Minimally Invasive Surgery in Breast Reconstruction: The Past and Future

Abstract

Restoring breast aesthetics and minimizing morbidity while providing excellent oncologic control has been the driving force in the evolution of both breast cancer and breast reconstructive surgery. This chapter will discuss recent developments using minimally invasive techniques to further move the needle towards even better patient outcomes. We outline the technical considerations and evidence behind minimally invasive breast reconstructive procedures including laparoscopic deep inferior epigastric perforator (DIEP) flap harvest, robotic DIEP flap harvest, and robotic latissimus dorsi flap harvest. We also introduce minimally invasive breast cancer surgery including robotic mastectomy. Finally, this chapter discusses future applications of emerging technology and the controversies surrounding the widespread adoption of minimally invasive techniques in breast cancer and breast reconstructive surgery.

1. Introduction

Breast cancer surgery has dramatically evolved since Halstead first described the radical mastectomy in 1894 [1]. Over time, radical mastectomy with resection of the entire breast, chest wall musculature, and axillary nodes, was abandoned due to its high morbidity and failure to achieve superior oncologic outcomes compared to less aggressive resections. Since then, the field has recognized the importance of achieving excellent cancer outcomes while also minimizing morbidity and preserving breast aesthetics. Skin-sparing mastectomy, breast conservation surgery, sentinel lymph node biopsy, and now nipple-sparing mastectomy (NSM) in the appropriate patient have become the standard of care.

While initially avoided for fear of the loss of local control, breast reconstruction is now considered part of routine breast cancer care. The late 1800s and first half of the twentieth century are spotted with case reports and small case series of autologous tissue reconstruction; however, autologous reconstruction really took hold in the 1970s [2]. The advent of the silicone breast implant in the 1960s also ushered breast reconstruction into the modern age.

Breast reconstruction using autologous flaps gained acceptance following descriptions of the pedicled latissimus dorsi flap in 1977 [2]. The flap was refined to allow for a single-stage reconstruction of breast defects; however, the volume was often insufficient to be used alone and thus the flap was paired with an implant. To replace the entire volume of the breast mound, surgeons turned to abdominal tissue. The pedicled transverse rectus abdominis myocutaneous (TRAM) flap was introduced by Hartrampf, Schelfan, and Black in 1982 [2]. The TRAM flap revolutionized breast cancer reconstruction as it allowed for a complete autologous reconstruction with an acceptable donor scar and body contouring effect similar to abdominoplasty. Unfortunately, the blood supply-to-tissue ratio from the superiorly-based pedicle contributed to high incidence of fat necrosis and harvest of the rectus abdominis muscle led to significant abdominal wall weakness. Initially described in 1979, the free TRAM uses microsurgical technique to transfer the disconnected abdominal tissue and connect the TRAM blood supply to distantly located recipient vessels. The free TRAM is based on the deep inferior epigastric vessels rather than the superior epigastric vessels that supply the pedicled TRAM. The deep inferior epigastric vessels are noted to be more robust and provide improved blood supply to the TRAM flap compared to the superior epigastric system. Therefore, the free TRAM optimizes the blood flow to the flap which reduces fat necrosis compared to the pedicled TRAM. The free TRAM did not, however, decrease abdominal wall morbidity compared to the pedicled TRAM. To address this, plastic surgeons adapted the dissection technique to reduce damage to the rectus abdominis muscle, first with the muscle-sparing TRAM (ms-TRAM) then the deep inferior epigastric artery perforator (DIEP) flap. Considered by most to be the current gold standard in autologous tissue reconstruction, the DIEP flap minimizes muscle sacrifice by carefully dissecting the muscle away from the vasculature (Figure 1). Additional soft tissue donor sites have been introduced including the thighs, gluteal region, and lower back, yet the DIEP flap remains the preferred operative approach for autologous tissue reconstruction for the majority of patients.

Figure 1.

(A) Preoperative (B) following bilateral nipple-sparing mastectomies and DIEP flap reconstruction.

As illustrated above, restoring breast aesthetics and minimizing morbidity while treating the patient’s underlying cancer has been a driving force in the evolution of both breast cancer and breast reconstructive surgery. This chapter will discuss recent developments using minimally invasive techniques to further move the needle towards even better patient outcomes.

2. Minimally invasive surgery in breast reconstruction

Donor site concerns including the risk of hernia or abdominal bulge following DIEP flap reconstruction have driven plastic surgeons to explore minimally invasive options for flap harvest. Hernia, muscle-bulging, and decreased core strength are the most significant donor site complications that minimally invasive surgery seeks to correct. Multiple studies have shown decreased abdominal wall morbidity as muscle preserving techniques increase [3, 4, 5, 6, 7, 8, 9, 10]. The increased abdominal wall morbidity is typically attributed to 3 factors: weakened musculature, denervated musculature, and violation of the anterior sheath. The first, inclusion of the rectus abdominus in the flap design (TRAM or ms-TRAM) may be minimized by performing a true perforator flap with perforators selected to minimize muscular disruption. The second, denervation of the rectus abdominus can be reduced by selecting medial row perforators when suitable and using a nerve-sparing or at least nerve-repairing technique for any motor nerves encountered during pedicle dissection [11]. The final factor associated with abdominal wall morbidity is the violation of the anterior sheath that occurs during dissection of the deep inferior epigastric vessels from the level of the perforating vessels to their origin off the external iliac artery and vein (Figure 2). The anterior rectus sheath is the primary strength layer of the abdominal wall, especially below the arcuate line where the only barrier between the rectus abdominis and the peritoneal cavity is the thin transversalis fascia and peritoneum.

Figure 2.

(A) Traditional harvest of open DIEP flap with longitudinal splitting of muscle and fascia. (B) Ruler illustrates the nearly 15 cm incision of the anterior sheath required for pedicle dissection.

To limit the fascial incision, short pedicle techniques were described by Saint-Cyr [12]. However, as the pedicle is shortened, the caliber of the artery and vein decrease. Additionally, the degrees of surgical freedom when performing the microsurgical anastomoses are reduced which can lead to increased microscopic complications in less experienced hands. Furthermore, visualization of the vessels is limited with a small fascial incision. These challenges have inspired plastic surgeons to innovate using minimally-invasive tools commonly used in other surgical disciplines.

2.1 Laparoscopic DIEP flap harvest

In 2017, a group in France published the first feasibility study of a laparoscopic technique for DIEP flap harvest [13]. They utilized a preperitoneal or total extraperitoneal (TEP) laparoscopic technique. The TEP technique uses insufflation to bluntly open the space between the posterior sheath/transversalis fascia and the posterior surface of the rectus abdominus muscles. Once this plane is separated, the vessels can be easily seen and dissected free of the muscles from the level of external iliacs to the perforating vessels without entering the abdominal cavity. The vessels are clipped and divided at their origin, and the entire length is extracted through a minimal fascial incision created during the open perforator dissection. In their series of 5 cadavers (10 hemiabdominal dissections), they were able to achieve a mean anterior fascial incision length of 3 cm compared to 12 cm for the traditional approach.

Laparoscopic DIEP flap harvest has subsequently been adopted by other groups. In 2020, a group at the University of Pennsylvania reported the then largest clinical series of patients who underwent laparoscopically-assisted harvest of DIEP vessels [14]. They reported a novel variation on previously published techniques to maximize flap blood flow while simultaneously reducing abdominal wall morbidity. They utilize a two-stage surgical delay technique to optimize the perforator most suitable for laparoscopic harvest. Prior to the initial procedure, a single perforator is selected not based on caliber but rather on location (low, central) and a short intramuscular course as seen on CT angiogram. At the initial operation, all other perforators and the superficial inferior epigastric artery and vein are ligated. This prompts the remaining perforator to dilate in response to relative tissue ischemia. At the second stage 2 weeks later, the single perforator is dissected through a minimal fascial incision and the pedicle is mobilized using a preperitoneal (TEP) approach similar to the description above. In their case series of 33 patients (57 flaps), the mean fascial incision length was 2 cm with 2 pedicle transections occurring during dissection which required repair.

2.2 Robotic DIEP flap harvest

Since the first robotic cholecystectomy was performed in 1997, the da Vinci surgical robot (Intuitive Surgical) has revolutionized the field of minimally invasive surgery. Indeed, use of the robotic platform has become the preferred approach over laparoscopy for many surgical procedures [15]. By 2018, cadaveric studies and case reports of robotic DIEP flap harvest began to arise in the plastic surgery literature [16]. In 2019, Jesse Selber at the University of Texas MD Anderson Cancer Center published his approach to robotic unilateral DIEP flap harvest [17]. He performs the procedure in a single step although usually delayed from the time of mastectomy. Similar to Kanchwala et al., the perforator is chosen preoperatively based on its short intramuscular course on CT angiography (Figure 3). Suprafascial dissection begins in standard fashion with the target perforator isolated and circumferentially dissected down to the posterior sheath via a small fascial incision (Figure 4). Robotic ports are then placed through the fascia of the contralateral hemiabdomen and the pedicle is mobilized from an intra-abdominal or transabdominal preperitoneal (TAPP approach) (Figure 5). The pedicle is then exteriorized and the fascia closed (Video 1, Figure 6).

Figure 3.

CT angiography identifies dominant DIEP medial perforator (red circle) with minimal intramuscular course. This anatomy makes the patient an ideal candidate for robotic DIEP flap harvest.

Figure 4.

Robotic DIEP flap with perforator dissection performed via 1 cm fascial opening.

Figure 5.

Robotic mobilization of the deep inferior epigastric inferior vessels.

Figure 6.

Abdominal wall after fascial closure following robotic DIEP approach.

Other groups have reported success with other approaches including use of a single port site and TEP approach [18, 19]. Many initial case series have focused on unilateral flap harvest; however, surgeons have begun to adapt the technique to allow bilateral flap dissection [20]. A group in Pittsburgh, has presented their technique for bilateral robotic DIEP pedicle harvest using a TAPP approach and 3 8 mm ports placed to target the pelvis. This allows access to both flap pedicles without undocking the robot or placing additional ports. They also report utilizing the da Vinci Firefly fluorescence technology following indocyanine green injection to better visualize the course of the vessels. In their cohort of 10 patients (20 flaps), the mean fascial incision length was 4.5 cm with an average of 1.9 perforators included in the flap design. Mesh was not required to reinforce the abdominal wall in any case. No pedicle or bowel injuries occurred during intraabdominal dissection [21].

2.3 Robotic latissimus flap harvest

For patients who have failed or are not candidates for implant-only reconstruction and who prefer to avoid free-flap breast reconstruction, a pedicled latissimus dorsi (LD) flap often combined with a tissue expander is a viable option for reconstruction. Traditional harvest technique for this flap requires a long posterior incision that presents an aesthetic challenge for many patients. While this may not be avoidable if a fasciocutaneous flap is used, an unsightly scar can be avoided using minimally invasive techniques if a muscle-only flap is desired.

While endoscopic harvest has been attempted, this approach is constrained by the curvature of the chest wall which limits the ability to maintain satisfactory visualization. More recently, several centers have begun to use the surgical robot for muscle-only LD muscle harvest. The first clinical case series was published by Selber et al. in 2013 [22]. To compete the dissection, three robotic ports are used. One may be placed in an already existing axillary incision if concurrent sentinel node biopsy or axillary node dissection is performed. The anterior border of the muscle is marked. The axillary incision is used to identify and isolate the thoracodorsal artery. Using a lighted retractor, the subcutaneous space anterior to the border of the muscle is opened to allow placement of 2 additional ports. The deep surface of the muscle is dissected first followed by the superficial surface. Finally, the inferior and posterior borders of the muscle are released. Once freed, the flap can be brought up through the axillary incision and transposed into the mastectomy space.

Subsequent reports of robotic latissimus flap harvest have been largely positive. A literature review performed in 2020 identified 32 cases in 5 studies of robotically harvested pedicled LD flaps for implant-based breast reconstruction [23]. All cases were completed successfully without conversion to an open approach. Only 1 study compared complication rates in robotic (n = 12) versus open harvest (n = 64). The authors found a lower rate of complications including seroma, infection, delayed wound healing, and capsular contracture in the robotic group although this was not statistically significant [24]. In all studies, patients were noted to have an excellent aesthetic result.

3. Minimally invasive surgery in breast cancer surgery

As reconstructive surgeons have begun to use minimally invasive surgery to minimize donor site morbidity, breast surgeons have also begun to push the envelope to optimize patient aesthetic concerns.

3.1 Robotic mastectomy

In 2016, Toesca et al. in Milan, Italy published the first robotic-assisted nipple sparing mastectomy (rNSM) [25]. Their technique utilized a single port with 4 working channels inserted through a 3 cm incision placed in the midaxillary line within the axillary fossa. Through this single site, the entire gland was dissected and implant-based reconstruction performed in either the subpectoral or prepectoral plane.

Since their initial feasibility and safety study, the Milan group has published their outcomes comparing standard nipple sparing mastectomy (sNSM) to rNSM [26]. They performed a randomized non-blinded clinical trial of patients with breast cancer or a genetic predisposition to cancer who were eligible for NSM by standard criteria. Eighty patients were included, 40 in each group. They found that, while rNSM took on average 78 minutes longer to complete compared to sNSM, there were lower rates of surgical complications in the robotic group although this was not statically significant. No ischemic complications were seen in the robotic group while 2 patients in the sNSM group had nipple alveolar complex (NAC) ischemia and 5 had skin flap necrosis. Additionally, Breast-Q scores reflecting satisfaction with breasts, psychosocial, and physical and sexual well-being were significantly higher in the rNSM group.

Other groups have pioneered similar techniques although the use of the surgical robot for mastectomy remains off-label according to the FDA. In response, an expert panel from the International Endoscopic and Robotic Breast Surgery Symposium released a consensus statement to provide guidance regarding the safe practice of robotic mastectomy [27]. The panel sited advantages to the technique including easy visualization and improved surgeon ergonomics. Disadvantages included prolonged operative time and increased cost and limited availability of the surgical platform. They noted the procedure was safe with notably low NAC necrosis rates. They ultimately produced 12 statements to guide patient selection, technique, and selection of surgical, oncologic, and aesthetic outcomes. They conclude that “robotic mastectomy is a promising technique and could well be the future of minimally invasive breast surgery.”

4. Future possibilities

As techniques continue to be refined for both minimally invasive mastectomy and minimally invasive flap harvest, the next natural step may be to combine the two. In 2020, French surgeons published their experience with combined robotic mastectomy and robotic pedicled LD flap harvest [28]. In their cohort, 35 patients underwent both robotic NSM and robotic LD flap harvest. Similar to the technique outlined above, they used a gel mono-trocar device placed via a 4-6 cm incision in the anterior axillary line. They dissected and removed the breast parenchyma then repositioned and used the same incision and trocar to mobilize the latissimus muscle. The muscle was then transposed and appropriately fixated the chest wall within the mastectomy cavity with or without an underlying implant.

Another permutation of this could combine robotic mastectomy with free flap breast reconstruction. A major limitation to this approach is the requirement for the surgical robot to have the capability to perform microvascular anastomosis. Currently, the dominant robotic system, the da Vinci surgical system, has optics and instruments that were not designed for tissue handling at this scale. Recently two robotic systems dedicated to microsurgery have been developed: MUSA by MicroSure and Symani by MMI [29]. These robots have the ability to handle delicate tissue all while eliminating tremor and providing motion scaling. This is a crucial advance, not only for microsurgery, but for the ability to perform supermicrosurgery which is defined as connecting vessels between 0.3 and 0.8 mm, commonly required during lymphedema surgery. Preclinical studies of the MUSA system illustrated that it is possible to use this platform to perform microsurgical anastomosis although overall time for anastomosis completion was longer and dexterity scores were lower using the robot compared to manual microsurgical anastomosis [30].

The first-in-human use of MUSA system to perform supermicrosurgical lymphovenous anastomosis (LVA) for the treatment of lymphedema was reported by a group in the Netherlands in 2020 [31]. They randomized 20 patients to robotic versus manual LVA. In this initial study, time to perform supermicrosurgical anastomosis was shorter in the manual group; however, they did note a steep decline in the time required for robotic-assisted LVA during the course of the study. All LVA’s were patent at the end of the procedure. Additionally, no adverse events occurred attributable to use of the surgical robot during the procedure; therefore, the authors concluded that use of the platform for supermicrosurgical anastomosis was feasible and safe. Subsequent studies by other groups using the Symani robot have seen similar promising results [32].

Whether these microsurgical robots will be integrated into simultaneous robotic mastectomy and breast reconstruction remains to be seen. Unlike the da Vinci surgical robot, they were designed to maximize surgeon precision while operating on minute and delicate structures rather than to minimize the invasiveness of the procedure. Thus, in their current iteration, they are ideal for open surgery, but their utility may be limited in a deep body cavity.

5. Conclusions

While initial studies evaluating minimally invasive techniques for breast cancer surgery and breast reconstruction illustrate their feasibility, their use remains controversial. Studies of rNSM consistently report low rates of mastectomy flap compromise and high patient satisfaction, yet the primary goal of the operation is oncologic control. At this time, the number of patients who have undergone this procedure is low and the length of follow-up short. Further studies will be needed to decisively establish the oncologic safety of this approach [33]. Similarly, larger studies and longer follow-up will be required to fully see the effect of minimally invasive flap harvest on donor site morbidity.

Another concern is the cost associated with the use of the surgical robot. This includes the cost of the console, disposable instrumentation, service contracts, and the operative time associated with a longer operative procedure. These costs may be offset by shortened hospital length of stay, but that has yet to be seen in any of the studies cited above. Laparoscopy is less expensive compared to the surgical robot; however, laparoscopy is more difficult in a small operative space as the instruments only provide 4-degrees of freedom of movement compared to the 7-degrees of freedom afforded by the da Vinci platform.

There is a learning curve that will have to be addressed prior to any surgeon attempting to perform these minimally invasive techniques. As most plastic surgery trainees complete integrated residency programs, they seldom encounter cases using laparoscopy or the surgical robot beyond the early years of their training, thus they are unlikely to have the opportunity to become proficient. Even breast surgeons, who must complete a residency in general surgery, may have variable exposure as robotic skills as these are not currently required for board certification unlike laparoscopy and endoscopy. This challenge is not insurmountable as numerous studies have shown rapid skill acquisition and validated tools have been developed to assess robotic microsurgical skill [25, 34].

In summary, minimally invasive breast cancer surgery and breast reconstruction is currently only offered at select centers. Further studies regarding the safety and efficacy of these techniques as well as surgeon training will be required before they are likely to gain widespread adoption. If this occurs, minimally invasive breast cancer surgery and reconstruction can truly serve as the next step in the quest for a further reduction in surgical morbidity and improved patient outcomes beyond the current standard of care.

Conflict of interest

The authors declare no conflict of interest.

Video link

https://youtu.be/kaw-uAXpGuw.