A modified radical mastectomy is a procedure in which the entire breast is removed, including the skin, areola, nipple, and most axillary lymph nodes; the pectoralis major muscle is spared. Historically, a modified radical mastectomy was the primary method of treatment of breast cancer. [1, 2] As the treatment of breast cancer evolved, breast conservation has become more widely used. [3, 4] However, mastectomy still remains a viable option for women with breast cancer. [5, 6]
It currently remains the patient’s choice to undergo breast conservation or mastectomy with or without reconstruction. The European Organization for Research and Treatment of Cancer 10801 trial found no significant difference in the 20-year overall survival rate between women who underwent breast-conserving surgery and radiation and those who were treated with modified radical mastectomy, for stage 1 or 2 breast cancer. Overall survival at 20 years was 44% in the breast-conserving surgery group and 39% in the modified radical mastectomy group. Time to distant metastasis also did not differ significantly between the two groups, although the study did find that the 10-year locoregional recurrence of cancer was higher in the breast-conserving group than in the mastectomy patients (20% vs 12%, respectively). 
There are a few contraindications to breast conservation for which a mastectomy is recommended. According to the National Comprehensive Cancer Network guidelines,  indications for mastectomy include the following:
Prior radiation therapy to the breast or chest wall
Radiation therapy contraindicated by pregnancy (except patients in the third trimester who can receive radiation postpartum)
Inflammatory breast cancer
Diffuse suspicious or malignant-appearing microcalcifications
Widespread disease that is multicentric, located in more than one quadrant, and cannot be removed through a single incision with negative margins
A positive pathologic margin after repeat re-excision and suboptimal cosmetic outcome
Relative indications for mastectomy include the following:
Tumors greater that 5 cm in diameter
Focally positive margin
Patients who are younger than 35 years of age or premenopausal with known BRCA1/2 mutations have an increased risk of local recurrence. Prophylactic bilateral mastectomy may be considered for risk reduction.
There are very few contraindications to a modified radical mastectomy. For patients who present with metastatic disease, the primary mode of treatment remains systemic therapy. Mastectomy is currently not the standard of care for patients with metastatic disease. Additional contraindications involve patients who are unable to receive general anesthesia. 
There has been recent national debate over the indication for axillary lymph node dissection. Current indications for a level I or II axillary dissection in patient undergoing a mastectomy include the following:
Preoperative diagnosis of positive axillary lymph node metastasis on fine-needle aspiration or core biopsy
Prior inadequate axillary lymph node dissection
Positive intraoperative sentinel lymph node biopsy
Failed mapping for a sentinel lymph node biopsy
Clinically suspicious nodes at the time of surgery
Neoadjuvant chemotherapy (outside clinical trials)
Axillary local recurrence
Patients should be evaluated for an axillary lymph node dissection on a case-by-case basis. Axillary dissection may not benefit patients with favorable tumor characteristics, elderly patients, patients with multiple comorbidities, or patients for whom a full axillary dissection will not influence the recommendation regarding systemic treatment.
Patients who undergo a mastectomy have the option for immediate or delayed reconstruction using autologous tissue or implants. Prior to the mastectomy, patients should be referred to a plastic surgeon. The decision for immediate or delayed reconstruction is made based on the need for postmastectomy radiation and surgeon preference.
Complications associated with a modified radical mastectomy include issues associated with wound healing, such as hematoma, infection, dehiscence, chronic seroma, and skin necrosis. The risk of skin necrosis often involves the superior flap and the wound edges. It is often treated with only local debridement and wound care.
Patients at a higher risk for postoperative complications are patients with diabetes, smokers, patients with a history of prior chest wall radiation, and other patients with diffuse small vessel disease. After an axillary dissection, along with the normal local healing issues, the alteration of the regional lymphatic system puts patients at an increased risk of complications.
For patients undergoing sentinel lymph node biopsy prior to axillary dissection, there is a risk of anaphylaxis related to the isosulfan blue contrast agent. The anesthesiologist and patient should be aware of this rare complication, which often resolves intraoperatively. 
Patients who have undergone a completion axillary dissection have an increased risk of developing lymphedema. They also are at increased risk of numbness under the axilla or even hypersensitization and chronic pain in that area. Patients are encouraged to ambulate the arm early with stretching exercises to prevent decreased shoulder function and scarring of the muscle, which can lead to cording and chronic pain syndromes.
The following equipment is needed to perform a modified radical mastectomy:
Sterile gloves and gowns
Preoperative skin preparation supplies
No. 15 blade
Sterile irrigation solution (water and normal saline)
Standard mastectomy tray
Freeman face lift or skin hooks
Several types of sutures and ties, silks available for ties, nylon for drain sutures, Vicryl, and Monocryl for skin closure
Clips for the axillary dissection
Drains for the axilla and chest wall under the mastectomy flaps (eg, Jackson-Pratt round 15-Fr)
General anesthesia is used without a neuromuscular blocking agent for the mastectomy and axillary dissection. If the patient is undergoing immediate breast reconstruction at the same time as the mastectomy, a paralytic is often used after completion of the axillary lymph node dissection.
A thoracic paravertebral block may also be used to provide both procedural and postprocedural analgesic effects, leading to a reduction in postoperative pain both immediately and over the following 24 hours.
Patients are placed in the operating room table in the supine position, with the arm at a 90-degree angle from the body.
A study by Ferreira Laso et al indicated that continuous infusion of local anesthetic following modified radical mastectomy results in decreased pain and reduced analgesic use but has no impact on rates of nausea and vomiting. The randomized, double-blind, placebo-controlled trial involved 73 women who underwent modified radical mastectomy, including 34 who received levobupivacaine for 48 hours postoperatively through a wound catheter and 39 who received a placebo (saline). 
There are several different techniques for a modified radical mastectomy, including simple or total mastectomy, skin-sparing mastectomy, nipple sparing, sentinel lymph node biopsy, and/or axillary lymph node dissection. This topic describes a simple mastectomy with an axillary lymph node dissection.
Simple Mastectomy with an Axillary Lymph Node Dissection
The anatomy of the breast and its boundaries include the clavicle superiorly, the sternum medially, the inframammary fold inferiorly, and the latissmus along the pectoralis major fascia laterally. The total mastectomy involves removal of the entire mammary gland including the nipple-areolar complex and pectoralis fascia.
In a simple mastectomy with no immediate reconstruction, the outline of the breast is marked and the medial and lateral endpoints of the breast are marked. The breast is then pulled downward and a horizontal line connecting the two endpoints is drawn to mark the upper incision. The breast is then pulled up and a second line connecting the endpoints is drawn to identify the lower incision. These lines form an ellipse around the nipple and can be adjusted to include prior incisions. See the image below.
These markings are checked to confirm that there is adequate skin for closure with minimal tension. The skin is then incised.
The next step is to make viable skin flaps that leave subcutaneous tissue and superficial vasculature but do not compromise the need to remove the entire mammary gland. These flaps are approximately 5 mm in thickness. The plane is identified by careful retraction with skin hooks and adequate countertraction, allowing the surgeon to identify the avascular plane (superficial breast fascia) between the breast and subcutaneous tissue. Either a knife, scissors, harmonic scalp, or electrocautery can be used, depending on the surgeon’s preference.
Tumescent solution of dilute epinephrine hydrochloride in lactated Ringer solution is commonly used in association with liposuction.  The solution is infused into the avascular plane to facilitate dissection and minimize blood loss during the surgery.
The flaps are raised to the borders of the breast as previously defined. The pectoralis fascia is divided both superiorly and medially. The pectoralis fascia is removed with the breast; muscle should only be removed when there is gross involvement. The dissection proceeds to the lateral edge of the pectoralis. See the images below.
Depending on surgeon preference, the breast may now be completely removed or axillary dissection may continue, allowing the breast to give gravity traction and assist with exposure. See the image below.
The axillary lymph node dissection follows the borders of the axilla and includes level I and II lymph nodes. The axilla is bordered by the axillary vein superiorly, the latissimus dorsi laterally, pectoralis muscle medially, and the serratus muscle anteriorly.
When performing an axillary dissection with a simple mastectomy, a separate incision is not required. However, if a skin-sparing mastectomy is performed, a separate incision may be needed.
The axilla is first entered by opening the clavipectoral fascia. See the image below.
The axillary vein is identified by locating the lateral border of the pectoralis major; the vein is identified as it runs posterior to the pectoralis muscle with careful blunt dissection and retraction inferiorly of the axillary contents. Once identified, lymphatics can be tied, clipped, or cauterized, depending on surgeon preference.
After the vein is identified, careful steps are taken to preserve its branches; the thoracodorsal bundle is identified as it runs in the axillary fat pad and then enters the latissimus dorsi. The long thoracic nerve should be preserved; it runs medial to the thoracodorsal bundle and is identified close to the chest wall posteriorly. See the image below.
Once these nerves and vein are identified, the axillary contents are dissected off the thoracodorsal bundle superiorly and medially up to the level of the axillary vein. The contents are then retracted inferiorly, the medial attachments to the serratus muscle are divided, and the specimen is handed off.
Once the axillary dissection is completed, two drains are placed: one in the axilla and one anterior to the pectoralis muscle. Drains should be shortened to allow for placement of the drain within a pocket for patient comfort and to avoid clotting in the tubing. The skin is then closed in an interrupted or running fashion according to the surgeon’s preference. See the image below.
Patients are normally discharged the next morning and drains are removed when the output is less than 30 mL in a 24-hour period. Patients are encouraged to ambulate early and begin arm stretches.