{"paper_id":"331e915e-3be0-4cb0-92c2-e1574f22d5ef","body_text":"Single-Port Insufflation Technique for Endoscopic Nipple-Sparing Mastectomy: Initial Experience and Learning Curve. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Single-Port Insufflation Technique for Endoscopic Nipple-Sparing Mastectomy: Initial Experience and Learning Curve. TERESA RAMOS GRANDE, Isable Silva Benito, Andres Juan Fernandez, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6237635/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background In recent years, breast surgery has undergone considerable development in the field of minimally invasive techniques such as endoscopic (E-NSM) or robotic (R-NSM) nipple sparing mastectomy. However, access to robotic platforms is not always possible. In this study, we present our initial experience with E-NSM through a single port and insufflation with immediate reconstruction (SPIE-NSM + IBR) as a surgical option for minimally invasive mastectomy. Methods The medical records of patients who underwent SPIE-NSM + IBR from February 2024 to February 2025, performed by the same surgeon at a single institution, were collected and analysed for feasibility, safety and reproducibility by evaluating the conversion rate to open surgery, the learning curve with operating times and the cumulative sum (CUSUM) plot method, and the number of complications. Results 23 SPIE-NSM + IBR were performed on 22 women. The times for SPIE-NSM and SPIE-NSM + IBR decreased with accumulated case experience, and according to Cusum's analysis, the improvement started from the 11th case in all two scenarios. The mean operative times for the final cases (12th-23rd) decreased to 105 ± 33.1 minutes in SPIE-NSM (p = 0.009), 118.7 ± 39.7 minutes in SPIE-NSM plus axilla (p = 0.002) and 167.6 ± 34 minutes in SPIE-NSM + IBR (p = 0.003), compared to the group of initial cases. There were no cases requiring open surgery (0%). The median hospital stay was 1(1–2) day. There was one serious complication (IIIa, 4.35%). No positive margins were found in the final pathological examination, nor were there any implant losses or recurrences during follow-up of 4.3 months. Conclusions Our study confirms that SPIE-NSM + IBR is a feasible and safe alternative to R-NSM-IBR. It is a technique available in all hospitals, as it uses laparoscopic instruments that allow more patients to benefit from minimally invasive mastectomy. An acceptable learning curve is necessary. Endoscopic Mastectomy Single port Insufflation Breast surgery Breast cancer Figures Figure 1 Figure 2 Introduction Open or conventional nipple sparing mastectomy with immediate reconstruction (C-NSM + IR) represents a significant advance in breast surgery due to its favourable results in terms of aesthetics and quality of life, without compromising oncological outcomes [ 1 , 2 ]. However, this technique leaves a large, visible scar on the breast, with a potential risk of skin and areola-nipple complex (NAC) necrosis, the incidence of which depends on the surgical approach used. In recent years, breast surgery has undergone considerable development in the field of minimally invasive techniques, giving rise to minimally invasive mastectomy, either endoscopic (E-NSM) or robot-assisted (R-NSM). These techniques allow for smaller and less visible incisions, located outside the breast footprint, with access to axillary surgery and reduce the psychological impact on the patient. E-NSM has been implemented using various strategies, including the use of two incisions (axillary and periareolar) [ 3 – 6 ], the use of endoscopic [ 7 ] or external retractors [ 8 , 9 ], the multiple port approach [ 10 – 12 ], and the single port technique with insufflation and endoscopic instruments [ 13 , 14 ]. The aim of the present study is to describe our initial experience with single-port insufflation endoscopic nipple-areola sparing (SPIE-NSM) and immediate breast reconstruction with silicone implant or expander (SPIE-NSM + IBR), analysing its feasibility, safety and reproducibility by evaluating the conversion rate to open surgery, the learning curve with operation times and the number of complications. Patients and Methods This is an observational clinical study with retrospective data, approved by the local institutional Research Ethics Committee (PI 2025 01 1793). From February 2024 to February 2025, all SPIE-NSM + IBR performed by the same surgeon (TRG) who has extensive experience in C-NSM + IR and performs laparoscopic surgery in the field of general surgery were analysed. Inclusion criteria were: a) women over 18 years of age; b) breast cancer not suitable for conservative surgery and the patient desires immediate reconstruction; c) small or medium-sized breasts (cup ≤ D); and d) risk-reducing mastectomy. The exclusion criteria were: a) locally advanced or T4 carcinoma; b) large breasts (cup ≥ E); and c) breasts suitable for NSM reduction (ptosis > 2). The number of conversions to open technique, operation times, hospital and drainage days, margins and number of complications were used to assess feasibility and safety. Complications included subcutaneous emphysema, haematoma, cutaneous ischaemia, partial or total necrosis of the NAC, infection, seroma, prosthesis removal or replacement. Postoperative complications were classified as major (≥ IIIa,b) and minor (I-II) according to the Clavien-Dindo classification, depending on whether they required reoperation or not. To assess the learning curve, we recorded the operation times in chronological order of the cases and divided them into a) axillary time , from incision to completion of the axillary study; b) endoscopic mastectomy time , from the completion of the axillary study to the extraction of the surgical sample, includes the installation of the single port; c) overall mastectomy time , is endoscopic mastectomy time plus axillary time; d) reconstruction time , from removal of the surgical specimen to closure of the incision and e) overall operating time from incision to closure. Preoperative, intraoperative and postoperative data were collected and analysed. Clinical-pathological characteristics, type of breast, type of incision, insufflation pressure, volume of prosthesis or expander filling, and weight of the surgical specimen were included. Adjuvant treatments and recurrences during follow-up were also recorded. Surgical Technique Once the landmarks, glandular borders and incision have been marked out, under general anaesthesia the surgeon uses ultrasound (Aplio, Canon) to mark the area of skin most at risk from the closest tumours. The ipsilateral thorax is then placed on the edge of the surgical table and the ipsilateral arm is placed on the head in a surgical support, with internal rotation and 90° abduction The sentinel node biopsy and/or axillary lymphadenectomy are performed through a 4 cm transverse incision in the axillary fold or parallel to the anterior axillary line at the level of the NAC. At the start of the SPIE-NSM + IBR, a subcutaneous dissection is carried out with direct vision of about 7 cm in diameter prior to the placement of the Gelpoint Mini (Applied Medical) single port system, with 3 cannulas of 10 mm arranged in a triangular and eccentrically. With an insufflation pressure of 8 mmHg, 0º or 30º optics with 2D visualisation systems and without prior tumescent injection, the mammary gland is dissected of the subcutaneous plane with the Voyant Maryland advanced bipolar sealing system with low thermal dispersion (Applied Medical, USA) in combination with external palpation. The retro-mammary and anterior spaces are dissected from the lateral margin to the parasternal region, with section of the base of the nipple, and from the upper mammary limit to the mammary fold. In the last endoscopic phase, the peripheral mammary limits are sectioned, ending in the internal or infero-internal quadrants. Once the release is complete, the gland is removed without removing the tissue protector and the surgical specimen is marked. In cases where the tumour is close to the skin, an intra-operative ultrasound examination of the specimen is carried out for the surgeon and, if necessary, re-excision is performed. The intraoperative nipple biopsy was taken from the residual tissue by endoscopy or the surgical specimen, with nipple excision in the case of infiltration. Finally, haemostasis, placement of drainage in the mastectomy bed, breast reconstruction and closure of the incision are performed after complete removal of glandular tissue has been verified by endoscopy, palpation o intraoperative ultrasound. Statistical Analysis Categorical variables are presented as frequencies and proportions, and quantitative/continuous variables are presented as median and interquartile range (IQR) and mean ± standard deviation (SD). Differences in continuous variables were tested by independent t-test and a p-value less than 0.05 was considered statistically significant; all tests were two-tailed. The cumulative sum method (CUSUM), which is useful for the early detection of trends in data, was used to analyze the learning curve of the different operation times. The inflection point, where the operation time begins to decrease in the CUSUM graph, indicates that the learning curve begins to improve and is considered complete/controlled when it is below the upper limit of 3 standard deviations. SPSS software (version 28.0.1.1) was used for the statistical analysis and Python 3.11.8 was used for the CUSUM calculation. Results Clinical characteristics From February 2024 to February 2025, 23 SPIE-NSM+IBR were performed on 22 women, of which 19 (82.6%) were therapeutic and 4 (17.4%) prophylactic. In 16 (84.2%) of the therapeutic mastectomies, conservative surgery could not be performed either due to a unfavourable tumour/breast ratio, multifocality/multicentricity or local recurrence/second tumour and in the remaining 3 (15.8%) it was due to the patient's decision: multiple diagnostic biopsies for suspicious lesions, partial response to primary systemic treatment and not want radiotherapy and metachronous carcinoma with contralateral mastectomy. The demographic and clinicopathological results are shown in Table 1. The median age was 51years (48 - 62). The pathological stages of the oncology patients were 15,8%, 42,1%, 26,3% and 15,8% for stages 0, I, II, and III respectively. The most common axillary procedure was sentinel node biopsy (78.9%), which was negative in 93.3% of cases. The intraoperative results are summarized in Table 2. The incision parallel to the anterior axillary line was the most frequent (69.6%), with the axillary incision being preferred (30.4%) in those patients who were candidates for axillary lymphadenectomy or due to technical difficulties in performing sentinel node biopsy. The median size of the incision was 40 mm (40–43). Immediate reconstruction was carried out with an implant in 19 patients (82.6%) and an expander in 4 patients (17.4%). The median weight of the mastectomy was 207 g (165–260) and the median prosthesis volume was 285 cc (255 - 350). Conversion rate, operation times and learning curves. All the SPIE-NSM were performed endoscopically with no cases of intraoperative conversion to conventional open surgery due to technical difficulties on the part of the surgeon. Figure 1 shows that the chronological operation times for endoscopic mastectomy and overall operation tended to decrease as the number of cases increased. The operation times are shown in table 3. The endoscopic mastectomy time (without axillary time) and the overall mastectomy time (with axillary time) was 125.2 ± 41.3 minutes and 151.8 ± 42.9 minutes for the 19 therapeutic mastectomies, respectively. The overall operation time was 190.5 ± 41.5 minutes for all series and 195.8 ±35.6 for 19 therapeutic mastectomies. In the CUSUM graph analysis of the learning curve (Fig. 2), the number of cases required to decrease endoscopic mastectomy time (A), and overall operation time (B) were 11 and 11 cases, respectively, and continued to improve. Based on this data, we compared the 11 initial cases (1st to 11th) with the 12 final cases (from 12th to 23rd) in our series and found that the mean endoscopic mastectomy time decreased from 148 ± 38.8 minutes in the initial cases to 105 ± 33.1 minutes in the final cases (p=0.009) and the overall mastectomy time decreased from 175.5 ± 39.3 minutes in the initial cases to 118.5 ± 39.7 minutes in the final cases (p=0.002). There was also a significant decrease in overall operation time between the initial and final cases (215 ± 34.7 and 167.6 ± 34, p = 0.003). (Table 4). The weights of the mastectomy specimens did not show significant differences between the initial phase (227.1±61gr) and the final phase (193.6±70gr) of our cases (p=0.24). Complications and follow-up Postoperative and follow-up results are shown in table 5. There were no losses of prostheses during follow-up. During the immediate postoperative period, 4 patients (17.4%) experienced a complication. Three of them were grade I-II: a seroma that required ultrasound-guided drainage, transient superficial ischaemia of the NAC that did not require treatment, and a wound in the NAC during the retroareolar biopsy, which was treated with sutures. One patient (4.35%) presented a grade IIIa complication that required partial removal of the skin and areola under local anaesthesia for necrosis. This patient was reconstructed with an expander due to the risk of skin necrosis from intraoperative dermal burns caused by the proximity of the tumour to the skin. No patient required reoperation under general anaesthesia (IIIb). Two patients had focal anterior margin involvement, but in one it was not possible to extend the excision anteriorly as it reached the dermis. The other patient presented with cutaneous and areolar ischaemia, which was removed with no evidence of residual tumour in the excised area. The result is free margins. Patients were hospitalized for a median of 1 (1-2) day and 17 patients (77.3%) were discharged 24 hours after surgery. The drainage tube was removed after a median of 7 (6-9) days. During a median follow-up period of 105 days, no local, regional or systemic recurrence was diagnosed (Table 5). Discussion SPIE-NSM and R-NSM are similar mastectomy endoscopic techniques, as they use a single access port and maintain the operation space by insufflating CO2. The difference lies in the surgical material used for the dissection of the mammary gland, with better vision and more precise movements in the R-NSM. Both surgical techniques require a learning curve to verify their feasibility and safety. Due to the difficulty in obtaining robotic operation theatre hours, we have initiated and analysed our experience and learning curve with SPIE-NSM + IBR, a technique performed by Tukenmez et al. [ 13 ] and Lai et al. [ 14 ]. Other authors use the same technique, but with the help of small instruments that are inserted into the skin of the breast [ 11 , 12 , 15 ]. As in other publications [ 11 , 16 – 19 ], we have analysed only those surgeries performed by a single surgeon to reduce bias associated with the surgical technique and to ensure consistency and accuracy in the evaluation of the learning curve. There were no cases of conversion to C-NSM, which coincides with the published studies on E-NSM and R-NSM [ 19 – 25 ]. However, in the early stages of the R-NSM technique, a moderate number of conversions to open surgery were recorded, although in later studies these were absent. [ 26 , 27 ]. In our analysis, the CUSUM curve showed that the inflection points in overall operation time and endoscopic mastectomy time occurred in the 11th case and in the following 12 cases a downward trend in mastectomy times can be seen. Other authors situate inflection points in their learning curves at the 10th [ 28 ], 13th [ 17 ] and 17th [ 16 ] cases and maintain this in subsequent cases. All this suggests to us that surgeons who start SPIE-NSM will become more familiar with endoscopic mastectomy and reduce operation times around the 11th-13th case. In agreement with other authors [ 11 , 16 , 20 ], in our learning curve we observe that with increased experience, safety and efficiency improve, leading to a progressive reduction in endoscopic mastectomy and in the overall operation times (Fig. 1 ). When we performed a comparative statistical study of the mean operative times between the initial 11 cases ( initial group) and the final 12 cases ( final group), we found that there was a significant reduction in endoscopic mastectomy times and overall operation times in favour of the final group. This reduction is not due to reconstructive time or the axillary time , which showed minimal variations (Table 4 ). This is entirely due to the reduction in time for endoscopic mastectomies, which includes the time taken to place the single port, as this is part of the endoscopic mastectomy. It should be noted that the time taken to perform endoscopic mastectomy decreased to an average of 105 minutes in the final phase of the learning curve, as the surgeon's experience increased. When analysing our operative times with those published by other authors, we found that our mean overall endoscopic mastectomy time (SPIE-NSM), without reconstruction, was 151.8 ± 43, comparable to other published series: 149.8 ± 37.7 minutes [ 28 ], 155.6 ± 43.2 minutes [ 18 ] and 159.7 ± 58.2 minutes [ 21 ]. The mean overall operation time (SPIE-NSM + IBR) was 195.8 ± 35.6 minutes, similar to that reported in other series, which show overall surgery times of around 200 minutes, with a range of variation between 159 and 205 minutes [ 11 , 12 , 21 , 29 – 32 ]. In contrast, there are authors [ 15 , 18 , 28 ] who exceed 250 minutes. This variability in the results may be due to confounding factors such as the type of reconstruction, pre or subpectoral [ 3 ], whether they are single or multicenter studies[ 21 ], the size of the breasts or the experience of the surgeons [ 21 , 33 ]. Another important factor in the learning curve is the previous training and skills that the surgeon has in C-NSM and laparoscopic surgery. The R-NSM learning curve improves after previous experience in E-NSM [ 17 ]. At SPIE-NSM, an experienced assistant improves visibility in limited surgical space and reduces operation time. Even small modifications to the technique can improve operation times. Within the existing discrepancies between whether to start by dissecting the anterior or posterior space of the mammary gland [ 13 , 34 ], we are in favour of dissecting the anterior space first in small breasts, but in medium-sized breasts (C-D cup) the posterior dissection of the glandular tissue should be performed first, as the greater weight of the breast would make it difficult to dissect if the anterior space has already been carried out. Due to our indications for mastectomy, SPIE-NSM-BRI were more frequently performed in patients with cup size ≤ C (83.3%). There are series of E-NSM with 85.7% of cup size ≤ C and they assume that the ideal patients for this technique should have small and medium breasts [ 19 , 21 ]. Safarti et al. [ 35 ] only included cup size ≤ C in their R-NSM series. Like these authors, we believe that the learning curve for SPIE-NSM + IBR should be performed on small and medium breasts with little ptosis. In our study, the average weight of surgical specimens was 209.6 g, comparable to the 228.9 g reported by Rathat et al.[ 19 ], but lower than other series [ 17 , 22 , 36 ]. Some authors believe that the weight of the mastectomy specimen influences operation times [ 18 ]. However, other authors such as Hung et al. [ 16 ] and Lai et al. [ 20 ] observe that the improvements in the learning curves are not due to differences in the weights of the surgical specimens but to the experience of the surgeons and the standardisation of surgical techniques. This is consistent with the data from our series, where the improvement in surgical times in the final phase does not coincide with a decrease in the weight of surgical specimens. In our cases, the incidence of minor and major perioperative complications was low with 13% y 4.3% respectively. The major complication was caused by a small area of skin and areola necrosis which required excision under local anaesthesia (Table 5 ). These results are comparable to those presented by Lai et al. [ 21 ] with 19.1% (I-II) and 4.8% (III). Chung et al. [ 11 ] present major and minor complications of 1.3% and 7.6% respectively in 79 E-NSM. Most of the complications in the report by Yu et al. [ 18 ] were due to the prostheses (14.3%) and very few were due to E-NSM (1.8%). In general, we can say that SPIE-NSM has few complications and they are equal to or fewer than C-NSM [ 18 ]. The number and type of complications depends on the E-NSM technique and the experience of the surgeon, the characteristics of the patient and the type of prosthetic reconstruction performed [ 11 ]. The complications of NAC, both ischaemia and necrosis, decreased significantly when the double areolar and axillary incision was changed to a single axillary incision and insufflation was used instead of retractors.[ 20 ] Our SPIE-NSM-BRI series has presented one of the shortest hospitals postoperative stays published[ 28 , 37 , 38 ] and many of our patients (77.3 %) could ave been treated in the 24-hour hospital. We concur with Zhou et al.[ 39 ] that soon, most SPIE-NSM-BRI will be carried out in a 24-hour hospital. All this means lower healthcare costs and improved patient well-being. We believe this is due to the lower incidence of immediate complications and easy access to outpatient post-operative consultation. In the most recent published series of minimally invasive mastectomies, whether endoscopic or robotic, the number of margins affected is less than 5%. In our study, we have all clear margins, which is in agreement with authors such as Lai et al. [ 21 ] and Toesca et al.[ 25 ]. We believe that intraoperative ultrasound was very useful in obtaining clear superficial margins in SPIE-NSM, as demonstrated by Esgueva et al.[ 40 ] in C-NSM. There are no differences in disease-free survival and overall survival between minimally invasive mastectomies and C-NSM in randomised clinical trials[ 25 ] and in individual series analyses[ 20 ] with follow-ups of 42 and 49.9 months respectively. In a group of 421 E-NSM, Sakamoto et al.[ 41 ] presented a recurrence rate of 2.6% during an average follow-up of 61 months. In our study we followed the surgical steps and principles of C-NSM, therefore, we think that the oncological results may be similar for both techniques. With a very short average follow-up of 4.3 months, no local or distant recurrences have been diagnosed in the therapeutic group. However, patients should be provided with detailed information on minimally invasive, endoscopic and robotic mastectomies, and treatment options to help them make an appropriate decision. This study shows the limitations inherent in the implementation of new surgical techniques, as it is monocentric, performed by a single surgeon and has preliminary results. Pending cosmetic results and patient satisfaction. Conclusion In conclusion, our study confirms that SPIE-NSM + IBR is a feasible y safe effective technique that represents an alternative to R-NSM-IBR. It requires more effort on the part of the surgeon due to more rigid instruments and poorer vision of the operative field, but better than C-NSM. It is a technique available in all hospitals, as it uses laparoscopic instruments, allowing more patients to benefit from minimal invasive mastectomy. It requires a short learning period. This series of cases could contribute to a deeper analysis of the factors that affect individual learning curves, allowing for the design of more effective training programmes that facilitate the implementation of SPIE-NSM + IBR. Declarations Declaration of interest: All the authors declare that there are no conflicts of interest regarding the publication of this article. Acknowledgements The authors would like to thank the surgical staff, the members of the breast unit and the administration for their cooperation and support in the implementation and development of this new surgical technique. References Cruz LDL, Moody AM, Tappy EE, Blankenship SA, Hecht EM. Overall Survival, Disease-Free Survival, Local Recurrence, and Nipple–Areolar Recurrence in the Setting of Nipple-Sparing Mastectomy: A Meta-Analysis and Systematic Review. Ann Surg Oncol 2015;22:3241–9. https://doi.org/10.1245/s10434-015-4739-1. Mota BS, Riera R, Ricci MD, Barrett J, Castria TB de, Atallah ÁN, et al. 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Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional Nipple-Sparing Mastectomy for Breast Cancer Based on Initial Experience. J Breast Cancer 2020;24:196–205. https://doi.org/10.4048/jbc.2021.24.e18. Lai H-W, Chen S-T, Liao C-Y, Mok CW, Lin Y-J, Chen D-R, et al. Oncologic Outcome of Endoscopic Assisted Breast Surgery Compared with Conventional Approach in Breast Cancer: An Analysis of 3426 Primary Operable Breast Cancer Patients from Single Institute with and Without Propensity Score Matching. Ann Surg Oncol 2021;28:7368–80. https://doi.org/10.1245/s10434-021-09950-8. Lai H-W, Chen S-T, Mok CW, Lin S-L, Tai C-M, Chen D-R, et al. Single-port 3-dimensional Videoscope-assisted Endoscopic Nipple-sparing Mastectomy in the Management of Breast Cancer. Plast Reconstr Surg Glob Open 2019;7:e2367. https://doi.org/10.1097/gox.0000000000002367. Feng Y, Liang F, Wen N, Yang H, Zhou J, Zhang S, et al. An Innovative and Highly Efficient Single-Port Endoscopic Nipple-/Skin-Sparing Mastectomy and Dual-Plane Direct-to-Implant Breast Reconstruction: A Prospective Study from a Single Institution. Aesthetic Plast Surg 2023:1–9. https://doi.org/10.1007/s00266-023-03402-2. Liu W-H, Wu S-S, Tian Y-M, Liu J, Gao G-X, Xie F, et al. Single-port insufflation endoscopic nipple-sparing mastectomy in early breast cancer: a retrospective cohort study. Gland Surg 2023;12:1348359–1341359. https://doi.org/10.21037/gs-23-148. Kim JH, Lee SB, Park HS, Kim KS, Choi JE, Lee MH, et al. Trends in Operation Times for Robot-assisted Nipple-sparing Mastectomy Performed by Expert Breast Surgeons. Ann Robot Innov Surg 2024;5:1. https://doi.org/10.37007/aris.2024.5.1.1. Sakamoto N, Fukuma E, Higa K, Ozaki S, Sakamoto M, Abe S, et al. Early Results of an Endoscopic Nipple-Sparing Mastectomy for Breast Cancer. Ann Surg Oncol 2009:1–8. https://doi.org/10.1245/s10434-009-0661-8. Sarfati B, Struk S, Leymarie N, Honart J-F, Alkhashnam H, Fremicourt KT de, et al. Robotic Prophylactic Nipple-Sparing Mastectomy with Immediate Prosthetic Breast Reconstruction: A Prospective Study. Ann Surg Oncol 2018;25:2579–86. https://doi.org/10.1245/s10434-018-6555-x. Kim JH, Ryu JM, Bae SJ, Ko BS, Choi JE, Kim KS, et al. Minimal Access vs Conventional Nipple-Sparing Mastectomy. JAMA Surg 2024;159:1177–86. https://doi.org/10.1001/jamasurg.2024.2977. Houvenaeghel G, Barrou J, Jauffret C, Rua S, Sabiani L, Troy AV, et al. Robotic Versus Conventional Nipple-Sparing Mastectomy With Immediate Breast Reconstruction. Front Oncol 2021;11:637049. https://doi.org/10.3389/fonc.2021.637049. Lai H-W, Chen S-T, Tai C-M, Lin S-L, Lin Y-J, Huang R-H, et al. Robotic- Versus Endoscopic-Assisted Nipple-Sparing Mastectomy with Immediate Prosthesis Breast Reconstruction in the Management of Breast Cancer: A Case–Control Comparison Study with Analysis of Clinical Outcomes, Learning Curve, Patient-Reported Aesthetic Results, and Medical Cost. Ann Surg Oncol 2020;27:2255–68. https://doi.org/10.1245/s10434-020-08223-0. Zhou J, Xie Y, Liang F, Feng Y, Yang H, Qiu M, et al. A novel technique of reverse-sequence endoscopic nipple-sparing mastectomy with direct-to-implant breast reconstruction: medium-term oncological safety outcomes and feasibility of 24-h discharge for breast cancer patients. Int J Surg (Lond, Engl) 2024;110:2243–52. https://doi.org/10.1097/js9.0000000000001134. Esgueva AJ, Sobrido C, Diaz-Botero S, Díez-Uriel E, Iscar T, Miguel VD, et al. Intraoperative ultrasound margin evaluation as a tool to reduce positive superficial margins in nipple and skin sparing mastectomy in breast cancer patients. Eur J Surg Oncol 2023;49:107049. https://doi.org/10.1016/j.ejso.2023.107049. Sakamoto N, Fukuma E, Teraoka K, Hoshi K. Local recurrence following treatment for breast cancer with an endoscopic nipple-sparing mastectomy. Breast Cancer 2016;23:552–60. https://doi.org/10.1007/s12282-015-0600-4. Tables Tables 1 to 5 are available in the Supplementary Files section. Supplementary Files Table12345.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-6237635\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":432597272,\"identity\":\"04c2cd1c-ef6f-4f19-8eb6-26bd697c7998\",\"order_by\":0,\"name\":\"TERESA RAMOS GRANDE\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7UlEQVRIiWNgGAWjYJADA4YPQJKNnYAyHmQtjDNAWphJ0cIM5hHSYi99+OmGD39q8/lnN298bPNrmzwfMwPjh485eGzhSzO7ObPtuOWMO8eKjXP7bhu2MTMwS87chkcLD4PZbd6GYwYMN3LMpHN7bjMCtbAx8+LVwv7tNs+fYwbyN3LMf1v23LYnQguP2W0ethoDA6AtzAw/bicS1nKGpwzolwMGhjfSiiV7G24ntzEzNuP1C3sP+7YbH/7UGcjdSN744cef27bz25sPfviIRwsUHIZQjG1gsoGgeiCog9J/iFE8CkbBKBgFIw0AAAbhT+44bjJRAAAAAElFTkSuQmCC\",\"orcid\":\"https://orcid.org/0000-0003-2579-1008\",\"institution\":\"Complejo asistencial de Salamanca: Hospital Universitario de Salamanca\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"TERESA\",\"middleName\":\"RAMOS\",\"lastName\":\"GRANDE\",\"suffix\":\"\"},{\"id\":432597273,\"identity\":\"f47b5423-1c12-41e6-9953-c0bb75256552\",\"order_by\":1,\"name\":\"Isable Silva Benito\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Complejo asistencial de Salamanca: Hospital Universitario de Salamanca\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Isable\",\"middleName\":\"Silva\",\"lastName\":\"Benito\",\"suffix\":\"\"},{\"id\":432597274,\"identity\":\"068c235b-3f0a-4d84-84e5-f3df7840f0cf\",\"order_by\":2,\"name\":\"Andres Juan Fernandez\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Complejo asistencial de Salamanca: Hospital Universitario de Salamanca\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Andres\",\"middleName\":\"Juan\",\"lastName\":\"Fernandez\",\"suffix\":\"\"},{\"id\":432597275,\"identity\":\"7af279fb-975b-497a-961f-e2c11ea4b4c5\",\"order_by\":3,\"name\":\"Francisco Blanco Antona\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Salamanca: Universidad de Salamanca\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Francisco\",\"middleName\":\"Blanco\",\"lastName\":\"Antona\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2025-03-16 12:47:18\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-6237635/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-6237635/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":79665777,\"identity\":\"074da243-b567-43c7-960c-c7dc00a3de81\",\"added_by\":\"auto\",\"created_at\":\"2025-04-01 10:10:07\",\"extension\":\"jpg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1088506,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eConsecutive chronological progression of operation times\\u003cstrong\\u003e. \\u003c/strong\\u003eBlue line: \\u003cem\\u003eoverall operation time\\u003c/em\\u003e; red line: \\u003cem\\u003eendoscopic mastectomy time\\u003c/em\\u003e; green line: \\u003cem\\u003ereconstruction time\\u003c/em\\u003e; orange line: \\u003cem\\u003eaxillary time\\u003c/em\\u003e.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig1Operationtimes.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6237635/v1/f6d72306dccf6ee7f967a841.jpg\"},{\"id\":79665775,\"identity\":\"019d3ecf-7431-4efe-ba21-eadc1ab4419f\",\"added_by\":\"auto\",\"created_at\":\"2025-04-01 10:10:06\",\"extension\":\"png\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1967923,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eThe CUSUM curve for \\u003cem\\u003eendoscopic mastectomy time\\u003c/em\\u003e (\\u003cstrong\\u003eA\\u003c/strong\\u003e) showed an improvement from the 11th case and remained below the upper limit at the 14th and 16th cases (3SD and 2SD, respectively). A similar improvement was observed in the CUSUM curve for \\u003cem\\u003eoverall operation time\\u003c/em\\u003e (\\u003cstrong\\u003eB\\u003c/strong\\u003e), which improved from the 11th case and remained below the upper limit at the 16th and 17th cases (3SD and 2SD, respectively). \\u003cem\\u003eSD standard deviation.\\u003c/em\\u003e\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6237635/v1/8834b17ea8749097b1e63199.png\"},{\"id\":82023887,\"identity\":\"1d4b318d-11fc-4339-8d19-b3568e1de9fd\",\"added_by\":\"auto\",\"created_at\":\"2025-05-06 06:15:15\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":3276897,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6237635/v1/f2d8d9f5-5fa8-40eb-9517-ae2a96cce213.pdf\"},{\"id\":79664582,\"identity\":\"fdf91f7a-4a05-4151-9d1d-8011621bea48\",\"added_by\":\"auto\",\"created_at\":\"2025-04-01 10:02:06\",\"extension\":\"docx\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":25070,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Table12345.docx\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6237635/v1/a7a7d58d54cbd4a7ecfa25a4.docx\"}],\"financialInterests\":\"\",\"formattedTitle\":\"Single-Port Insufflation Technique for Endoscopic Nipple-Sparing Mastectomy: Initial Experience and Learning Curve.\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003eOpen or conventional nipple sparing mastectomy with immediate reconstruction (C-NSM\\u0026thinsp;+\\u0026thinsp;IR) represents a significant advance in breast surgery due to its favourable results in terms of aesthetics and quality of life, without compromising oncological outcomes [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e]. However, this technique leaves a large, visible scar on the breast, with a potential risk of skin and areola-nipple complex (NAC) necrosis, the incidence of which depends on the surgical approach used.\\u003c/p\\u003e \\u003cp\\u003eIn recent years, breast surgery has undergone considerable development in the field of minimally invasive techniques, giving rise to minimally invasive mastectomy, either endoscopic (E-NSM) or robot-assisted (R-NSM). These techniques allow for smaller and less visible incisions, located outside the breast footprint, with access to axillary surgery and reduce the psychological impact on the patient.\\u003c/p\\u003e \\u003cp\\u003eE-NSM has been implemented using various strategies, including the use of two incisions (axillary and periareolar) [\\u003cspan additionalcitationids=\\\"CR4 CR5\\\" citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e], the use of endoscopic [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e] or external retractors [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e], the multiple port approach [\\u003cspan additionalcitationids=\\\"CR11\\\" citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e], and the single port technique with insufflation and endoscopic instruments [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe aim of the present study is to describe our initial experience with single-port insufflation endoscopic nipple-areola sparing (SPIE-NSM) and immediate breast reconstruction with silicone implant or expander (SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR), analysing its feasibility, safety and reproducibility by evaluating the conversion rate to open surgery, the learning curve with operation times and the number of complications.\\u003c/p\\u003e\"},{\"header\":\"Patients and Methods\",\"content\":\"\\u003cp\\u003e This is an observational clinical study with retrospective data, approved by the local institutional Research Ethics Committee (PI 2025 01 1793). From February 2024 to February 2025, all SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR performed by the same surgeon (TRG) who has extensive experience in C-NSM\\u0026thinsp;+\\u0026thinsp;IR and performs laparoscopic surgery in the field of general surgery were analysed.\\u003c/p\\u003e \\u003cp\\u003eInclusion criteria were: a) women over 18 years of age; b) breast cancer not suitable for conservative surgery and the patient desires immediate reconstruction; c) small or medium-sized breasts (cup\\u0026thinsp;\\u0026le;\\u0026thinsp;D); and d) risk-reducing mastectomy. The exclusion criteria were: a) locally advanced or T4 carcinoma; b) large breasts (cup\\u0026thinsp;\\u0026ge;\\u0026thinsp;E); and c) breasts suitable for NSM reduction (ptosis\\u0026thinsp;\\u0026gt;\\u0026thinsp;2).\\u003c/p\\u003e \\u003cp\\u003eThe number of conversions to open technique, operation times, hospital and drainage days, margins and number of complications were used to assess feasibility and safety. Complications included subcutaneous emphysema, haematoma, cutaneous ischaemia, partial or total necrosis of the NAC, infection, seroma, prosthesis removal or replacement. Postoperative complications were classified as major (\\u0026ge;\\u0026thinsp;IIIa,b) and minor (I-II) according to the Clavien-Dindo classification, depending on whether they required reoperation or not.\\u003c/p\\u003e \\u003cp\\u003eTo assess the learning curve, we recorded the operation times in chronological order of the cases and divided them into a) \\u003cem\\u003eaxillary time\\u003c/em\\u003e, from incision to completion of the axillary study; b) \\u003cem\\u003eendoscopic mastectomy time\\u003c/em\\u003e, from the completion of the axillary study to the extraction of the surgical sample, includes the installation of the single port; c) \\u003cem\\u003eoverall mastectomy time\\u003c/em\\u003e, is endoscopic mastectomy time plus axillary time; d) \\u003cem\\u003ereconstruction time\\u003c/em\\u003e, from removal of the surgical specimen to closure of the incision and e) \\u003cem\\u003eoverall operating time\\u003c/em\\u003e from incision to closure.\\u003c/p\\u003e \\u003cp\\u003ePreoperative, intraoperative and postoperative data were collected and analysed. Clinical-pathological characteristics, type of breast, type of incision, insufflation pressure, volume of prosthesis or expander filling, and weight of the surgical specimen were included. Adjuvant treatments and recurrences during follow-up were also recorded.\\u003c/p\\u003e \\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eSurgical Technique\\u003c/h2\\u003e \\u003cp\\u003eOnce the landmarks, glandular borders and incision have been marked out, under general anaesthesia the surgeon uses ultrasound (Aplio, Canon) to mark the area of skin most at risk from the closest tumours. The ipsilateral thorax is then placed on the edge of the surgical table and the ipsilateral arm is placed on the head in a surgical support, with internal rotation and 90\\u0026deg; abduction\\u003c/p\\u003e \\u003cp\\u003eThe sentinel node biopsy and/or axillary lymphadenectomy are performed through a 4 cm transverse incision in the axillary fold or parallel to the anterior axillary line at the level of the NAC. At the start of the SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR, a subcutaneous dissection is carried out with direct vision of about 7 cm in diameter prior to the placement of the Gelpoint Mini (Applied Medical) single port system, with 3 cannulas of 10 mm arranged in a triangular and eccentrically.\\u003c/p\\u003e \\u003cp\\u003eWith an insufflation pressure of 8 mmHg, 0\\u0026ordm; or 30\\u0026ordm; optics with 2D visualisation systems and without prior tumescent injection, the mammary gland is dissected of the subcutaneous plane with the Voyant Maryland advanced bipolar sealing system with low thermal dispersion (Applied Medical, USA) in combination with external palpation. The retro-mammary and anterior spaces are dissected from the lateral margin to the parasternal region, with section of the base of the nipple, and from the upper mammary limit to the mammary fold.\\u003c/p\\u003e \\u003cp\\u003eIn the last endoscopic phase, the peripheral mammary limits are sectioned, ending in the internal or infero-internal quadrants. Once the release is complete, the gland is removed without removing the tissue protector and the surgical specimen is marked. In cases where the tumour is close to the skin, an intra-operative ultrasound examination of the specimen is carried out for the surgeon and, if necessary, re-excision is performed. The intraoperative nipple biopsy was taken from the residual tissue by endoscopy or the surgical specimen, with nipple excision in the case of infiltration. Finally, haemostasis, placement of drainage in the mastectomy bed, breast reconstruction and closure of the incision are performed after complete removal of glandular tissue has been verified by endoscopy, palpation o intraoperative ultrasound.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec4\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eStatistical Analysis\\u003c/h2\\u003e \\u003cp\\u003eCategorical variables are presented as frequencies and proportions, and quantitative/continuous variables are presented as median and interquartile range (IQR) and mean\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;standard deviation (SD). Differences in continuous variables were tested by independent t-test and a p-value less than 0.05 was considered statistically significant; all tests were two-tailed. The cumulative sum method (CUSUM), which is useful for the early detection of trends in data, was used to analyze the learning curve of the different operation times. The inflection point, where the operation time begins to decrease in the CUSUM graph, indicates that the learning curve begins to improve and is considered complete/controlled when it is below the upper limit of 3 standard deviations. SPSS software (version 28.0.1.1) was used for the statistical analysis and Python 3.11.8 was used for the CUSUM calculation.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eClinical characteristics\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eFrom February 2024 to February 2025, 23 SPIE-NSM+IBR were performed on 22 women, of which 19 (82.6%) were therapeutic and 4 (17.4%) prophylactic. In 16 (84.2%) of the therapeutic mastectomies, conservative surgery could not be performed either due to a unfavourable tumour/breast ratio, multifocality/multicentricity or local recurrence/second tumour and in the remaining 3 (15.8%) it was due to the patient\\u0026apos;s decision: multiple diagnostic biopsies for suspicious lesions, partial response to primary systemic treatment and not want radiotherapy and metachronous carcinoma with contralateral mastectomy.\\u003c/p\\u003e\\n\\u003cp\\u003eThe demographic and clinicopathological results are shown in Table 1. The median age was 51years (48 - 62). The pathological stages of the oncology patients were 15,8%, 42,1%, 26,3% and 15,8% for stages 0, I, II, and III respectively. The most common axillary procedure was sentinel node biopsy (78.9%), which was negative in 93.3% of cases.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eThe intraoperative results are summarized in Table 2. The incision parallel to the anterior axillary line was the most frequent (69.6%), with the axillary incision being preferred (30.4%) in those patients who were candidates for axillary lymphadenectomy or due to technical difficulties in performing sentinel node biopsy. The median size of the incision was 40 mm (40\\u0026ndash;43).\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eImmediate reconstruction was carried out with an implant in 19 patients (82.6%) and an expander in 4 patients (17.4%). The median weight of the mastectomy was 207 g (165\\u0026ndash;260) and the median prosthesis volume was 285 cc (255 - 350).\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConversion rate, operation times and\\u0026nbsp;\\u003c/strong\\u003e\\u003cstrong\\u003elearning curves.\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll the SPIE-NSM were performed endoscopically with no cases of intraoperative conversion to conventional open surgery due to technical difficulties on the part of the surgeon.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eFigure 1 shows that the chronological operation times for endoscopic mastectomy and overall operation tended to decrease as the number of cases increased. The operation times are shown in table 3. The \\u003cem\\u003eendoscopic mastectomy time\\u003c/em\\u003e (without axillary time) and the \\u003cem\\u003eoverall mastectomy time\\u003c/em\\u003e (with axillary time) was 125.2 \\u0026plusmn; 41.3 minutes and 151.8 \\u0026plusmn; 42.9\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003eminutes for the 19 therapeutic mastectomies, respectively. The \\u003cem\\u003eoverall operation time\\u003c/em\\u003e was 190.5 \\u0026plusmn; 41.5 minutes for all series and 195.8 \\u0026plusmn;35.6 for 19 therapeutic mastectomies.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eIn the CUSUM graph analysis of the learning curve (Fig. 2), the number of cases required to decrease \\u003cem\\u003eendoscopic mastectomy time\\u003c/em\\u003e (A), and \\u003cem\\u003eoverall operation time\\u003c/em\\u003e (B) were 11 and 11 cases, respectively, and continued to improve. Based on this data, we compared the 11 \\u003cem\\u003einitial\\u003c/em\\u003e cases (1st to 11th) with the 12 \\u003cem\\u003efinal\\u003c/em\\u003e cases (from 12th to 23rd) in our series and found that the mean \\u003cem\\u003eendoscopic mastectomy time\\u003c/em\\u003e decreased from 148 \\u0026plusmn; 38.8 minutes in the \\u003cem\\u003einitial\\u003c/em\\u003e cases to 105 \\u0026plusmn; 33.1 minutes in the \\u003cem\\u003efinal\\u003c/em\\u003e cases (p=0.009) and the \\u003cem\\u003eoverall mastectomy time\\u003c/em\\u003e decreased from 175.5 \\u0026plusmn; 39.3 minutes in the \\u003cem\\u003einitial\\u003c/em\\u003e cases to 118.5 \\u0026plusmn; 39.7 minutes in the \\u003cem\\u003efinal\\u003c/em\\u003e cases (p=0.002). There was also a significant decrease in \\u003cem\\u003eoverall operation time\\u003c/em\\u003e between the \\u003cem\\u003einitial\\u003c/em\\u003e and \\u003cem\\u003efinal\\u003c/em\\u003e cases (215 \\u0026plusmn; 34.7 and 167.6 \\u0026plusmn; 34, p = 0.003). (Table 4). The weights of the mastectomy specimens did not show significant differences between the initial phase (227.1\\u0026plusmn;61gr) and the final phase (193.6\\u0026plusmn;70gr) of our cases (p=0.24).\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eComplications and follow-up\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003ePostoperative and follow-up results are shown in table 5. There were no losses of prostheses during follow-up. During the immediate postoperative period, 4 patients (17.4%) experienced a complication. Three of them were grade I-II: a seroma that required ultrasound-guided drainage, transient superficial ischaemia of the NAC that did not require treatment, and a wound in the NAC during the retroareolar biopsy, which was treated with sutures. One patient (4.35%) presented a grade IIIa complication that required partial removal of the skin and areola under local anaesthesia for necrosis. This patient was reconstructed with an expander due to the risk of skin necrosis from intraoperative dermal burns caused by the proximity of the tumour to the skin. No patient required reoperation under general anaesthesia (IIIb).\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eTwo patients had focal anterior margin involvement, but in one it was not possible to extend the excision anteriorly as it reached the dermis. The other patient presented with cutaneous and areolar ischaemia, which was removed with no evidence of residual tumour in the excised area. The result is free margins.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003ePatients were hospitalized for a median of 1 (1-2) day and 17 patients (77.3%) were discharged 24 hours after surgery. The drainage tube was removed after a median of 7 (6-9) days. \\u0026nbsp;During a median follow-up period of 105 days, no local, regional or systemic recurrence was diagnosed (Table 5).\\u003c/p\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eSPIE-NSM and R-NSM are similar mastectomy endoscopic techniques, as they use a single access port and maintain the operation space by insufflating CO2. The difference lies in the surgical material used for the dissection of the mammary gland, with better vision and more precise movements in the R-NSM. Both surgical techniques require a learning curve to verify their feasibility and safety. Due to the difficulty in obtaining robotic operation theatre hours, we have initiated and analysed our experience and learning curve with SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR, a technique performed by Tukenmez et al. [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e] and Lai et al. [\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e]. Other authors use the same technique, but with the help of small instruments that are inserted into the skin of the breast [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. As in other publications [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e, \\u003cspan additionalcitationids=\\\"CR17 CR18\\\" citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e], we have analysed only those surgeries performed by a single surgeon to reduce bias associated with the surgical technique and to ensure consistency and accuracy in the evaluation of the learning curve.\\u003c/p\\u003e \\u003cp\\u003eThere were no cases of conversion to C-NSM, which coincides with the published studies on E-NSM and R-NSM [\\u003cspan additionalcitationids=\\\"CR20 CR21 CR22 CR23 CR24\\\" citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. However, in the early stages of the R-NSM technique, a moderate number of conversions to open surgery were recorded, although in later studies these were absent. [\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eIn our analysis, the CUSUM curve showed that the inflection points in overall operation time and endoscopic mastectomy time occurred in the 11th case and in the following 12 cases a downward trend in mastectomy times can be seen. Other authors situate inflection points in their learning curves at the 10th [\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e], 13th [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] and 17th [\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e] cases and maintain this in subsequent cases. All this suggests to us that surgeons who start SPIE-NSM will become more familiar with endoscopic mastectomy and reduce operation times around the 11th-13th case.\\u003c/p\\u003e \\u003cp\\u003eIn agreement with other authors [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e], in our learning curve we observe that with increased experience, safety and efficiency improve, leading to a progressive reduction in endoscopic mastectomy and in the overall operation times (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e). When we performed a comparative statistical study of the mean operative times between the initial 11 cases (\\u003cem\\u003einitial\\u003c/em\\u003e group) and the final 12 cases (\\u003cem\\u003efinal\\u003c/em\\u003e group), we found that there was a significant reduction in \\u003cem\\u003eendoscopic mastectomy times\\u003c/em\\u003e and \\u003cem\\u003eoverall operation times\\u003c/em\\u003e in favour of the \\u003cem\\u003efinal\\u003c/em\\u003e group. This reduction is not due to \\u003cem\\u003ereconstructive time\\u003c/em\\u003e or the \\u003cem\\u003eaxillary time\\u003c/em\\u003e, which showed minimal variations (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e). This is entirely due to the reduction in time for endoscopic mastectomies, which includes the time taken to place the single port, as this is part of the endoscopic mastectomy. It should be noted that the time taken to perform endoscopic mastectomy decreased to an average of 105 minutes in the final phase of the learning curve, as the surgeon's experience increased.\\u003c/p\\u003e \\u003cp\\u003eWhen analysing our operative times with those published by other authors, we found that our mean \\u003cem\\u003eoverall endoscopic mastectomy\\u003c/em\\u003e time (SPIE-NSM), without reconstruction, was 151.8\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;43, comparable to other published series: 149.8\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;37.7 minutes [\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e], 155.6\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;43.2 minutes [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e] and 159.7\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;58.2 minutes [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e]. The mean \\u003cem\\u003eoverall operation time\\u003c/em\\u003e (SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR) was 195.8\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;35.6 minutes, similar to that reported in other series, which show overall surgery times of around 200 minutes, with a range of variation between 159 and 205 minutes [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e, \\u003cspan additionalcitationids=\\\"CR30 CR31\\\" citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e]. In contrast, there are authors [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e] who exceed 250 minutes. This variability in the results may be due to confounding factors such as the type of reconstruction, pre or subpectoral [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e], whether they are single or multicenter studies[\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e], the size of the breasts or the experience of the surgeons [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR33\\\" class=\\\"CitationRef\\\"\\u003e33\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eAnother important factor in the learning curve is the previous training and skills that the surgeon has in C-NSM and laparoscopic surgery. The R-NSM learning curve improves after previous experience in E-NSM [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e]. At SPIE-NSM, an experienced assistant improves visibility in limited surgical space and reduces operation time.\\u003c/p\\u003e \\u003cp\\u003eEven small modifications to the technique can improve operation times. Within the existing discrepancies between whether to start by dissecting the anterior or posterior space of the mammary gland [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR34\\\" class=\\\"CitationRef\\\"\\u003e34\\u003c/span\\u003e], we are in favour of dissecting the anterior space first in small breasts, but in medium-sized breasts (C-D cup) the posterior dissection of the glandular tissue should be performed first, as the greater weight of the breast would make it difficult to dissect if the anterior space has already been carried out.\\u003c/p\\u003e \\u003cp\\u003eDue to our indications for mastectomy, SPIE-NSM-BRI were more frequently performed in patients with cup size\\u0026thinsp;\\u0026le;\\u0026thinsp;C (83.3%). There are series of E-NSM with 85.7% of cup size\\u0026thinsp;\\u0026le;\\u0026thinsp;C and they assume that the ideal patients for this technique should have small and medium breasts [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e]. Safarti et al. [\\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e35\\u003c/span\\u003e] only included cup size\\u0026thinsp;\\u0026le;\\u0026thinsp;C in their R-NSM series. Like these authors, we believe that the learning curve for SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR should be performed on small and medium breasts with little ptosis.\\u003c/p\\u003e \\u003cp\\u003eIn our study, the average weight of surgical specimens was 209.6 g, comparable to the 228.9 g reported by Rathat et al.[\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e], but lower than other series [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR36\\\" class=\\\"CitationRef\\\"\\u003e36\\u003c/span\\u003e]. Some authors believe that the weight of the mastectomy specimen influences operation times [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e]. However, other authors such as Hung et al. [\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e] and Lai et al. [\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e] observe that the improvements in the learning curves are not due to differences in the weights of the surgical specimens but to the experience of the surgeons and the standardisation of surgical techniques. This is consistent with the data from our series, where the improvement in surgical times in the final phase does not coincide with a decrease in the weight of surgical specimens.\\u003c/p\\u003e \\u003cp\\u003eIn our cases, the incidence of minor and major perioperative complications was low with 13% y 4.3% respectively. The major complication was caused by a small area of skin and areola necrosis which required excision under local anaesthesia (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab4\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). These results are comparable to those presented by Lai et al. [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e] with 19.1% (I-II) and 4.8% (III). Chung et al. [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e] present major and minor complications of 1.3% and 7.6% respectively in 79 E-NSM. Most of the complications in the report by Yu et al. [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e] were due to the prostheses (14.3%) and very few were due to E-NSM (1.8%). In general, we can say that SPIE-NSM has few complications and they are equal to or fewer than C-NSM [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e]. The number and type of complications depends on the E-NSM technique and the experience of the surgeon, the characteristics of the patient and the type of prosthetic reconstruction performed [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e]. The complications of NAC, both ischaemia and necrosis, decreased significantly when the double areolar and axillary incision was changed to a single axillary incision and insufflation was used instead of retractors.[\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e]\\u003c/p\\u003e \\u003cp\\u003eOur SPIE-NSM-BRI series has presented one of the shortest hospitals postoperative stays published[\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR37\\\" class=\\\"CitationRef\\\"\\u003e37\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR38\\\" class=\\\"CitationRef\\\"\\u003e38\\u003c/span\\u003e] and many of our patients (77.3 %) could ave been treated in the 24-hour hospital. We concur with Zhou et al.[\\u003cspan citationid=\\\"CR39\\\" class=\\\"CitationRef\\\"\\u003e39\\u003c/span\\u003e] that soon, most SPIE-NSM-BRI will be carried out in a 24-hour hospital. All this means lower healthcare costs and improved patient well-being. We believe this is due to the lower incidence of immediate complications and easy access to outpatient post-operative consultation.\\u003c/p\\u003e \\u003cp\\u003eIn the most recent published series of minimally invasive mastectomies, whether endoscopic or robotic, the number of margins affected is less than 5%. In our study, we have all clear margins, which is in agreement with authors such as Lai et al. [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e] and Toesca et al.[\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. We believe that intraoperative ultrasound was very useful in obtaining clear superficial margins in SPIE-NSM, as demonstrated by Esgueva et al.[\\u003cspan citationid=\\\"CR40\\\" class=\\\"CitationRef\\\"\\u003e40\\u003c/span\\u003e] in C-NSM.\\u003c/p\\u003e \\u003cp\\u003eThere are no differences in disease-free survival and overall survival between minimally invasive mastectomies and C-NSM in randomised clinical trials[\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e] and in individual series analyses[\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e] with follow-ups of 42 and 49.9 months respectively. In a group of 421 E-NSM, Sakamoto et al.[\\u003cspan citationid=\\\"CR41\\\" class=\\\"CitationRef\\\"\\u003e41\\u003c/span\\u003e] presented a recurrence rate of 2.6% during an average follow-up of 61 months. In our study we followed the surgical steps and principles of C-NSM, therefore, we think that the oncological results may be similar for both techniques. With a very short average follow-up of 4.3 months, no local or distant recurrences have been diagnosed in the therapeutic group. However, patients should be provided with detailed information on minimally invasive, endoscopic and robotic mastectomies, and treatment options to help them make an appropriate decision.\\u003c/p\\u003e \\u003cp\\u003eThis study shows the limitations inherent in the implementation of new surgical techniques, as it is monocentric, performed by a single surgeon and has preliminary results. Pending cosmetic results and patient satisfaction.\\u003c/p\\u003e\"},{\"header\":\"Conclusion\",\"content\":\"\\u003cp\\u003eIn conclusion, our study confirms that SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR is a feasible y safe effective technique that represents an alternative to R-NSM-IBR. It requires more effort on the part of the surgeon due to more rigid instruments and poorer vision of the operative field, but better than C-NSM. It is a technique available in all hospitals, as it uses laparoscopic instruments, allowing more patients to benefit from minimal invasive mastectomy. It requires a short learning period. This series of cases could contribute to a deeper analysis of the factors that affect individual learning curves, allowing for the design of more effective training programmes that facilitate the implementation of SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eDeclaration of interest:\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll the authors declare that there are no conflicts of interest regarding the publication of this article.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAcknowledgements\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors would like to thank the surgical staff, the members of the breast unit and the administration for their cooperation and support in the implementation and development of this new surgical technique.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eCruz LDL, Moody AM, Tappy EE, Blankenship SA, Hecht EM. Overall Survival, Disease-Free Survival, Local Recurrence, and Nipple\\u0026ndash;Areolar Recurrence in the Setting of Nipple-Sparing Mastectomy: A Meta-Analysis and Systematic Review. Ann Surg Oncol 2015;22:3241\\u0026ndash;9. https://doi.org/10.1245/s10434-015-4739-1.\\u003c/li\\u003e\\n\\u003cli\\u003eMota BS, Riera R, Ricci MD, Barrett J, Castria TB de, Atallah \\u0026Aacute;N, et al. Nipple‐ and areola‐sparing mastectomy for the treatment of breast cancer. Cochrane Database Syst Rev 2016;2016:CD008932. https://doi.org/10.1002/14651858.cd008932.pub3.\\u003c/li\\u003e\\n\\u003cli\\u003eLai HW, Chen ST, Chen DR, Chen SL, one TCP, 2016. Current trends in and indications for endoscopy-assisted breast surgery for breast cancer: results from a six-year study conducted by the Taiwan Endoscopic \\u0026hellip;. JournalsPlosOrg 2016;11:e0150310. https://doi.org/10.1371/journal.pone.0150310.\\u003c/li\\u003e\\n\\u003cli\\u003eLai HW, Wu HS, Chuang KL, Surgical DC, 2015. 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Single-Axillary-Incision Endoscopic-Assisted Hybrid Technique for Nipple-Sparing Mastectomy: Technique, Preliminary Results, and Patient-Reported Cosmetic Outcome from Preliminary 50 Procedures. Ann Surg Oncol 2018;25:1340\\u0026ndash;9. https://doi.org/10.1245/s10434-018-6383-z.\\u003c/li\\u003e\\n\\u003cli\\u003eLee H, Lee J, Lee K, Kim JY, Park HS. Comparison between Gasless and Gas-Inflated Robot-Assisted Nipple-Sparing Mastectomy. J Breast Cancer 2020;24:183\\u0026ndash;95. https://doi.org/10.4048/jbc.2021.24.e20.\\u003c/li\\u003e\\n\\u003cli\\u003eWang Y, Wu J, Guan S. A Technique of Endoscopic Nipple-Sparing Mastectomy for Breast Cancer. JSLS 2017;21:e2017.00028-8. https://doi.org/10.4293/jsls.2017.00028.\\u003c/li\\u003e\\n\\u003cli\\u003eDu J, Liang Q, Qi X, Ming J, Liu J, Zhong L, et al. Endoscopic nipple sparing mastectomy with immediate implant-based reconstruction versus breast conserving surgery: a long-term study. Sci Rep 2017;7:45636. https://doi.org/10.1038/srep45636.\\u003c/li\\u003e\\n\\u003cli\\u003eChung K, Xie Y, Liang F, Qiu M, Yang H, Zhang Q, et al. Reverse-sequence endoscopic nipple-sparing mastectomy with immediate implant-based breast reconstruction: an improvement of conventional minimal access breast surgery. Front Oncol 2024;14:1366877. https://doi.org/10.3389/fonc.2024.1366877.\\u003c/li\\u003e\\n\\u003cli\\u003eYang H, Liang F, Xie Y, Qiu M, Du Z. Single axillary incision reverse-order endoscopic nipple/skin-sparing mastectomy followed by subpectoral implant-based breast reconstruction: Technique, clinical outcomes, and aesthetic results from 88 preliminary procedures. Surgery 2023;174:464\\u0026ndash;72. https://doi.org/10.1016/j.surg.2023.05.037.\\u003c/li\\u003e\\n\\u003cli\\u003eTukenmez M, Ozden BC, Agcaoglu O, Kecer M, Ozmen V, Muslumanoglu M, et al. Videoendoscopic Single-Port Nipple-Sparing Mastectomy and Immediate Reconstruction. Journal of Laparoendoscopic \\u0026amp; Advanced Surgical Techniques 2014;24:77\\u0026ndash;82. https://doi.org/10.1089/lap.2013.0172.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Chen S-T, Mok CW, Chang Y-T, Lin S-L, Lin Y-J, et al. Single-Port Three-Dimensional (3D) Videoscope-Assisted Endoscopic Nipple-Sparing Mastectomy in the Management of Breast Cancer: Technique, Clinical Outcomes, Medical Cost, Learning Curve, and Patient-Reported Aesthetic Results from 80 Preliminary Procedures. Ann Surg Oncol 2021;28:7331\\u0026ndash;44. https://doi.org/10.1245/s10434-021-09964-2.\\u003c/li\\u003e\\n\\u003cli\\u003eWang Z-H, Gao G-X, Liu W-H, Wu S-S, Xie F, Xu W, et al. Single-port nipple-sparing subcutaneous mastectomy with immediate prosthetic breast reconstruction for breast cancer. Surg Endosc 2023;37:3842\\u0026ndash;51. https://doi.org/10.1007/s00464-023-09862-6.\\u003c/li\\u003e\\n\\u003cli\\u003eHung C-S, Chang S-W, Liao L-M, Huang C-C, Tu S-H, Chen S-T, et al. The learning curve of endoscopic total mastectomy in Taiwan: A multi-center study. PLoS ONE 2017;12:e0178251. https://doi.org/10.1371/journal.pone.0178251.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Wang C-C, Lai Y-C, Chen C-J, Lin S-L, Chen S-T, et al. The learning curve of robotic nipple sparing mastectomy for breast cancer: An analysis of consecutive 39 procedures with cumulative sum plot. Eur J Surg Oncol 2019;45:125\\u0026ndash;33. https://doi.org/10.1016/j.ejso.2018.09.021.\\u003c/li\\u003e\\n\\u003cli\\u003eYu D young, Lee TY, Kim DW, Chang YW, Son GS, Lee HY. Preliminary experience and learning curve of endoscopic nipple-areolar-complex sparing total mastectomy: A single-center retrospective study. PLOS ONE 2025;20:e0311764. https://doi.org/10.1371/journal.pone.0311764.\\u003c/li\\u003e\\n\\u003cli\\u003eRathat G, Chaumette M, Fontaine V, Rebel L, Pissarra J, Duflos C, et al. Endoscopic prophylactic nipple-sparing mastectomy: First French survey of 10 patients. J Gynecol Obstet Hum Reprod 2025;54:102862. https://doi.org/10.1016/j.jogoh.2024.102862.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Chen S-T, Lin Y-J, Lin S-L, Lin C-M, Chen D-R, et al. Minimal Access (Endoscopic and Robotic) Breast Surgery in the Surgical Treatment of Early Breast Cancer\\u0026mdash;Trend and Clinical Outcome From a Single-Surgeon Experience Over 10 Years. Front Oncol 2021;11:739144. https://doi.org/10.3389/fonc.2021.739144.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Chen D-R, Liu L-C, Chen S-T, Kuo Y-L, Lin S-L, et al. Robotic Versus Conventional or Endoscopic-assisted Nipple-sparing Mastectomy and Immediate Prosthesis Breast Reconstruction in the Management of Breast Cancer. Ann Surg 2024;279:138\\u0026ndash;46. https://doi.org/10.1097/sla.0000000000005924.\\u003c/li\\u003e\\n\\u003cli\\u003eLoh Z-J, Wu T-Y, Cheng FT-F. Evaluation of the Learning Curve in Robotic Nipple-sparing Mastectomy for Breast Cancer. Clin Breast Cancer 2021;21:e279\\u0026ndash;84. https://doi.org/10.1016/j.clbc.2020.09.013.\\u003c/li\\u003e\\n\\u003cli\\u003eRyu JM, Kim JY, Choi HJ, Ko B, Kim J, Cho J, et al. Robot-assisted Nipple-sparing Mastectomy With Immediate Breast Reconstruction. Ann Surg 2022;275:985\\u0026ndash;91. https://doi.org/10.1097/sla.0000000000004492.\\u003c/li\\u003e\\n\\u003cli\\u003eNessa A, Shaikh S, Fuller M, Masannat YA, Kastora SL. Postoperative complications and surgical outcomes of robotic versus conventional nipple-sparing mastectomy in breast cancer: meta-analysis. Br J Surg 2023;111:znad336. https://doi.org/10.1093/bjs/znad336.\\u003c/li\\u003e\\n\\u003cli\\u003eToesca A, Sangalli C, Maisonneuve P, Massari G, Girardi A, Baker JL, et al. A Randomized Trial of Robotic Mastectomy Versus Open Surgery in Women With Breast Cancer or BrCA Mutation. Ann Surg 2022;276:11\\u0026ndash;9. https://doi.org/10.1097/sla.0000000000004969.\\u003c/li\\u003e\\n\\u003cli\\u003eSarfati B, Honart J, Leymarie N, Rimareix F, Khashnam HA, Kolb F. Robotic da Vinci Xi‐assisted nipple‐sparing mastectomy: First clinical report. Breast J 2018;24:373\\u0026ndash;6. https://doi.org/10.1111/tbj.12937.\\u003c/li\\u003e\\n\\u003cli\\u003eToesca A, Peradze N, Manconi A, Galimberti V, Intra M, Colleoni M, et al. Robotic nipple-sparing mastectomy for the treatment of breast cancer: Feasibility and safety study. Breast 2017;31:51\\u0026ndash;6. https://doi.org/10.1016/j.breast.2016.10.009.\\u003c/li\\u003e\\n\\u003cli\\u003eLee HY, Chang YW, Yu DY, Lee TY, Kim DW, Kim WY, et al. Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional Nipple-Sparing Mastectomy for Breast Cancer Based on Initial Experience. J Breast Cancer 2020;24:196\\u0026ndash;205. https://doi.org/10.4048/jbc.2021.24.e18.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Chen S-T, Liao C-Y, Mok CW, Lin Y-J, Chen D-R, et al. Oncologic Outcome of Endoscopic Assisted Breast Surgery Compared with Conventional Approach in Breast Cancer: An Analysis of 3426 Primary Operable Breast Cancer Patients from Single Institute with and Without Propensity Score Matching. Ann Surg Oncol 2021;28:7368\\u0026ndash;80. https://doi.org/10.1245/s10434-021-09950-8.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Chen S-T, Mok CW, Lin S-L, Tai C-M, Chen D-R, et al. Single-port 3-dimensional Videoscope-assisted Endoscopic Nipple-sparing Mastectomy in the Management of Breast Cancer. Plast Reconstr Surg Glob Open 2019;7:e2367. https://doi.org/10.1097/gox.0000000000002367.\\u003c/li\\u003e\\n\\u003cli\\u003eFeng Y, Liang F, Wen N, Yang H, Zhou J, Zhang S, et al. An Innovative and Highly Efficient Single-Port Endoscopic Nipple-/Skin-Sparing Mastectomy and Dual-Plane Direct-to-Implant Breast Reconstruction: A Prospective Study from a Single Institution. Aesthetic Plast Surg 2023:1\\u0026ndash;9. https://doi.org/10.1007/s00266-023-03402-2.\\u003c/li\\u003e\\n\\u003cli\\u003eLiu W-H, Wu S-S, Tian Y-M, Liu J, Gao G-X, Xie F, et al. Single-port insufflation endoscopic nipple-sparing mastectomy in early breast cancer: a retrospective cohort study. Gland Surg 2023;12:1348359\\u0026ndash;1341359. https://doi.org/10.21037/gs-23-148.\\u003c/li\\u003e\\n\\u003cli\\u003eKim JH, Lee SB, Park HS, Kim KS, Choi JE, Lee MH, et al. Trends in Operation Times for Robot-assisted Nipple-sparing Mastectomy Performed by Expert Breast Surgeons. Ann Robot Innov Surg 2024;5:1. https://doi.org/10.37007/aris.2024.5.1.1.\\u003c/li\\u003e\\n\\u003cli\\u003eSakamoto N, Fukuma E, Higa K, Ozaki S, Sakamoto M, Abe S, et al. Early Results of an Endoscopic Nipple-Sparing Mastectomy for Breast Cancer. Ann Surg Oncol 2009:1\\u0026ndash;8. https://doi.org/10.1245/s10434-009-0661-8.\\u003c/li\\u003e\\n\\u003cli\\u003eSarfati B, Struk S, Leymarie N, Honart J-F, Alkhashnam H, Fremicourt KT de, et al. Robotic Prophylactic Nipple-Sparing Mastectomy with Immediate Prosthetic Breast Reconstruction: A Prospective Study. Ann Surg Oncol 2018;25:2579\\u0026ndash;86. https://doi.org/10.1245/s10434-018-6555-x.\\u003c/li\\u003e\\n\\u003cli\\u003eKim JH, Ryu JM, Bae SJ, Ko BS, Choi JE, Kim KS, et al. Minimal Access vs Conventional Nipple-Sparing Mastectomy. JAMA Surg 2024;159:1177\\u0026ndash;86. https://doi.org/10.1001/jamasurg.2024.2977.\\u003c/li\\u003e\\n\\u003cli\\u003eHouvenaeghel G, Barrou J, Jauffret C, Rua S, Sabiani L, Troy AV, et al. Robotic Versus Conventional Nipple-Sparing Mastectomy With Immediate Breast Reconstruction. Front Oncol 2021;11:637049. https://doi.org/10.3389/fonc.2021.637049.\\u003c/li\\u003e\\n\\u003cli\\u003eLai H-W, Chen S-T, Tai C-M, Lin S-L, Lin Y-J, Huang R-H, et al. Robotic- Versus Endoscopic-Assisted Nipple-Sparing Mastectomy with Immediate Prosthesis Breast Reconstruction in the Management of Breast Cancer: A Case\\u0026ndash;Control Comparison Study with Analysis of Clinical Outcomes, Learning Curve, Patient-Reported Aesthetic Results, and Medical Cost. Ann Surg Oncol 2020;27:2255\\u0026ndash;68. https://doi.org/10.1245/s10434-020-08223-0.\\u003c/li\\u003e\\n\\u003cli\\u003eZhou J, Xie Y, Liang F, Feng Y, Yang H, Qiu M, et al. A novel technique of reverse-sequence endoscopic nipple-sparing mastectomy with direct-to-implant breast reconstruction: medium-term oncological safety outcomes and feasibility of 24-h discharge for breast cancer patients. Int J Surg (Lond, Engl) 2024;110:2243\\u0026ndash;52. https://doi.org/10.1097/js9.0000000000001134.\\u003c/li\\u003e\\n\\u003cli\\u003eEsgueva AJ, Sobrido C, Diaz-Botero S, D\\u0026iacute;ez-Uriel E, Iscar T, Miguel VD, et al. Intraoperative ultrasound margin evaluation as a tool to reduce positive superficial margins in nipple and skin sparing mastectomy in breast cancer patients. Eur J Surg Oncol 2023;49:107049. https://doi.org/10.1016/j.ejso.2023.107049.\\u003c/li\\u003e\\n\\u003cli\\u003eSakamoto N, Fukuma E, Teraoka K, Hoshi K. Local recurrence following treatment for breast cancer with an endoscopic nipple-sparing mastectomy. Breast Cancer 2016;23:552\\u0026ndash;60. https://doi.org/10.1007/s12282-015-0600-4.\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"},{\"header\":\"Tables\",\"content\":\"\\u003cp\\u003eTables 1 to 5 are available in the Supplementary Files section.\\u003c/p\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Endoscopic Mastectomy, Single port, Insufflation, Breast surgery, Breast cancer\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-6237635/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-6237635/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003ch2\\u003eBackground\\u003c/h2\\u003e \\u003cp\\u003eIn recent years, breast surgery has undergone considerable development in the field of minimally invasive techniques such as endoscopic (E-NSM) or robotic (R-NSM) nipple sparing mastectomy. However, access to robotic platforms is not always possible. In this study, we present our initial experience with E-NSM through a single port and insufflation with immediate reconstruction (SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR) as a surgical option for minimally invasive mastectomy.\\u003c/p\\u003e\\u003ch2\\u003eMethods\\u003c/h2\\u003e \\u003cp\\u003eThe medical records of patients who underwent SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR from February 2024 to February 2025, performed by the same surgeon at a single institution, were collected and analysed for feasibility, safety and reproducibility by evaluating the conversion rate to open surgery, the learning curve with operating times and the cumulative sum (CUSUM) plot method, and the number of complications.\\u003c/p\\u003e\\u003ch2\\u003eResults\\u003c/h2\\u003e \\u003cp\\u003e23 SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR were performed on 22 women. The times for SPIE-NSM and SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR decreased with accumulated case experience, and according to Cusum's analysis, the improvement started from the 11th case in all two scenarios. The mean operative times for the \\u003cem\\u003efinal\\u003c/em\\u003e cases (12th-23rd) decreased to 105\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;33.1 minutes in SPIE-NSM (p\\u0026thinsp;=\\u0026thinsp;0.009), 118.7\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;39.7 minutes in SPIE-NSM plus axilla (p\\u0026thinsp;=\\u0026thinsp;0.002) and 167.6\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;34 minutes in SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR (p\\u0026thinsp;=\\u0026thinsp;0.003), compared to the group of \\u003cem\\u003einitial\\u003c/em\\u003e cases. There were no cases requiring open surgery (0%). The median hospital stay was 1(1\\u0026ndash;2) day. There was one serious complication (IIIa, 4.35%). No positive margins were found in the final pathological examination, nor were there any implant losses or recurrences during follow-up of 4.3 months.\\u003c/p\\u003e\\u003ch2\\u003eConclusions\\u003c/h2\\u003e \\u003cp\\u003eOur study confirms that SPIE-NSM\\u0026thinsp;+\\u0026thinsp;IBR is a feasible and safe alternative to R-NSM-IBR. It is a technique available in all hospitals, as it uses laparoscopic instruments that allow more patients to benefit from minimally invasive mastectomy. An acceptable learning curve is necessary.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Single-Port Insufflation Technique for Endoscopic Nipple-Sparing Mastectomy: Initial Experience and Learning Curve.\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-04-01 10:02:02\",\"doi\":\"10.21203/rs.3.rs-6237635/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"0eb914df-01aa-432c-a2cd-e8010bd67320\",\"owner\":[],\"postedDate\":\"April 1st, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-05-06T05:51:06+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-04-01 10:02:02\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-6237635\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-6237635\",\"identity\":\"rs-6237635\",\"version\":[\"v1\"]},\"buildId\":\"XKTyCvWXoU3ODBz1xrDgd\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}