General anesthesia is usually used, but local anesthesia may be used +/− IV sedation.
Partial mastectomy (PM) or lumpectomy is indicated for breast conservation for excision of invasive breast usually cancer or ductal carcinoma in situ (DCIS).
The aim is to remove the carcinoma with surrounding normal tissue to achieve
margins of 1–2 cm. Preoperative mammogram and ultrasound (and occasionally
MRI) are used to determine the nature and extent of the lesion and identify other
lesions in either breast.
PM may follow an excisional, incomplete, or localization biopsy. A specimen
MMG or U/S is often used to assess margins and may be used to guide resection
of more tissue intraoperatively. Separate samples may be used to assess the biopsy
margins. Marker sutures or clips are used to orientate the specimen for the pathologist.
Marker clips may be used for guiding the radiation therapy.
The incision chosen may be peri-areolar, curvilinear, horizontal, or even
radial according to the location and desired cosmesis. Dissection usually aims to
excise a wide margin of normal tissue around the lesion, often including pectoral
fascia. Mobilization of remaining breast tissue may be necessary to reapproximate
the breast parenchyma, especially in the medial and lower breast, to reduce
shape deformity. Electrocautery and deep, absorbable suture closure is used for
hemostasis, often avoiding wound drains, with a subcuticular skin suture. A separate
axillary incision is often used for axillary lymph node surgery (described
separately).
Anatomical Points
The anatomical base of the breast extends from the inferior clavicle to the inframammary
fold and from the lateral sternum into the axilla. Occasionally, islands
of breast tissue exist in the axilla, isolated from the axillary tail. The nipple-areolar
complex and main breast mass may vary considerably between individuals, with
age and posture. A breast mass can be located anywhere within the breast. The size
and nature of the mass and breast essentially determines the placement and type of
incision, surgical result, and cosmesis. The possibility of mastectomy or further surgery
is often a consideration in preoperative placement of incision. Care should be
taken to avoid downward repositioning of the nipple with large excisions, notably
the lower breast tissue. This deformity may be avoided by mobilizing nearby normal
breast tissue into the area of the defect. Cancer specimens involving the nipple
by direct extension require removal of the nipple as part of the segmental resection.
Invasive cancer may invade any of the structures surrounding the breast including
the skin, the pectoralis muscle, the ribs, and the chest wall. Usually very large
cancers that invade one of these structures will be initially treated with neoadjuvant
chemotherapy prior to operation.
Perspective
See Table 2.4 . The most signifi cant, but infrequent, complications are development
of a large hematoma, infection, abscess formation, incomplete excision
with close or involved margins, and the requirement for further surgery due to
these. Favorable cosmetic outcome and optimal margins can be competing goals.
Surgical judgment is important to maximize both goals. Poor cosmesis, dimpling,
skin necrosis, and hypertrophic scarring are usually less severe, but more frequent
complications. There may be some temporary paresthesia surrounding the incision.
Patients often describe it as burning or shooting pain. Acute postoperative
pain is usually controlled with oral pain medication. Chronic pain is rare. The risk
of infection after a partial mastectomy is minimal and prophylactic antibiotics are
rarely indicated.
Major Complications/Consequences
A major consequence of conservative breast surgery is incomplete carcinoma excision
, often necessitating further surgery. Occasionally, a 3rd resection or a total mastectomy
may be advisable, if excision is still incomplete. The cosmetic outcome may
be reduced after more than one re-excision such that mastectomy becomes a more
appealing alternative. Mastectomy may be followed by immediate reconstruction.
Hematoma formation can be avoided by meticulous control of bleeding during
surgery. Most hematomas can be managed nonoperatively. Large hematomas
require surgical evacuation. Infection and abscess formation may complicate
large hematomas if left untreated and can spontaneously drain. Draining of infected
hematomas can lead to open wounds that last for months. Recurrent large seromas
or lymphatic sinuses are rare, but also signifi cant complications.
If skin fl aps are raised to remove a superfi cial mass, care should be taken not
to make the fl aps too thin, causing reduced blood supply to the skin, resulting in
skin necrosis , tissue loss, or skin dimpling. Extensive skin necrosis may require
dressings and/or excision and skin fl ap repair.
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