Two-stage Implant-based Reconstruction Research Articles

Using a Machine Learning Approach to Predict the Need for Elective Revision and Unplanned Surgery after Implant-based Breast Reconstruction.

Two-stage implant-based reconstruction after mastectomy may require secondary revision procedures to treat complications, correct defects, and improve aesthetic outcomes. Patients should be counseled on the possibility of additional procedures during the initial visit, but the likelihood of requiring another procedure is dependent on many patient- and surgeon-specific factors. This study aims to identify patient-specific factors and surgical techniques associated with higher rates of secondary procedures and offer a machine learning model to compute individualized assessments for preoperative counseling. A training set of 209 patients (406 breasts) who underwent two-stage alloplastic reconstruction was created, with 45.57% of breasts (185 of 406) requiring revisional or unplanned surgery. On multivariate analysis, hypertension, no tobacco use, and textured expander use corresponded to lower odds of additional surgery. In contrast, higher initial tissue expander volume, vertical radial incision, and larger nipple-inframammary fold distance conferred higher odds of additional surgery. The neural network model trained on clinically significant variables achieved the highest collective performance metrics, with ROC AUC of 0.74, sensitivity of 84.2, specificity of 63.6, and accuracy of 62.1. The proposed machine learning model trained on a single surgeon's data offers a precise and reliable tool to assess an individual patient's risk of secondary procedures. Machine learning models enable physicians to tailor surgical planning and empower patients to make informed decisions aligned with their lifestyle and preferences. The utilization of this technology is especially applicable to plastic surgery, where outcomes are subject to a variety of patient-specific factors and surgeon practices, including threshold to perform secondary procedures.

Machine-Learning Prediction of Capsular Contraction after Two-Stage Breast Reconstruction

BackgroundTwo-stage breast reconstruction is a common technique used to restore preoperative appearance in patients undergoing mastectomy. However, capsular contracture may develop and lead to implant failure and significant morbidity. The objective of this study is to build a machine-learning model that can determine the risk of developing contracture formation after two-stage breast reconstruction. MethodsA total of 209 women (406 samples) were included in the study cohort. Patient characteristics that were readily accessible at the preoperative visit and details pertaining to the surgical approach were used as input data for the machine-learning model. Supervised learning models were assessed using 5-fold cross validation. A neural network model is also evaluated using a 0.8/0.1/0.1 train/validate/test split. ResultsAmong the subjects, 144 (35.47%) developed capsular contracture. Older age, smaller nipple-inframammary fold distance, retropectoral implant placement, synthetic mesh usage, and postoperative radiation increased the odds of capsular contracture (p < 0.05). The neural network achieved the best performance metrics among the models tested, with a test accuracy of 0.82 and area under receiver operative curve of 0.79. ConclusionTo our knowledge, this is the first study that uses a neural network to predict the development of capsular contraction after two-stage implant-based reconstruction. At the preoperative visit, surgeons may counsel high-risk patients on the potential need for further revisions or guide them toward autologous reconstruction.

61. Wise-pattern Versus Transverse Pattern Mastectomy in Two-stage Implant-Based Breast Reconstruction: A Propensity Score-matched Analysis

PURPOSE: The wise pattern adapted to the mastectomy incisions has become a valuable asset for breast reconstruction in patients with large and ptotic breasts. Herein, we compared the time for exchange, time to initiate postmastectomy radiotherapy (PMRT) and complications rate between reconstructions performed with wise pattern versus a transverse incision pattern. METHODS: We retrospectively reviewed the record of patients who underwent immediate two-stage implant-based reconstruction (IBBR) between January 2011 and December 2020. Two cohorts were compared according to the incision pattern: wise versus transverse incision pattern. Complications were compared after propensity score matching. RESULTS: We initially analyzed 393 two-stage immediate IBBR in 239 patients, 91 (23.2%) in the wise-pattern group and 302 (76.8%) in the transverse pattern group. The expansion time (53 days versus 50 days, p=0.9), the time for TE-to-implant exchange (154 versus 175 days, p=0.547), and the time to initiate PMRT (144 days versus 126 days, p=0.616) were not different between groups. Before propensity score matching, the 30-day rate of wound-related complications (32% versus 10%, p<.001) and 30-day rate of wound complications requiring E/D+C procedures (20% versus 7%, p<.001) were significantly higher in the wise-pattern group. After propensity score matching, the 30-day rate of wound-related complications persisted significantly higher (25% versus 10%, p=0.03) in the wise-pattern group. CONCLUSION: The wise pattern mastectomy independently increases the incidence of wound-related complications versus only transverse patterns during two-stage IBBR, even after propensity score matching. Delayed TE placement may improve the safety profile of this procedure.

21. A Tale of Two Surgeries: Predicting the Need for Secondary Revision Procedures after Breast Reconstruction Using Machine Learning

PURPOSE: Breast revision surgery after two-stage implant-based reconstruction is an effective way to correct existing defects and improve aesthetic outcomes. For new patients, providing a quantifiable “likelihood of revision surgery to achieve satisfaction” may enable them to make a more informed decision regarding the modality of reconstruction. METHODS: Retrospective chart review was done on two-stage breast reconstruction patients between 2012-2021. The outcome of revision/corrective surgery was determined based on physician note and operative record. Patient characteristics that emerged as significant on both univariate and multivariate analysis were used to construct the machine learning model. Supervised learning models were evaluated using k-fold cross validation (k=3). A neural network model was also evaluated with a 0.8/0.1/0.1 train/validate/test split on the dataset. RESULTS: 185/406 (45.57%) required post-operative revision surgery to achieve more optimal aesthetic outcomes. On multivariate analysis, never smoking (OR 0.61), hypertension (OR 0.40), and textured expander (OR 0.52) corresponded to lower odds of undergoing revision surgery (p<0.05). Higher initial tissue expander volume (OR 1.002), vertical radial incision (OR 4.79), and larger nipple-inframammary fold distance (OR 1.12, p-value 0.03) conferred higher odds of needing additional revisions. Support Vector Machine achieved the highest performing machine learning model, with an accuracy of 61.3, and ROC AUC 0.67+/-0.05. CONCLUSION: Machine learning can help predict the probability of requiring secondary surgeries after implant-based reconstruction. As an example, for patients at high risk of needing further revisions, surgeons can provide more robust counseling on the use of autologous abdominal tissue vs. tissue expander/implant.

Long-Term Outcomes in Prepectoral versus Subpectoral Two-Stage Implant-Based Breast Reconstruction after Nipple-Sparing Mastectomy.

Implant-based breast reconstruction remains the most often used method following mastectomy, but data are lacking regarding differences in complications and long-term patient-reported outcomes for two-stage subpectoral versus prepectoral reconstruction. This study sought to better understand the risks and impact of these reconstructive approaches on overall satisfaction. Patients who underwent unilateral or bilateral nipple-sparing mastectomy and two-stage implant-based reconstruction from 2014 to 2019 were identified from the electronic medical records and contacted via email to complete the BREAST-Q survey. Overall satisfaction was measured by the question, "How happy are you with the outcome of your breast reconstruction?" using a six-point Likert scale. Patients were grouped into subpectoral or prepectoral cohorts. Complications were evaluated retrospectively. Only patients who were at least 6 months from their final reconstruction were included in the analysis. Of the 582 patients contacted, 206 (35%) responded. The subpectoral ( n = 114) and prepectoral ( n = 38) groups did not differ significantly by demographic or treatment characteristics. BREAST-Q scores were also comparable. Complication rates were similar, but prepectoral patients had a significantly higher rate of capsular contracture (16% versus 4%, P < 0.05). Bivariate ordered logistic regression identified prepectoral implant placement, having any postoperative complication, and capsular contracture as predictors of less overall happiness. The authors' study suggests that prepectoral patients may have slightly higher complication rates but are as satisfied as subpectoral patients after at least a year of follow-up. Further studies should investigate risk factors for capsular contracture, how the risk changes over time, and how the risk affects patient satisfaction.

Can Skin Sparing Mastectomy and Immediate Submuscular Implant-Based Reconstruction Be a Better Choice in Treatment of Early-Stage Breast Cancer?

To discuss if skin sparing mastectomy (SSM) with immediate submuscular implant-based reconstruction (IBR) can be the preferred treatment in early-stage breast cancer. Patients treated for clinical in situ or early-stage invasive breast cancer with SSM and immediate submuscular IBR between October 2016 and October 2018 were retrospectively evaluated. Twenty-one cases were reviewed, of whom18 had two-stage and three had one-stage IBR. Median (range) follow-up period was 42 (32-61) months. Five underwent axillary dissection and 1-2 metastatic nodes were found in three (60%). Eight patients (38.09%) with two-stage IBR had radiotherapy because of upstaging and three (37.5%) experienced radiotherapy-linked complications. Rate of complications and mean number of events recorded per patient were higher with radiotherapy. Four patients (44%) had unwanted events after secondary surgery. The mean number of surgeries was higher after two-stage IBR. Mean duration increased in those with chemo-radiotherapy. Six with two-stage and two with one-stage IBR discontinued secondary surgeries. SSM with immediate submuscular IBR is not suitable in all patients with early-breast cancer. It takes long to have aesthetically pleasing, symmetrical breasts after primary operation because of additional corrective/matching surgeries. Radiotherapy may still be required because of upstaging. Expectation and tolerability of the patient to the process should be evaluated as well as tumor biology and the status of the axilla.

Impact of Radiation Dosimetry and Clinical Factors on Implant-Based Breast Reconstruction Outcomes Following Post-Mastectomy Radiotherapy

<h3>Purpose/Objective(s)</h3> Post-mastectomy radiotherapy (PMRT) is associated with increased risk of implant-based breast reconstruction complications. We sought to examine the relationship between clinical/dosimetric factors and implant reconstruction complications. <h3>Materials/Methods</h3> We conducted a retrospective study of breast cancer patients (pts) who underwent simulation for PMRT from 2012 to 2015 following single-stage or two-stage implant-based reconstruction. Demographic, disease, treatment, and reconstruction outcomes data were collected. Major reconstruction complication (MRC) was defined as any complication requiring unplanned reoperation or removal. Clinical/dosimetric factors associated with MRC were determined by Cox regression. Cutpoints for dosimetric variables were determined by the Contal and O'Quigley method. <h3>Results</h3> We identified 111 pts who underwent PMRT following implant-based reconstruction. 91% underwent two-stage reconstruction with PMRT to a tissue expander (TE) and 9% underwent single-stage reconstruction with PMRT to the permanent implant (PI). All pts were treated using 3D-CRT with conventional fractionation (1.8-2 Gy/day) for the majority of their treatment. 11 pts (10%) received hypofractionated (2.1-3 Gy) treatment for the last 2-5 fractions for scheduling reasons and were excluded from dosimetric analysis. 44% received a chest wall boost (4-10 Gy). At a median follow-up of 6.6 years, 45 pts (41%) experienced an MRC (8 had MRC while TE was in place, 7%; 37 had MRC while PI was in place, 33%). Following MRC, at time of last follow-up/death, 15 pts lacked replacement reconstruction and 12 had autologous reconstruction. Median time from end of PMRT to MRC was 1.6 yrs. The most common types of MRC were contracture (31%), infection (22%), asymmetry (18%), and threatened exposure of the PI (7%). On univariate analysis, there was no significant difference between pts with or without MRC with respect to age, race, smoking history, menopause status, chemotherapy or hormonal therapy, or reconstruction timing. Obesity (<i>P</i> = 0.03; HR 2.26, 1.08-4.76) and infection occurring after mastectomy and within 30 days after PMRT (<i>P</i> < 0.0001; HR 7.37, 2.78-19.55) were significantly associated with MRC. Dosimetric characteristics (excluding boost), including maximum chest wall hot spot ≥ 5464 cGy (P = 0.003; HR 4.08, 1.60-10.41), D_2cc ≥ 5410 cGy (<i>P</i> = 0.01; HR 3.51, 1.37-8.95), D_0.03cc ≥ 5420 cGy (P = 0.01; HR 4.73, 1.46-15.33), V100% ≥ 640 cc (P = 0.01; HR 2.72, 1.26-5.91), V105% ≥ 250 cc (P = 0.003; 2.58, 1.39-4.77), and V108% ≥ 3.5 cc (P = 0.01; HR 2.97, 1.25-7.07) were significantly associated with MRC. <h3>Conclusion</h3> Patients undergoing PMRT and implant-based reconstruction are at significant risk of MRC. Obesity, infection within 30 days of PMRT, increased treatment volume, and plan heterogeneity further increase this risk. Additional studies are needed to validate these findings and determine dosimetric constraints or other prophylactic measures that can limit complication risk.

Risk Factors for Anteroposterior Implant Malposition in Postmastectomy Patients with Cohesive Round Implants

BACKGROUND: Round cohesive implants are increasingly popular due to their ability to maintain shape, higher fill volume, and projection. However, they have also been associated with a higher risk of implant flipping. The current literature on risk factors of anteroposterior implant malposition in patients with two-stage implant-based reconstruction (IBR) is scarce. We identified predisposing factors of implant anteroposterior malposition in postmastectomy patients with prepectoral round, cohesive, smooth implants. METHODS: A retrospective review of patients who underwent postmastectomy two-stage IBR with prepectoral Natrelle Inspira Cohesivity Level 3 implants, from 2013 to 2020 at our institution, was conducted. Inclusion criterion was patients 18 years or older who had a prepectoral tissue expander and prepectoral breast implant. Patients who had prior breast reconstruction or aesthetic surgeries were excluded. RESULTS: A total of 214 implants (84.9% bilateral) in 106 patients were included. The mean age at surgery was 51.1 ± 11.4 years, and the mean body mass index was 27.0 ± 4.8 kg/m2. In total, 22.35% had a history of radiation to the chest wall, and 46.3% had chemotherapy. Of all breasts, 79.4% had prior MX tissue expanders, the median implant volume was 485 cm3 (Q1-3: 385–580), and acellular dermal matrix was placed in 65.4% of breasts. Anteroposterior malposition was reported in 19 (8.9%) breasts, 50% of which underwent surgery to correct the flipping. The mean time to implant flipping was 6.1 months (Q1-3: 3.5–16.8), and the mean follow-up time was 12.2 months (5.0–17.5). On univariate analysis, SCX implants [OR= 3.4 (1.3–8.7), P = 0.01], implant volume > 400 cm3 [OR 8.9 (1.2–68.2), P = 0.011], older age at surgery (OR = 1.1 P = 0.022), and BMI (OR=1.1, P = 0.005) were correlated with a higher risk of anteroposterior malposition. CONCLUSIONS: Use of SCX implants, implants with a volume > 400 cm3, older age at surgery, and high BMI increase the risk of anteroposterior malposition in Natrelle Inspira Cohesivity Level 3 implants. These results can be useful for patient counseling, better surgical planning, and improving clinical practice.

Adjuvant Chemotherapy in Two-Stage Tissue Expander/Implant Breast Reconstruction: Does it Affect Final Outcomes?

In immediate two-stage implant-based breast reconstruction, adjuvant chemotherapy, when indicated, is usually conducted between the stages, which might influence the outcomes of the second-stage operation. The purpose of this study was to evaluate the potential influence of adjuvant chemotherapy on the final outcomes of two-stage implant-based reconstructions. Patients who underwent immediate tissue expander/implant breast reconstruction between 2010 and 2016, with completion of both stages, were reviewed. Cases were categorized into two groups-adjuvant chemotherapy and no adjuvant chemotherapy. The rates of adverse outcomes were compared between the groups. A total of 602 cases in 568 patients were analyzed, with a mean follow-up period of 58.5months, including 236 patients receiving adjuvant chemotherapy and 366 patients not receiving adjuvant chemotherapy. The two groups had similar baseline characteristics, except for a significantly higher rate of adjuvant radiotherapy in the former group. The adjuvant chemotherapy group showed significantly higher rates of overall complications (odds ratio [OR] 2.127, 95% confidence interval [CI] 1.231-3.676), including infections (OR 4.239, 95% CI 1.059-16.970), severe capsular contractures (OR 2.107, 95% CI 1.067-4.159), and reconstruction failures (OR 12.754, 95% CI 1.587-102.481) compared with the control group, after adjusting for other variables, including adjuvant radiotherapy. In the analysis regarding the influence of chemotherapy regimens, the use of sequential anthracycline/cyclophosphamide and taxane, and concurrent 5-fluorouracil, doxorubicin and cyclophosphamide, were associated with increased risks for adverse outcomes compared with the no chemotherapy group, while the use of other regimens, including anthracycline/cyclophosphamide alone, was not. Adjuvant chemotherapy might influence the final outcomes of two-stage implant-based reconstruction.

Characteristics of adhesion areas between the tissue expander and capsule in implant-based breast reconstruction.

BackgroundThe use of anatomic implants has improved the aesthetic results of breast surgery; however, implant malrotation is an uncommon, but serious complication of these procedures. Nevertheless, little research has explored implant adhesion. In this study, we investigated adhesion between the expander and the capsule.MethodsSeventy-nine cases of immediate breast reconstruction via two-stage implantbased reconstruction performed between September 2016 and November 2017 were evaluated. Mentor CPX4 expanders were used in 14 breasts, and Natrelle expanders in 65. We analyzed areas of adhesion on the surfaces of the tissue expanders when they were exchanged with permanent implants. We investigated whether adhesions occurred on the cephalic, caudal, anterior, and/or posterior surfaces of the expanders.ResultsTotal adhesion occurred in 18 cases, non-adhesion in 15 cases, and partial adhesion in 46 cases. Of the non-adhesion cases, 80% (n=12) were with Mentor CPX4 expanders, while 94.4% (n=17) of the total adhesion cases were with Natrelle expanders. Of the partial adhesion cases, 90.7% involved the anterior-cephalic surface. The type of tissue expander showed a statistically significant relationship with the number of attachments in both univariate and multivariate logistic regression analyses (P<0.001) and with total drainage only in the univariate analysis (P=0.015).ConclusionsWe sought to identify the location(s) of adhesion after tissue expander insertion. The texture of the implant was a significant predictor of the success of adhesion, and partial adhesion was common. The anterior-cephalic surface showed the highest adhesion rate. Nevertheless, partial adhesion suffices to prevent unwanted rotation of the expander.

The impact of postmastectomy radiotherapy on two-stage implant breast reconstruction: an analysis of long-term surgical outcomes, aesthetic results, and satisfaction over 13 years.

Postmastectomy radiation therapy is increasingly indicated in patients with node-positive breast cancer. The authors prospectively evaluated long-term outcomes in patients with two-stage implant-based reconstruction and postmastectomy radiation therapy to the permanent implant. A cohort of 1415 patients operated on by a single surgeon from 1998 to 2010 was evaluated annually. Outcomes were recorded prospectively. Complication rates were compared between irradiated and nonirradiated implants, including reconstructive failure (implant loss), complications (e.g., capsular contracture), aesthetic results, and satisfaction. Predicted implant loss and replacement rates were examined by irradiation status with Kaplan-Meier analysis and the log-rank test. A total of 2133 breast implant reconstructions with a mean follow-up of 56.8 months (range, 12 to 164 months) were included. Three hundred nineteen implants received radiation. Implant loss occurred in 9.1 percent of irradiated implants and 0.5 percent of nonirradiated implants (p < 0.01). Capsular contracture grade IV was present in 6.9 percent of irradiated and 0.5 percent of nonirradiated implants (p < 0.01). There was no difference between groups regarding implant replacement. Ninety-two percent of irradiated patients had good to excellent aesthetic result, and 94.2 percent would choose implants again. Predicted implant loss rates were 17.5 percent and 2.0 percent for irradiated and nonirradiated implants, respectively, at 12 years (p < 0.01), and predicted implant replacement rates were 12.7 percent and 8.8 percent, respectively, at 8 years (p = not significant). This is the largest prospective long-term outcomes evaluation in women with immediate tissue expander/implant reconstruction and postmastectomy radiation therapy. Most patients had a good to excellent aesthetic result and preserve their reconstruction at 12 years. Therapeutic, III.

Radiotherapy and Implant-Based, Two-Stage Breast Reconstruction

One-stage and two-stage reconstructions are the major approaches to implant-based breast reconstruction in use today and chest wall irradiation is becoming increasingly common for mastectomy patients who have opted for immediate breast reconstruction with tissue expanders and implants. The optimal approach for such patients has not yet been defined. Although most reconstructive surgeons agree that breasts reconstructed with autologous tissue tend to fare better than breasts reconstructed with implants in patients who have received or will receive postmastectomy radiation therapy, reconstruction with autologous tissue is not always feasible or desired. The debate continues as to whether to perform the second stage (placement of the permanent implant) of two-stage implant-based reconstruction before or after postmastectomy radiation therapy, and many strategies can be used in order to reduce complication rates and optimize aesthetic outcomes in implant-based breast reconstruction for irradiated patients.