5 Endoscopic approaches to the breast
Endoscopic approaches to conventional surgical problems have significantly enhanced treatment options since their introduction in the latter half of the 20th century (Berger 1996; Paige 1997).6,15 Less traumatic tissue dissection in conjunction with smaller surgical incisions have enabled many patients to benefit from reduced postoperative pain, expedited recovery, and improved cosmesis (Cho 1997).8 The surgical endoscope has been used by the senior author to perform over 200 endoscopic augmentation mammaplasties and over 50 endoscopic lumpectomy reconstructions. Unlike intra-abdominal or thoracic applications, plastic surgery frequently involves extensive soft tissue and neurovascular dissection within enclosed potential spaces. Limited surgical apertures and confined optical cavities have therefore inhibited the development and widespread usage of minimally invasive plastic surgical techniques. Widespread availability of endoscopic equipment and refinements in technique have improved the relevance and utilization of endoscopic approaches in a wide variety of plastic surgical applications in recent years. As endoscopic approaches to the breast and other areas of plastic surgery have gained acceptance, it is important to have a fundamental understanding of the basic concepts of surgical endoscopy. These include the principle of the optical cavity, support systems, illumination equipment, imaging technology, incision planning, and some basic technical considerations.
The development and maintenance of an optical cavity is the primary technical challenge of endoscopic surgery. Optical cavities may be formed from preexisting, potential, or dissected spaces and can vary greatly with bony and soft tissue anatomy. Optical cavities are characterized by space, support, medium, and pressure. Space refers to the anatomic space which they occupy and may be existing, potential, or dissected. Support may be provided by existing bony or soft tissue anatomy, mechanical retraction, or through the infiltration of an optical medium. The optical medium refers to the gaseous or liquid contents of the cavity which allow for transmission of visible light. The pressure within the cavity can be modulated in closed endoscopic systems depending on the anatomic constraints of the space in which the surgeon is working. In plastic surgical approaches to the breast, be they cosmetic or reconstructive, the optical cavity is a mechanically maintained, dissected space with room air providing the optical transmission medium.
Due to the fact that the optical cavity in both endoscopic flap harvest for breast reconstruction and endoscopic augmentation mammaplasty are continuous with the ambient air of the operating room, support cannot be provided by an optical fluid medium under pressure. Further, since the planes are ones which are dissected rather than preexisting, there is no inherent anatomic support for maintenance of the optical cavity. Therefore, the only option for creation and maintenance of the optical cavity is mechanical retraction. Internal mechanical retractors apply a centrifugally directed force on the roof of the optical cavity. This provides the lift necessary to deepen the space for optimal visualization and manipulation of the surgical field. The force applied must be sufficient to counteract the elastic and gravitational forces acting to collapse the optical cavity. Mechanical retraction for cosmetic and reconstructive breast surgery can be free or coaxial with the camera. A single, well designed coaxial retractor allows a single surgeon to control both the visual field and optical cavity with relative ease. If necessary, an assistant may use a free retractor to briefly enhance the optical cavity during a particularly challenging or distant portion of the operation.
Several technological advances in illumination and imaging technology have proven instrumental in the development of surgical endoscopy. Glass fiber optic cables allow for the use of distant light sources bright enough to provide full spectrum illumination of the surgical field.
The transaxillary approach to breast augmentation was described by Troques in 1972 and Hoehler in 1973. Besides the obvious advantage of the hidden incision, this approach facilitated direct access to the subpectoral plane. With this technique, the inframammary crease was altered and the origin of the pectoralis muscle was dissected blindly, accounting for a significantly higher incidence of implant malposition. The limited exposure of the blind technique did not allow complete division of the prepectoral fascia, resulting in the tendency of high-riding implants or the double-bubble appearance of the inframammary crease.
In the early 1990s, there was a surge in interest in endoscopic plastic surgery, primarily as an extension of the success of endoscopic cholecystectomy in general surgery. This expanded to application of the endoscope to breast surgery. The Emory group reported their experience with endoscopic breast augmentation through an axillary incision in 1993 using a specialized retractor and an air-filled optical cavity. Ho reported a technique that used glycine irrigation to create a liquid-filled optical cavity, although he now also uses a specialized retractor and an air-filled optical cavity.10 The increased control resulting from direct visualization of the dissection obviated many of the previous downfalls of the blind axillary approach. Howard demonstrated the benefits of the endoscope with the axillary approach by decreasing the incidence of implant malposition from 8.6% to 2%, when the endoscope was used.11
The latissimus dorsi flap was first described by Dr Tansini in 1897 for the coverage of a chest wall defect. For over a century, this flap has been utilized reliably in free and pedicle-based myocutaneous and myofascial flaps to cover soft tissue defects . The harvesting technique, which involves a large dorsal skin incision for flap elevation, has remained essentially the same since its introduction. Initial application of latissimus dorsi flaps involved coverage of soft tissue defects from a variety of anterior chest wall pathologies, ranging from bony malignancy to radical mastectomy. These early techniques, while clearly efficacious, were associated with a large harvesting incision which can be troubling to a woman who is concerned with scaring and cosmesis.
Fine and colleagues were the first to report a clinical experience with endoscopic latissimus dorsi flaps in 1994.20 This harvesting technique utilized smaller incisions and was performed with the use of modified laparoscopic cholecystectomy instruments. Since this publication, the limiting factor for improving endoscopic harvest has been creation of an adequate optical cavity. Innovative ideas to optimize visualization within soft tissue planes have gradually emerged. Several authors have described external retraction with sutures, balloon dilation, CO2 insufflation, and the use of additional ports. We have further refined our technique, namely the endoscopic assisted reconstruction with latissimus dorsi (EARLi) flap. This procedure, first performed by the senior author in 1998, for reconstruction after breast conserving therapy, only requires an axillary incision and is therefore cosmetically appealing. Seminal studies in the late 1990s, documenting the equivalence of BC with mastectomy for the treatment of small breast cancers resulted in many women requesting BCT. Unfortunately, adequate carcinoma excisions, especially excisions for relatively large T2 or T3 breast cancers, may lead to poor cosmetic results. The severity of the aesthetic defect is a direct relation between the size of the tumor resection with adequate margins, and the size of the affected breast. A recent report has shown that BCT combining radiation and immediate myosubcutaneous latissimus dorsi flap reconstruction is an oncologically safe treatment for larger breast cancers. Several authors have described a latissimus mini-flap, a procedure for filling in the breast defect which utilizes an incision running from the apex of the axilla along the lateral border of the breast towards the outer aspect of the inframammary fold. This innovative approach allows both wide local excision in women who would otherwise have required a mastectomy as well as a more cosmetically appealing outcome. At our institution, we perform the EARLi flap, a procedure with even less scarring, to achieve a favorable cosmetic outcome after BCT. The principle goals of the EARLi flap are to replace excised tissue volume and prevent breast deformity following lumpectomy. In addition, breast size and contour are maintained, and scar tissue contracture is minimized. Because of the small incision and limited soft tissue dissection, postoperative pain is reduced and recovery time is diminished.
The female breast covers the anterior chest wall from approximately the second rib superiorly to the fourth or fifth rib inferiorly. Its upper one half overlies the pectoralis major muscle, the serratus anterior its lower one half, and some of the axillary fascia laterally. The breast is essentially a skin organ. It is attached intimately to the skin by suspensory ligaments (Cooper ligaments). This is because developmentally it forms from the ectoderm of the anterolateral body wall, and epithelial proliferation from that site creates the gland. For this reason, opening the natural plane between the muscle and the breast is easy; an implant can be inserted into this space. The blood supply of the breast is derived from branches of the axillary artery, the intercostal arteries, and the internal mammary artery. Few if any vessels penetrate into the gland from the underlying central muscle. The nerve supply to the breast comes from the anterior and lateral cutaneous branches of the third, fourth, and fifth thoracic nerves. One of the larger lateral cutaneous branches often can be visualized and preserved during augmentation surgery.
Micromastia or mammary hypoplasia is chief complaint in patients seeking an enlargement procedure. Significant breast asymmetry, ptosis, or tubular breast deformity are difficult if not impossible to address through the transaxillary approach and, as such, must be comprehensively assessed and ruled out. Absence of any significant abnormality must be ruled out clinically and, when appropriate, mammographically prior to any elective breast surgical procedure.
Indications for endoscopic breast augmentation include the patient’s desire for a remote incision and the absence of a well-developed inframammary crease to hide a crease incision from view in the horizontal visual axis. Patients without significant ptosis are ideal candidates. This minimizes the need for excessive manipulation or dissection during creation of the implant pocket from a remote site. A constricted lower pole with a short distance from the inframammary crease to the areola is significantly more difficult and can require radial scoring of the breast parenchyma. The potential exists for inferior implant displacement from over-dissection (lowering) of the inframammary crease and superior implant displacement from under-dissection of the inframammary crease. Tubular breast deformities also present a contraindication to endoscopic transaxillary augmentation mammaplasty. The need for correction of the herniated areola and the scoring of the constricted lower-pole parenchyma makes the periareolar access incision ideal for tubular breast deformity. Some degree of ptosis can also represent a relative or absolute contraindication to the technique. Mild pseudoptosis and Regnault grade 1 ptosis may be addressed during a transaxillary, endoscopically assisted dissection, but this anatomy requires manipulation of the inframammary crease to control the vertical descent of the breast. Due to the need for control and accuracy in this dissection and concerns over the risk of under- or over-dissection, aggressive management of ptosis via this approach is not recommended for the inexperienced surgeon. While it is possible to place an implant into the subglandular plane from the axillary approach to improve moderate ptosis, the very fact that moderate (or greater) ptosis exists means that an inframammary crease incision will be well hidden and a periareolar incision may be hidden by or incorporated into a mastopexy incision, negating a primary benefit of the endoscopic transaxillary approach: a hidden scar in a breast that would show other incisions. Both silicone and saline devices may be introduced through the transaxillary approach, although due to the physical constraints of the transaxillary tunnel, introduction of silicone gel implants >300 cc may be challenging and require special care to avoid damage to the device or surrounding anatomic structures during insertion. This limitation is due to a desire to have a ‘hidden’ transaxillary scar. For the scar to blend into a high transverse axiliary crease it can rarely be longer than 5 cm. As the scar becomes longer in runs the risk of being more visible if a woman’s arm is raised. A saline implant of any size can be placed through an incision of 3 cm. Therefore, women who desire a hidden scar and an implant >300 ccs will need to consider the trade-off of a longer, more visible scar with a silicone implant vs a short, hidden scar with a saline device.
Preoperative considerations include accurate marking of the native and proposed placement of the inframammary crease, as well as anticipated areas of release of the pectoralis major muscle. The pectoralis muscle should be completely divided along its inferior origin from the rectus fascia (Fig. 5.1). This complete myotomy is transitioned gradually to a partial thickness release as the dissection approaches the medial origins along the sternal border until the level of the nipple is reached. Mark the first axillary crease with an incision behind the anterior axillary line. The incision should measure 3 cm if a saline implant is planned, 4.5–5 cm if silicone is to be used. If concealed in a natural skin crease within the hair bearing portion of the axilla, the incision will typically be extremely favorable if not disappear almost completely when fully mature (Fig. 5.2).