Obesity, defined as a body mass index (BMI ) above 30, is a worldwide epidemic. Selecting obese patients appropriate for breast reconstruction poses a challenge for the reconstructive surgeon due to the fact that this patient population is predisposed to other comorbidities (diabetes, hypertension, coronary artery disease, and lymphedema), as well as an increased risk of postoperative complications including seromas, skin and soft tissue infections, bronchopneumonia, and venous thromboembolism (VTE ) [10]. In addition, operation-specific complications are more likely to occur in the obese patient. Understanding the risks associated with obese patients and each reconstruction option is critical to ensure a safe and appropriate method is chosen.

Implant-based breast reconstruction remains the most common type of breast reconstruction worldwide. When performed in the obese patient, there is a total complication rate ranging from 18 to 30%. The obese patient is twice as likely to suffer implant loss and seven times more likely to have reconstructive failure [11, 12]. Although flap survival rates are similar to autologous reconstruction in the nonobese patient, patients with a BMI >30 are significantly more likely to experience an abdominal donor site complication, including ventral hernias [13]. Examination of the NSQIP registry confirms an increased risk for postoperative morbidity in this patient population regardless of reconstruction technique [14].

Attempts to mitigate operative risk in the obese patient have included weight loss prior to operative intervention; however no clear evidence exists that this actually reduces postoperative complications [15]. Ozturk et al. examined 182 abdominal free flap-based breast reconstructions and reported significantly higher flap and donor site complications in obese patients than those with lower BMIs. Interestingly, the authors did not find preoperative weight loss to significantly reduce these complication rates [16]. Despite these results, obese patients should still be encouraged to lose weight prior to surgery due to the well-known health and psychological benefits of this practice and higher rates of patient satisfaction with respect to surgical outcomes [17].

Postoperative venous thromboembolism (VTE ) is a serious yet preventable disorder with the potential to cause short-term mortality and long-term morbidity. Early identification of VTE is critical to its successful management; however clinical signs are notoriously unreliable, which may lead to a delay in diagnosis [18, 19]. The potential for debilitating consequences secondary to VTE has fueled efforts to identify patients who are at high risk of VTE development and the institution of prophylactic measures when appropriate. The Caprini Risk Assessment Model (RAM) and guidelines provided by the American College of Chest Physicians (ACCP ) have predominantly been applied to non-plastic surgical procedures to aid in identification of those patients who may benefit from chemical VTE prophylaxis. Recently, the Venous Thromboembolism Prevention Study (VTEPS) was completed in order to specifically apply the Caprini RAM as a screening tool to identify patients who would benefit from DVT prophylaxis after plastic and reconstructive surgical procedures. The Caprini RAM has been validated by the American Society of Plastic Surgeons (ASPS ) and has been shown to decrease the rate of VTE events without an increased risk of postoperative bleeding complications. Similar to its use in non-plastic surgical procedures, a numerical score is assigned to each patient after review of different patient and operation-specific risk factors and recommends using chemical prophylaxis for “high risk” patients who have a Caprini score ≥7 [20].

Perforating vessels arising from the larger named blood vessels supplying the various breast reconstruction soft tissue donor sites have variations within an individual patient and among patients. Knowledge of these anatomic variations preoperatively aids in appropriate perforator selection and improves operative efficiency. Multiple diagnostic techniques including Doppler ultrasonography, computed tomography angiography (CTA), magnetic resonance angiography (MRA), and fluorescent angiography (FA) have been utilized to facilitate preoperative perforator mapping to provide reconstructive surgeons with invaluable information regarding vessel origin, caliber, branching patterns, and magnitude of flow [21, 22].

Doppler/duplex ultrasonography was first used in the 1990s to assist with perforator-based free flaps and is a cheap, widely available imaging modality that does not expose patients to radioactive or nephrotoxic contrast agents [23]. Despite these benefits, its known disadvantages include long study times, operator dependence, and the inability to reliably identify perforator caliber. Computed tomography angiography has supplanted ultrasound as the preferred method of preoperative perforator identification with sensitivities and specificities approaching 100% [24] (Fig. 7.2). Despite the established benefits of preoperative imaging with CTA , it can only provide a static view of the abdominal vasculature in its preoperative state, and it cannot provide information about flow within the perforators. In addition, radiation exposure and the potential to develop a contrast allergy may complicate the performance of this imaging test.

Magnetic resonance angiography has received recent attention as an option for perforator mapping [25]. The safer side effect profile of gadolinium and recent use of higher field strength scanners have improved the accuracy of MRA for perforator characterization [21]. With regard to perforator mapping, MRA has demonstrated high specificity when compared to CTA [26]. Furthermore, the image quality of MRA is generally considered to be inferior to that of CTA; however its muscle-to-vessel contrast ratio is excellent and most accurately delineates perforator intramuscular course. The disadvantages of MRA include its high cost, low availability, susceptibility to motion artifact, and limited capacity to detect perforators with a diameter <0.8 mm [25]. Although gadolinium is less likely to cause an anaphylactic reaction, it may produce nephrogenic systemic fibrosis limiting its use to a specific subset of patients including those with iodine allergies and impaired renal function. Additionally, MRA should be avoided in patients who are morbidly obese, those with pacemakers, and in patients who suffer from anxiety or claustrophobia.

Indocyanine green fluorescent angiography (ICGFA ) is an accepted imaging technique newly applied to plastic and reconstructive surgery [27, 28]. This imaging technique allows direct visualization of macrovascular anastomoses, microvascular anastomoses, and tissue perfusion. The ICG fluorescent dye emits energy upon excitation by a light source (laser or LED light), which is then captured and recorded by a variety of image capture devices available creating real-time videos of blood flow and/or tissue perfusion. This unique feature allows images to be captured before, during, and after a flap is elevated, providing a live and continuous assessment of flap perfusion. Although the benefits of intraoperative fluorescent angiography are established, its role in the preoperative setting is being evaluated. A prospective study examining ICGFA perforator mapping of the abdominal wall in preparation for free tissue transfer breast reconstruction from the abdominal donor site demonstrated that skin blushes identified by ICGFA do not correlate with preoperative CTA or intraoperative perforator characteristics and therefore should not replace other forms of preoperative perforator mapping techniques [22].

The skin-sparing mastectomy (SSM ) was developed in the early 1990s by Toth and Lappert and involves removal of the breast gland and nipple-areolar complex (NAC) while preserving the overlying skin envelope and inframammary fold (IMF) [45, 46]. Maintenance of these critical landmarks allows the breast to assume a more natural shape and contour and facilitates the process of immediate breast reconstruction with any technique [47]. Incision patterns employed in SSM are limited to the immediate periareolar skin and are easily concealed with completion of nipple reconstruction or areolar tattoo.

The goal of the breast surgeon in SSM is to secure negative margins and to provide optimal cosmetic results. The balance between the two depends on mastectomy skin flap thickness, which is recommended to be approximately 10 mm. The surgical literature has confirmed the oncologic safety of SSM, finding no significant difference in local recurrence or disease-free survival when compared to traditional mastectomy. The combination of SSM and immediate breast reconstruction is also safe in patients with advanced Stage IIB and III breast cancer [47].

First reported by Hinton in the 1980s, the nipple-sparing mastectomy (NSM ) is more frequently used today and differs from the SSM by sparing the nipple-areolar complex (NAC). The NAC is a unique visual detail of a breast, and its preservation has proven to be a safe surgical option in a select group of patients, providing superior aesthetic outcomes and improved patient psychological well-being [48]. A recent systematic review highlights several factors that facilitate the process of appropriate patient selection to minimize breast cancer recurrence rates. These criteria include peripherally located tumors <5 cm in diameter, tumors located >2 cm from the NAC, lack of HER2 overexpression, and positive ER/PR status [49].

Common problems specific to NSM include nipple ischemia, partial or complete NAC loss, and nipple malposition (Fig. 7.3). Data regarding risk factors contributing to NSM complications are limited, conflicting, and variable, leading to a lack of consensus with respect to optimal surgical techniques. In light of this, Donovan et al. evaluated the effects of NSM incision location on rates of NAC ischemia, wound infection, and implant loss. There was an increased rate of NAC necrosis with use of periareolar incisions, while inframammary incisions had fewer ischemia-related compilations [50]. A retrospective review of 340 NSMs by a single surgeon over a 5-year period was completed to define specific and critical steps that should be utilized during NSM to reduce the risk of nipple necrosis and optimize cosmetic outcomes. The overall rate of nipple necrosis was reported to be 2.6%, with complete necrosis occurring in three cases (0.8%) and partial loss affecting six patients (1.8%) [51]. The authors recommend:

The earliest of tissue expanders were designed by Dr. Chedomir Radovan and consisted of a silicone prosthesis with remotely placed valves/ports allowing for fluid injection in one port and its removal from the other [52]. Since then, breast tissue expanders have improved and have superior silicone shells and integrated filling ports. This type of expander is associated with lower infection rates and complications caused by using a remote valve/port such as valve flipping, tube kinking, and pain associated with repeated needle sticks for port access.

More recent technological advances in breast tissue expanders include changes in expander shape and the development of self-filling expanders. The round shape of initial expanders has been modified to a more anatomic or “tear-drop” shape, which allows for a more natural breast appearance as well as accommodation of shaped devices at the second stage. The geometry of this device allows for differential expansion and maximization of the lower pole of the breast. These expanders have produced lower complication rates with reported capsular contracture rate of 3%, infection rate of 1.2%, and no valve dysfunction [53]. Self-filling tissue expanders were introduced due to the theoretical benefit of fewer office visits for expansion, decreased number of needle sticks for implant access, and the potential for patient-controlled inflation of prostheses. They contain either an osmotic agent or gas to allow for progressive tissue expansion.

First-generation osmotic expanders were devised by Austed and Rose [54]. Rapid expansion of these expanders, which did not have an envelope, resulted in soft tissue ischemia at times. Modifications of early osmotic expanders, including integration of a silicone membrane, allow for safer, slower expansion speed. Vinyl pyrrolidone, an osmotic hydrogel, is the agent utilized within this type of expander producing migration of water through the silicone membrane of the device resulting in progressive expansion. This is in contrast to the self-inflating expander which use gas (CO2) for filling. This expander type includes a small cylinder which releases small amounts of gas into the expander allowing for progressive expansion. Gas-based self-filling expanders were introduced by Connell and have shown 100% expansion success rate with minor adverse events [55, 56].

Recreation of the inframammary fold and maintenance of natural breast ptosis is the ultimate goal of breast reconstruction thus making expander shape and implant location of critical importance. Originally, breast tissue expanders were placed in the subcutaneous plane. This evolved to the preference of the subpectoral plane due to lower rates of capsular contracture which produced the firm, round, and unnatural appearance associated with subcutaneous placement. Subsequently, the partial submuscular plane was popularized due to the ability to place the prostheses lower on the chest wall augmenting lower pole expansion of the breast and accentuating the inframammary fold resulting in improved breast cosmesis. Currently, the inferolateral portions of the breast prosthesis are covered by the lateral inferior chest musculature (serratus anterior) or a form of dermal graft (see below).

The evolution of the contemporary breast prosthesis began with the “first-generation” silicone gel implant introduced by Cronin in 1962 and the first saline-filled breast implant by Arion in 1965. Since that time, both silicone gel and saline-filled implants have undergone several technical alterations and improvements to maximize safety and aesthetic results [57]. Saline implants are available as deflated devices which are to be filled with normal saline at the time of implantation. This allows for placement through a small incision as well as subtle size adjustments to be made at the time of surgery. These implants tend to be less popular than their silicone counterpart due to a less natural consistency similar to that of water compared to the more viscous natural breast tissue. In addition, overfilling may lead to a spherical shape and scalloping along the edge of the implant causing a firmer feel upon palpation.

Several versions of silicone gel implants have been developed since their introduction and differ with respect to the characteristics of the silicone gel filler, characteristics of the silicone shell surrounding the filler, and implant shape. Silicone is a mixture of polymeric molecules which can exhibit different physical properties depending on polymer chain length and degree of cross-linking between polymer chains [58]. There are two basic categories of silicone options available for use in breast implants, and they are termed “fluid form” and “form stable.” The “fluid-form” liquid silicones are short polymers with very little cross-linking and have the consistency of oil [59]. They are usually used as surgical lubricants and are not cohesive enough to hold a given anatomic shape. When enough cross-linking is achieved, a more viscous “form-stable” silicone gel is created which allows the implant to maintain its dimensions and hold a given shape, affording the surgeon more control over the device. Technology exists to measure the cohesivity of silicone gel implants allowing measurement of implant stiffness. Form stability correlates with lower rates of capsular contracture, implant rupture, rippling, and improved patient satisfaction compared to low-cohesive fillings [60].

Extensive chemical cross-linking of the silicone gel polymers will create a solid form of silicone called an elastomer shell. Implant shell modifications, including barrier layers, have been introduced to protect the silicone gel filler. Shell characteristics, such as shell thickness, are important to consider as they contribute to the stability of implant shape. The maintenance of gel distribution within the implant shell helps to preserve this stability. The cohesivity of the gel and gel-shell fill ratio improves shape maintenance and varies among implant shapes. In addition to shell thickness, surface characteristics of the shell have undergone modifications with the ultimate goal of creating a surface texture that can minimize implant capsule formation [61]. The evolution of textured implants stemmed from the introduction of polyurethane-coated implants. These were foam-coated implants which were eventually dismissed due to concerns about possible carcinogenic conversion after chemical degradation of the foams. In the 1980s, a shift from foam-coated shells to textured silicone shells was made. Studies have shown that the pore size is critical to allow for tissue adherence leading to the adhesive effect of implant texturing and implant stabilization.

Round-shaped implants have been available for breast reconstruction since the 1980s and are described as having a “disk-like” shape. Several years later, anatomic or “tear-drop”-shaped implants were popularized outside of the United States and were subsequently approved by the FDA for use in the United States in 2013 [62]. Anatomic implants were developed to optimize the natural look of the reconstructed breast through implementation of a lower point of maximal projection resulting in a more prominent lower breast contour. They provide greater versatility and control of breast shape, which leads to a more “natural” aesthetic result. Although the anatomic, form-stable, silicone gel implants are gaining popularity, gel fracture and implant rotation are known risks associated with their use.

The “first-generation” prosthesis was anatomically shaped (“tear-drop”), filled with a viscous silicone gel, and covered with a smooth, thick outer silicone elastomer shell. In addition, they had Dacron fixation patches on their posterior aspect to maintain the proper position of the implant on the chest wall. The shell kept the liquid filler in one place creating a natural breast-like shape. Unfortunately, these devices had a high rate of capsular contracture due to the quality of the shells and the lack of cohesivity of the gel. Second-generation silicone gel implants were introduced about a decade later in attempts to address these complications. They were round in shape, had a thinner shell without Dacron patches, and were filled with a less viscous silicone gel. While these looked and felt more natural, the combination of the lower viscosity gel filler and permeable shell made them more likely to rupture and leak resulting in “gel bleed”. The third-generation implants were developed in the 1980s to reduce the rate of implant rupture with subsequent gel migration by using a stronger multilayer silicone elastomer shell. Despite attempts to improve implant design, a moratorium on the use of third-generation silicone gel breast implants was issued by the FDA in 1992 in response to concern about the possible association between “gel bleed” and the development of connective tissue disorders. Subsequent studies and literature reviews failed to show this relationship, and restrictions on their use were lifted in 2006. The most recently designed silicone-filled breast implants are manufactured using the highest standards, concentrating on optimal shell thickness and gel cohesiveness to create a more natural feeling breast with reduced rates of complications [57]. Currently, fourth- and fifth-generation silicone implants are utilized. Fifth-generation implants have a more cohesive “form-stable” silicone gel and a textured surface and were manufactured with improved quality control allowing for several surface textures and implant shapes. Although they have been shown to be safe, a possible association between their use and anaplastic large-cell lymphoma (ALCL) was reported by the FDA in 2011. Although extremely rare, this finding must be reported to anyone considering having silicone breast implants.