Thoracoabdominal Flaps for Breast Reconstruction: Different Types and Classification

Abstract

The thoracoabdominal flaps allow the closure thoracic defects with a lower technical difficulty and morbidity compared to remote flaps. In mammary oncological reconstructive surgery, they were used primarily as fasciocutaneous flaps for patients with locally advanced breast cancer (T3 and T4 tumors) that require large skin resections and a fast and effective coverage of the thoracic defect. In recent years, they have resurged as a therapeutic option to solve postoperative complications due to ischemia and skin necrosis with exposure of tissue expanders or breast implants. The increase in the practice of risk-reducing mastectomies (RRM) has led to areas of small skin suffering or necrosis that require local flaps to solve the complication. It is in these indications, where these flaps have an optimal application. In the present study, the thoracoabdominal flaps are presented as a very useful reconstructive technique to cover skin defects in breast surgery complications. A classification is presented to clarify these fasciocutaneous flaps, as well as examples of their applications.

1. Introduction

The reconstruction of breast deformities secondary to procedures for oncological disease is still one of the main challenges of reconstructive plastic surgery. Immediate reconstruction with alloplastic materials is one of the most common alternatives for selected patients, who often prefer this type of surgery over reconstruction with more extensive and complex procedures that involve the use of autologous tissues [1]. However, the resection techniques and the adjuvant treatments for oncological surgery condition (particularly radiotherapy) frequently give a hostile and inadequate adaptation of the organism to implants and tissue expanders, producing in numerous cases the dehiscence of wounds, necrosis of the cutaneous tissues, and the exposure of the alloplastic material, risking the esthetic result of the surgery, and on unfortunate occasions, lead to the failure of the repair technique due to the need for explantation, producing a transient deformity that has a high emotional impact for the patient [2].

The thoracoabdominal flaps are one of the best known and most used flaps in breast reconstruction surgery, particularly in resolving complications.

This chapter details the thoracoabdominal flaps described in the literature, as well as clarifies their planning and rotation. A classification is presented to avoid confusion in the nomenclature.

2. History

The lateral pedicle thoracoabdominal flap or also called the lateral thoracodorsal flap is a rotation/transposition fasciocutaneous flap based on the posterior perforators of the intercostal vessels of the thoracodorsal vessels and was initially described by Hölmstrom and Lossing [3] in 1986. In their publication, the flap is combined with breast implants as an alternative to musculocutaneous flaps for breast reconstruction. The Hölmstrom technique is based on the description of the thoracoepigastric flap described by Cronin [4] and Bohmert [5], a technique that describes a similar flap but with a medial pedicle (based on the perforators of the superior epigastric artery).

The use of this lateral pedicle thoracoabdominal flap has had numerous publications in Scandinavian countries, where there are several publications [6, 7, 8]. In Latin America, although is less widespread, there are works published such as Pontes [9] from Brazil, Carriquiri [10] from Uruguay, and Fullana Sastre from Barcelona [11].

3. Anatomy of the toracoabdominal flaps

When considering the anatomy of the intercostal vessels, it is important to understand its origins. The intercostal vessels form an arcade between the aorta posteriorly and the internal mammary vessels anteriorly.

The arcade is divided into vertebral, costal, and muscular segments. In the lateral area of the thorax, the six, seven, and eight intercostal vessels give lateral anterior perforators (LICAP: lateral intercostal anterior perforator) that provide irrigation to the skin, subcutaneous tissues, and muscular fascias (Figure 1).

Figure 1.

Intraoperative image at the level of the submammary fold in its external area, where the lateral perforator of the intercostal vessels (LICAP) is marked (red arrow).

These perforators supply the anterior region of the thorax and abdomen below the lower outer quadrant (LOQ) of the mammary region. The intercostal vessels continue their internal course below the costal arches and deliver the second anterior perforators. This perforator is called AICAP (anterior intercostal perforator), which supplies the regions of the thorax and abdomen at the level of the lower inner quadrant (LIQ) of the mammary region (Figure 2).

Figure 2.

Intraoperative image of breast reduction surgery, where the anterior perforating vessels of the fifth intercostal artery are observed (AICAP).

These perforators of the intercostal vessels six, seven, and eight can be identified with echo Doppler, although they can constantly be marked in an imaginary vertical line from the submammary fold to the nipple-areola complex. Continuing along the route, the intercostal vessels join to the internal mammary or middle thoracic artery, closing the vascular circuit (Figure 3). This artery is a collateral vessel from the subclavian artery.

Figure 3.

Image obtained from fresh cadaveric dissection, where the second, third, fourth, and fifth intercostal arteries are observed in the direction of joining with the internal mammary artery. The red arrows show the perforators.

In this thoracoabdominal area below the lower internal quadrant of the breast, the middle thoracic artery delivers perforators at the level of the sixth costal arch and subsequently delivers perforators that cross the rectus abdominis muscle. In this area, the internal mammary artery changes name to the superior epigastric artery. These perforators supply the central part and lower inner quadrants of the thoracic region and upper hemiabdomen, making the MICAP perforators (Middle Intercostal Anterior Perforator) (Figure 4).

Figure 4.

Image where the first perforator of the superior epigastric artery is identified with a red arrow. This perforator comes from the internal mammary artery that changes its name when it crosses the diaphragm. The perforator of the sixth intercostal artery provides irrigation to the innermost sectors of the lower region of the thorax (MICAP) (yellow arrow). Anatomically, the perforators of the epigastric artery do not join the intercostal vessels.

It should also be mentioned that the lateral irrigation of the thorax and upper hemiabdomen receive irrigation from the lateral thoracic artery, which comes from the axillary artery, and delivers two to three perforators in its lower part, creating perforators called LTAP (lateral thoracic artery perforator) (Figure 5). These perforators supply the skin, subcutaneous tissue, and muscle fascia at the level of the midaxillary line in the region of the sixth, seventh, and eighth ribs.

Figure 5.

Intraoperative image of breast reconstruction showing the lateral thoracic artery perforator, base of the fasciocutaneous flap LTAP.

In conclusion, the area of the chest wall beneath the inframammary fold and upper abdominal area can be divided into four regions. Medially, the medial intercostal artery perforator (MICAP) is present; centrally, the AICAP is present, and laterally, the LICAP and the LTAP are present.

4. Surgical variants

The following table classifies the fasciocutaneous flaps of the upper hemiabdomen and lower parts of the thorax. Different thoracoabdominal flaps and their surgical variants are listed.

5. Classification

5.1 Fasciocutaneous flaps of the upper hemiabdomen and lower part of the thorax

• TYPE I: Lateral Thoracoabdominal Flaps.

  • I A: Anterior rotation base (based on the TLAP).

  • I B: Posterior rotation base (based on the LICAP).

• TYPE II: Medial Thoracoabdominal Flap or Thoracoepigastric Flap (based on the MICAP and 1st SEP).

• TYPE III: Thoracoabdominal Island Flaps.

  • III A: Lateral rotation base (based on the LICAP).

  • III B: Medial rotation base (based on the MICAP).

• TYPE IV: Thoracoabdominal Dermofat Flaps.

  • IV A: Lateral rotation base (based on the LICAP).

  • IV B: Medial rotation base (based on the MICAP).

5.1.1 TYPE I: Lateral thoracoabdominal flaps

See Figure 6.

Figure 6.

TYPE I A: Anterior rotation base (based on the TLAP). Red dot indicates the location of perforating artery.

See Figure 7.

Figure 7.

TYPE I B: Posterior rotation base (based on the LICAP). Red dot indicates the location of perforating artery.

5.1.2 TYPE II: Medial thoracoabdominal flap or thoracoepigastric flap

See Figure 8.

Figure 8.

TYPE II: Medial Thoracoabdominal Flap or Thoracoepigastric Flap (based on the MICAP and 1st SEP: red dot).

5.1.3 TYPE III: Thoracoabdominal Island flaps

See Figure 9.

Figure 9.

TYPE III A: Lateral rotation base (based on the LICAP). Dotted lines indicate desepidermized area. Circular zone indicates the skin area to be transposed.

See Figure 10.

Figure 10.

TYPE III B: Medial rotation base (based on the MICAP). Dotted lines indicate desepidermized area. Circular zone indicates the skin area to be transposed.

5.1.4 TYPE IV: Thoracoabdominal dermofat flaps

See Figure 11.

Figure 11.

TYPE IV A: Lateral rotation base (based on the LICAP). Dotted lines indicate desepidermized area.

See Figure 12.

Figure 12.

TYPE IV B: Medial rotation base (based on the MICAP). Dotted lines indicate desepidermized area.

6. Fasciocutaneous flaps of the upper abdomen and lower part of the thorax

6.1 Clinical cases

6.1.1 TYPE I: Lateral thoracoabdominal flaps

The lateral thoracoabdominal flap or type I is a local flap that allows elevation and rotation of the skin, subcutaneous tissue, and fascia surface from the upper abdomen and lower part of the thorax. It is supplied by the perforators of the arteries tributaries of the lateral thoracic artery and the intercostal artery. It is a very versatile flap that allows to resolve local complications of the lower outer quadrant (LOQ) and/or medial region of the breast [12].

The initial description, as well as in most of the published works, uses the skin and subcutaneous tissues with the inner fascia (Superficial Fascia System — Fascia of Scarpa) provided from the lateral and posterior region of the thorax. In this way, the flap has an anterior base and rotates 90 degrees from back to front (CASE 1 and 2). The flap can also be used but with a posterior base. In this case, it provides tissues from the anterior region of the upper abdomen (CASE 3, 4, AND 5). It is, therefore, according to our classification, there are two variants of the lateral pedicle thoracoabdominal flap (Figures 13–16).

Figure 13.

TYPE I A: I A: Anterior rotation base (based on the TLAP).

Figure 14.

36-year-old patient with right breast reconstruction in another institution. The patient was hospitalized in our hospital and immediately removed the expander. The TYPE I A flap was designed and applied in the area of the surgical defect. Three months later, an anatomically shaped implant was placed, and risk-reducing mastectomy (RRM) was performed in the left breast. Postoperative control images 1 year after the procedure.

Figure 15.

TYPE I B: Posterior rotation base (based on the LICAP).

Figure 16.

66-year-old patient with left mastectomy and risk-reducing mastectomy were performed on the right breast. A well-defined area of skin necrosis in the right breast was observed after 10 days. No signs of infection. A TYPE IB thoracoabdominal flap was planned, preserving the implant placed in the first surgical procedure. Images were taken at 6 months with reconstruction of bilateral nipple-areola complexes and solution of the skin defect.

6.1.2 TYPE II: Medial thoracoabdominal flap or Thoracoepigastric flap

The thoracoabdominal axial flap to the medial pedicle or also frequently called “thoracoepigastric flap” is presented as an option for the local reconstruction of lesions in the lower inner quadrant (LIQ) of the breast. Its irrigation is given by the perforator of the middle thoracic artery, generally the sixth perforator, and perforators of the superior epigastric artery.

This flap exclusively has a base of rotation directed from the epigastrium, which is why it has no variants. It is a flap that allows the use of tissues from the upper hemiabdomen and contributes tissues to defects in the middle of the breast, especially to central areas and lower internal quadrants.

See Figure 17.

Figure 17.

TYPE II: Medial Thoracoabdominal flap or Thoracoepigastric flap.

See Figure 18.

Figure 18.

68-year-old patient with 10 years postoperative right mastectomy for breast carcinoma and risk-reducing mastectomy of the left breast. She presented capsulitis with an inferior infection process and a tendency to decubitus of the implant placed. It was decided to remove the implant, toilette the area, plan a TYPE II thoracoepigastric flap, and place a new breast implant. Images obtained at 3 months with resolution of the problem.

6.1.3 TYPE III: Thoracoabdominal Island flaps

The thoracoabdominal island flap is described by Rose and Svensson [13] for small defects circumscribed to the inferior-external quadrant (Variant III A) and the inferior-internal quadrant (Variant III B). The length-to-width ratio of the flap should not be greater than 2:1 because it is an axial flap. The defect caused by the cutaneous island must be covered by an abdominal flap detaching to the subdermal plane.

The design of the island must be calculated, as well as the length of the flap, which should normally be 5 centimeters longer than the distance between the base and the defect to allow for the resulting bulging of the flap transposition and loss in distance due to rotation.

This flap is very effective in salvaging exposed implants after reconstructive surgery when the area is small and in the lower quadrants.

See Figure 19.

Figure 19.

TYPE III A: Lateral rotation base (based on the LICAP).

See Figure 20.

Figure 20.

44-year-old patient with bilateral breast reconstruction. Right breast reconstructed with a latissimus dorsi flap and anatomical breast implant and left risk-reducing mastectomy (RRM). Circumferential necrosis is observed at 6 months in the left breast (the patient applied heat to the area). A type III A flap is placed to cover the localized skin defect. Remote result at 6 months.

See Figure 21.

Figure 21.

TYPE III B: Medial rotation base (based on the MICAP).

See Figure 22.

Figure 22.

40-year-old patient with breast reconstruction due to right breast cancer. An area of cutaneous distress is observed in the right breast. Implant close to exposure. A type III B flap is placed on the medial pedicle to cover the localized skin defect. Remote result at 6 months.

6.1.4 TYPE IV: Thoracoabdominal dermofat flaps

The thoracoabdominal dermo-fat flap with a lateral pedicle (Variant IV A) and a medial pedicle (Variant IV B) is a procedure developed by Kijima [14] with a medial pedicle. In the literature, lateral adipose tissue with a medial pedicle in obese patients for bilateral reconstructions is described [15]. The lateral pedicle variant is proposed for selected cases that have correct skin coverage but present esthetic asymmetries with the contralateral breast. It allows greater coverage of the implant and a more natural appearance of the breast. This technique can be complemented with the use of fat grafting (lipofilling), widely used in breast reconstruction to achieve better symmetry, and thus obtain a better esthetic result.

No previous publications have been reported on the use of this lateral pedicle flap. There is a dermo-fat flap in the literature, described for the first time by Rose [16] and later expanded by Irwin et al. [17], to increase the submuscular pocket, thus creating a composite dermal flap, which is sutured to the free edge of the pectoralis major. The authors describe it as a myodermal flap. It consists of the use of de-epithelialized skin from the lower part of the breast.

The adipose tissue is used, as well as the dermis of the upper abdomen to the lateral pedicle to give better thickness to the lower quadrants of the breast. Unlike fat grafting, this procedure is a flap, which ensures greater survival of adipose tissue. It is a simple technique, and when it is performed in selected patients, the resulting scar is cosmetically acceptable.

See Figure 23.

Figure 23.

TYPE IV A: Lateral rotation base (based on the LICAP).

See Figure 24.

Figure 24.

51-year-old patient with bilateral breast reconstruction. Left mastectomy was performed with immediate implant placement. Right breast underwent risk-reducing mastectomy (RRM). An area of cutaneous suffering is observed in the right complex. Exposure and removal of the implant. A type IV A flap is placed on the lateral pedicle to provide a better cover over the implant to be placed. Remote result at 180 days with the reconstruction of both complexes.

See Figure 25.

Figure 25.

TYPE IV B: Medial rotation base (based on the MICAP).

See Figure 26.

Figure 26.

59-year-old patient with left mastectomy and risk-reducing mastectomy (RRM) in the right breast. A right latissimus dorsi flap and a type IV B left thoracoabdominal flap were made to fill the defect in the lower outer quadrant of the mammary area.

7. Discussion

The thoracoabdominal flaps and variants have been widely used in the field of plastic surgery since, being local flaps, they provide tissue with a similar coloration and texture. They constitute an excellent alternative for the resolution of complications derived from reconstruction surgery with implants since they are remarkably versatile with reliable vasculature, do not involve a sacrifice of muscular structures, and allow an adequate esthetic result [18].

Adequate knowledge of the mechanisms of rotation and sliding of skin tissues is necessary to indicate the use of these types of flaps and to perform them [19, 20]. These flaps make it possible to obtain good results in many patients through a technique that is quick to perform and has a short postoperative stay, especially when compared with other flaps, such as the latissimus dorsi flap or the anterior rectus flap (TRAM, DIEP).

8. Conclusion

The thoracoabdominal flaps are one of the best known and most used flaps when appears a skin necrosis in breast surgery. This publication demonstrates the benefit of using these flaps in complications of breast reconstruction surgeries. A classification is presented to avoid confusion in the nomenclature and two unusual variants of these flaps are exposed (the thoracoabdominal island flap and the thoracoabdominal dermal-fat flap).

The thoracoabdominal flaps have allowed to successfully solve, on numerous occasions, complications that occurred after breast reconstruction.

Conflict of interest

No conflict of interest.