This study involved a retrospective chart review of a prospectively maintained database and was approved by the respective Institutional Review Board (IRB No. 3-2022-0162). We identified patients diagnosed with primary breast cancer, who had undergone mastectomy with DTI breast reconstruction at our hospital between August 2011 and June 2021. The exclusion criteria were previous breast surgery, refusal to sign the consent form, previous radiotherapy, follow-up period < 6 months, and missing data for the pertinent variables.
Each breast was considered individually and categorized according to the type of implant surface as textured anatomical implant or smooth round implant. The implant brands used were Mentor MemoryGel (Mentor Worldwide LLC, Irvine, USA), Allegan (Allergan plc, Dublin, Ireland), and BellaGel (Hans Biomed Corp., Seoul, Korea). Patient demographics, operative characteristics, radiation therapy, medical oncology treatments, and relevant data for the analysis of risk factors were collected by reviewing the medical records. The parameters included age, body mass index (BMI), pathologic tumor stage, mastectomy type (nipple-sparing, skin-sparing, or total mastectomy), axillary surgery (sentinel lymph node biopsy or axillary lymph node dissection), implant size, implant insertion plane, ADM use, laterality, number of dissected lymph nodes or positive lymph nodes, chemotherapy (neoadjuvant or adjuvant), target therapy (trastuzumab), hormone therapy, radiotherapy, comorbidities (diabetes mellitus or hypertension), smoking (non-smoker, ex-smoker, or active smoker), follow-up duration, and drainage duration. Furthermore, complications including capsular contracture, infection, seroma, hematoma, implant rupture, implant exposure, rippling, implant malposition, and nipple-areolar complex (NAC) necrosis were analyzed. Capsular contracture was evaluated by reconstruction surgeons. Any incidence of clinically relevant capsular contracture, defined as Spear–Baker grade III or IV, occurring during the study period was recorded.
Variables were compared between the groups using Pearson χ2 test or Fisher exact test to examine the associations of the categorical variables. The independent t-test or Mann-Whitney U test was used for continuous variables. Logistic regression models were used to evaluate the risk factors associated with the development of complications and capsular contracture. Multiple logistic regression analyses were performed using a stepwise model selection method to predict the risk factors for overall complications and capsular contracture based on the age, BMI, pathologic tumor stage, mastectomy type, axillary surgery, implant-based breast reconstruction (size, surface, and insertion plane), number of positive lymph nodes, number of dissected lymph nodes, neoadjuvant and adjuvant chemotherapy, target treatment, hormone therapy, radiotherapy, comorbidities of diabetes mellitus or hypertension, smoking, drainage duration, and follow-up duration. Further subgroup analyses were conducted to determine whether the impact of the implant surface on the risk of capsular contracture varies with higher BMI or adjuvant radiotherapy after adjusting for risk factors. We divided the patients into the following two BMI categories according to the World Health Organization classification: < 25 kg/m2 and ≥ 25 kg/m2. Statistical significance was set at p-value < 0.05. All statistical analyses were conducted using Statistical Product and Service Solutions (version 24.0; SPSS Inc., Chicago, USA).
Each breast was considered individually and categorized according to the type of implant surface as textured anatomical implant or smooth round implant. The implant brands used were Mentor MemoryGel (Mentor Worldwide LLC, Irvine, USA), Allegan (Allergan plc, Dublin, Ireland), and BellaGel (Hans Biomed Corp., Seoul, Korea). Patient demographics, operative characteristics, radiation therapy, medical oncology treatments, and relevant data for the analysis of risk factors were collected by reviewing the medical records. The parameters included age, body mass index (BMI), pathologic tumor stage, mastectomy type (nipple-sparing, skin-sparing, or total mastectomy), axillary surgery (sentinel lymph node biopsy or axillary lymph node dissection), implant size, implant insertion plane, ADM use, laterality, number of dissected lymph nodes or positive lymph nodes, chemotherapy (neoadjuvant or adjuvant), target therapy (trastuzumab), hormone therapy, radiotherapy, comorbidities (diabetes mellitus or hypertension), smoking (non-smoker, ex-smoker, or active smoker), follow-up duration, and drainage duration. Furthermore, complications including capsular contracture, infection, seroma, hematoma, implant rupture, implant exposure, rippling, implant malposition, and nipple-areolar complex (NAC) necrosis were analyzed. Capsular contracture was evaluated by reconstruction surgeons. Any incidence of clinically relevant capsular contracture, defined as Spear–Baker grade III or IV, occurring during the study period was recorded.
Variables were compared between the groups using Pearson χ2 test or Fisher exact test to examine the associations of the categorical variables. The independent t-test or Mann-Whitney U test was used for continuous variables. Logistic regression models were used to evaluate the risk factors associated with the development of complications and capsular contracture. Multiple logistic regression analyses were performed using a stepwise model selection method to predict the risk factors for overall complications and capsular contracture based on the age, BMI, pathologic tumor stage, mastectomy type, axillary surgery, implant-based breast reconstruction (size, surface, and insertion plane), number of positive lymph nodes, number of dissected lymph nodes, neoadjuvant and adjuvant chemotherapy, target treatment, hormone therapy, radiotherapy, comorbidities of diabetes mellitus or hypertension, smoking, drainage duration, and follow-up duration. Further subgroup analyses were conducted to determine whether the impact of the implant surface on the risk of capsular contracture varies with higher BMI or adjuvant radiotherapy after adjusting for risk factors. We divided the patients into the following two BMI categories according to the World Health Organization classification: < 25 kg/m2 and ≥ 25 kg/m2. Statistical significance was set at p-value < 0.05. All statistical analyses were conducted using Statistical Product and Service Solutions (version 24.0; SPSS Inc., Chicago, USA).
