Abstract

Objective

Loss of breast, which is an important body marking of women, causes a huge decrease in quality of life (QoL) after treatment. In order to overcome this morbidity and increase QoL, nipple sparing mastectomy (NSM) has been developed. Even though the demand for better cosmetic results has yielded endoscopic nipple sparing mastectomy, limitations like unsuitable optical window and limited manual control of rigid-tip instruments, and struggling to keep dissection space have led robotic nipple sparing mastectomy (rNSM) to be developed.

Materials and Methods

Records of three patients who underwent to rNSM for invasive breast carcinoma with DaVinci Xi (Intuitive Surgical, Sunnyvale, CA) in affiliated hospitals of xxxxx xxxxx xxx xxxx University, Research Institute of xxxxx in 2018 were investigated retrospectively. In all breasts (n=4), dissection was started from the posterior side of breast.

Results

In the unit, 738 breast cancer patients underwent surgery between 2018 and 2019 with an NSM ratio of 31.4% (n=232). Of these patients, three underwent rNSM with DaVinci Xi robotic system. The operation was performed on the left breast in one patient, right in one, and bilateral in one patient. Only in patient #2, who was a neoadjuvant chemotherapy recipient, seroma was observed six weeks after surgery (3 weeks after removal of drains) and spontaneously resolved in 4 weeks. No other complication was seen in all patients. In the follow-up period of median 21 months, no loco-regional recurrence or distant metastasis was seen.

Conclusion

A single incision robotic mastectomy can be performed easily and safely when the dissection starts from the pre-pectoral plane rather than the subcutaneous plane.

Introduction

In early periods, radical mastectomy (i.e. extended removal of the breast and neighboring tissues) was considered as the ultimate treatment (1). However, advancements in medical oncology and surgical technique (such as proven safety and efficiency with the protection of pectoral muscles and even the skin with or without nipple areolar complex in appropriate cases, tools with increased precision) have provided surgeons and patients with a better cosmetic outcome (2). Loss of breast, which is an important body marking of women, causes a huge decrease in quality of life (QoL) after treatment (2). In order to overcome this morbidity and increase QoL, nipple sparing mastectomy (NSM) has been developed (2). After proven oncological safety, patients and surgeons demanded better cosmetic results which yielded endoscopic nipple sparing mastectomy (eNSM) (2, 3). Even though eNSM was facilitated by many authors with oncological safety, limitations like unsuitable optical window due to two-dimensional endoscopic in-line camera and limitations in manual control of rigid-tip instruments by the natural curvature of the breast, and struggling to keep dissection space, robotic nipple sparing mastectomy (rNSM) was developed in Milan, in August of 2015 (4).

The search from the Web of Science (WOS) database for“robotic”and“mastectomy” words yielded 58 results; however, only 25 of them were related to robotic nipple sparing mastectomy (4-28).

In the literature, eight studies have investigated rNSM through single incision for therapeutic or prophylactic purposes (5, 6, 9, 21, 22, 26-28). The current study is the first report of rNSM from Turkey and showed a different approach from the literature.

Material and Methods

Records of three patients who underwent to rNSM for invasive breast carcinoma with DaVinci Xi (Intuitive Surgical, Sunnyvale, CA) (robot) in Acıbadem Maslak Hospital Hospital (an affiliation of Acıbadem Mehmet Ali Aydınlar University, Research Institute of Senology) in 2018 were investigated retrospectively. Demographics and operative and histopathology information of the patients were recorded. All patients had given informed consent for rNSM prior to surgery independent from this study.

This study was approved by Acıbadem Mehmet Ali Aydınlar University, Clinical Research Evaluation Ethical Board on 27.06.2019 with number of 2019-11/24.

Patient Positioning

All surgical procedures were performed under general anesthesia. Patient lied flat supine, contralateral arm to operation side was adducted, a soft pad was placed under the ipsilateral scapula, and ipsilateral arm was positioned over the head covered with sterile covering (Figure 1). The table was positioned in 5o tilted to the contralateral side.

Set-up of the Robotic System

The robot was positioned at the opposite side of the patient, middle of the robot’s shoulder positioned to the nipple line, and arms crossed over the torso of the patient. Target markings of the robot was aligned with the incision and the nipple. Three ports of the robot were introduced through a single access system (SAS) in triangular setting to prevent collision and sustain better approximation (Figure 2). A monopolar cautery attached scissor was placed on the right arm and a bipolar cautery attached fenestrated forceps was placed on the left arm of the robot. A 30o camera (Intuitive Surgical®, Denzlingen, Germany) was introduced through the port in the top center. Following that, the other two instruments were introduced to the pouch under camera vision.

While the surgeon was sitting in the console, the assistant surgeon was waiting next to the patient to watch over the robot arms and trans-illumination (visual observation) through the breast skin to prevent injuries.

Surgical technique

A 5-cm lateral peripheral incision starting from the middle portion of the breast to the cranial direction, positioned on the anterior axillary line in parallel to the curvature of the breast, was performed (Figure 3, 4). Sentinel lymph node biopsy (SLNB) was performed through this incision with conventional open technique via radioisotope method. The incision was planned to allow axillary lymph node dissection (ALND) through the same incision after removal of the breast tissue, in case SLNB resulted positive.

After SLNB, a pouch, 3-cm in length, was dissected between the fascia and anterior side of the pectoralis muscle with Bouvie cautery to introduce SAS. After that, GelPOINT Mini (Applied Medical, Rancho Santa Margarita, CA) was positioned as SAS to the pouch, and the posterior cavity was insufflated with CO₂ gas at a pressure of 6 mmHg (Figure 5).

Posterior side of the breast was dissected with electrocautery attached scissor, while the breast tissue was handled with fenestrated forceps (Figure 6). Extension of the dissection was observed externally by the assistant surgeon next to the patient. Caution for the preservation of the perforating branch from the 2nd intercostal artery was sustained to reduce risk for loss of nipple areolar complex (NAC).

After having completed the posterior dissection, the robotic system was undocked and SAS removed. In order not to cause ischemia, 500 mcg of adrenaline was diluted in 1000 mL 0.9% NaCl solution as tumescent solution (TS). Two-hundred milliliters of TS was injected to the subdermal layer of the breast skin by liposuction cannula to sustain hydro-dissection between the skin and breast tissue with additional effect of vasoconstriction to lower bleeding. After that, an anterior pouch between the skin and breast tissue for SAS was created with scissor under direct vision and SAS was placed similarly. The anterior cavity was insufflated with CO₂ gas at a pressure of 6 mmHg (Figure 7), and dissection was performed with scissor and fenestrated forceps. Retro-nipple breast tissue was coredout and sent to frozen section assessment for malignant cells. If malignancy was detected in the frozen section, then NAC was removed.

After completion of NSM, an implant (either silicone-gel or expender according to the necessity of radiotherapy depending on the result of SLNB) was placed by a plastic, reconstructive and esthetic surgeon through the same incision.

Results

In the Breast Unit, 738 breast cancer patients underwent surgery between 2018 and 2019 with an NSM ratio of 31.4% (n= 232). Of these patients, three underwent robotic nipple sparing mastectomy with the DaVinci Xi robotic system. All patients were females.

All three patients were operated on for breast carcinoma. Patient #2 received neoadjuvant chemotherapy. The operation was performed on the left breast in one patient, right in one, and bilateral in one patient (patient #1). All patients underwent SLNB (patient #1 underwent SLNB only on the malignant side); however, ALND was not performed in any of the patients. Median age was 43 (38-47) years, median docking time (anterior and posterior in total) was 12 (10-15) minutes, median anterior dissection time was 86 (60-108) minutes, and median posterior dissection time was 32 (30-39) minutes. Median length of the rNSM was 134 (105-161) minutes. In the pathology report, all margins were clear and far from the tumor, and the retro-nipple tissue was free from tumor. None of the patients were converted to another technique, no complications observed, and no subcutaneous shaving needed. All patients were admitted on the morning of the operation day and stayed two nights after surgery. In the pathology report, the average tumor size was 25.7 ± 9 mm, margins were negative, estrogen receptor positivity was 67 ± 58%, and Ki-67 score was 49±44%. In all patients, progesterone receptor was negative and human epidermal growth factor receptor 2 (Her-2) was negative in two patients. Only in patient #2 (who received neoadjuvant chemotherapy due to axillary lymph node involvement), seroma was observed six weeks after surgery (3 weeks after the removal of drains) and spontaneously resolved in 4 weeks. No other complication was seen in all patients. In the follow-up period of median 21 (range: 19-24) months, no loco-regional recurrence nor distant metastasis was seen. Data of each patient is given in Table 1 and Table 2.

Discussion

The search from the Web of Science (WOS) database for “robotic” and “mastectomy” words yielded 58 results; however, only 25 were related with robotic nipple sparing mastectomy (4-28). Of these 25 articles, six were congress abstracts (4, 11-15), five were letters to the editor (16-20), six were case reports(5-10), and eight were original articles. Of these 14 articles (case reports and original articles), when institute of the first or majority of the authors was assumed as the origin of country, eight (57%) were originated from Asia (seven from Far East) and six (43%) were from Europe (one (7%) was co-authored from the USA).

The center where the operations were performed has a volume of 1688 breast cancer surgeries, in which 35% (n= 590) was NSM in a period of 4 years.

In the current literature, eight studies investigated rNSM through a single incision for therapeutic or prophylactic purposes. In all of these articles, authors (three different first authors: Lai H, Park H, and Toesca A) preferred to start the dissection from the subcutaneous side of the breast. Toesca, A et al. (21) and Lai, H et al. (22) have mentioned that it is needed to pull up the breast to create sufficient working space during the dissection of the breast tissue from the pectoralis major muscle, and even they insufflated the cavity with CO₂ gas at a 8 mmHg pressure. In addition, Park, H (6) has presented a gasless technique and used a special retractor (Modified Chung’s retractor) to create space.

In NSM, it is important to preserve the integrity of the skin and pectoralis muscle. Skin integrity is required to prevent necrosis, and pectoralis muscle integrity is required to preserve the retroprectoral positioned implant. It is known that direct contact of the implant with the skin will result with erosion of the skin and exposure of the implant to the atmosphere with time. There are other precautions such as the use of acellular dermal matrix; however, cost and seroma formation increase (29).

In the present study, dissection was first performed between the breast tissue and pectoralis major muscle. By this way, breast tissue is not separated from the skin and insufflated CO

2 stays only on the posterior of the breast, and thus, even a 6-mm

Hg pressure is enough to create space for dissection. Since the breast tissue is still attached to the skin, posterior dissection can be performed more precisely without injuring the pectoralis major muscle and bleeding. A stable breast tissue eases direct visualization of the second intercostal artery, which is an important blood supply to NAC, during dissection. Anterior dissection is performed after completion of the posterior dissection. Due to lower CO₂ pressure, breast gland will hang down from the skin with its own weight, and anterior dissection can be easily performed by scissor with aid of fenestrated forceps. In addition to not rising the breast tissue, complications related to air pressure, such as pneumothorax, subcutaneous emphysema, and hypercarbia can be prevented with lower CO₂ pressure (6). Extend of the dissection is observed by the assistant via palpation and trans-illumination.

While performing NSM with conventional retractors, surgeons cannot easily visualize upper quadrants through infra-mammarian fold incision. Endoscopic mastectomy, with/without insufflation, can be performed with rigid tools; however, visibility and access decrease during dissection beyond the dome of the breast, but with DaVinci Xi robotic system, these restrictions can be avoided (21, 23, 28).

Seroma was the only complication encountered in the current study, and similarly, Toesca et al. (28) have reported seroma as the most common complication. Even though patient number was small, the only complication was observed in the patient who received systemic treatment as first-line. Although we are aware that this cannot be concluded from the current study, when experience from NSM is adjoined and when first line treatment is systemic treatment, then complication increases after NSM, contrary to the literature (30).

Lai et al. (26) have utilized a higher and oblique incision located in the axilla, Toesca et al. (21) have performed the incision in the axilla on the mid axillary line, and Park et al. (6) have performed a vertical incision on the anterior axillary line but did not mention the exact position. Sarfati et al. (23) have performed the incision on the projection of the bra and proposed it could be hidden easily by the patient; however, the surgery was not performed with single incision. In this study, a 5-cm lateral peripheral incision starting from the middle portion of the breast to the cranial direction, which is positioned on the anterior axillary line in parallel to curvature of the breast, was performed. Since the incision stays on the outer border of the breast, it is hidden and with this position, it is both easy to access upper and lower quadrants in addition to medial portion of the breast and SLNB can still be performed.

Conclusion

A single incision robotic mastectomy can be performed easily and safely when the dissection starts from the pre-pectoral plane rather than the subcutaneous plane. It is important to hide the scar to improve QoL of the patient either by positioning it more laterally or on the natural curves, but it must not harden surgery.