Endoscopic Bilateral Nipple-sparing Mastectomy via a Single Axillary Incision with Immediate Pre-pectoral Implant-based Breast Reconstruction

Summary

Here, we present detailed surgical procedures for endoscopic bilateral nipple-sparing mastectomy via a single axillary incision with immediate pre-pectoral implant-based breast reconstruction. This procedure is a secure and viable method for breast cancer patients.

Abstract

Oncoplastic breast surgery, with its focus on improving cosmetic outcomes while maintaining oncological safety, has fundamentally transformed the landscape of breast cancer surgical treatment, giving rise to an array of techniques for breast reconstruction. Nipple-sparing mastectomy (NSM) with immediate implant-based breast reconstruction (IBBR) has emerged as a cornerstone in managing early breast cancer. Aligned with the principles of minimally invasive surgery, recent years have witnessed the widespread integration of endoscopic approaches in breast surgery, encompassing procedures like endoscopic breast-conserving surgery (E-BCS) and endoscopic nipple-sparing mastectomy (E-NSM), among others. Capitalizing on the advantages of inconspicuous and shorter incisions, improved visibility, and the avoidance of radiation therapy, the popularity of E-NSM with IBBR is on the rise. However, conventional E-NSM with IBBR often requires two or more incisions, which can result in suboptimal cosmetic outcomes and even prosthesis loss.This paper presents a comprehensive account of the intricate surgical procedures involved in endoscopic bilateral nipple-sparing mastectomy with immediate pre-pectoral implant-based breast reconstruction. The insights shared are drawn from the collective experience of our institution. Notable benefits associated with the described surgical approach encompass enhanced cosmetic outcomes, improved postoperative quality of life, and enhanced physiological functions attributable to the application of pre-pectoral implant-based breast reconstruction through a single incision.

Introduction

As breast cancer treatment continues to advance, an increasing number of breast surgeons are shifting their focus beyond solely addressing malignant tumors. They also place greater emphasis on addressing the post-treatment appearance and quality of life of their patients. Nipple-sparing mastectomy (NSM), characterized by comparable oncologic outcomes, favorable patient satisfaction, and cosmetic outcomes, has now become a standard surgical option for patients with bilateral early breast cancer and those undergoing prophylactic mastectomy^1,2,3.

Endoscopic breast surgery (EBS) is an emerging and forward-looking surgical approach that is gaining popularity in both nipple-sparing mastectomy (NSM) and breast-conserving surgery. When compared to traditional breast surgery methods, EBS has demonstrated superior cosmetic outcomes, increased patient satisfaction owing to its less noticeable incisions, and similar levels of oncological safety^4,5,6.

However, the conventional approach to endoscopic nipple-sparing mastectomy (E-NSM) with immediate implant-based breast reconstruction (IBBR) often requires two or more incisions, typically located in the axilla, anterior axillary line, and peri-areolar regions^4,7. Unfortunately, this technique frequently yields suboptimal cosmetic outcomes. This is especially pronounced in cases involving peri-areolar incisions, where E-NSM eliminates the vertical blood supply route to the nipple-areola complex (NAC), relying solely on the dermal vascular network for nourishment⁸. This scenario potentially leads to ischemic necrosis in the NAC. Moreover, for pre-pectoral breast reconstruction, incisions on the breast surface can create openings for infection or flap ischemia, increasing the risk of prosthetic exposure, nipple necrosis, and even prosthesis loss^7,9,10. Given the rapid advancements in endoscopic techniques and instrumentation, novel variations of E-NSM with IBBR predominantly focus on a single axillary incision and insufflation technique^11,12. These innovations offer distinct advantages, including reduced risk of nipple necrosis, decreased patient discomfort leading to quicker recovery, significantly improved cosmetic outcomes, and optimized patient benefits, among others^12,13.

This article provides a comprehensive description of the surgical procedures involved in endoscopic bilateral nipple-sparing mastectomy via a single axillary incision with immediate pre-pectoral implant-based breast reconstruction. The aim is to showcase the feasibility, exceptional cosmetic outcomes, and physiological considerations associated with this surgical approach.

To facilitate readers' comprehension of the protocol, we present a representative case for elucidation. The patient was a 33-year-old female who exhibited bilateral breast lumps on ultrasound, categorized as BI-RADS 4, with relatively large-sized lumps (Figure 1). Histopathological confirmation through Mammotome-assisted minimally invasive resection identified bilateral ductal carcinoma in situ¹⁴ (Figure 2). This young woman had bilateral nipple asymmetry and a strong desire to rectify it. Given her passion for dance, she also had a significant demand for favorable cosmetic outcomes. After introducing our surgical plan, the patient ultimately opted to undergo endoscopic bilateral nipple-sparing mastectomy via a single axillary incision with immediate pre-pectoral implant-based breast reconstruction.

Protocol

The study was approved by the Ethics Review Committee of The Sixth Affiliated Hospital, Sun Yat-sen University (No.2023ZSLYEC-171). Photographs and videos were utilized with informed consent duly obtained from the patients. The video is for educational purposes only.

1. Preoperative marking

1. Mark the inferior fold of the axilla, the edge of the breast, and the inframammary fold of bilateral breasts (Figure 3).

2. Positioning and anesthesia

1. Induce general anesthesia and perform tracheal intubation.
2. Place the patient in a supine position with bilateral arms abducted at 90°.
3. Sterilize the surgical area with povidone-iodine skin disinfectant.
4. Wrap the bilateral limbs with sterile drapes and fix them abducted at 90°.

3. Sentinel lymph node biopsy (SLNB)

1. Use a 1 mL syringe to aspirate a suspension mixture of carbon nanoparticles in saline, mixed in a 1:1 ratio to achieve a total volume of 1 mL, for the formulation of the sentinel lymph node tracer. Inject the tracer (0.3 mL) into the parenchyma of the outer upper quadrant of the breast at any 3 points, massage for 5 min, and wait for 5 min.
2. Use a 10 mL syringe to aspirate a mixture of methylene blue and saline in a 1:5 ratio to a total volume of 10 mL and inject it into the circum-mammary ligaments of the breast, known as the breast footprint¹⁵, guided by ultrasound or preoperative marking to make the boundary and extent of dissection.
   NOTE: Staining is not a necessary step in the surgery. It assists breast surgeons who have not yet overcome the learning curve to control the extent of dissection.
3. Make an approximately 4 cm curved axillary incision along the line marked previously to complete SLNB under direct vision.
   NOTE: The sentinel lymph node biopsy was examined to be negative by an intraoperative frozen section biopsy.
   1. Perform a complete axillary lymph node dissection (ALND) with the removal of level I and II axillary lymph nodes if SLNB is positive.
   2. Ensure that the anterior edge of the incision is more than 1 cm from the anterior edge of the pectoralis major muscle and does not extend beyond the anterior axillary line. If necessary, the incision can be appropriately extended posteriorly.

4. Air cavity building

1. Bend the arm of the patient on the operation side and secure it to the head rack.
2. Seek the lateral edge of the pectoralis major muscle from the axillary incision. Dissect the retro-mammary space for 2 cm and the subcutaneous flap for 3 cm under direct vision.
3. Insert the wound protector into the incision, then connect with the four-trocar single port (Figure 4). Place a 12 mm trocar above, 10 mm trocar below, and two 5 mm trocars on both sides.
4. Connect the 12 mm trocar with the constant pressure pneumoperitoneal device to construct a working space. Maintain the air cavity by applying CO₂ insufflation at 8 mmHg pressure and 40 L/min air flow.
5. Then insert an oblique-ended rigid endoscope measuring 5 mm in diameter with a viewing angle of 30° through the 10 mm trocar.
6. Insert an electric hook and laparoscopic grasping forceps through two 5 mm trocars, respectively.

5. Retromammary space dissection

1. Use the circum-mammary ligaments as the boundary of the breast, paying attention to exposing and identifying ligamentous structures¹⁵. The integrity of the ligament can be ensured by staining, finger-press, and resistance from endoscopic instruments.
   NOTE: The assistant can help with finger pressing during the operation. Additionally, the chief surgeon can temporarily suspend the endoscopic operation and do finger pressing for assessment. None of these procedures impacts observation under endoscopic vision.
2. Perform the dissection by following the sequence shown in Figure 5. Dissect the retro-mammary space under endoscopic vision using the electric hook. Extend this dissection superiorly to the subclavian ligament, medially to the parasternal ligament, inferiorly to the inframammary fold, and laterally to the lateral border of the mammary gland.
   NOTE: In this case, ductal carcinoma was confirmed preoperatively (see Figure 2), therefore, the pectoralis major fascia is completely preserved intraoperatively^16,17. This approach serves a dual purpose: it minimizes surgical trauma and postoperative discomfort, thereby improving the patient's quality of life. Additionally, preserving the pectoralis major fascia allows for secure mesh fixation, preventing prosthesis displacement.

6. Subcutaneous layer dissection

1. Pull the wound protector to reach the subcutaneous layer.
   NOTE: The following measures can ensure that surgeons have reached the subcutaneous layer. Firstly, during the air cavity-building phase, a portion of the subcutaneous flap is dissected under direct vision. Secondly, through the magnifying effect of the endoscope, the superficial fascia of the breast can be clearly observed under endoscopic vision. Thirdly, the breast is suspended on the dermal layer through Cooper's ligaments, which can be observed under the endoscope, guiding surgeons into the dissection of the subcutaneous layer¹⁸.
2. Follow the zoning dissection sequence (Figure 6) and perform the dissection with the electric hook in the following sequence: outer upper quadrant, inner upper quadrant, outer lower quadrant, retro nipple area, and inner lower quadrant.
3. Use endoscopic scissors to cut off the root of the nipple, preventing NAC necrosis caused by thermal effects.
4. Take a tissue biopsy specimen from the posterior margin of the nipple for intraoperative frozen sectioning.
5. Utilize the electric hook to carefully dissociate the inner lower quadrant of the mammary gland.
6. Remove the intact breast specimen through the axillary incision.
   NOTE: Achieving hemostasis through a single port under endoscopic vision is difficult. Using the electric hook to achieve hemostasis may lead to eschar formation at the bleeding site, potentially hindering the observation of the bleeding point and posing a risk of skin burns.

7. Implant placement

1. Weigh the breast specimen, measure the diameter of the implant cavity, and combine the preoperative measurements to select the appropriate prosthesis.
2. Irrigate the implant cavity with 2,000 mL of warm, sterile distilled water.
3. Adjust the implant cavity pressure to 5 mmHg to carefully inspect the implant cavity and complete hemostasis under endoscopic vision.
4. Soak the implant cavity with 0.45%-0.55% povidone-iodine solution for 10 min, disinfect the surgical region, and change gloves.
5. Cover the prosthesis fully with 2 meshes. Suture the meshes with 3-0 absorbable sutures and simple interrupted sutures for fixation.
6. Insert the prosthesis into the implant cavity.

8. Drainage

1. Place one drainage tube on each of the inframammary fold and axilla in the subcutaneous layer, maintained under low negative pressure suction.
2. Close the axillary incision wound with 4-0 absorbable sutures (Figure 7).

9. Postoperative nursing

1. Apply an elastic bandage to achieve pressure dressing of the breast and axilla.
2. Perform proper pressure dressing at the axillary wound.
   NOTE: It is mainly pressurized to the superior and inferior margins of the prosthesis rather than the nipple-areolar complex in order to prevent ischemic necrosis of the NAC.
3. Administer proper prophylactic antibiotics for 24 h (1.5 g of cefuroxime dissolved in 100 mL of saline) administered intravenously.
4. Pay attention to the blood circulation of the NAC when changing the wound dressing. Apply nitroglycerin around the NAC to promote blood circulation if necessary. Look at the color of the NAC, the presence of edema, and bruising.
5. Maintain the patency of the drainage tubes; observe and record the color, nature, and drainage volume of the drainage fluid daily. If the drainage volume is less than 20 mL for 24 h for 3 days, remove the drainage tubes.
6. Ask the patient to perform functional exercises of the upper limbs for 2 weeks postoperatively¹⁹.
7. Ensure the patient wears a pressure garment for 3-6 months starting on the 2^nd postoperative day.
8. Ensure the patient performs breast implant displacement exercises for smooth implants^20,21,22.
   NOTE: The contralateral breast is operated in the same way.

Discussion

Represented by mastectomy, conventional breast surgery often yields unsatisfactory cosmetic outcomes and can adversely affect the functioning of the affected upper limb. This situation can cause considerable psychological distress, ultimately resulting in a reduced postoperative quality of life for patients^24,25,26. Minimally invasive surgery represents a pivotal advancement in modern surgical practices. With the introduction of endoscopic techniques, significant improvements have been made to address the shortcomings of conventional surgery. Simultaneously, breast reconstruction has gained popularity as it offers the ability to restore the breast contour in breast cancer patients²⁴. It has been shown to reduce the incidence of postoperative depression among breast cancer patients and enhance their postoperative quality of life²⁷. This aligns with the emerging paradigm of the "biopsychosocial" medical model. With the integration of endoscopic techniques and breast reconstruction, breast surgery has entered a novel phase characterized by a focus on humanization and the optimization of patient outcomes. These objectives stand as the central tenets we strive for and uphold.

When compared with conventional E-NSM with IBBR, the benefits of endoscopic nipple-sparing mastectomy via a single axillary incision with immediate pre-pectoral implant-based breast reconstruction are evident. Firstly, this approach allows for the completion of all surgical procedures through a discreet single axillary incision, ensuring minimal visibility and achieving favorable postoperative cosmetic outcomes^11,28,29. Moreover, the technique of E-NSM disrupts the vertical blood supply system to the nipple-areola complex (NAC), relying exclusively on the dermal vascular network. Avoiding incisions on the breast skin reduces the likelihood of NAC and flap ischemic necrosis^8,30,31,32. In comparison to subpectoral reconstruction, pre-pectoral reconstruction is simpler, resulting in a more natural breast contour and minimizing chest functional deficits and pain³³. However, in the context of pre-pectoral reconstruction, the absence of protection from the pectoralis major muscle means that direct contact between implants or meshes and the breast surface incision could lead to prosthetic exposure or even loss. Such complications may arise due to flap infection or ischemic necrosis^34,35. Hence, the technique we present not only ensures the safety of tumor management but also yields superior cosmetic outcomes and a higher postoperative quality of life.

Several critical technical aspects warrant attention. First, it is imperative to preoperatively demarcate the extent of the patient's breast. Experienced surgeons can preoperatively manually mark the extent of the breast, while less experienced surgeons can employ preoperative ultrasound to delineate the breast boundaries. The circummammary ligaments are considered the natural boundaries of the breast and can serve as anatomical landmarks for breast dissection^15,36. They can be observed both preoperatively with ultrasound and intraoperatively under endoscopic vision. Second, follow the dissection sequence from the retromammary space to the subcutaneous layer of the breast, which is recognized as a convenient and efficient strategy³⁷. Third, while conducting the dissection of the retromammary space, meticulous attention is required when separating along the edges of the breast. This can be assessed through the utilization of dyes, finger press, and the pressure feedback sensation from endoscopic instruments. Whether through preoperative marking or employing techniques such as dyeing to delineate the breast boundaries, the central aim remains to guide surgeons to expose and identify the circummammary ligaments and precisely excise mammary glands. This is crucial for breast reconstruction surgery and contributes to achieving favorable postoperative cosmetic outcomes³⁶. Fourth, it is advisable to ensure consistent flap thickness during the dissection of the subcutaneous layer within the breast. A technique we employ involves turning off the operating room lights and observing the extent to which the endoscope's light source penetrates through the breast's surface skin within the cavity, thereby assessing the uniformity of flap thickness.

There are some limitations to this method. First, even though E-NSM with IBBR has garnered extensive adoption and is considered a relatively mature technique, there remains a dearth of high-level evidence from evidence-based medicine to definitively establish its safety. Additionally, within our institution, we exclusively employ the single-port method for conducting endoscopic breast surgery. This decision is rooted in the fact that the lead surgeon has successfully overcome the learning curve and holds the belief that the single-port approach can reduce the number of incisions, obscure scars, and diminish the occurrence of ischemic necrosis in both the NAC and flap. Nevertheless, it's important to note that this perspective is subjective and currently lacks controlled studies to substantiate our standpoint.

In conclusion, when considering specific patients, the endeavor to enhance practice for improved cosmetic outcomes and heightened patient satisfaction holds significant value. This endeavor encapsulates the ethos of humanistic care and aesthetics. Our collective aspirations encompass the pursuit of beauty and the assurance of maximizing patient benefits.

Materials

Name	Company	Catalog Number	Comments
Carbon nanoparticles suspension injection	LUMMY	H20041829
Drainage tube	Yangtze River	20142140359
Electric hook	TNKJ	20222010212
Endoscopic scissors	YOUSHI	P20200702015
5-mm 35cm 30° rigid endoscope	Karl Storz	26046BA
Implant	MENTOR	9718984-037
Laparoscopic grasping forceps	YOUSHI	P20200108013
Mesh	pfm medical titanium gmbh	20163131539
Methylene blue	JUMPCAN	H32024824
1 mL syringe (0.45×16RWLB)	WEGO	20163141593
Single port	SURGAID	5012151092
10 mL syringe (0.8×38TWLB)	WEGO	20163141593