The surgical principles underlying simple mastectomy have a long history. First defined in ancient Egyptian literature, mastectomy was systematically detailed in 1882 by Halsted, who advocated a radical extensive procedure that involved excision not only of the breast but also of the underlying pectoral muscles and axillary lymph nodes.  This operation was associated with poor cosmesis and significant impairment of shoulder movements.
For decades, this operation was the only treatment of breast cancer. Gradually, it became clear that an extensive local procedure did not necessarily translate into a marked improvement in patient survival. Accordingly, surgeons began experimenting with less radical procedures, and various modifications of the radical mastectomy were developed. A National Surgical Adjuvant Breast Project study from 1977 showed that the cure rate for the Halsted operation was no higher than that for a simple mastectomy. 
A simple mastectomy involves removing the breast along with an ellipse of skin that encompasses the nipple-areola complex. Unlike a radical mastectomy, it does not involve removal of the underlying muscles and uninvolved lymph nodes (see the images below).
As medical knowledge of tumor biology has grown, surgeons have come to realize that combining surgical treatment with adjuvant treatments such as chemotherapy, radiotherapy, hormone therapy, and immunotherapy allows better control of the cancer and results in higher disease-free survival and local recurrence rates. Breast-conserving surgery, the safety of which has been proven in randomized controlled trials, is another surgical option for selected patients.
Indications for a simple mastectomy without an axillary procedure are as follows:
Local recurrence in a previously treated breast cancer
Malignant phyllodes tumor
Indications for a simple mastectomy with a concomitant axillary procedure, which may be either a sentinel node biopsy or an axillary clearance, are as follows:
Locally advanced breast cancer
Multifocal breast cancer
Large tumor relative to the size of the breast, excision of which may compromise final cosmesis
Extensive ductal carcinoma in situ (DCIS)
Patient unsuitability for breast-conserving approaches as a result of contraindications for radiation therapy - Such contraindications include a previous history of chest wall irradiation, either after previous breast-conserving therapy or in mantle field radiation therapy for lymphoma; severe skin disorders, such as scleroderma and psoriasis; and severe pulmonary dysfunction
Patient preference for mastectomy - A patient who is a suitable candidate for breast conservation may opt for a mastectomy instead
A mastectomy is contraindicated in patients who have locally advanced breast cancer that is inoperable.
A basic surgical set is required for a simple mastectomy. The key instruments are as follows:
Littlewoods, Lahey, or skin hooks for lifting the flaps
Langenbeck retractors (medium-sized and large)
Small artery forceps
Nontoothed and toothed forceps
General anesthesia is preferred for a simple mastectomy. The patient is placed supine with the ipsilateral arm stretched out level with the shoulder. The head end of the operating table is raised to 30º. The side being operated on is raised by 30º. The patient is draped with the arm free to allow for movements during the procedure. It is important not to hyperextend the arm when positioning the patient; hyperextension may cause significant postoperative neurapraxia.
The technique described below is the standard approach to a simple mastectomy. However, the following variations on the procedure have been developed and may be considered:
"Lazy S" skin incision - This incision is preferred by some surgeons, especially if they are not contemplating breast reconstruction; it also allows old scars to be incorporated in the excised skin
Hydrodissection - A mixture of saline, local anesthetic, and epinephrine can be infiltrated into the subcutaneous plane of the flaps before the skin incision is made; the flaps can then be raised by means of sharp dissection with scissors or a blade
Nipple- and skin-sparing mastectomy  - This modification allows the nipple-areola complex to be preserved; the procedure is performed through a periareolar incision around approximately half the circumference of the areola with a lateral horizontal extension
A 20-in. blade is used to make an elliptical skin incision that includes the nipple-areola complex (see the image below). The skin ellipse should be tailored so as to ensure the following:
The resulting defect can be closed without tension
Any old biopsy sites or surgical scars are included in the ellipse if possible
The lateral end of the ellipse is medial to the midaxillary lineElliptical skin incision enclosing nipple-areola complex.
The incision is then deepened by means of a coagulation diathermy device.  Subdermal veins will be encountered that must be coagulated.
Littlewoods or skin hooks are applied to the superior flap, and the assistant lifts the superior flap (see the image below). Flaps should always be lifted straight up, perpendicular to the chest wall. Sufficient tension should be maintained during lifting to ensure that the flap is the same thickness throughout and to prevent buttonholing.
With the diathermy device held parallel to the flap, the breast tissue is dissected away from one end of the incision to the other. There is no specific anatomic landmark that defines the depth of the dissection. However, if the flaps are approximately 5-10 mm thick, a bloodless plane becomes evident, representing the transition zone between subcutaneous tissue and breast tissue. If the wrong plane is used, bleeding will be heavy while the flap is raised.
The dissection is deepened to the pectoralis major, with care taken to coagulate vessels as they are encountered (see the image below) so as to minimize blood loss during the operation. It is important always to identify the limits of the dissection before starting to dissect the breast off the chest wall. The medial limit is the lateral border of the sternum, the lateral limit is the anterior border of the latissimus dorsi, the superior limit is the second rib, and the inferior limit is the inframammary crease.
This process is repeated for the lower flap, proceeding from the medial end to the lateral end. Toward the lateral end of the dissection, a Littlewoods forceps is placed on the superior flap and another on the inferior flap, close to the lateral angle of the incision. The dissection is deepened until the anterior border of the latissimus dorsi (the lateral limit of the dissection) is identified.
With the skin envelope raised completely, the next step is to lift the breast off the pectoralis major. Langenbeck retractors may be used to retract the flaps, starting at the medial angle. A perforating branch of the internal mammary artery is commonly encountered here; it should be coagulated with the diathermy device before it retracts. The breast is then lifted off the muscle, with care taken to ensure that all the perforators along the way are coagulated (see the image below).
At the lateral end of the dissection, the superior limit of the breast tissue as it approaches the axilla is the first intercostal nerve.
Complications of Procedure
Early complications of simple mastectomy include pain, infection, hematoma, and flap necrosis. A study by Chatterjee et al indicated that simple mastectomy has a higher rate of wound complications, bleeding, infection, and overall complications than does breast conservation surgery, although early postoperative complication rates are still low for both procedures. The study, which utilized the National Surgical Quality Improvement Program database, included 6682 patients who underwent breast conservation surgery and 3339 patients who were treated with simple mastectomy. 
In general, simple mastectomy is not very painful. Patients feel slight discomfort and soreness at the wound site, which are easily managed by taking mild analgesics. The risk of postoperative wound infection is approximately 5%; this may result in wound breakdown if not appropriately managed.
Hematoma generally develops within 24 hours after the operation but is a very rare complication. Patients notice swelling of the wound site and bruising over the breast. Flap necrosis is an uncommon complication; causes include thin flaps and a wound that is under tension.
Delayed complications of simple mastectomy include seroma  and shoulder stiffness. The observed rates of seroma after a mastectomy range from 2.5% to 51%. [9, 10] It may be necessary to perform needle drainage on one or more occasions.  Shoulder stiffness is a temporary and self-limited side effect.