4.1.2 Main Points of Surgery
For most patients，general anesthesia is safer.The standard incision for a simple mastectomy is a shuttle incision that includes a complex of tumor and nipple mastulic complex，suitable for any form of tumor.In theory，if the tumor is in the direction of 3 o'clock，a horizontal incision can be made.If it is at 12 o'clock，it can be made a vertical incision.In practice，most are horizontal or diagonal cuts.The inneredge is 2-3cm away from the edge of the sternum，and the outer edge should be to the outer edge of the chest muscle or the edge of the back muscle.If you are considering immediate breast reconstruction，an“skin retention”incision should be used.If the profile is to be implanted，a small pritnal incision can be made in the nipple mastulic complex.If tissue reconstruction is to be performed with tissue and skin，a ring-shaped cut can be done around or on the nipple masticillosis.
The scope of the removal of the breast to the collarbone，down to the abdominal straight muscle front，the inner chest bone side，the outer to the back of the broad muscle anatomy boundary，along the chest large fission complete removal of breast tissue and nipple mastullum complex.The thickness of the flap should be thin subcutaneous sebum and surface blood vessels left behind after removing all the whole breast essence tissue to reduce the risk of flap necrosis.The thickness of the flap depends mainly on factors such as surgeon preferences and techniques，as well as the patient's size.However，if the flap thickness is too thick，there may be significant residual breast tissue and there is no reliable assessment of the thickness of the flap technology.Surgeons usually choose to use a scalpel，scissors or electric knife to separate the flap according to personal preference.When breast reconstruction is not required，the purpose of surgery is only to remove the breast，while retaining enough skin without excess skin covering the chest wall，and to facilitate the later placement of prosthesis.At the time of mastectomy，a large pectoral fascia should be removed for all patients with invasive breast cancer only if the tumor invades the chest muscles.
When removing the breast，the blood vessels that have been worn out from the chest wall should be cut off and liganded to avoid the broken end of the blood vessels retracted.After thorough hemorrhage，place the drainage tube under the flap through the lowest position of the middle line of the armpit to lead and secure，stitchthe the subcutaneous tissue and skin.The large range of skin excision for malignant tumors led to a possible free skin transplant and pressurized bandage stomping in those with excessive suture tension.If immediate breast reconstruction is required，you will need to choose an surgical incision that retains the skin.If you choose a mastectomy that preserves nipple mastectomy or retains all skin，the choice of incision includes a circumstifying and horizontal lychee，an incision that extends inside or horizontally of the halo and a wrinkled wall cut under the breast.For patients with post-mast lesions within 1cm of the nipple masticillosis，calcification lesions extended by the nipple masticillosis，tumors exceeding 3cm or positive biopsy positive for nipple mastification complexes.It is not appropriate to choose a mastectomy to retain the nipple mastication complex.In the operation of patients who are suitable for retaining the nipple mastullis complex，ensure that the cut edge is thin enough and avoid the nipple masticillosis and other problems.
Case Analysis 1
The patient，female，aged 41，was admitted to hospital in March after“discovering a right breast lump”.
Admission：double breasts basic symmetry，skin normal，double nipples scavened，right breast can touch the size of 2 x 2cm lumps，hard，unclear boundaries，mobility acceptable.The left breast was not visible，and the enlarged lymph nodes were not touched under the double armpits and collarbone.(https://www.daowen.com)
Auxiliary inspection：B ultrasound：inside the right breast 4 o'clock direction probed a 2.lx 1.8cm low echo group，the boundary is not clear，the form is irregular，the rear accompaniment attenuation，seeing rich blood flow signal around.BI-RADS：Class 5.There are no swollen lymph nodes in the right armpit.
Mammary X-rays：The lower part of the right breast sees 2.0x2.0cm irregular lumps，with different lengths of burrs visible around.There are no swollen lymph nodes in the right armpit.BI-RADS：Class 5.
MRI：The lower in the right breast sees a visible swelling swollen，about 19x20mm in size，long T1 long T2 signal，unclear boundaries，irregular pattern，visible burrs at the edge of the lesions，DWI with unevenly higher signal，ADC value reduced.There are no swollen lymph nodes in the right armpit.BIRADS：Class 5.
Patients with right breast cirrhosis puncture biopsy，the disease was shown：right breast-soaked catheter cancer Grade I，ER（+，80%），PR（+85%），Cerb-B2（+），Ki-67（10%）.Operate right mastectomy and outpost lymph node biopsy.Postoperative medical examination：right breast-drenched catheter cancer Grade I，ER（+，80%），PR（+，90%），Cerb-B2（+），Ki-67（15%）.The right armpit outpost lymph nodes（0/4）did not see cancer metastasis.
Fig.1 After a single mastectomy