the iliac crest inferiorly. The suprailiac fat compartment lies superficial to the iliac crest and can extend up to 5 cm into the gluteal region, but dissection of this compartment is avoided due to potential distal flap fat necrosis (see Fig. 8.5 : 5). For the purpose of this chapter, the LD flap design and harvest do not incorporate any additional fat compartments except for a moderate amount of subcutaneous tissue cephalad to the skin paddle and overlying the descending branch of the LD muscle. This is done to harvest as many perforators along the descending branch as possible. Immediate fat grafting will serve to provide additional volume without the risks of harvesting additional fat compartments, as seen in the traditional extended LD flap.