Breast reconstruction is considered as a part of breast cancer treatment to restore breasts to their near-normal shape, size, and symmetry, and to enhance the quality of patients’ lives. Nowadays, the demand for breast reconstruction is increasing constantly, which leads plastic surgeons to look for new methods to obtain a more natural and aesthetically pleasing appearance of the reconstructed breasts.
Because a large amount of skin and a considerable volume of inner tissue have been lost due to mastectomy, the restoration of skin envelope and the compensation for the breast tissue loss are two key issues that need to be considered during reconstructive surgery. In fact, tissue expansion two-stage reconstruction, which could expand the pectoralis major muscle and its overlapped skin at the same time, so as to restore the soft tissue cover, has become the most popular reconstruction method in China. Then volume replacement techniques, like implants insertion or distant autologous tissue flaps transfer, could help to compensate for the tissue loss. Among these, the implant is one of the most frequently used for most Chinese patients. Yet the implant always makes the breast feel stiff and the transition area between breast and chest wall looks unnatural, especially when the implant size is large to fit the large contralateral breast. As for the autologous tissue flap, mastectomy with latissimus dorsi (LD) flap transfer could only be beneficial for women with small-to-medium-sized breasts with upper outer quadrant breast cancer who desire breast conservation surgery [2, 3, 6], because the provided volume is insufficient to achieve the total breast reconstruction.
In this study, we designed a new two-stage breast reconstruction protocol, which included tissue expansion on the first stage and implant insertion combined with LDMF transfer on the second stage. Using this method, the total extension of the pectoralis major muscle together with the transferred LDMF provide a robust muscular cover over the permanent implant, which makes the breast feel soft and smooth the transition region between the breast mound and the chest wall. Moreover, the additional volume of the LDM adding to the reconstructed breast allows choosing a small-sized implant, which also enhances the touch feeling of the breast.
Feng et al.  reported a similar two-stage breast reconstruction protocol, but the difference was that the LDMF transfer was applied together with the tissue expander insertion on the first stage. Regarding tumor staging, it is important to identify patients who will require adjuvant radiation therapy. Under this circumstance, the LDMF should be preserved as a salvage option for use in a delayed reconstruction setting. Because the non-irradiated autologous tissue flap could provide non-irradiated cellular elements which can lead to the repair of the dermal fibrosis resulted from post-mastectomy radiation therapy . Moreover, it also showed that the harvest of the LDMF is associated with a low complication rate and reliable results for delayed reconstruction of the irradiated breast [9, 10]. So, under consideration of the uncertainty about the application of radiation therapy in the immediate reconstruction cases, we leave the LDMF transfer on the second stage for breast reconstruction in this difficult to predict clinical scenario.
Previously, the breast envelope often needs to be enlarged with an LD skin paddle to maximize the size of the implant in a single-stage reconstruction. However, this leads to a skin patch presented on the reconstructed breast which does not match the color, texture, or thickness of the native breast skin . In our new breast reconstruction protocol, tissue expansion and the use of endoscopic assistance in muscle harvest are operative modalities designed to avoid the cutaneous patch effect of the transposed musculocutaneous paddle, which results in no skin mismatch from the donor to the recipient site.
The conventional LD flap harvest requires a long incision that often results in an apparent scar over the back which becomes the main concern of the patients. The endoscopy-assisted muscle harvest technique is becoming popular in breast reconstruction because it obviates the need for an obvious posterior donor site scar by using a small lateral extension of the mastectomy incision.
Many techniques for creating the optical cavity for endoscopic operation have been described already. Some authors preferred manual traction with endoscopic retractors [11–13] or operated with the aid of traction stitches in the skin , while others favored gas inflation using trocars to fit the laparoscopic instruments [3, 15] or robotic arms [2, 9, 16, 17]. All these procedures achieved harvest of the LDMF with fewer visible scars than the conventional technique. Nevertheless, all of them created a vertical scar or three to four incisions vertically lined along the side of the chest for insertion of the trocars. Although a vertical incision is much easier to harvest the LDMF , a transverse incision is preferred for its better aesthetic outcome. Unlike setting the incision or multiple ports cut along the vertical posterior axillary line in other reports, we apply a transverse incision extending along the mastectomy scar, which enables the incision to be concealed under the axillary fold.
Dividing the LDM from its paravertebral origin and iliac attachments is the challenging part of the procedure, because of the narrow operative view and the difficulty in the resection of the distant LDM over the thorax anatomic curvature. Moreover, it is hard to control the bleeding during the medial dissection encountering the lumbar perforators, precisely where the access is most restricted. Some studies reported techniques for LDMF harvest via the mastectomy incision and axillary incision under the endoscopic guidance [11, 18]. Although these techniques have the advantage of no scar on the back, various specific retractors and other self-designed instruments are essential for the procedure. Moreover, these techniques require rich endoscopic surgery experience and a long learning curve to achieve efficiency and safety, which are quite unfriendly to beginners.
We add one more approach for endoscopy-assisted LDMF harvest to balance the difficulty of the procedure and the complication issues against the negative effects of longer scars. In this study, an additional short incision was applied on the posterior waist under the level of the posterior superior iliac ridge to facilitate the LDMF harvest, which made it easy to divide the inferoposterior origin of the muscle and perform the hemostasis. Also, this incision can be concealed perfectly when wearing pants.
The endoscopic technique does have a learning curve because of the lack of tactile sensation when using the long endoscopic instruments and the lack of depth nature from the two-dimensional video screen. Therefore, endoscopy-assisted LDMF harvest does require prolonged surgical time. Although various techniques had been employed to facilitate this procedure, the average LDMF harvest time was still around 120 ~ 240 minutes [3, 15, 19]. Even the latest da Vinci robotic technique required over 120 minutes [16, 20]. The mean LDMF harvest time in this study was 90.4 minutes, which was much shorter than previous studies. The short duration was attributed to the aid of the supplementary posterior lumbar approach. To be sure, the endoscopy-assisted harvest time can also decrease once the learning curve is overcome by the constant use of this technique.
Previous studies have demonstrated that this scarless LDMF harvest technique can be performed with a lower complication rate compared with traditional open techniques . And the most common complication of breast reconstruction with LD flap is donor site seroma . There was no donor site seroma occurrence postoperatively in this study, which is better than the 28.6% seroma formation rate in research including 14 cases undergoing endoscopic LDMF harvest for breast reconstruction . The good result can be attributed to the prolonged drainage periods. Compared with 8.0 days in a recent study applying endoscopy-assisted LDMF harvest for breast reconstruction , the mean drain time in our research was 10.1 days. As for the reason, the strict criteria for drain removal was considered (less than 20 ml VS 50 ml per day). Although the surgical drain tubes were kept for a longer time, the relevant complications like secondary infection or wound dehiscence did not arise due to the meticulous medical care.
There were several limitations in this study. First, the sample size of this research was small. Therefore, further studies involving a larger number of patients are needed to evaluate the effectiveness and safety of this type of breast reconstruction protocol. Second, although the mean follow-up time reached 11.2 months, it is not long enough to reveal unpleasant complications like capsular contracture which might occur many years after the surgery. Additionally, the final outcomes were evaluated just by the volume symmetry, while the contour symmetry including base width and projection are also important indicators to be assessed, which is believed to be involved in the subsequent researches. Despite the limitations, early success in this type of breast reconstruction protocol has indicated a good application prospect.