Diseccion Axilar-1

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Axillary Dissection for Breast Cancer

Hiram S. Cody, III, MD

The justification for axillary lymph node staging in breastcancer is threefold. Stated in order of importance, theseare (1) prognostication, (2) local control of disease, and (3)

the possibility of a small survival benefit.1

The options for axillary staging are axillary dissection

(ALND), axillary sampling, sentinel lymph node (SLN) bi-

opsy, and clinical/nonsurgical staging. While many have re-

garded ALND as the gold standard, relatively few studies

directly compare ALND with other methods of staging. Two

randomized trials (Edinburgh)2,3 compare ALND with axil-

lary sampling, one (Milan)4 compares ALND with SLN bi-

opsy, and one (NSABP B-04)5 compares ALND with no axil-

lary surgery. An extensive literature,6 largely observational,

hasnow established SLNbiopsy as a newstandardfor axillary

staging, and one that offers substantial advantages over the

other approaches. Based on the overwhelming prognostic

importance of axillary node status and on the availability of

effective systemic therapies, clinical/nonsurgical methods to

establish axillary node status remain investigational.

Regarding prognosis, SLN biopsy allows routine enhanced

pathologic analysis with serial sections and/or anti-cytokera-

tin stains, identifying prognostically significant nodal metas-

tases in 9% to 20%7,8 of patients initially deemed node-neg-

ative by standard methods. Regarding local control, axillarylocal recurrence (LR) after ALND ranges from 0% to 2% and

may be even lower after SLN biopsy, where we have observed

axillary LR in only 0.12% of SLN-negative patients.9 Regard-

ing survival, which may be adversely affected by LR,10 the

first of three randomized trials comparing ALND with SLN

biopsy has demonstrated no difference in survival at 4 years

of follow-up, a comparable rate of other adverse events in

both study arms, and reduced local morbidity with SLN bi-

opsy.4

SLN biopsy has become the initial axillary staging proce-

dure of choice in virtually all patients with clinically node-

negative invasive breast cancer, and is also reasonable for

those patients with ductal carcinoma in situ (DCIS) who aresuspected to have underlying invasive disease.11 Of note,

many putative contraindications to SLN biopsy (including

surgical biopsy, large tumor/excision cavity, multifocal/mul-

ticentric disease, prior breast surgeries, prior axillary surgery,etc) have been disproved.

Indications for ALND

Despite the success of SLN biopsy, ALND will continue toplay a role in breast cancer surgery. Current indications for

ALND include:

1. Axillary node metastasis proven by fine needle aspira-

tion (FNA), core biopsy, or SLN biopsy,2. Validation trials of SLN biopsy (in which a planned

backup ALND is done to establish the proportion offalse-negative results),

3. Failed SLNbiopsy (even in experthands, SLNmappingfails in a few percent of cases),

4. Clinically suspicious nodes palpated at the time of anotherwise successful SLN biopsy procedure,

5. Inflammatory breast cancer (following neoadjuvantchemotherapy, SLN biopsy appears accurate for non-inflammatory disease, but remains investigational forinflammatory breast cancer),

6. Unavailability of SLN biopsy, and

7. Isolated loco-regional recurrence, either in the ipsilat-eral axilla after SLN biopsy or in the contralateral axilla,with no evidence of a contralateral breast primary.

Axillary Topography

The axillary contents lie within a complex space best de-scribed as an eccentrically shaped pyramid. Viewed througha transverse section (Fig 1), the axilla is a triangular space,bounded by the chest wall medially, the subscapularis pos-teriorly, the latissimus posterolaterally, and the pectoralismajor and minor muscles anteriorly. Viewed from the frontthrough a coronal section (Fig 2), the triangle is bounded by

the axillary vein superiorly, the latissimus laterally and thechest wall medially.The axillary contents are arbitrarily divided into three lev-

els: level I lying lateral to, level II lying posterior to, and levelIII lying medial to the pectoralis minor muscle. Level I com-prises the largest volume of axillary tissue and the largestproportion of the axillary nodes (perhaps 70%), with level IIcomprising perhaps 20% and level III 10% or less. The ana-tomic distinction between axillary levels I and II is somewhatarbitrary, while level III is more anatomically distinct. His-torically, breast cancer prognosis was related to the highest

From the Breast Service, Department of Surgery, Memorial Sloan-Kettering

Cancer Center, New York, NY.

Address reprint requests to Dr. Hiram S. Cody, III, Breast Service, Depart-

ment of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York

Avenue, New York, NY 10021. E-mail: [email protected]

66 1524-153X/06/$-see front matter 2006 Elsevier Inc. All rights reserved.

doi:10.1053/j.optechgensurg.2006.04.001


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Figure 3 Possible incisions for ALND, done with either breast-conservation or mastectomy. For either procedure, a

separate transverse axillary incision is almost always cosmetically superior to a single incision. (2005 MemorialSloan-Kettering Cancer Center)

Figure 4 Elevation of thesuperior flap. It is not necessary to fully expose theaxillary vein at this time. (2005Memorial

Sloan-Kettering Cancer Center)

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level of axillary node involvement, but since about 1970 the

number of positive nodes, and not the level, has emerged asthe prognostically relevant variable.

Extent of Procedure

The extent of ALND is formally classified as level I, level I toII, or level I-III (complete ALND). While axillary node me-tastases usually proceed sequentially from levels I to II to III,a large literature addressesthe subject of skip metastases,ie,disease limited to levels II to III, sparing level I, or limited tolevel III, sparing levels I-II. Because most skip metastaseswere found in level II (isolated level III disease is rare), manyauthorities recommended a level I-II ALND as the standardoperation. At present, skip metastases are best viewed sim-

ply as level II or III SLN, receiving drainage directly from thebreast. Nothing is being skipped and these nodes should bereadily identified by lymphatic mapping and submitted asSLN.

In our own practice, ALND (done for the indications listedabove) is usually a level I-II dissection. We add a level IIIdissection for all patients found at operation to have palpablysuspicious nodes in levels II to III, or other high-risk featuressuch as T3 or T4 (inflammatory) cancers.

Choice of Incision

The possible incisions for ALND are either separate from (Fig

3:1, 2, 4) or contiguous with (Fig 3:3, 5) the incision used for

the breast operation. A separate incision is best done trans-

versely, gently curved following a skin-line, andplaced abouttwo finger-breadths inferior to the axillary skin crease. Itshould be of adequate length for exposure, but should not gobeyond the pectoral border anteriorly, where it would bevisible. Extensions if needed should be made posteriorly.Separate axillary and breast incisions are almost always cos-metically superior to contiguous ones, especially in the set-ting of skin-sparing mastectomy with immediate reconstruc-tion (Fig 3:2), and for patients with upper outer quadranttumors having breast conservation (Fig3:4), where thetemp-tation to perform a single incision (Fig 3:5) is the strongestbut where the tumor may prove to be deceptively far from theaxilla, requiring resection of a large volume of interveningtissue.

A contiguous incision is perfectly reasonable for patientshaving mastectomy without reconstruction (Fig 3:3), and forpatients having breast conservation for tumors very high inthe axillary tail (Fig 3:5). In either case, SLN biopsy is easilydone through the axillary end of the incision before proceed-ing with the breast operation.

Beginning the Operation

While ALND is possible under local anesthesia with sedation(in patients with severe comorbidity), it is best done undergeneral anesthesia. I prefer to position the OR table tiltedaway and with the back slightly raised to facilitate exposure

of the axillary area. The ipsilateral chest and arm should be

Figure 5 Elevationof theanteriorflap to thepectoralborder. It is notnecessary to dissect aroundthe pectoral borderand

expose the medial pectoral nerve at this time. (2005 Memorial Sloan-Kettering Cancer Center)

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prepped, with a sterile sleeve covering the arm to allow

changes in position during surgery. The operation is begun

(Fig4) with a transverse skin line incision extending from thelateral border of the pectoralis major back toward the latissi-

mus. An inadequate axillary incision reflects poorly on thesurgeon and does not reduce morbidity, so (within reason)

the incision should be adequate for good exposure.

Flap Elevation

The first and foremost technical element of ALND is to fullydissect the skin flaps to their anatomic limits before entering

the axilla. This point cannot be emphasized enough: virtuallyall-technical difficulties with ALND stem from inadequate

flap elevation at the outset of the procedure. The second keytechnical element of ALND is to have adequate countertractionat all times (tissue under tension, surgeon at ease). As the

flap dissection deepens, Richardson retractors are placed ateach end of the field and traction constantly applied parallel

to the line of dissection (Figs 5-17).Flap thickness should be uniform and depends on the

patients body habitus. For thin patients I dissect in the are-olar plane just beneath the axillary sweat glands, but other-

wise I leave 2 to 5 mm of fatty tissue on the flap. Any axillarybreast tissue, often visible as a bulge preoperatively, should

be encompassed by the skin flaps as well. Flaps of uniform

thickness will mold smoothly into the axillary defect at the

end of the procedure, with a good cosmetic result.

Retracting the skin edges upward and using electrocau-

tery, the superior flap is elevated first (Fig 4). I usually stop

within the fatty tissue somewhat short of the axillary vein,

and have found that definitive exposure of the axillary vein is

easiest once the other flaps have been elevated fully.

The medial flap is dissected next (Fig5), proceeding to the

lateral border of the pectoralis major muscle, and exposing as

much of the pectoral border as possible. Retracting the axil-

lary contents laterally, dissection is carried around the lateral

borderof themuscle, staying about 1-cm lateral to themuscle

border and outside of the pectoral fascia so as to avoid injuryto the medial pectoral nerve.

The lateral flap is dissected next (Fig 6), retracting the

axillary contents anteriorly, and proceeding laterally to the

anterior border of the latissimus dorsi muscle. The muscle is

easily identified in thin/muscular patients, but can be surpris-

ingly difficult to identify if it is atrophic or buried in fat; in

this context, I dissect the flap out to the mid-axillary line and

then gradually deepen the plane of dissection back toward

the chest wall until reaching the anterior border of the latis-

simus. Dissecting in toward the chest wall too soon will miss

the latissimus in an anterior direction, leading to the serratus

instead. Dissecting in toward the chest wall too far laterally

will lead to the posterolateral aspect of the latissimus, and

Figure 6 Elevation of the lateral flap to the anterior border of the latissimus, and superiorly along the latissimus to thewhite tendon, identifying theaxillary vein passing just anterior to it. (2005Memorial Sloan-Kettering CancerCenter)

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Figure 8 Division of the clavipectoral fascia superiorly, exposing the axillary vein and allowing retraction of the axillarycontents inferiorly. (2005 Memorial Sloan-Kettering Cancer Center)

Figure 9 Division of the small side branches of the medial pectoral neurovascular bundle, allowing a retractor to beplaced deep to both pectoral muscles, exposing level II (and possibly level III). (2005 Memorial Sloan-Kettering

Cancer Center)

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Figure 11 Division of the intercostobrachial (T2)sensory nerve, allowing the axillary contents to be

further mobilized laterally, exposing the long tho-racic nerve. (2005 Memorial Sloan-Kettering

Cancer Center)

Figure 12 Division of thefinal andlargest side

branch of the axillary vein (thoracoepigas-tric), further freeing the axillary contents

and allowing exposure of the long thoracicand thoracodorsal nerves. (2005 Memorial

Sloan-Kettering Cancer Center)

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Figure 14 Exposure of the thoracodorsal neurovascular bundle, proceeding about 45 degrees posteriorly to theplane of

the other axillary side branches. The thoracodorsal nerve usually runs along the medial aspect of the bundle. (2005

Memorial Sloan-Kettering Cancer Center)

Figure 13 Retraction of the axillary contents

laterally, exposing the long thoracic nerve as

it runs beneath the thin veil of fascia com-prising the medial face of the axillary speci-

men. (2005 Memorial Sloan-KetteringCancer Center)



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the intercostobrachial nerve). The T3 and (if necessary) T4sensory nerve roots are similarly divided to further free the

axillary contents from the lateral chest wall.

Identifying theLong Thoracic Nerve

As the dissection continues laterally, the largest side branchof the axillary vein (thoracoepigastric) is divided and li-gated (Fig 12). As the axillary contents are retracted laterallyto look for the long thoracic nerve, the first white line onesees is usually a thin fold of fascia enclosing the serratusmuscle, and not the nerve. The long thoracic nerve is usuallyvisible lateral to this, running just beneath the thin layer offascia encompassing the medial aspect of the axillary contents

(Fig 13). After carefully incising this layer, the nerve is easily

separated from the axillary contents by placing both indexfingers into the space just lateral to the nerve, and by simul-

taneously sweeping superiorly and inferiorly. This frees andexposes the nerve along most of its length, and preventsinjury later on.

Identifying theThoracodorsal Nerve

Most side branches of the axillary vein, including the tho-racoepigastric, enter the vein along roughly the same plane.In contrast, the thoracodorsal neurovascular bundle is angu-lated about 45 degrees posteriorly. Once all of the anteriorlylocated side branches have been ligated, the thoracodorsalneurovascular bundle is identified by simply retracting the

axillary contents inferiorly. The thoracodorsal nerve is easily

Figure 15 Division of the bridge of tissue

between the long thoracic and thora-codorsal nerves, taking care to keep both

nerves under direct vision at all times.(2005 Memorial Sloan-Kettering Can-

cer Center)

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identified, lying just medial to the artery and vein, by sweep-ing a finger inferiorly along, and just medial to, the thora-codorsal bundle. In Fig 14, this maneuver has been com-pleted, leaving a bridge of fatty level I tissue between the longthoracic and thoracodorsal nerves.

Completing theAxillary Dissection

This intervening bridge of level I tissue is then clamped asclose to the vein as possible (Fig 15), divided distal to theclamp, and ligated proximally. The clamp should be applied

carefully, with the axillary vein and both nerves under directvision at all times. If the long thoracic nerve has not beenswept completely free of the axillary tissue at this level, or ifthe thoracodorsal nerve is crossing the axilla diagonally andhas not been fully exposed, then either nerve could easilysneak into the clamp and be cut during this maneuver.Once the bridge of tissue has been cut, the specimen is sweptinferiorly, exposing the subscapularis muscle posteriorly,and leaving a clean operative field between the two nerves(Fig 16). As the axillary contents are mobilized inferolater-ally, dissection is carried directly along the thoracodorsalnerve, and the small side branches of the thoracodorsal ves-sels are easily identified and ligated (Fig 17). As the thora-

codorsal bundle begins to curve back toward the chest wall,

theoperation is completedby dividing thefew remaining softtissue attachments inferolateral to the bundle and removingthe specimen. For levels I to II and I to III dissections, I orientthe specimen with metal tags indicating each anatomic level,before handing it off.

Closing

Figure 18 shows the field of the completed ALND. The axil-lary vein (with its ligated side branches) is visible superiorly,the cut ends of the T2 (intercostobrachial), T3 and T4 sen-sory nerves are visible medially, and the long thoracic nerve

and the thoracodorsal neurovascular bundle (with its ligatedside branches) are seen posteriorly. After inspecting the fieldfor hemostasis, a flat 7-mm Jackson-Pratt drain is placedthrough a stab wound in the lower skin flap. I prefer to makethe stab wound within 2 cm of the incision, where the skin isnumb, rather than in the most dependent portion of theaxilla, where thepatient will complain of discomfort from thedrain. The drain is cut to a length that will fit comfortably inthe operative defect, and sutured to the skin. The skin inci-sion is closed with a running subcuticular suture of absorb-able monofilament, and confirmed to be airtight by applyingsuction to the drain. A dressing of gauze, fluffs and surgicalbra is applied, and the patient is awakened and returned to

the recovery room.

Figure 16 Dissection along the course

of the thoracodorsal bundle, dividingand ligating small side branches, and

further freeing the axillary specimen.(2005 Memorial Sloan-Kettering

Cancer Center)



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Postoperative Care

Patients having ALND with breast conservation are nor-mally discharged the following day, and with mastectomyon the second postoperative day. All patients are in-structed in wound care (I normally allow showering theday after surgery), given a log book to record their wounddrainage (the drains are removed when 24-hour drainageis less than 30 mL), and given a program of postoperativeshoulder exercises (that they can usually begin immedi-

ately except in the setting of breast reconstruction). Whileit is common practice to give patients detailed i nstructionson the steps they can take to prevent lymphedema, thereis no evidence whatever that such measures work,12 otherthan to make patients who develop lymphedema feel thatit is somehow their own fault, rather than a well-recog-nized side effect of ALND. Accordingly, I encourage all ofmy patients to resume using their arm as soon, and asnormally, as possible.

Future Directions

ALND will be performed less often in the future, for sev-

eral reasons. First, widespread screening has led to a grow-

ing proportion of breast cancers diagnosed as DCIS or

node-negative invasive disease.

Second, there may be subsets of SLN-positive patients

who do not require a completion ALND. A multivariate

nomogram13 can identify SLN-patients at very low risk of

having residual axillary disease, and in our own practice

we have observed a very low rate of axillary recurrence,

1.4%, in selected SLN-positive patients for whom ALND

was not done.9 A clinical trial (ACOSOG Z0011),14 by

randomizing SLN-positive patients to ALND versus nofurther surgery, promises a definitive answer to this issue.

Third, and finally, we are entering an exciting era in

which tumor classification,15 prognostication,16,17 and the

prediction of response to treatment18 will be increasingly

determined at the level of gene expression rather than

phenotype. Gene expression profiling promises to render

conventional methods of cancer staging (including ALND)

obsolete, and to identify therapeutic targets that may ulti-

mately render surgery itself obsolete. The present reality,

however, is that breast cancer remains a heterogeneous

disease for which surgery remains the singl e most effective

treatment, and for which systemic adjuvant therapy ben-

efits a small minority of those treated.19

With the success

Figure 17 Identification and divisionof thefinal thoracodorsal side branch,

allowing the axillary specimen to behanded off. (2005 Memorial Sloan-

Kettering Cancer Center)

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