Traditional surgical education is based on observation and assistance in surgical practice. Recently introduced deep learning (DL) techniques enable the recognition of the surgical view and automatic identification of surgical landmarks. However, there was no previous studies have conducted to develop surgical guide for robotic breast surgery. To develop a DL model for guiding the dissection plane during robotic mastectomy for beginners and trainees. Ten surgical videos of robotic mastectomy procedures were recorded. Video frames taken at 1-s intervals were converted to PNG format. The ground truth was manually delineated by two experienced surgeons using ImageJ software. The evaluation metrics were the Dice similarity coefficient (DSC) and Hausdorff distance (HD). A total of 8,834 images were extracted from ten surgical videos of robotic mastectomies performed between 2016 and 2020. Skin flap dissection during the robotic mastectomy console time was recorded. The median age and body mass index of the patients was 47.5 (38–52) years and 22.00 (19.30–29.52) kg/m2, respectively, and the median console time was 32 (21–48) min. Among the 8,834 images, 428 were selected and divided into training, validation, and testing datasets at a ratio of 7:1:2. Two experts determined that the DSC of our model was 0.828 ± 5.28 and 0.818 ± 6.96, while the HDs were 9.80 ± 2.57 and 10.32 ± 1.09. DL can serve as a surgical guide for beginners and trainees, and can be used as a training tool to enhance surgeons’ surgical skills.

PURPOSE:Oncologic and surgical outcomes of robot-assisted nipple-sparing mastectomy (RNSM) compared to conventional nipple-sparing mastectomy (CNSM) is under investigation. This study compared the clinical outcomes of recurrence-free survival and postoperative complication after RNSM and CNSM. MATERIALS AND METHODS:We retrospectively reviewed data of 401 patients who underwent da Vinci Si/Xi/SP-assisted RNSM or CNSM with immediate reconstruction between November 2016 and November 2020 at a single institute. Oncological outcomes were collected until March 2022. Primary endpoints were long-term outcomes, such as local recurrence, distant metastasis, disease-free survival, overall survival, and postoperative complications, while secondary endpoints were pathology results, and oncological outcomes. RESULTS:Patients underwent RNSM (n=162) or CNSM (n=239). Of RNSM cases, 9 (5.6%) were performed using the da Vinci Si System, 96 (59.3%) using the da Vinci Xi System, and 57 (35.2%) using the da Vinci SP System. No significant difference in recurrence-free survival was found between the RNSM and CNSM group, and both groups had a median follow-up of 37 months. The recurrence rate in RNSM patients after a median follow-up of 24.5 months was 3.8%, compared with 5.9% in CNSM patients after a median follow-up of 42 months. No difference in recurrence was seen among RNSM patients with respect to surgical systems (multiport vs. SP, p =0.136). In addition, grade III postoperative complication rate was lower in patients with RNSM than in those with CNSM. Transfusion was only applied in 6.2% of patients. CONCLUSION:Robot-assisted surgical systems can be safely used to perform nipple-sparing mastectomy in patients with early breast cancer.

Purpose: The use of advanced energy devices for mastectomy and axillary lymph node dissection can reduce perioperative blood loss, seroma formation, and drainage duration/volume. Retraction using fiberoptic retractors can help visualize deep and narrow surgical fields. We aimed to compare the postoperative outcomes between single-incision breast-conserving surgery (SIBCS) and conventional breast-conserving surgery (CBCS) with axillary staging using advanced energy devices and conventional equipment, respectively. Materials and Methods: We retrospectively reviewed the medical records of 244 patients who underwent BCS with axillary surgery between March 2018 and September 2019 at Severance Hospital. The patients were grouped based on the device used to aid in axillary staging: CBCS group (n=117) used conventional electrocautery; and SIBCS group (n=127) used advanced energy devices and fiberoptic retractors. The two groups were compared for postoperative outcomes. Results: The mean patient age was 55.9 and 53.1 years in the CBCS and SIBCS groups, respectively. Incision size was significantly smaller in the SIBCS group than in the CBCS group (6.3 +/- 2.1 cm vs. 7.5 +/- 2.5 cm, p=0.044). There were no significant differences between the two groups in terms of operating time (126.0 +/- 40.0 min vs. 127.0 +/- 63.0 min, p=0.828), operative blood loss (11.0 +/- 31.0 mL vs. 7.0 +/- 18.0 mL, p=0.100), drainage duration (7.0 +/- 3.0 d vs. 8.0 +/- 4.0 d, p=0.288), and complications (1.70% vs. 2.36%, p=0.523). Conclusion: Using advanced energy devices for SIBCS with axillary staging reduced incision size and provided better cosmetic outcomes compared to those using the conventional method. Advanced energy devices may offer better surgical outcomes in patients who undergo BCS with axillary staging.

PURPOSE:The partner and localizer of breast cancer 2 (PALB2) mutation is a predisposition to breast cancer development. However, limited clinical data are available for the Korean population. Therefore, this study aimed to compare the characteristics and oncological outcomes of patients with PALB2-mutated and non-mutated PALB2 in Korea. METHODS:A total of 1,463 breast cancer (BRCA) 1/2 mutation-negative breast cancer underwent comprehensive multigene sequencing between 2016 and 2019 at Severance Hospital, Seoul, Korea. Clinicopathological data and oncological results of PALB2 mutated patients were prospectively collected and compared with those of the non-mutated group. RESULTS:PALB2 mutations were identified in 1.2% (17/1,463) of the patients. The median age at diagnosis was 46 (30-73) years, and the median tumor size was 1.8 (0.05-3.5) cm. All patients with PALB2 mutations had histologic grades II-III, and a triple-negative subtype was found in 23.5% (4/17); however, there were no significant differences in clinicopathological data between the groups. During the median follow-up time of 38.5 months, locoregional recurrence occurred in 4.2% (44/1,043), distant recurrence was reported in 3.0% (31/1,043), and contralateral breast cancer was diagnosed in 0.8% (9/1,043) of patients, with no significant difference observed between the groups. All-cause mortality was observed in 1.8% (19/1,028) of the non-mutated group and none in the PALB2 mutation group. However, survival analyses demonstrated no significant differences in all-cause mortality (p = 0.524) and recurrence-free survival (p = 0.319). CONCLUSION:Clinicopathological features and oncological outcomes of PALB2 mutated breast cancer were not significantly different from those of non-mutated breast cancer in the Korean population.

Background: Axillary evaluation is unnecessary for pure ductal carcinoma in situ (DCIS); however, it is performed because of the risk of upstaging to invasive cancer. We assessed the role of intraoperative frozen section (IOF) biopsy in reducing invasive cancer upstaging and axillary evaluation in preoperative DCIS patients. Methods: We reviewed patients with preoperative DCIS who underwent breast-conserving surgery (BCS) with IOF biopsy. Positive IOF biopsy findings were defined as the presence of invasive or micro-invasive cancer. The IOF biopsy and permanent pathology findings were compared. Results: Seventy-eight patients underwent BCS with IOF biopsy. Six patients showed positive IOF biopsy findings; five of these patients showed concordant permanent pathology findings. Sentinel lymph node biopsy (SLNB) was positive in one patient. Thirteen patients with invasive breast cancer were missed by IOF biopsy; they underwent SLNB during the second surgery. None of them had metastatic lymph nodes. The sensitivity and specificity of IOF biopsy were 27.7% and 98.3%, respectively, with 82.1% accuracy. None of the other factors showed statistically significant relationships with the permanent pathology findings, except for the IOF biopsy findings. Conclusion: IOF evaluation can aid in detecting the invasiveness of tumors in patients with preoperative DCIS.

Caveolae are 50-100 nm plasma membrane invaginations, which function in cell signaling and transcytosis, as well as in regulating cellular cholesterol homeostasis. These subcompartments of the plasma membrane are characterized by the presence of caveolin proteins. Recent studies have indicated that caveolae may be involved in the regulation of cellular cholesterol efflux to HDL, as well as selective uptake mediated by SR-BI. In the present study, we have determined the effect of caveolin-1 overexpression in mouse liver on plasma lipoprotein metabolism. We evaluated this effect using an adenovirus-mediated gene delivery system. C57BL/6J mice were injected with adenoviruses encoding either caveolin-1 (Adcav-1) or green fluorescent protein (AdGFP) together with a transactivator adenovirus (AdtTA). We found that, after adenovirus injection, caveolin-1 was overexpressed in hepatocytes. Moreover, the recombinant protein was localized to the plasma membrane. We also found that caveolin-1 overexpression induced a marked change in the lipoprotein profile of injected animals. In caveolin-1 overexpressing animals, plasma HDL-cholesterol levels were found to be approximately 2-fold elevated, as compared with control animals. To determine the effect of caveolin-1 on SR-BI-mediated selective uptake, we infected murine hepatocytes in culture with an adenoviral vector carrying the caveolin-1 cDNA or GFP as a control protein. We show that, in primary cultures of hepatocytes, caveolin-1 inhibits DiI-HDL uptake mediated by SR-BI. This result would mechanistically explain the increased plasma HDL-cholesterol levels we observed in caveolin-1 adenovirus-injected animals. In addition, caveolin-1 expression increased the secretion of apolipoprotein A-I in cultured hepatocytes and increased apolipoprotein A-I plasma levels in mice. Our study therefore demonstrates an important role for caveolin-1 in regulating HDL metabolism.

BACKGROUND:Robotic nipple-sparing mastectomy (RNSM) has emerged as a new treatment option for breast cancer and risk-reducing mastectomy (RRM) for women who have a high risk of pathogenic variants. Even though several studies have reported that RNSM is a feasible procedure, some argue that it should only be performed by specialized surgeons, and data on oncologic outcomes and patient-reported outcomes (PROs) are limited. Recently, the United States Food and Drug Administration and several surgeons warned that robotic breast surgery should be performed only by specialized surgeons and recommended that the benefits, risks, and alternatives of all available treatment options be discussed with patients so they can make informed treatment decisions. The Korea Robot-Endoscopy Minimal Access Breast Surgery Study Group (KoREa-BSG) has been established to evaluate, standardize, and teach this state-of-the-art procedure. We have designed a multicenter prospective cohort study entitled Mastectomy with Reconstruction Including Robot Endoscopic Surgery (MARRES) to report surgical, PRO, and oncologic outcomes.METHODS:MARRES is a multi-institution cohort study prospectively collecting data from patients undergoing mastectomy and reconstruction. The patient inclusion criteria are adult women older than 19 with breast cancer or a high risk of breast cancer (patients with BRCA1/2, TP53, PALB2 mutations, etc.), who have scheduled therapeutic or RRM and want immediate reconstruction. Surgical outcomes, including pre- and postoperative photos, oncologic outcomes, cost-effectiveness, and PRO, are collected. The primary endpoints are postoperative complication rates within 30 postoperative days and the Clavien-Dindo grade of postoperative complications within 180 postoperative days. The secondary endpoints are 5-year postoperative recurrence-free survival and cancer incidence rate (for those who underwent RRM), patient satisfaction with reconstruction expectations preoperative (baseline) and results within 6 to 12 postoperative months, surgeon satisfaction with postoperative results in 6 postoperative months, and cost-effectiveness of the definitive surgery. Patient recruitment will be completed in April 2025, and the target number of enrolled patients is 2000.DISCUSSION:This study will provide evidence about the surgical outcomes, oncologic outcomes, and patient satisfaction with RNSM and endoscopic nipple-sparing mastectomy (NSM), compared with conventional NSM.TRIAL REGISTRATION:ClinicalTrials.gov Identifier NCT04585074. Registered April 8, 2020.

BACKGROUND:Robotic nipple-sparing mastectomy (RNSM) has been developed to reduce conspicuous scar and increase the quality of life in women. This study aimed to evaluate the surgical and oncologic outcomes of RNSM with immediate breast reconstruction (IBR) compared with conventional nipple-sparing mastectomy (CNSM).PATIENTS AND METHODS:This international multicenter, pooled analysis of individual patient-level data enrolled a total of 755 procedures in 659 women (609 had breast cancer and 50 underwent risk-reducing mastectomy) who underwent nipple-sparing mastectomy with IBR. Surgical and oncologic outcomes, including 30-days postoperative (POD 30d) complication rate, nipple necrosis rate, grade of Clavien-Dindo classification, disease-free survival, and overall survival, were evaluated. Propensity score-matched analyses were performed to adjust for confounding factors.RESULTS:The median age of both the RNSM and CNSM groups was 45 years. The RNSM group had lower body mass index (BMI) and a higher proportion of benign disease compared with the CNSM group. POD 30d complications and postoperative complication grade III rates were lower in the RNSM group than in the CNSM group (p < 0.05). The nipple necrosis rate was 2.2% and 7.8% for RNSM and CNSM, respectively (p = 0.002). After propensity score matching, significantly lower rates of POD 30d complications, nipple necrosis, and postoperative complication grade III occurred in the RNSM group than in the CNSM group (all p < 0.05). Oncologic outcomes were not significantly different between the two groups.CONCLUSION:RNSM can provide better cosmetic results with favorable surgical and oncologic outcomes for women with early breast cancer or BRCA mutation.

Background As patients tend to be diagnosed with breast cancer at an early stage, the demand for better cosmetic outcomes has increased. Several studies revealed that robot-assisted nipple-sparing mastectomy (RNSM) shows favorable outcomes. The aim of the study was to reveal the feasibility of RNSM using the da Vinci single-port (SP) system with a minimal incision, hidden in the arm. Methods From 2018 to 2021, 81 cases (70 patients) were retrospectively reviewed. Clinicopathologic characteristics, operative outcomes, and postoperative complications were evaluated. The operative outcomes were analyzed using the Mann-Whitney U test. Results The median age was 42 years (range, 26-60 years). Bilateral RNSM was performed in 11 (27.2%) patients. The median size of the initial skin incision was 40 mm (range, 20-55 mm). Immediate reconstruction with direct-to-implant was performed in 54 (66.7%) patients and deep inferior epigastric perforator (DIEP) flaps in 15 (18.5%) patients. Postoperative complications of Clavien-Dindo Classification III occurred in six (7.5%) patients. Patients reconstructed with a DIEP flap had large breasts with more severe ptosis, yet grade III complications did not occur. Conclusions RNSM using the SP system can be applied for curative and risk-reducing mastectomy, regardless of breast size or ptosis grade.

Robotic surgical systems enable surgeons to perform precise movement in the surgical field using high-resolution 3D vision and flexible robotic instruments. We aimed to evaluate the feasibility and safety of performing axillary lymph node dissection using a robotic surgical system in patients with node-positive breast cancer. Thirty-two women with breast cancer who underwent robot-assisted nipple-sparing mastectomy (RNSM) and level I/II axillary lymph node dissection were analyzed. Patients were divided into two groups: RNSM with conventional axillary lymph node dissection (CALND) vs. RNSM with robotic axillary lymph node dissection (RALND). Clinicopathological features and surgical outcomes were analyzed. The median age of the patients was 44 (range 20–59) years. Eleven patients underwent RALND. None of the clinicopathologic features differed between the two groups. There were no statistically significant differences in surgical outcomes, except for the final incision size, between the two groups. The proportion of cases with an incision ≤ 40 mm was 63.6

PURPOSE:Advanced energy devices, including electrosurgical bipolar systems or ultrasonic shears, are widely used in various surgeries. An electrosurgical bipolar device allows surgeons to grasp and dissect tissues, as well as simultaneously ligate and cut vessels and lymphatics during surgery. This study aimed to evaluate the effects of advanced bipolar energy devices on the reduction in seroma formation during mastectomy, axillary staging, and/or reconstruction.METHODS:This prospective randomized clinical trial with a 1:1 ratio compared the use of an electrosurgical bipolar device, LigaSureTM (LGS), against conventional cut-and-ligate techniques in mastectomy with axillary procedures for patients with breast cancer. A total of 82 patients with breast cancer who underwent definitive surgery were enrolled in this study. The primary endpoint was the total drainage volume after surgery.RESULTS:The clinicopathological characteristics of the two groups were not significantly different. The total postoperative drainage volume was significantly lower in the LGS group than in the control group (756.26 mL vs. 1,167.74 mL, p = 0.009). The actual postoperative drainage volume and duration also decreased significantly in the LGS group compared with those in the control group (all p < 0.05). The rate of postoperative complications was lower in the LGS group than in the control group (9.8% vs. 27.5%, p = 0.05).CONCLUSION:Electrosurgical bipolar devices showed better performance in terms of decreasing postoperative drainage during mastectomy and axillary staging and/or reconstruction.

Objective: The aim of this study was to present the results of early experience of robot-assisted nipple sparing mastectomy (RANSM). Background: RANSM improves cosmetic outcomes over conventional nipple-sparing mastectomy. However, data on the feasibility and safety of the RANSM are limited. Methods: Patients who underwent RANSM with immediate breast reconstruction as part of the Korea Robot-endoscopy Minimal Access Breast Surgery Study Group (KoREa-BSG) from November 2016 to January 2020 were enrolled. clinicopathologic characteristics, perioperative complications, and operation time were collected. Results: Overall, 73 women underwent 82 RANSM procedures conducted by 11 breast surgeons at 8 institutions. The median patient age was 45.5 years old (20-66 years), and 52 (63.4%) patients were premenopausal. Invasive breast cancer was noted in 55 cases (40 cases were stage i, 11 cases were stage ii, and 4 cases were stage iii, respectively) and ductal carcinoma in-situ was recorded in 20 cases. Of those, 3 patients with BRCA1/2 mutation carriers underwent contralateral risk-reducing RANSM. The median length of hospitalization was 12.0 days (5.0-24.0 days). The incision location was the mid-axillary line and the median incision length was 50.0 mm (30.0-60.0 mm). Median total operation time, median total mastectomy time, and median reconstruction time was 307.0 minutes (163.0-796.0 minutes), 189.5 minutes (97.5-325.0 minutes), and 119.5 minutes (45.0-689.0 minutes). Only 2 cases (2.5%) required reoperation. Nipple ischemia was found in 9 cases (10.9%) but only 1 case (1.2%) required nipple excision given that 8 cases (9.7%) resolved spontaneously. Skin ischemia was observed in 5 cases (6.1%) and only 2 (2.4%) cases needed skin excision whereas 3 cases (3.6%) resolved spontaneously. There was no conversion to open surgery orcases of mortality. The mean time for mastectomy among surgeons who performed more than 10 cases was 182.3 minutes (+/- 53.7, minutes) and 195.4 minutes (+/- 50.4, minutes). Conclusion: This was the first report of RANSM conducted in the KoREa-BSG. RANSM is technically feasible and acceptable with a short learning curve. Further prospective research to evaluate surgical and oncologic outcomes is needed.

Nipple-areolar complex (NAC)-related complications are common during nipple-sparing mastectomy (NSM), with obesity as a risk factor. Although the incidence of NAC-related complications after robotic NSM (RNSM) with immediate breast reconstruction (IBR) is lower than that after conventional NSM, it remains one of the most unwanted complications. We aimed to evaluate body composition-based risk factors for NAC-related complications after RNSM with IBR. Data of 92 patients with breast cancer who underwent RNSM with IBR using direct-to-implant or tissue expander from November 2017 to September 2020 were analyzed retrospectively. Risk factors for NAC-related complications were identified with a focus on body composition using preoperative transverse computed tomography at the third lumbar vertebra level. Postoperative complications were assessed for 6 months. The most common complication was NAC ischemia, occurring in 15 patients (16%). Multivariate analysis revealed a low skeletal muscle index/total adipose tissue index (SMI/TATI) ratio as an independent NAC ischemia risk factor. An increase in the SMI/TATI ratio by one decreased the incidence of NAC ischemia by 0.940-fold (p = 0.030). A low SMI/TATI ratio is a risk factor for postoperative NAC ischemia in patients undergoing RNSM with IBR for breast cancer. Preoperative body composition-focused evaluation is more valuable than simple body mass index assessment.

Purpose Nipple-sparing mastectomy (NSM) includes various techniques, including conventional or endoscopic mastectomies. Since the introduction of robot-assisted NSM (RANSM) in 2015, 2 main methods have been used: gasless and gas-inflated techniques. The aim of this study was to compare clinicopathologic characteristics, surgical outcomes, and postoperative complications between patients treated with gasless RANSM and those treated with gas-inflated RANSM. Methods We conducted a retrospective study of women who underwent gasless or gas-inflated RANSM with immediate breast reconstruction between November 2016 and May 2019. The indications for RANSM were early breast cancer, interstitial mastopathy, or BRCA1/2 mutation carriers. Clinicopathologic characteristics, surgical outcomes, and postoperative complications were analyzed. The severity of complications was graded using the Clavien-Dindo system. Results A total of 58 RANSM procedures were performed in 46 women: 15 cases of gasless RANSM and 43 cases of gas-inflated RANSM. The proportion of node-negative disease was higher in the gas-inflated group (97.1%) than in the gasless group (69.2%, p = 0.016). Adjuvant radiotherapy was administered in 30.6% of the cases in the gasless group and only 5% of the cases in the gas-inflated group. Other clinicopathological factors were not significantly different between the groups. Regarding surgical outcomes, the initial incision was 1 cm longer in the gasless group (5.17 ± 0.88 cm) than that in the gas-inflated group (4.20 ± 1.05 cm; p = 0.002). The final incision was also longer in the gasless group (5.17 ± 0.88 cm) than that in the gas-inflated group (4.57 ± 1.07 cm; p = 0.040). Operation time, complication rate, and complication grade were not significantly different between the 2 groups. Conclusion In this study, there were no significant differences in surgical outcomes or postoperative complications between gasless and gas-inflated RANSM, except for a longer incision with the gasless technique. Both techniques are reasonable options for RANSM followed by immediate reconstruction.

Aims: Nipple-sparing mastectomy (NSM) is a surgical procedure for patients with breast cancer without nipple-areolar complex (NAC) involvement. Robotic NSM (RNSM) with immediate breast reconstruction has been recently introduced; however, reports regarding RNSM are still lacking. Therefore, this study aimed to evaluate the postoperative assessment with a focus on postoperative pain of RNSM with prepectoral immediate prosthesis breast reconstruction (IPBR) compared with conventional NSM (CNSM) in patients with breast cancer without NAC invasion. Methods: This retrospective study included 81 patients who underwent RNSM (n = 40) or CNSM (n = 41) with prepectoral IPBR using direct-to-implant or tissue expander between January 2018 and June 2020. The primary endpoint was to compare postoperative pain intensity based on a numerical rating scale (NRS). The secondary endpoint was to evaluate the postoperative recovery profile, including postoperative nausea/vomiting (PONV) and complications. Results: A statistical difference was observed in the resting NRS scores at 0-6 postoperative hours between the RNSM and CNSM groups (3.2 ± 1.5 versus 4.2 ± 1.6, respectively; Bonferroni corrected P = 0.005), however, no difference was shown at other time periods. Also, no between-group difference was found in the NRS scores for acting pain within 48 postoperative hours and the number of patients requiring additional analgesics. Conclusions: Despite a statistical difference in the resting NRS scores during the early postoperative phase, the absence of any significant difference in the requirement of additional analgesics between the groups suggested that RNSM does not significantly attenuate postoperative pain intensity.

Purpose: According to the American Joint Committee on Cancer’s 8th Edition Manual, lobular carcinoma in situ (LCIS) is no longer considered a malignant disease, although it may be a precursor to the development of breast cancer. The present study aimed to evaluate the clinicopathological features and prognosis of LCIS. Methods: This study retrospectively analyzed clinicopathological features and prognosis data of LCIS among patients who underwent breast surgery at Severance Hospital, Seoul, South Korea from 1991 to 2016. Results: Of the 47 patients, 49 cases of LCIS were confirmed by postoperative pathology. The mean patient age was 48.15±8.34 years. Most patients (81.6%) did not have palpable tumors at diagnosis, and 51.0% showed no microcalcification on mammography. Breast-conserving surgery was performed more frequently than total mastectomy (77.6% vs. 22.4%). The mean tumor size was 1.63±2.11 cm. There were only 3 cases of pleomorphic LCIS. Hormone receptor-positive tumors were noted in 47 cases, however, the hormone receptor status was unknown in the other 2 cases. There were no LCIS recurrences or deaths during the follow-up period (mean 56 months). Conclusion: LCIS is often incidentally diagnosed without clinical symptoms, especially in women aged <50 years. The prognosis of LCIS is excellent in cases that are surgically treated.

Robotic nipple-sparing mastectomy (RNSM) provides better cosmetic outcomes and improves the quality of life of women with breast cancer. However, this has not been widely adapted due to the lack of well-structured training programs. The present study aimed to report the establishment of cadaveric and animal skill laboratory training programs for RNSM and the participants' perception on the training programs. We performed 24 RNSMs using 11 cadavers and one porcine model. Then, the skill laboratory characteristics were reviewed. Five trainers and 10 trainees participated in the programs. The first four cadaveric RNSMs with latissimus dorsi flaps and implants were performed using the da Vinci Si® system. We performed 14 and six RNSMs using the Xi® and SP® systems, respectively. The scores for questionnaires on the satisfaction with the training consisted of the trainees' perceived goals in attending the course, teaching/learning environment, and teaching staff performance. The scores were excellent. Cadaveric or porcine RNSM skill laboratory training may be essential programs that can provide safe and efficient training.

PurposeThis study is to directly compare surgical outcomes between conventional nipple-sparing mastectomy (CNSM) and robot-assisted nipple-sparing mastectomy (RNSM).Materials and MethodFor this case–control study, 369 cases of 333 patients who underwent CNSM or RNSM with immediate reconstruction between November 2016 and January 2019 at Severance Hospital in Seoul, Republic of Korea were reviewed. Patients with stage IV breast cancer (n = 1), receiving neoadjuvant chemotherapy (n = 43), or subjected to previous operations (n = 14) or radiotherapy on the breasts were excluded. The main outcomes were comparing rates of post-operative complications, of high-grade post-operative complications as defined by the Clavien-Dindo classification, and nipple necrosis between the CNSM and the RNSM groups.ResultsA total of 311 cases, including 270 CNSMs and 41 RNSMs, were analyzed. The rates of post-operative nipple necrosis (p = 0.026, 2.4 vs. 15.2%) and of high-grade post-operative complications (p = 0.031, 34.8 vs. 17.1%) in the RNSM group were significantly lower than those in the CNSM group.ConclusionRNSM was associated with lower rates of high-grade post-operative complications and nipple necrosis than CNSM for patients with small breast volumes and less ptotic breasts.

Objective: The aim of this study was to present the results of early experience of robot-assisted nipple sparing mastectomy (RANSM). Background: RANSM improves cosmetic outcomes over conventional nipple-sparing mastectomy. However, data on the feasibility and safety of the RANSM are limited. Methods: Patients who underwent RANSM with immediate breast reconstruction as part of the Korea Robot-endoscopy Minimal Access Breast Surgery Study Group (KoREa-BSG) from November 2016 to January 2020 were enrolled. clinicopathologic characteristics, perioperative complications, and operation time were collected. Results: Overall, 73 women underwent 82 RANSM procedures conducted by 11 breast surgeons at 8 institutions. The median patient age was 45.5 years old (20–66 years), and 52 (63.4%) patients were premenopausal. Invasive breast cancer was noted in 55 cases (40 cases were stage i, 11 cases were stage ii, and 4 cases were stage iii, respectively) and ductal carcinoma in-situ was recorded in 20 cases. Of those, 3 patients with BRCA1/2 mutation carriers underwent contralateral risk-reducing RANSM. The median length of hospitalization was 12.0 days (5.0–24.0 days). The incision location was the mid-axillary line and the median incision length was 50.0 mm (30.0–60.0 mm). Median total operation time, median total mastectomy time, and median reconstruction time was 307.0 minutes (163.0–796.0 minutes), 189.5 minutes (97.5–325.0 minutes), and 119.5 minutes (45.0–689.0 minutes). Only 2 cases (2.5%) required reoperation. Nipple ischemia was found in 9 cases (10.9%) but only 1 case (1.2%) required nipple excision given that 8 cases (9.7%) resolved spontaneously. Skin ischemia was observed in 5 cases (6.1%) and only 2 (2.4%) cases needed skin excision whereas 3 cases (3.6%) resolved spontaneously. There was no conversion to open surgery orcases of mortality. The mean time for mastectomy among surgeons who performed more than 10 cases was 182.3 minutes (± 53.7, minutes) and 195.4 minutes (± 50.4, minutes). Conclusion: This was the first report of RANSM conducted in the KoREa-BSG. RANSM is technically feasible and acceptable with a short learning curve. Further prospective research to evaluate surgical and oncologic outcomes is needed.