Key Points

Introduction

For a long time we have been used to seeing the breast as a homogeneous organ with unpredictable location of the neurovascular structures. In the course of numerous clinical breast reductions, nourished by the inferior pedicle¹ I always came across a distinct layer of vascular networks. It emerged from the thoracic wall along the level of the fourth intercostal space and passed through the whole breast within the inferior pedicle to supply the nipple. The vascular layer was caudally attached to a horizontal septum of dense connective tissue.

Anatomical investigations showed that this septum is part of a suspension apparatus, which is attached to the thoracic wall, mainly following the borders of pectoralis major.^2–4 This ligamentous suspension carries the whole weight of the breast like a sling. The horizontal septum takes its origin from the periosteum of the fifth rib and merges medially into a vertical medial ligament, which attaches to the sternum. Laterally, the septum merges into a lateral vertical ligament, which originates from the pectoral fascia at the lateral edge of pectoralis minor (Fig. 14.1). These vertical ligaments continue into the capsule of the breast in an anterior direction (Fig. 14.1). A ligamentous structure also arises from the origin of this deep part of the ligamentous suspension, which inserts into the overlying skin, thereby determining the shape of the breast. This structure can be seen as a densification of Cooper’s ligaments and builds the intermammary sulcus and the cleavage medially as well as the inframammary fold inferiorly. Laterally, it forms a strong ligament heading into the skin of the axilla, the suspensory ligament of the axilla, which shapes the axillary hollow.

Fig. 14.1 Diagram of left breast, anteromedial view.

The deep part of the ligamentous suspension emerging from the thoracic wall is coloured gray, the superficial part inserting into the overlying skin is yellow.

Redrawn from Würinger E, Mader N, Posch E, Holle J. Nerve and vessel supplying ligamentous suspension of the mammary gland. Plast Reconstr Surg 1998;101:1486–500.

The ligamentous suspension is not only important because of its shaping potential. Its main importance lies in the fact that it is the guiding structure of the main nerves and vessels to the nipple. Rising from the thoracic wall, the neurovascular structures attach to the ligamentous sling, while travelling to the nipple, where they build a subdermal plexus. From there the breast tissue is mainly supplied in a retrograde direction. This retrograde supply may be the reason for the possible occurrence of fat necrosis after breast operations.

The neurovascular supply runs along two main pathways, a central source along the horizontal septum, as well as a superficial source along the vertical ligaments merging into the capsule of the breast. The horizontal septum guides a cranial vascular layer, which comprises branches of the thoracoacromial artery as well as a branch of the lateral thoracic artery. The caudal vascular layer consists of cutaneous perforating branches from anastomoses of the intercostal arteries.

Most importantly, the deep branch of the lateral cutaneous branch of the fourth or fifth intercostal nerve (also the main nerve to the nipple), attaches to the caudal vascular layer (Fig. 14.2).

Fig. 14.2 Diagram of left breast, anteromedial view, cranial and caudal vascular layer guided by horizontal septum.

Redrawn from Würinger E, Mader N, Posch E, Holle J. Nerve and vessel supplying ligamentous suspension of the mammary gland. Plast Reconstr Surg 1998;101:1486–500.

The second main path comprises perforating branches from anastomoses of the internal thoracic artery and the anterior cutaneous branches of the second to fourth intercostal nerves along the medial ligament as well as branches of the lateral thoracic artery and the corresponding lateral cutaneous nerve branches along the lateral ligament (Fig. 14.3).

Fig. 14.3 Diagram of left breast, anteromedial view, neurovascular supply guided by vertical ligaments.

Redrawn from Würinger E, Mader N, Posch E, Holle J. Nerve and vessel supplying ligamentous suspension of the mammary gland. Plast Reconstr Surg 1998;101:1486–500.

The ligamentous suspension can be developed easily by blunt dissection along the retromammary space in a caudal direction. At the level of the fourth intercostal space the retromammary space changes its direction to continue as a horizontal plane of loose areolar tissue heading toward the nipple. This areolar tissue provides a pre-existing bipartition of the breast, as it divides the breast and its system of milk ducts into a cranial and a caudal glandular layer. Below this areolar tissue is the horizontal septum (Fig. 14.4).

Fig. 14.4 Vertical sectional view.

The horizontal septum can be found by opening up the retromammary space in a caudal direction.

Redrawn from Würinger E, Mader N, Posch E, Holle J. Nerve and vessel supplying ligamentous suspension of the mammary gland. Plast Reconstr Surg 1998;101:1486–500.

The ability to localize the course of the neurovascular supply of the breast is important for any surgical treatment of this organ; it has allowed maintenance of the neurovascular supply in breast reduction procedures to be more precise.^5–7

Among the many different techniques of breast reduction and mastopexy, two principal groups can be differentiated concerning the neurovascular supply of the nipple-carrying pedicle.

The nipple can be supplied by the vessels running along either of the vertical ligaments, merging into the subdermal plexus along the capsule of the breast, which affords a dermal pedicle to elevate the nipple. These pedicles can be cranial, medial, or lateral pedicles.^8–10

The second big group of pedicles derives its neurovascular supply via the horizontal septum by a central parenchymal pedicle. These are the central and inferior pedicle techniques such as the techniques of Georgiade,¹ Levet,¹¹ Hester,¹² or McKissock.¹³ Combining those two main neurovascular sources is possible.

Patient Selection

The technique could be offered to patients with large and ptotic breasts, to elderly patients, to smokers and obese patients, to pre-irradiated breasts, and to patients with weak connective tissue. Because of its safe neurovascular supply it can be applied to all these difficult cases. In secondary reduction the technique can be applied, when the horizontal septum was maintained previously.⁶

Of course the patients must be informed about increased risks in special situations. In case of very weak connective tissue, a certain ptosis may recur. A severe smoker must be informed that she might be at increased risk for skin necrosis. An obese patient is always at increased surgical risk and should be motivated to lose weight.

In any case the method is preferable in patients who are anxious to preserve the sensitivity of their nipples and to preserve their breastfeeding ability. As it ends up with a short scar, it is also a good choice in patients, especially young women, who are anxious to have inconspicuous scars.

In a severely ptotic breast the method might be preferable to techniques supplied by dermal pedicles, as a dermal pedicle may be a limiting factor to raise the nipple.

Indications

Women suffering from carrying the weight of their breasts often get diseases of their cervical spine, have eczema, refrain from sport and social contacts, and often have problems in finding clothing that fits. A reduction and lifting of the breast for cosmetic reasons is also a good indication. A beautiful breast can be a big help in raising the patient’s self-esteem.