Breast reconstruction is an important part of the field of plastic surgery repair and reconstruction. Having worked in breast surgery for decades, we have developed new feelings about our work. I. Overview 1. Breast cancer is one of the most common malignant tumors in women, the incidence rate is increasing year by year, and the age of onset is trending younger. Breast cancer is the first cancer among women in China. 2. Breast cancer advocates individualized and comprehensive treatment. Surgery is still an important component of comprehensive treatment for breast cancer, and the rate of breast-conserving surgery is increasing year by year. 3.Breast reconstruction not only has cosmetic changes, but also can reduce the pain of missing breast for breast cancer patients and improve the quality of life and psychological satisfaction of patients after surgery. After surgery, the satisfaction, happiness and sexual health of breast reconstruction patients gradually improve over time. Breast reconstruction has become more and more widely appreciated by the whole society, and the demand for breast reconstruction is growing among domestic patients. 4. The relevant papers published in China show that the number of breast reconstruction in China is increasing year by year, the methods of reconstruction are becoming more and more perfect, and the concept and awareness of breast reconstruction are recognized and accepted by more and more breast surgeons. The safety of breast reconstruction 1. The oncological safety of breast reconstruction after breast cancer surgery is certain, breast reconstruction does not affect the evolution of tumor and does not increase the risk of recurrence and metastasis. A large number of studies have shown that whether the tumor recurs or metastasizes locally is related to the stage of the disease and whether adjuvant radiotherapy is administered after surgery, but not to whether breast reconstruction is performed, the timing of reconstruction and the way of reconstruction. The safety of immediate breast reconstruction in oncology has also been confirmed, and the local recurrence rate of immediate breast reconstruction patients is no different from that of patients undergoing radical breast cancer surgery alone. Local recurrence, distant metastasis, and recurrence-free survival rates are not significantly different from those of patients who did not undergo breast reconstruction. 3. Breast reconstruction does not affect the survival rate and survival time of breast cancer patients after surgery. The basic principles of breast reconstruction for breast cancer resection 1. Tumor treatment must be put in the first place. All treatment of breast cancer must be based on oncological safety, and breast reconstruction must be carried out under the premise of determining oncological safety and ensuring oncological treatment. Breast reconstruction must take into account the biological characteristics of breast cancer and follow the principles of oncological surgery such as comprehensive treatment and tumor-free operation. Any plastic surgery treatment for breast reconstruction should not delay the adjuvant treatment of breast cancer and should not interfere with the adjuvant treatment of breast cancer. When there is a contradiction between plastic surgery treatment and surgical oncology principles, the surgical oncology principles should be followed first. 2. Breast reconstruction must be included in the whole treatment plan of breast cancer, and doctors are obliged to inform patients of their right to choose to undergo breast reconstruction. When patients have the conditions for breast reconstruction, they should be advised to choose a hospital with the conditions to perform breast reconstruction surgery. While ensuring the effect of breast cancer treatment, the conditions for breast reconstruction should be created as much as possible. 3. In the process of mastectomy, the skin, subcutaneous tissues and important aesthetic structures of the breast (such as the inframammary fold) should be preserved as much as possible without violating oncological principles, so as to maximize the conditions for breast reconstruction and improve the aesthetic effect of reconstructed breast and patient satisfaction. Radical mastectomy with skin preservation is the best choice, with the incision preferably along the semi-lateral edge of the areola and extending laterally. If only the nipple and areola are allowed to be removed, the best incision is an areolar circumferential incision, with an axillary incision if axillary clearance is required; in many cases, only the nipple is removed and the areola is preserved, so only a straight or curved incision through the areola is required to remove the nipple. In cases where the nipple and areola cannot be preserved, the incision should encompass the skin of the nipple, areola, tumor surface, and biopsy area (including the puncture needle tract and surgical biopsy). From the aesthetic point of view, the incision is most favorable for reconstruction when it is designed to be transverse, followed by oblique incision, and the worst is longitudinal incision. 4. Whether it is a local flap after mastectomy for immediate reconstruction or a distant transfer flap in second-stage reconstruction, good blood flow is a prerequisite for tissue viability and achieving all aesthetic results must be guaranteed as a priority. When reconstructing with expanders or prostheses, it is important to ensure that there is good blood flow to cover the tissue, to ensure a good blood supply to both edges of the incision, to ensure good wound healing, and to avoid exposing the expanders or prostheses. Risk factors that may cause flap necrosis should be taken into consideration, including: preoperative skin radiotherapy, smoking, obesity, excessive volume, age, immune diseases, etc. 5. Treatment of breast cancer should be carried out within the framework of multidisciplinary teamwork, including radiology, breast surgery, plastic surgery, imaging, pathology, psychology, nuclear medicine, immunology, etc. Plastic surgeons are an indispensable part of this team and must be aware of the importance of multidisciplinary cooperation. Pre-operative examination and evaluation of breast reconstruction 1. The technical difficulty and risk of breast reconstruction are large, and it is not easy to achieve complete symmetry on both sides. The success of surgery depends on the accurate grasp of all conditions of the patient before surgery, therefore, comprehensive pre-operative examination and accurate pre-operative evaluation of the patient are required to reduce the risk of surgery and obtain good surgical results. 2. The patient’s condition should be tested and evaluated before surgery, analyzing the oncological condition, medical condition, tissue condition, contralateral breast condition, etc., so as to select the surgical plan with less trauma, simplified surgery, less cost, low complication rate and good effect by combining these conditions. 3. Oncological situation of patients’ oncological staging and treatment is very important in the preoperative evaluation of breast reconstruction. The type and stage of breast cancer suitable for breast reconstruction: Tis including ductal carcinoma in situ, lobular carcinoma in situ and Paget’s disease, most invasive breast cancer within stage IIA, and breast cancer with local recurrence but no metastasis after breast conservation surgery. Types and stages of breast cancer that require relative caution for breast reconstruction: stage IIIA breast cancer with internal breast lymph node metastasis (N2b), lobulated tumors, etc. Types and stages of breast cancer that are contraindicated for breast reconstruction: stage IV invasive breast cancer, recurrent metastatic breast cancer. For patients with advanced pathological stage, prone to metastasis and local recurrence (e.g. inflammatory reactive breast cancer), breast reconstruction is contraindicated. It is usually considered that breast reconstruction is prohibited during radiotherapy and within six months after radiotherapy. For patients who have received radiotherapy or are preparing for radiotherapy, the timing and surgical method of breast reconstruction should be carefully selected. 4. Systemic condition: ① In addition to the routine examination and evaluation before surgery, special attention should be paid to whether the patient has the following combined conditions: cardiovascular disease, whistling system disease, diabetes, history of deep vein thrombosis, malnutrition, obesity, smoking, immune diseases, etc. Severe obesity and smoking are important risk factors for postoperative complications and are relative contraindications to breast reconstruction, regardless of whether the breast is reconstructed with prosthesis or autologous tissue. ② Whether skin necrosis, incision infection and delayed healing have occurred after breast cancer surgery should be taken seriously. ③The patient’s age and reproductive history also affect the choice of surgical approach. Breast reconstruction with rectus abdominis muscle flap is not recommended for patients with future pregnancy and childbirth intention. ④For patients with medical diseases that affect the tolerance of surgery, such as diabetes, hypertension, heart disease, etc., the surgical plan should be simplified as much as possible and a short, less invasive and technically simple surgical procedure should be used. If the medical disease is serious and difficult to tolerate surgery, immediate or postponed breast reconstruction is not recommended. ⑤ For patients with a long-term history of smoking or peripheral vascular disease, the surgical procedure of microsurgical flap should be used with caution to reduce the chance of postoperative anastomosis formation of thrombus. 5. Psychological status: ① When patients learn that they have breast cancer, most of them will react with depression, frustration and irritability; patients with second-stage breast reconstruction will have body image, social and family relationship disorders after mastectomy. ②Patients should be evaluated before breast reconstruction for psychosocial problems and unrealistic expectations for reconstructive surgery.