Modified Radical Mastectomy

Abstract

This chapter discusses technical aspects of modified radical mastectomy including instrumentation and equipment, patient positioning, incision, anterior chest wall and axillary dissection, hemostasis, irrigation and drainage, and wound dressing. The authors also offer pearls and pitfalls.

Preference Card

• Drapes: laparotomy sheet, ¾ sheets × 3

• Sutures: 3-0 Vicryl. 4-0 Monocryl, 3–0 nylon (drain stitch)

• Equipment: mastectomy set, #15 blade scalpel, electrocautery (set 40/40) and pad, Blake drain ×2, liga clip, major lap pack, Yankauer suction and suction tubing, Kerlix, 0.25 inch Steri-Strips, surgical glue, and surgical bra

Patient Positioning/Operating Room Setup (Fig. 5.1)

• Patient is supine with the arm abducted 90°.

• All pressure points are padded, pillow under knees.

• Surgeon stands ipsilateral to dissection site – below arm.

• Surgical assistant stands ipsilateral to dissection site – above arm.

Fig. 5.1

Position of patient for left modified radical mastectomy at margin of operative table. The first assistant is cephalad to the arm board and shoulder of the patient to allow access to the axillary contents without undue traction on major muscle groups

Nodal Points

Incision

• An oblique elliptical incision is made using a 15 blade scalpel. The incision should encompass the nipple-areolar complex and any biopsy scar (Fig. 5.2).

• Incision may be tailored if reconstructive surgery is planned.

• Medial border of the incision is approximately 2 cm from the sternal edge.

• Lateral border of the incision should coincide with the lateral border of the pectoralis major.

Fig. 5.2

Elliptical incisions. (a) Elliptical incision including the nipple-areola compex and with lateral extension. (b) Circumareolar incision with lateral extension

Dissection

• The anatomy of modified radical mastectomy is delineated laterally by latissimus dorsi muscle, medially by sternal border, superiorly by the clavicle, and inferiorly by the inframammary fold.

• Superior and inferior skin flaps are raised using electrocautery, and gentle traction is applied to facilitate dissection (Fig. 5.3, panel 2).

• Skin flap thickness varies per patient, and body habitus should be 7–8 mm thick.

• Raise the superior flap in the avascular plane between the breast tissue and subdermal fat.

• The superior flap is elevated to the level of the clavicle and edge of the sternum medially.

• The inferior flap extends to inframammary fold inferiorly and to edge of latissimus dorsi laterally.

Fig. 5.3

Modified radial mastectomy

Anterior Chest Wall Dissection

• Once flaps developed, the specimen is retracted inferiorly to facilitate dissection of breast tissue off pectoralis muscles.

• Use the electrocautery to remove the breast en bloc, meticulously dissecting the fascia off pectoralis major from medial to lateral following the fibers of pectoralis major (Fig. 5.3, panels 3 and 4).

• Intercostal perforating arterial branches may require ligation.

• Retract the pectoralis major to visualize pectoralis minor; the interpectoral space is visualized for enlarged Rotter’s nodes (interpectoral lymph nodes).

Axillary Dissection

• Attention is made to axilla; electrocautery should be avoided due to proximity of nerves and vessels.

• The clavipectoral fascia is incised along the lateral aspect of the pectoralis minor.

• With the pectoralis major retracted, the tissue overlying the axillary vein is gently dissected, exposing the axillary vein (Fig. 5.3, panel 5).

• The pectoralis major and minor are retracted cephalad and medially, exposing the level I and II lymph nodes (lateral and inferior to pectoralis minor muscle); this tissue is included in the en bloc specimen.

• Identify and avoid the medial and lateral nerves supplying the pectoralis major muscle. The medial nerve arises from the medial cord of the brachial plexus and passes through the pectoralis minor muscle, but this anatomy varies. The lateral branch arises from lateral cord and passes medial to the pectoralis minor near its insertion and found in close proximity to the thoracoacromial artery (Fig. 5.3, panels 6–10).

• The dissection continues inferiorly and laterally.

• Identify the long thoracic nerve, which extends inferiorly along the serratus anterior and lies deep to axillary vein.

• Identify the thoracodorsal nerve, which lies deep to the subscapular vein and artery.

• The intercostobrachial nerve is identified originating beneath the second rib and extending transversely.

• The breast is retracted laterally; the long thoracic nerve and thoracodorsal nerve are preserved.

• The specimen is freed from latissimus dorsi laterally and suspensory ligaments in the axilla and scapularis muscle posteriorly; superficial veins and lymphatic should be ligated with 3-0 Vicryl.

• The specimen should be oriented and marked for pathologic examination.

Hemostasis, Irrigation, and Drainage

• The wound is irrigated with saline and inspected for hemostasis.

• Two Blake drains are introduced in two separate stab incisions made inferior to the flap midaxillary position. One is placed in the axilla and the other in anterior chest. Drains are secured with 3-0 nylon (Fig. 5.3, panel 11).

• Wound is closed in two layers. The deep dermal layer is re-approximated with interrupted 3-0 Vicryl, and the skin is re-approximated with 4-0 running subcuticular Monocryl suture.

Dressing

• The surgical site is cleaned and dried.

• 0.25 inch Steri-Strips (may use surgical glue) are placed along the length of the incision, Kerlix fluff dressing and surgical bra are placed.

Pearls and Pitfalls

• Postoperative complications include seroma, wound infection, skin flap necrosis, chest wall pain, and lymphedema.

• Seromas are usually prevented with drain placement.

• Thin flaps should be avoided to prevent possible skin flap ischemia and tissue necrosis.

• Careful dissection of axilla with identification of nerves to avoid injury.

Access Reader Checklist Appendix