новая папка / Operative Standards for Cancer Surgery Volume I 1st Edition

from The University of Texas MD Anderson Cancer Center reported that in high-risk patients who did not receive PMRT, positive margins and

fascial invasion were significant predictors of locoregional recurrence.15 A systematic review confirmed that muscle or fascial invasion increased the

relative risk for local recurrence (relative risk, 1.7) in patients who did not receive PMRT.16 Although excision of focal muscular

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involvement followed by PMRT is often used to achieve clear margins, strong data supporting the benefit of muscle excision in this setting are lacking.

5. PREVENTION OF SEROMA/DRAIN PLACEMENT

Recommendation: Drains must be optimally placed to prevent seroma formation and reduce seroma-related morbidity after total mastectomy in order to avoid delays to adjuvant treatment.

Type of Data: Small prospective and multiple retrospective trials.

Strength of Recommendation: The group strongly recommends drain placement to limit seroma formation which could delay adjuvant treatment.

Rationale

Drains are placed at the completion of total mastectomy to evacuate fluid from the surgical site and prevent seroma formation. Seromas form from the inflammatory reaction to the surgical trauma. Electrocautery, which is widely used for mastectomy flap elevation, has been shown to exacerbate

the inflammatory processes that lead to seroma formation.17,18 With the exception of a body mass index greater than 30 kg/m2, which is associated

with prolonged seroma drainage,19 no patient-, procedure-, or tumor-related factors have been found to affect seroma extent or duration. In patients at high risk of persistent seroma following total mastectomy, closure of the dead space with sutures and/or tissue sealants may be considered; however, this approach offers limited benefit in patients undergoing uncomplicated simple total mastectomy that does not include extensive axillary node dissection.

Persistent seroma can lead to mild or severe infections and/or delays in adjuvant therapy, thus potentially affecting oncologic outcomes.20,21 The most widespread approach to reducing seroma-related morbidity after mastectomy is the use of closedsuction drainage. Small prospective trials

have shown no difference in benefit between the use of multiple drains and a single drain21,22,23 or between the use of low-pressure and high-

pressure suction.24 At least one closed suction drain should be placed at the time of wound closure; this drain should extend across the pectoralis major muscle towards the axillary space. Data from one randomized controlled trial supports placing a chlorhexidine disc at the drain site and using

antiseptic bulb irrigation to reduce drain colonization.25

Various strategies have been employed to limit seroma formation without drain placement. For example, prospective trials have shown that fibrin

sealant reduces the duration and quantity of wound drainage in patients undergoing total mastectomy and concomitant axillary node dissection.26,27

Fixation of the flap with sutures may also result in earlier drain removal, although this approach is not widely used.28,29 In most settings, removing

the drain only after an output of <30 mL/day has achieved results in optimal outcomes.30 Early drain removal without consideration of drainage

volume is not recommended because it has been associated with a higher rate of postoperative complications.28

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REFERENCES

1.Kuerer HM, ed. Kuerer’s Breast Surgical Oncology. New York, NY: McGraw-Hill; 2010.

2.Garwood ER, Moore D, Ewing C, et al. Total skin-sparing mastectomy: complications and local recurrence rates in 2 cohorts of patients. Ann Surg 2009;249:26-32.

3.Harris JR, Lippman ME, Osborne CK, et al. Diseases of the Breast. Philadelphia, PA: Lippincott Williams & Wilkins; 2011.

4.Torresan RZ, dos Santos CC, Okamura H, et al. Evaluation of residual glandular tissue after skin-sparing mastectomies. Ann Surg Oncol

2005;12:1037-1044.

5.Nickell WB, Skelton J. Breast fat and fallacies: more than 100 years of anatomical fantasy. J Hum Lact 2005;21:126-130.

6.Newman LA, Kuerer HM, Hunt KK, et al. Presentation, treatment, and outcome of local recurrence afterskin-sparing mastectomy and immediate breast reconstruction. Ann Surg Oncol 1998;5:620-626.

7.Yilmaz KB, Dogan L, Nalbant H, et al. Comparing scalpel, electrocautery and ultrasonic dissector effects: the impact on wound complications and pro-inflammatory cytokine levels in wound fluid from mastectomy patients. J Breast Cancer 2011;14(1):58-63.

8.Cortadellas T, Córdoba O, Espinosa-Bravo M, et al. Electrothermal bipolar vessel sealing system in axillary dissection: a prospective randomized clinical study. Int J Surg 2011;9(8):636-640.

9.Miller E, Paull DE, Morrissey K, et al. Scalpel versus electrocautery in modified radical mastectomy. Am Surg 1988;54(5):284-286.

10.Abbott AM, Miller BT, Tuttle TM. Outcomes after tumescence technique versus electrocautery mastectomy. Ann Surg Oncol 2012;19:26072611.

11.Chun YS, Verma K, Rosen H, et al. Use of tumescent mastectomy technique as a risk factor for native breast skin flap necrosis following immediate breast reconstruction. Am J Surg 2011;201:160-165.

12.Seth AK, Hirsch EM, Kim JYS, et al. Additive risk of tumescent technique in patients undergoing mastectomy with immediate reconstruction.

Ann Surg Oncol 2011;18(11):3041-3046.

13.Shoher A, Hekier R, Lucci A Jr. Mastectomy performed with scissors following tumescent solution injection. J Surg Oncol 2003;83:191-193.

14.Halstead W. The results of operations for the cure of cancer of the breast performed at the Johns Hopkins Hospital from June 1889 to January 1894. Ann Surg 1894;20:497-555.

15.Baker RR. A comparison of modified radical mastectomy to radical mastectomy in the treatment of operable breast cancer. Ann Surg

1978;189:553-557.

16.Fisher B, Jeong JH, Anderson S, et al. Twenty-five-year follow-up of a randomized trial comparing radical mastectomy, total mastectomy, and total mastectomy followed by irradiation. N Engl J Med 2002;347(8):567-575.

17.Nielsen HM, Overgaard M, Grau C, et al. Loco-regional recurrence after mastectomy in highrisk breast cancer—risk and prognosis. An analysis of patients from the DBCG 82 b&c randomization trials. Radiother Oncol 2006;79:147-155.

18.Katz A, Strom EA, Buchholz TA, et al. The influence of pathologic tumor characteristics on locoregional recurrence rates following mastectomy. Int J Rad Oncol Biol Phys 2001;50:735-742.

19.Rowell NP. Are mastectomy resection margins of clinical relevance? A systematic review. Breast 2010;19:14-22.

20.Hashemi E, Kaviani A, Najafi M, et al. Seroma formation after surgery for breast cancer. World J Surg Oncol 2004;2:44.

21.Porter KA, O’Connor S, Rimm E, et al. Electrocautery as a factor in seroma formation following mastectomy. Am J Surg 1998;176:8-11.

22.Kuroi K, Shimozuma K, Taguchi T, et al. Evidence-based risk factors for seroma formation in breast surgery. Jpn J Clin Oncol

2006;36(4)197-206.

23. Terrell GS, Singer JA. Axillary versus combined axillary and pectoral drainage after modified radical mastectomy. Surg Gynecol Obstet

1992;175:437-440.

24.Petrek JA, Peters MM, Cirrincione C, et al. A prospective randomized trial of single versus multiple drains in the axilla after lymphadenectomy. Surg Gynecol Obstet 1992;175:405-409.

25.Saratzis A, Soumian S, Willetts R, et al. Use of multiple drains after mastectomy is associated with more patient discomfort and longer postoperative stay. Clin Breast Cancer 2009;9:243-246.

26.Bonnema J, van Geel AN, Ligtenstein DA, et al. A prospective randomized trial of high versus low vacuum drainage after axillary dissection for breast cancer. Am J Surg 1997;173:76-79.

27.Degnim AC, Scow JS, Hoskin TL, et al. Randomized controlled trial to reduce bacterial colonization of surgical drains after breast and axillary operations. Ann Surg 2013;258(2):240-247.

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28.Kuroi K, Shimozuma K, Taguchi T, et al. Effect of mechanical closure of dead space on seroma formation after breast surgery. Breast Cancer 2006;13(3):260-265.

29.Sakkary MA. The value of mastectomy flap fixation in reducing fluid drainage and seroma formation in breast cancer patients. World J Surg Oncol 2012;10:8.

30. Barton A, Blitz M, Callahan D, et al. Early removal of postmastectomy drains is not beneficial: results from a halted randomized controlled

trial. Am J Surg 2006;191(5):652-656.

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Nipple-Sparing Mastectomy: Key Question

In women with breast cancer or at high risk for breast cancer, what are the technical components of a nipple-sparing mastectomy for it to be performed in an oncologic fashion comparable to skin-sparing mastectomy?

INTRODUCTION

Many women still undergo mastectomy for breast cancer despite advances in local therapy. The significant psychological impact associated with mastectomy has driven the search to identify surgical approaches that optimize cosmetic outcomes while offering appropriate oncologic outcomes. The preservation of the nipple-areola complex (NAC) following breast cancer surgery increases a woman’s perception of wholeness, and this has led to a resurgence of interest in nipple-sparing mastectomy (NSM). However, guidelines for selecting patients and performing NSM are lacking. We performed a systematic literature review to identify the optimal approaches to the main technical components of NSM that would enable surgeons to perform the procedure in an oncologic fashion comparable to that of skin-sparing mastectomy (SSM) in women who have breast cancer or who are at an increased risk for breast cancer.

METHODOLOGY

We performed a PubMed search with the assistance of professional medical librarians. All articles from 1978 to 2013 restricted to the English language using the Medical Subject Headings (MeSH) “genes, BRCA1,” “genes, BRCA2,” “hereditary breast,” “ovarian cancer syndrome,” “carcinoma, ductal, breast,” “carcinoma, intraductal, noninfiltrating,” “neoplasms, ductal, lobular, and medullary,” “carcinoma in situ,” “breast neoplasms/pathology,” “breast neoplasms/surgery,” “intraoperative complications,” “postoperative complications,” “necrosis,” “treatment outcome,” “neoplasm recurrence, local,” “prognosis,” “risk reduction behavior,” and keywords brca1, brca2, hereditary breast, ovarian cancer syndrome, carcinoma ductal breast, breast neoplasms and (pathology OR surgery), breast and (neoplasm OR cancer OR carcinoma OR in situ OR invasive OR infiltrating), oncologic principles, oncologic technique, nipple coring, skin flap, incision, flap elevation, flap thickness, retroareolar tissue removal, retroareolar intraoperative assessment, nipple areola complex, nipple-areola complex, NAC, nipple areola complex sparing mastectomy, nippleareola complex sparing mastectomy, NSM, total skin sparing mastectomy, intraoperative complications, postoperative complications, necrosis, treatment outcome, cosmesis, neoplasm recurrence locoregional, neoplasm recurrence locoregional, neoplasm recurrence local OR, prognosis, and risk reduction behavior were searched with a total of 370 abstracts identified.

Our search identified 370 abstracts; of these, 17 were duplicates, leaving 354 abstracts for review. Two reviewers identified 67 abstracts that focused on the oncologic

P.41 technical considerations of NSM, including complications and oncologic outcomes. Each of the 67 articles summarized by these abstracts was then screened by two of six reviewers assigned randomly. Articles that lacked oncologic technical considerations or outcomes, had study populations of less than 30 patients, or had patient populations reported in another study already included in the review were excluded. An article’s inclusion or exclusion was based on reviewer agreement. If the two reviewers did not agree on whether to include or exclude an article, a third reviewer was brought in to review the article, which was then included or excluded based on the third reviewer’s decision. Forty-five articles were included in the final literature review. Our review included no randomized clinical trials; most studies reported outcomes from single institutions, and the vast majority were prospective or retrospective cohorts.

FINDINGS

Historical Prevalence of Nipple-Areola Complex Involvement in Mastectomy Specimens

The prevalence of tumor involvement in the NAC is one concern that affects the oncologic safety of NSM. Retrospective pathologic analyses of consecutive mastectomy specimens have found that 9% to 29% of patients undergoing mastectomy for breast cancer have NAC

involvement.1,2,3,4,5,6 This wide range likely reflects these studies’ differing criteria for mastectomy. Factors associated with tumor in the NAC included a central location of the tumor, a tumor size greater than 5 cm, and a tumor-to-nipple distance of less than 2 cm. However, women who are considered appropriate candidates for NSM have been found to have a much lower rate of NAC involvement. Most series of women undergoing planned NSM have shown that fewer than 10% require excision of the NAC owing to positive findings on pathologic analysis (Table 2-1).

Patient Selection

The success of any surgical procedure relies in part on appropriate patient selection. Specific patient selection guidelines for NSM have not been established, but numerous studies have investigated patient selection for NSM in both the therapeutic and risk-reducing settings. Most series have limited the consideration for NSM to patients presenting with either ductal carcinoma in situ or stage I or II invasive cancer. Absolute contraindications for NSM include nipple changes, such as nipple discharge, nipple inversion, or ulceration of the NAC. Patients with inflammatory breast cancer, retroareolar tumors, Paget disease, and frozen section analysis-based confirmation of NAC involvement should not have NSM.

Relative contraindications for NSM include tumor size (most commonly greater than 2.5 to 3.5 cm)7,8,9,10,11,12,13,14,15 and nipple-to-tumor distance

(often less than 2.0 to 2.5 cm).8,10,11,13,15,16,17

There is a general consensus that preoperative imaging should be used to rule out radiographically evident NAC involvement, with some

NSM for patients carrying BRCA mutations also continues to be controversial, as the few series that have included patients with BRCA mutations

who underwent prophylactic NSM offer only short-term data so far.14,17,19,20 However, the long-term cancer incidence rate of patients with BRCA mutations who undergo prophylactic NSM is anticipated to be low.

Intraoperative Management of the Nipple-Areola Complex

NSM preserves the skin of the NAC with the mastectomy flap. However, the extent to which the glandular and/or ductal tissue underlying and within the NAC should be excised requires clarification. Most authors who have described their technique for NSM report completely removing all ductal tissue from the nipple, leaving only the epidermis and dermis of the NAC. Nipple eversion during this aspect of the procedure may facilitate the complete removal of the ductal tissue within the nipple (the nipple “core”). To avoid thermal injury to the preserved skin of the NAC, surgeons

should perform delicate, sharp dissection with a scalpel or scissors, rather than electrocautery.7,12,14,15,17,21,22,23,24,25

A few authors advocate preserving the nipple core and a few millimeters of glandular tissue beneath the NAC.26,27 Voltura et al,26 citing anatomical studies demonstrating that terminal ductal-lobular units are present in only 9% of nipple specimens, argue that complete removal of the nipple core

is unwarranted. Petit et al27 report preserving a 5-mm layer of glandular tissue beneath the NAC and treating this preserved tissue with radiation intraoperatively.

Based on the aforementioned evidence, all glandular and ductal tissue should be completely removed from the NAC during NSM for patients who will not receive radiation to the preserved NAC. The mastectomy flap must be meticulously elevated up to the edge of the NAC to preserve the blood supply to the NAC.

NSM Incision Placement

Correct incision placement is key to reducing surgical complications following NSM. Numerous incisions for NSM have been described, and familiarity with each, as well as working closely with the reconstructive surgeon to plan incision placement, will help to ensure that NSM yields optimal surgical and cosmetic outcomes. The most commonly used incisions are periareolar, radial, and inframammary incisions. Although no randomized studies of incision placement have been conducted, some general conclusions about incision placement for NSM can be derived from the findings of cohort studies. For example, periareolar incisions involving greater than 30% of the NAC are associated with a higher rate of NAC-

related complications.28 Overall, radial incisions are associated with the lowest rate of NAC compromise; studies comparing incision types have

shown that the complication rate associated with radial incisions is significantly lower than those of periareolar and inframammary incisions.20,29 In experienced hands, inframammary incisions yield both a low complication rate and provide good

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exposure, particularly in women with smaller breasts.21,29 Medial incisions, which can compromise the second intercostal perforator, should

generally be avoided.7,15

Incision through an existing surgical scar may result in complication rates as low as 4%,18 but in general, this approach offers the least flexibility and is less relevant than other approaches given that most breast cancers are diagnosed on the basis of core biopsy rather than surgical excision findings. Those making the incisions should keep in mind the patient’s unique breast size and shape. For example, a small report of 33 women

undergoing concurrent NSM, mastopexy, and tissue expander placement demonstrated that nipple preservation is feasible in women with ptosis.19

Good communication with the reconstruction team will yield the best cosmetic results with different breast shapes and sizes.

Reconstruction Types

Because NSM preserves the entire skin envelope overlying the breast, NSM is always performed in conjunction with breast reconstruction. The breast reconstruction approaches used with SSM are also options for NSM. These approaches include reconstruction using staged tissue expanders and an implant, reconstruction with one-stage implant placement, and reconstruction using autologous tissue. Consultation with a plastic surgeon experienced with NSM reconstruction will help determine the best reconstruction option for each patient.

Surgical Complications

Low surgical complication rates are a critical component of performing NSM in an oncologic fashion. Studies that have reported the surgical complications associated with NSM are shown in Table 2-2. The rate of nipple loss secondary to partial or complete NAC necrosis ranges from 0.7% to 7.3%.

Recurrence Rate

Achieving low rates of locoregional and distant recurrence is the key to performing NSM in an oncologic fashion similar to that of SSM. Studies with follow-up durations ranging from 10 to 139 months have shown that rates of local recurrence in the NAC or breast and rates of regional and distant recurrence following NSM are low (Table 2-3).

CONCLUSION

Technically successful NSM is a multistep process which begins outside the operating room with careful patient selection, planning of incision, and reconstruction. In the operating room, meticulous surgical technique for flap elevation and excision of ductal tissue under NAC are key to good outcomes. NSM has become more widespread in the past decade and represents a significant technical advance over traditional skinsparing approaches. Although NSM is technically more demanding than traditional skin-sparing approaches, its cosmetic outcomes are clearly

Mastectomy for Breast Cancer

NAC, nipple-areola complex; NSM, nipple-sparing mastectomy.

REFERENCES

1.Gulben K, Yildirim E, Berberoglu U. Prediction of occult nipple-areola complex involvement in breast cancer patients. Neoplasma 2008;56:72-

2.Laronga C, Kemp B, Johnston D, et al. The incidence of occult nipple-areola complex involvement in breast cancer patients receiving a skinsparing mastectomy. Ann Surg Oncol 1999;6: 609-613.

3.Wang J, Xiao X, Wang J, et al. Predictors of nipple-areolar complex involvement by breast carcinoma: histopathologic analysis of 787 consecutive therapeutic mastectomy specimens. Ann Surg Oncol 2012;19:1174-1180.

4.Li W, Wang S, Guo X, et al. Nipple involvement in breast cancer: retrospective analysis of 2323 consecutive mastectomy specimens. Int J Surg Pathol 2011;19:328-334.

5.Brachtel EF, Rusby JE, Michaelson JS, et al. Occult nipple involvement in breast cancer: clinicopathologic findings in 316 consecutive mastectomy specimens. J Clin Oncol 2009;27:4948-4954.

6.Mallon P, Feron J-G, Couturaud B, et al. The role of nipple-sparing mastectomy in breast cancer: a comprehensive review of the literature.

Plast Reconstr Surg 2013;131:969-984.

7.Crowe JP Jr, Kim JA, Yetman R, et al. Nipple-sparing mastectomy: technique and results of 54 procedures. Arch Surg 2004;139:148-150.

8.de Alcantara Filho P, Capko D, Barry JM, et al. Nipple-sparing mastectomy for breast cancer and risk-reducing surgery: the Memorial SloanKettering Cancer Center experience. Ann Surg Oncol 2011;18:3117-3122.

9.Kroll SS, Schusterman MA, Tadjalli HE, et al. Risk of recurrence after treatment of early breast cancer with skin-sparing mastectomy. Ann Surg Oncol 1997;4:193-197.

10.Maxwell GP, Storm-Dickerson T, Whitworth P, et al. Advances in nipple-sparing mastectomy: oncological safety and incision selection. Aesthet Surg J 2011;31:310-319.

11.Psaila A, Pozzi M, Barone Adesi L, et al. Nipple sparing mastectomy with immediate breast reconstruction: a short term analysis of our experience. J Exp Clin Cancer Res 2006;25:309-312.

12.Regolo L, Ballardini B, Gallarotti E, et al. Nipple sparing mastectomy: an innovative skin incision for an alternative approach. Breast

2008;17:8-11.

13. Rulli A, Caracappa D, Barberini F, et al. Oncologic reliability of nipple-sparing mastectomy for selected patients with breast cancer. In Vivo

2013;27:387-394.

14.Sacchini V, Pinotti JA, Barros AC, et al. Nipple-sparing mastectomy for breast cancer and risk reduction: oncologic or technical problem? J Am Coll Surg 2006;203:704-714.

15.Stolier AJ, Levine EA. Reducing the risk of nipple necrosis: technical observations in 340 nipplesparing mastectomies. Breast J

2013;19:173-179.

16.Gerber B, Krause A, Dieterich M, et al. The oncological safety of skin sparing mastectomy with conservation of the nipple-areola complex and autologous reconstruction: an extended follow-up study. Ann Surg 2009;249:461-468.

17.Wagner JL, Fearmonti R, Hunt KK, et al. Prospective evaluation of the nipple-areola complex sparing mastectomy for risk reduction and for early-stage breast cancer. Ann Surg Oncol 2012;19:1137-1144.

18.Boneti C, Yuen J, Santiago C, et al. Oncologic safety of nipple skin-sparing or total skin-sparing mastectomies with immediate reconstruction. J Am Coll Surg 2011;212:686-693; discussion 693-695.

19.Al-Mufarrej FM, Woods JE, Jacobson SR. Simultaneous mastopexy in patients undergoing prophylactic nipple-sparing mastectomies and immediate reconstruction. J Plast Reconstr Aesthet Surg 2013;66:747-755.

20.Algaithy ZK, Petit JY, Lohsiriwat V, et al. Nipple sparing mastectomy: can we predict the factors predisposing to necrosis? Eur J Surg Oncol

2012;38:125-129.

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21. Margulies AG, Hochberg J, Kepple J, et al. Total skin-sparing mastectomy without preservation of the nipple-areola complex. Am J Surg

2005;190:907-926.

22.Kim HJ, Park EH, Lim WS, et al. Nipple areola skin-sparing mastectomy with immediate transverse rectus abdominis musculocutaneous flap reconstruction is an oncologically safe procedure: a single center study. Ann Surg 2010;251:493-498.

23.Paepke S, Schmid R, Fleckner S, et al. Subcutaneous mastectomy with conservation of the nippleareola skin: broadening the indications.

Ann Surg 2009;250:288-292.

24.Sakurai T, Zhang N, Suzuma T, et al. Long-term follow-up of nipple-sparing mastectomy without radiotherapy: a single center study at a Japanese institution. Med Oncol 2013;30:1-7.

25.Burdge EC, Yuen J, Hardee M, et al. Nipple skin-sparing mastectomy is feasible for advanced disease. Ann Surg Oncol 2013;20:32943302.

26.Voltura AM, Tsangaris TN, Rosson GD, et al. Nipple-sparing mastectomy: critical assessment of 51 procedures and implications for selection criteria. Ann Surg Oncol 2008;15:3396-3401.

27.Petit J, Veronesi U, Orecchia R, et al. Nipple-sparing mastectomy with nipple areola intraoperative radiotherapy: one thousand and one cases of a five years experience at the European institute of oncology of Milan (EIO). Breast Cancer Res Treat 2009;117:333-338.

28.Warren Peled A, Foster RD, Stover AC, et al. Outcomes after total skin-sparing mastectomy and immediate reconstruction in 657 breasts.

Ann Surg Oncol 2012;19:3402-3409.

29.Garwood ER, Moore D, Ewing C, et al. Total skin-sparing mastectomy: complications and local recurrence rates in 2 cohorts of patients. Ann Surg 2009;249:26-32.

30.Radovanovic Z, Radovanovic D, Golubovic A, et al: Early complications after nipple-sparing mastectomy and immediate breast reconstruction with silicone prosthesis: results of 214 procedures. Scand J Surg 2010;99(3):115-118.

31.Komorowski AL, Zanini V, Regolo L, et al: Necrotic complications after nipple-and areolasparing mastectomy. World J Surg

2006;30(8):1410-1413.

Chapter 3

Axillary Lymphadenectomy

CRITICAL ELEMENTS

Identification of Anatomical Structures for Level I and II Axillary Dissection

Removal of Level III Nodes

Removal of Rotter Nodes

Removal of a Sufficient Number of Lymph Nodes for Axillary Staging

Identification and Preservation of the Long Thoracic, Thoracodorsal, and Medial Pectoral Nerves

Identification and Preservation of the Second and Third Intercostobrachial Nerves

Drain Placement

1A. IDENTIFICATION OF ANATOMICAL STRUCTURES FOR LEVEL I AND II AXILLARY DISSECTION

Recommendation: Identification of the axillary vein and latissimus dorsi, pectoralis major, pectoralis minor, serratus anterior, and subscapularis muscles is essential for the resection of sufficient level I and II axillary nodes for breast cancer staging and adjuvant treatment planning.

Type of Data: Retrospective case series.

Strength of Recommendation: The consensus of the group supports this guideline based on historic evidence.

Rationale

Breast cancer typically spreads to the axillary lymph nodes first, and axillary dissection is important for both local control and treatment planning. The anatomic borders of the axilla must be identified to adequately resect level I and II axillary lymph nodes (see Fig. 3-1). The axilla is a triangular space that is delineated by the axillary vein

P.50 superiorly, the latissimus dorsi muscle laterally, the serratus anterior muscle medially, the subscapularis muscle posteriorly, and the pectoralis minor and major muscles anteriorly. Lymph nodes in the axilla are identified by their location in one of three anatomical levels. Level I contains the axillary lymph nodes between the latissimus dorsi and the lateral border of the pectoralis minor muscle; level II contains the axillary lymph nodes between the lateral and medial borders of the pectoralis minor muscle; and level III encompasses the lymph nodes between the medial border of the pectoralis minor muscle and Halsted’s ligament. Level III axillary nodes can be exposed by resecting or dividing the pectoralis minor muscle. Axillary lymph nodes are located primarily in level I (60% to 70% of nodes), followed by level II (20% to

30%) and level III (10% to 20%).1,2,3 Axillary metastases are most often identified in level I nodes followed by level II nodes. Single-node

metastasis occurs in level I nodes almost exclusively.1,2 Metastases that occur in level II or III nodes in the absence of level I metastasis

(“skip” metastases) are rare and typically occur in level II nodes.2,4