Upper limb lymphedema is a common complication after breast cancer surgery, which can lead to upper limb dysfunction and mental tension of patients. In mild cases, it will be relieved with the establishment of collateral circulation, while in serious cases, it can affect the quality of postoperative life, and even lead to the inability to live and work normally. Clinical management is tricky, and its treatment can be divided into conservative treatment and surgical treatment, both of which aim to improve the balance between lymphatic fluid production and reflux and reduce the circumference of the upper limb. Mechanisms of upper limb lymphedema after breast cancer surgery (1) Axillary lymph node dissection surgery Upper limb lymphedema after breast cancer surgery is mainly caused by lymphatic reflux obstruction, and its possible mechanisms are as follows: because axillary lymphatic dissection cuts off lymphatic reflux in the upper limb, and changes the hemodynamics of axillary venous hemodynamics, so that the lymph in the upper limb can not be adequately diverted, resulting in the increase of the protein concentration in the upper limb lymphatic fluid, and increase of filtration pressure, and due to the decrease of plasma proteins, the protein concentration in the upper limb lymph fluid increases, and the filtering pressure increases, the lymphatic fluid in the upper limb lymphatic fluid increases. Due to the decrease of plasma protein, the osmotic pressure of the fluid decreases, at the same time, the osmotic pressure of the capillaries increases, so the edema of the upper limbs of varying degrees can appear, followed by the lymphedema of the upper limb tissues with fibrosis and inflammation. Postoperative lymphedema of breast cancer is related to the number of positive lymphatic cells, age, preoperative body mass index, incision infection, and circumference of the arm, and postoperative lymphedema of breast cancer is related to the number of positive lymphatic cells, but not to others. Therefore, it is believed that breast cancer develops lymphatic metastasis, changes lymphatic network, lymphatic network reconstruction and proliferation. (2) Postoperative infection: The invasion of bacteria causes lymphangitis, which inevitably leads to lymphatic vessel damage and blockage, resulting in lymphedema. (3) Postoperative radiotherapy Radiotherapy can cause dilatation and edema of lymphatic vessels, followed by proliferation of connective tissues, infiltration of inflammatory cells, fibrosis of lymphatic vessels and obstruction of lymphatic reflux, thus causing lymphedema. (4) Functional exercise Early functional rehabilitation of the upper limbs after surgery can promote blood and lymphatic return and circulation of the upper limbs. On the contrary, the regeneration of lymphatic vessels will be delayed and the duration of edema will be longer. Upper limb lymphedema is divided into three degrees according to its degree: 1. Mild edema: the circumference of the affected side of the upper limb is less than 3 cm thicker than that of the healthy side, mostly limited to the proximal end of the upper arm, and it often occurs in a short period of time after surgery. 2.Moderate edema: the circumference of the upper limb on the affected side was 3-6 cm thicker than that of the healthy side, and the scope of edema affected the whole upper limb, including the forearm and the back of the hand. Severe edema: the circumference of the affected upper limb is more than 6 cm thicker than that of the healthy side, the skin is hard and tough, and the edema affects the whole upper limb including the fingers, so that the patient’s activities of the whole upper arm and shoulder joints are seriously limited. Prevention of upper limb lymphedema after breast cancer surgery Early detection and early treatment of breast cancer, make reasonable surgical plan before surgery, try to preserve the breast, perform sentinel lymph node surgery, otherwise perform modified radical surgery, avoid radical surgery of breast cancer with removal of the pectoralis major and minor muscles; pay attention to the protection of axillary vascular sheaths during surgery; prevent and control infections after surgery to avoid accumulation of fluid in the axilla, keep the drainage unobstructed, and keep pressure on the incision with moderate bandage pressure. Keep the incision under pressure to prevent necrosis of large skin flaps; choose the appropriate radiotherapy mode and dose to prevent dermatitis; prohibit blood and fluid transfusion to the affected upper limb; exercise the affected upper limb appropriately after surgery and avoid injuries; timely anti-inflammatory and symptomatic treatment when suffering from acute lymphadenitis. Postoperative patients with high-risk factors should be examined regularly. Treatment of upper limb lymphedema after breast cancer surgery I. Conservative treatment: 1. Physiotherapy Elevate the affected limb, pillow elevation of the affected limb, so that the elbow joint is higher than the shoulder, the wrist is higher than the elbow joint, the incline slope is 30 degrees, which will be used right after the operation, at least 10 hours a day. Effectively elevate the affected upper limb above the level of the heart, the blood is easy to flow from the high place to the low place, which can effectively promote the lymphatic reflux and venous reflux, the method is convenient and simple to use, and the patient’s compliance is good. Functional Exercise Proper postoperative exercise can help the collateral lymphatic vessels to establish and can replace some of the vessels damaged by surgery. Activities can be started on the first postoperative day, and should focus on the movement of the affected side of the elbow, wrist and hand, elbow flexion and extension, deep breathing to stimulate the flow of lymphatic fluid, and shrug the shoulders and other active movements on the second postoperative day. Avoid excessive pressure on the pipeline and incision site, and be careful not to overactivity to avoid fatigue. 7~10 days after extubation, you can start to make movements above 90 degrees, including scapula and shoulder movements in various directions. It is important to exercise twice a day and to do a moderate amount of daily activities. Centripetal Massage First massage the normally functioning lymphatic vessels near the lymphedematous limb to improve lymphatic reflux, then massage the edematous limb repeatedly, centripetally from distal to proximal direction. Care should be taken to be gentle, as excessive massage may aggravate lymphedema. Pressure pump therapy is the most common and effective method. An inflatable cuff is placed on the edematous limb and inflated intermittently to allow centripetal flow of edema fluid. This method can reduce limb volume by 30% to 47%. Continuous application is required, otherwise the edema quickly re-accumulates in the limb. To maintain the effectiveness of the treatment, elastic gloves and cuffs can be used between treatments. This method is most effective in the early stages of lymphedema, before significant subcutaneous fibrosis occurs. Microwave physiotherapy Microwave therapy is used to obtain better results and is one of the effective methods of conservative treatment of lymphedema. Pharmacotherapy Coumarin analogs, B-heptapodophylloside sodium, phenylpyrazone, and so on. Surgery After surgery, there is a long period of time (generally 2 years), persistent upper limb lymphedema is difficult to recover through compensation, this kind of obstructive upper limb lymphedema, conservative treatment is difficult to achieve satisfactory results, need to be treated by surgery, the purpose of the surgery is to reduce the load of the lymphatic system or (and) improve the lymphatic system’s ability to transport (including the promotion of lymphatic reflux or rebuild the lymphatic channel). 1. Diseased tissue is removed, thereby reducing the load on the lymphatic system. Lead surgery has now been rarely applied. Mainly through surgical excision of diseased tissue, skin grafting, or the application of negative pressure suction method, can remove the lymphatic fluid and hyperplasia in the subcutaneous tissue, effectively reduce limb swelling, improve the appearance, and achieve the purpose of reducing the circumference and infection. The former is mainly applied to stubborn upper limb edema, but there are big trauma, obvious scar, poor wound healing, easy to produce lymphatic leakage and recurrence and other shortcomings; the latter is mainly used in the lipoedema stage of lymphedema, the recent effect of shrinking the fibrotic lymphedema limb is not ideal, but the negative pressure pumping treatment of lymphedema has the characteristics of small incision, slight trauma, safe and effective, and can be repeated many times for the serious recurrence of the patient. However, negative pressure suction treatment for lymphedema has the characteristics of small incision, slight trauma, safety and effectiveness, and can be repeated many times for patients with serious recurrence, etc. Therefore, the latter treatment for postoperative upper limb lymphedema after breast cancer is still applied, but it can not solve the problem of obstructive upper limb lymphedema caused by tumor from the root. 2.Myocutaneous flap drainage of lymphedema is through the rich capillaries of myocutaneous flap to absorb the lymphatic fluid overflowed to the operative area back into the body circulation and a small amount of lymphatic fluid through the myocutaneous flap of the lymphatic reflux, not due to the newborn of lymphatic vessels. Drainage with a pedicled flap is applied to the latissimus dorsi myocutaneous flap for the treatment of upper extremity lymphedema after breast cancer surgery. Similarly, fascial strip drainage is also used. Mainly buried in the subcutaneous drainage, trying to drain the superficial fascia lymphatic fluid to the deep fascia, through the deep fascia reflux, to create a functional lymphatic drainage, the application of the method of silk thread, rubber tubing, plastic, silicone tube implantation, as well as dermal tissue flap buried under the deep fascia, etc., but the effect is not exact. 3, lymphatic vessels (nodes) direct anastomosis reconstruction of lymphatic channels in addition to lymphatic vein anastomosis, lymph node vein anastomosis, collection of lymph node anastomosis and cluster lymphatic anastomosis, there are also lymphatic vessels and vein grafts bridging both sides of the lymphatic vessels and other surgical methods. At present, the lymphatic venous system anastomosis is carried out relatively more often in lymphatic venous anastomosis and collecting lymphatic venous anastomosis, and its near-term therapeutic effect is certain. The success of surgery lies in the selection of normal and functional lymphatic vessels and anastomosis technique, only normal lymphatic vessels and multiple anastomoses are smooth to rebuild lymphatic channels, establish effective drainage and reduce upper limb lymphedema after breast cancer surgery. Repairing the defect of lymphatic vessels with lymphatic vessels is the most physiological surgical method to restore the lymphatic balance, which is not affected by the difference of venous pressure, and the lymphatic vessels will maintain the function of contracting independently after transplantation. The success of the procedure depends on the preoperative estimation of lymphatic vessel defects, knowledge of the function of lymphatic vessels in the donor area, and skillful microsurgical techniques. However, due to the limited source of lymphatic vessels for transplantation, and the lymphatic vessels for transplantation should not only have a considerable caliber, but also have a certain length, the ideal source is the superficial lymphatic vessels of the lower limbs, and it is still debatable whether the removal of lymphatic vessels from the healthy side will cause secondary lymphatic reflux obstruction of the healthy limbs. 5. Others. Lymph node transplantation, combined treatment with multiple techniques, etc. The treatment of upper limb lymphedema after breast cancer surgery is still in the exploratory stage, conservative treatment can improve the symptoms, but not cure. The role of drugs and surgery is still uncertain. Postoperative upper limb lymphedema seriously jeopardizes the physical and mental health and quality of life of patients. Physical therapy such as massage, pressure pump and microwave is effective for mild to moderate edema, but it is easy to be repeated; drug therapy is not effective; surgery can be considered for severe patients. Although there are a variety of surgical methods, and also achieved a better therapeutic effect, but it is difficult to solve the problem from the root, the effect is difficult to sustain, often repeated and there are large individual differences. Once edema is formed, it is difficult to cure, and the focus should be on prevention. With the deepening of research, the development of related biological drugs, the reduction of lymphatic system load, the promotion of lymphatic vessel regeneration, the reconstruction of lymphatic network and the development of microsurgery, the reconstruction of lymphatic channels and lymphatic to lymphatic, lymphatic to venous and venous to venous become possible. All these can alleviate upper limb lymphedema after breast cancer surgery and improve patients’ quality of life.