Duct and Nipple Surgery (Microdochectomy and Central Duct Excision)

Description
General anesthesia is often used, but local anesthesia with IV sedation is sometimes
preferred. The aims are to diagnose or exclude malignancy or control discharge. Microdochectomy is used for a discharging duct that can be identifi
ed, cannulated, and excised. If available, ductoscopy can be used to visualize the
lumen of the duct.
The aim is to remove a localized duct system, leaving the others
intact, to obtain a pathological diagnosis. Central duct excision is indicated
for patients with unilateral bloody nipple discharge, particularly from multiple
ducts, or when identifi cation of the discharging duct or cannulation is not feasible.
Most bilateral and non-bloody nipple discharges are caused by pregnancy, lactation,
pituitary tumors, or most commonly benign ectasia/fi brocystic changes. The
majority of bloody nipple discharge represents either a papilloma or duct ectasia.
Most are benign, but malignancy must be ruled out for bloody or copious unilateral
discharge. Radial or peri-areolar incisions can be used for microdochectomy or
central duct excisions. Preoperative mammogram and ultrasound should be performed
to detect abnormalities that may require separate consideration. The lesion
in question is usually within 1–3 cm of the nipple, in the infundibular subareolar
part of the duct. Hemostasis is achieved with electrocautery. The incision should
then be closed using absorbable deep dermal interrupted sutures and a subcuticular
skin suture.
Anatomical Points
The ductal system of the breast has complex arborization. Some 10–12 individual
ducts open onto the nipple. Occasionally, a duct may open at the side or base of the
nipple or even within the areola. The ducts do not travel only in a radial direction,
but often branch and overlap adjacent ducts. If possible, it is important to properly
identify the duct in question and ensure that it is excised. A ductoscope or a lacrimal
probe can often help identify the abnormal discharging duct at the time of surgery.
The nipple may be inverted and require eversion, increasing the diffi culty of cannulation
or resection.
Perspective
See Table 2.6 . Complications are not usually severe or frequent, however, some
can occur. Most cases of bloody nipple discharge are caused by benign intraductal
papillomas. Carcinoma is the cause of bloody nipple discharge in approximately
5–10 % of cases. Accurate identifi cation of the discharging duct is important for
microdochectomy. The discharging duct should be checked, noted, and marked preoperatively
by the operating surgeon. Occasionally the duct may not produce any
blood on the day of the operation. Blind resection should not be attempted, rather
the operation should be delayed until the blood can be expressed. Central duct excision
is also a possible alternative to microdochectomy in this situation. Adverse
scarring is not a common problem because the incision is often made at the edge of
the nipple-areolar complex.
Postoperative pain is usually easily controlled with oral analgesics. Chronic pain
is a rare complication. Some patients develop nipple pain and sensitivity that can
last for several months. Loss of nipple sensation can occur as a consequence of this
operation. The sensory nerves to the nipple may be transected or stretched. The
nipple may retract postoperatively in some cases. Nipple retraction may be avoided
by placing a purse-string suture posterior to the nipple to reconstruct normal projection.
Even with only a full-thickness fl ap and no tissue posterior to the nipple, devascularization
is rare, but it can result in nipple necrosis (Fig. 2.5 ). The patient may
need reconstructive surgery to recreate a nipple. If the majority of ducts are removed
in the central duct excision, breastfeeding may be impeded; however, this is rare if
only one or two ducts are removed. Hematoma formation can usually be avoided
with meticulous hemostasis. Rarely will a hematoma require operative drainage.

Most resolve without further intervention. Prophylactic antibiotics are sometimes
used. Infection may infrequently occur, but abscess formation is very rare.
Major Complications
Although relatively rare, serious complications can occur and patients should be
advised of these. These include nipple necrosis which may be partial or complete,
particularly with central duct excision where devascularization of the nipple-areolar
complex results, sometimes compounded by infection. Reconstructive surgery may
be required. Failure to diagnose and remove the underlying abnormality can occur,
as can subsequent close follow-up. Persistent nipple discharge may result or
recurrent discharge may occur. A repeat ductogram and/or further surgery may be
required. Loss of ability to breastfeed from the operated breast is uncommon with
microdochectomy, but usual with central duct excision. Loss of nipple sensation
and chronic breast pain are potential important long-term major consequences.
Adverse cosmetic results, including nipple retraction and nipple-areolar distortion,
may be considered major sequelae by some patients.