Cervical Mediastinal l SUSAN ALEXANDER l FOR STAGING OF LUNG CANCER

ervical mediastinal exp- bronchogenic lung cancer by sam-

loration (CME), or pling selected lymph nodes in and mediastinoscopy, is a around the trachea, its major surgical procedure to bifurcation and the great vessels. C explore and sample Lymph nodes are removed and lymph nodes in the space between sent to pathology for tissue diag-

the lungs, (the mediastinum), nosis to determine the histology when diagnostic imaging studies of the tumor. CME is performed (X-ray, CT scan, etc) suggest a primarily to stage lung cancer growth in the lungs or mediasti- and determine the extent of the

nal region. The most common pur- disease and establish treatment pose of the CME is to diagnose options.

DECEMBER 2002 The Surgical Technologist 9 224 DECEMBER 2002 CATEGORY 1

If cancer exists in the lymph nodes, the cell type nodes that are not accessible through CME. In (histology) identifies the type of cancer and one series of 100 patients with tumors in this extent of the lymph nodes involved. If tumor area, 22 were found to be inoperable despite hav­ involvement in the mediastinal area is demon­ ing a negative mediastinoscopy.5 Left anterior strated in the pathology review of the speci- mediastinotomy through the second intercostal men(s) (lymph nodes), the patient may be space is the preferred method to assess the oper­ spared an unnecessary thoracotomy; however, ability of these patients, as suggested by Pearson this means that the tumor is inoperable.5 and coworkers.5 Less than 50% of patients undergoing cura­ History tive resection for bronchogenic carcinoma sur­ CME was originally described by Harken and vive five years. Most deaths are due to local associates (1954).1 The procedure is done to recurrence or disseminated disease. Analysis of sample lymph nodes in the paratracheal area and the causes of death within a year of surgery sug­ the superior mediastinum for the tissue diagno­ gests that a third of patients have metastases. sis of mediastinal disease with the use of a modi­ Likely sites of metastases include bone, brain, fied laryngoscope. The original technique was an liver, and adrenal glands. extension of scalene node biopsy that had been Metastases is less frequent for squamous cell developed by Daniels (1949).2 This procedure carcinoma, than for adenocarcinoma. In resect­ was further refined by E Carlens (1959)1 and FG ed patients with Stage I squamous cell cancers, Pearson (1965)2, who reported on an anterior metastases occurred in 15% versus 27% with icervical mediastinoscopy using a midline adenocarcinomas. approach, the technique currently used today. Hillers et al performed a literature review TM McNeil and JM Chamberlain (1966)3 (1966-1991) to determine the proportion of described the technique in which lymph nodes patients with potentially operable non-small cell not accessible by the CME in the aortopul­ lung cancer that could be spared thoracotomy by monary window could be sampled by an anteri­ a search for extrathoracic metastases. Although or mediastinotomy. This is referred to as the only 17 studies were suitable for analysis, the Chamberlain procedure. RJ Ginsberg and asso­ frequency of metastases was as follows: ciates (1987),2 “extended” the technique as an alternative to left anterior mediastinoscopy. The • Liver Imaging 2.3% (0.9–3.3%) Chamberlain procedure may also be used to • Head CT 3.3% (2.1–4.4%) stage lung cancer. • CT adrenal 4.7% (3.0–6.4%) • Bone Scan 9.3% (6.7–12%) Incidence and histology American Cancer Society reports figures on Staging patients with thoracic neoplasms. In 2001, there Having a common way to describe a patient’s were 169,400 new cases of lung and bronchus can­ cancer enables doctors everywhere to share cers for both genders in the United States. Estimat­ information about cancers and their treatments. ed total deaths from lung cancer were 154,900.4 The international system used is the TNM sys­ Different types (histology) of lung and bron­ tem. The letters TNM are used for describing chogenic cancers are diagnosed as: squamous cell the cancer: T indicates the size of the tumor; N (also known as epidermoid), small cell (also called indicates if the cancer has spread to lymph oat cell), adenocarcinoma and large cell. The type nodes; and M indicates whether the cancer has indicates the rate of growth and prognosis. spread to other parts of the body (metastasis). A Patients with tumors involving the left hilum number is then added to each letter to indicate or left upper lobe present a special problem, in the degree of size and spread. For example, a that these tumors frequently spread to lymph cancer could be described as T1 N2 M0.6 This

The Surgical Technologist DECEMBER 2002 10 Mountain/Dresler modifications from Naruke/ATS-LCSG Map © 1997 . Reprints are permissible for educational use only. compared stageT1N0(Table thosewith 1). stageT2N1tumors metastases inpatientswith Grading means thetumorisunder3cminsiz In grading, Intumor grading, cells are examined undera a cancer.describing isanotherwayGrading of TNM stage and the histology type. TNM stageandthehistology to.metastases dependsonthe probability of The organs thatlungcancer to isknown metastasize tases to targetorgans. Target organsare those distant metas- carinal), exists of and noevidence involved (ipsilateral mediastinaland/orsub- example, there isa12-foldincrease incerebral the stage, the more frequent themetastases. For 12, 13, 14R Br (innominate) a. achiocephalic Phrenic n. Azygos v.Azygos 11R 10R 2R 4R 3 Ao 8 7 4L Ao 6 10L PA 9 PA arteriosum arteriosum Ligamentum 5 Inf. pulm. ligt. L. 11L pulmonary a. pulmonary 6 e, nodes are 12, 13, 14L The higher The higher 7 Superior mediastinalnodes N Inferior mediastinalnodes nodes Aortic 1 nodes Subaortic (A-Pwindow) 5 Subaortic 8 Paraesophageal (below carina) 7 Subcarinal orphrenic)6 Para-aortic (ascending aorta 14 Subsegmental 13 Segmental 12 Lobar 11 Interlobar 10 Hilar N 2 Upperparatracheal Pulmonary ligament 9 Pulmonary N 4 Lower paratracheal Nodes) (includingAzygos 3 Pre-vascular andretrotracheal 1 Highestmediastinal 3 2 =single digit, contralateral orsuperclavicular =singledigit, ipsilateral The anatomic basisfordeveloping thisproce­ superior mediastinum with identification and mediastinum with superior the peritracheal nodes. lymph of Exploration carinal, paratracheal, and finallysupraclavicular that proceeds from thehilarnodes to thesub- the lungs of dure drainage rests onthelymphatic anatomySurgical microscope to seehow much resemble they nor- respond to therapy. Usually, isdoneon grading grade, the better thechance thetumorwill slowly orrapidly. Like staging, the lower the about whethertumorcells are likely to grow mal cells. canmakeA pathologist aprediction a scale of one to three, a scaleof or oneto four. DECEMBER 2002 staging. cancer lung stations for nodal Regional FIGURE 1 The Surgical Technologist 11 biopsy of lymph nodes in and around the tra­ the result of this procedure determines the chea and its major bifurcation can be accom­ course of treatment, or whether further evalua­ plished (Figure 1). tion needs to be done. Harken and associates1 method was to sample the lymph nodes in the peritracheal area through Diagnosis and preoperative preparation a lateral supraclavicular incision. Note these A complete history and physical examination are lymph nodes are unavailable for biopsy by the carried out with emphasis on any respiratory standard mediastinoscopy: anterior mediastinal, symptoms, wheezing, coughing, dyspnea, and subaortic, and posterior subcarinal. To safely orthopnea. On occasion, a patient may have a biopsy these nodes, the Chamberlain approach is chest X-ray or CT-scan of the chest for evalua­ needed. tion of another problem and a mass in the chest The McNeil and Chamberlain3 approach is discovered. The preoperative work up should involved a vertical incision on either the right or include chest X-rays, CT scans of the chest and left side of the chest over the lateral sternal border neck, and a pulmonary function test. If the eval­ through which the mediastinum can be entered. uation reveals a potential serious obstruction The disadvantage for this technique is that it only due to a mediastinal mass, a preoperative course allows for unilateral exploration. If bilateral of chemotherapy, or radiation is suggested to exploration is necessary, the procedure has to be reduce the size of the tumor and decrease the risk repeated on the contralateral side. The incision of respiratory compromise during induction on the left side allows for biopsies of subaortic and maintenance of anesthesia. and para-aortic nodes as well as the hilar, inter­ It is also important to determine whether any lobar, lobar, segmental, and subsegmental nodes respiratory symptoms are exacerbated by exer­ (also referred to as N1 nodes) (Table 2). The inci­ cise or by assuming the supine position. Presence sion on the right side allows for biopsies of just of these changes should raise the question of a the N1 nodes. Carlen’s midline CME approach major airway obstruction secondary to the via a suprasternal incision allows for a safe bilat­ mediastinal mass. Dysphagia as a preoperative eral exploration and biopsy.1 finding may indicate the presence of a mediasti­ nal mass impinging on both the trachea and Thoracic neoplasms esophagus. If tracheal deviation is suspected, Mediastinoscopy is also a valuable tool in diag­ then specific studies should be obtained to eval­ nosing other tumors such as thymic, tracheal, uate the location and extent of the mass as well as and bronchial cysts, thymic lymphomas or the degree of airway compromise. hyperplasia, nervous system tumors, thyroid masses, or ascending aortic aneurysms, as well as Procedure enlarged lymph nodes associated with sarcido- CME is a sterile procedure performed under sis.1,2 The major indications for a cervical medi­ general endotracheal anesthesia. The patient is astinal exploration are evaluation of lymph node placed in the supine position with a bolster involvement in patients with lung cancer, and under the shoulders and the neck fully extended. tissue biopsy of suspected tumors. If necessary, the patient is shaved and the entire Mediastinoscopy and mediastinotomy are chest is prepped (in case an emergency median used primarily for staging of lung cancer, to eval­ sternotomy or thoracotomy becomes necessary) uate the lymph nodes in patients with potential and draped. A small, short transverse incision is cancer of the lung. The tumors identified dur­ made through the skin and soft tissue, just above ing mediastinoscopy include primary malignant the suprasternal notch, about one fingerbreadth tumors such as bronchogenic lung cancer, lym­ above the manubrium. The lymph nodes that phoma, as well as bone, vascular, or connective may be biopsied are the hilar, subcarinal, para- tissue tumors. The staging of lung cancer due to tracheal (including the Azygos node), and the

The Surgical Technologist DECEMBER 2002 12 Table 1 The TNM staging system for lung cancer

TUMOR Stages: (T) NODE Stages: (N) METASTASIS Stages: (M)

T(X): Primary tumor cannot be N(X): Regional lymph nodes cannot M(X): Presence of distant metastasis assessed, or tumor proven by pres- be assessed cannot be assessed ence of malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy

T(O): No evidence of primary tumor N(0): No regional lymph node metas- M(0): No distant metastasis tasis Tis: Carcinoma in situ

T(1): Tumor 3 cm or less in greatest N(l): Metastasis in ipsilateral peri- M(1): Distant metastasis dimension,surrounded by lung or vis- bronchial and/or ipsilateral hilar ceral pleura, without bronchoscopic lymph nodes, including direct exten­ evidence of invasion more proximal sion than the lobar bronchus (ie not in main bronchus)

T(2):Tumor with any of the following N(2): Metastasis in ipsilateral medi­ features of size or extent:More than 3 astinal and/or subcarinal lymph cm in greatest dimension. Involves node(s) main bronchus, 2 cm or more distal to the carina Invades the visceral pleura. Associated with atelectasis or obstructive pneumonitis which extends to the hilar region but does not involve the entire lung

T(3):Tumor of any size that directly N(3): Metastasis in contralateral invades any of the following: chest mediastinal, contralateral hilar, ipsi­ wall (including superior sulcus lateral or contralateral scalene or tumors), diaphragm, mediastinal supraclavicular lymph node(s) pleura,parietal pericardium;or tumor in the main bronchus less than 2 cm distal to the carina but without involvement of the carina; or associ­ ated atelectasis or obstructive pneu­ monitis of the entire lung

T(4):Tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, esopha­ gus, vertebral body, carina; or tumor with a malignant pleural effusion

DECEMBER 2002 The Surgical Technologist 13 FIGURE 2 Mediastinoscope.

ILLUSTRATION From Surgical Technology for the Surgical Technologist: A Positive Care Approach, 1st edition by AST (c)2001.Reprinted with permission of Delmar Learning, a division of Thompson Learnin:www.thompsonrights.com.Fax 800-730-2215. upper paratrachael nodes. If the visual exami­ If there is any question as to the vascular nation by the surgeon indicates that these nodes nature of a structure, a spinal needle mounted look normal, the Chamberlain procedure may on a small syringe to aspirate the structure in be performed allowing the surgeon to obtain the question is used. Any small bleeding vessels are subaortic, para-aortic, as well as any N1 lymph coagulated electrosurgically. The incidence of nodes, which are not accessible through the cer­ complications is relatively low when the proce­ vical mediastinoscopy. dure is performed by experienced surgeons, and A mediastinoscope with light source is intro­ the mortality rate is about 0.5%.5 duced into the area between the lungs (Figure 2). The surgeon then examines the mediastinum Intraoperative risks through the viewing instrument and removes Major complications during mediastinoscopy tissue samples from any suspicious areas. This are most commonly encountered at either tra­ procedure is often performed in combination cheobronchial angle. On the right side, the azy­ with bronchoscopy. gos vein and anterior pulmonary arterial branch A muscle retracting exposure of the trachea to the right upper lobe are at risk of injury. The then allows for finger dissection into the medi­ azygos vein is easily mistaken for the anthracotic astinum. The fascia is divided, allowing entry lymph node and inadvertently biopsied. Experi­ into the pretracheal space. During this dissec­ ence and the liberal use of a long aspirating nee­ tion, the surgeon palpates for any abnormali­ dle prior to biopsy will prevent this complica­ ties, including enlarged lymph nodes. It is tion. Lymph nodes in this area are often directly extremely important to open the fascia below the adherent to branches of the pulmonary artery, level of the innominate artery. The right paratra­ which are therefore at risk if deep biopsies are cheal and pretracheal nodes will be more easily taken or if excessive traction is applied. The api­ accessible if this fascia is opened prior to inser­ cal arterial branch can also be injured if the tion of the mediastinoscope. mediastinoscope is “levered” anteriorly, result­ Specimen labels are prepared in advance to ing in a traction injury to the artery. At the left avoid errors in labeling the potentially large tracheobronchial angle, the recurrent laryngeal number of specimens. Some surgeons assign the nerve is in close proximity to regional lymph node its anatomical number to identify the loca­ nodes and can be easily traumatized. The entire tion of the node. An anatomical chart should lymph node should not be sampled since the always be available in the operating room. recurrent laryngeal nerve is usually directly

The Surgical Technologist DECEMBER 2002 14 adherent to nodes in the area. Bleeding is best Table 2 Lymph nodes and their locations handled with packing placed through the medi­ astinoscope rather than elecrosurgically, which Superior Mediastinal Nodes may cause permanent damage to the recurrent 1. Highest Mediastinal nerve. 2. Upper Paratracheal In the event of massive bleeding, mediastinal 3. Pre-vascular and Retrotracheal packing will usually control the hemorrhage 4. Lower Paratracheal (including Azygos Nodes) while blood is obtained and preparations are N2=single digit, ipsilateral made for a possible thoracotomy or median ster­ N3=single digit, contralateral or supraclavicular notomy. Following 10 minutes of gauze tampon­ ade, with the operating room prepared for a Aortic Nodes major procedure; the gauze packing is gently 1. Subaortic (A-P window) removed. In many cases the hemorrhage will 2. Para-aortic (ascending aorta or phrenic) have subsided or decreased so that the bleeding site can be identified. In the face of persistent Inferior Mediastinal Nodes uncontrollable hemorrhage, the mediastinum 1. Subcarinal should be repacked and a decision made as to 2. Paraesophageal (below carina) whether thoracotomy or median sternotomy 3. Pulmonary Ligament offers the best approach to control the hemor­ rhage. N1 Nodes Median sternotomy is a most versatile inci­ 1. Hilar sion and allows most injuries to be easily identi­ 2. Interlobar fied and controlled. It also allows the surgeon to 3. Lobar expeditiously institute cardiopulmonary bypass 4. Segmental to gain control of major vessel injuries. A disad­ 5. Subsegmental vantage of sternotomy is the difficulty in carry­ ing out a definitive pulmonary resection once the hemorrhage is controlled. Injuries to the esophagus are extremely rare. As the esophagus lies directly posterior to the subcarinal space, most injuries occur during the exploration of this space and the biopsy of sub- carinal lymph nodes. This injury is often not rec­ the mediastinal area and the potential for bleed­ ognized at the time of surgery and often is only ing in this area are crucial for the surgical tech­ diagnosed postoperatively when the patient nologist to appreciate. CME requires a relatively develops mediastinitis and an esophagogram is short amount of surgical time, but is not without obtained.2 the potential for serious intraoperative bleeding. The surgical technologist is key in being pre­ Conclusion pared for “going open” if the case should warrant Mediastinoscopy is a valuable technique to it. obtain biopsies of benign or malignant lymph node diseases involving the nodes in the visceral About the author compartment of the mediastinum. The value of Susan Alexander graduated in May 2002 from mediastinal staging in the management of can­ Springfield Technical Community College, cer of the lung cannot be underestimated. The School of Health Science, with an AS degree in detection of early stages of cancer only increases surgical technology. She currently works as a the survival rate. Knowledge of the anatomy of surgical technologist at Baystate Medical Center

DECEMBER 2002 The Surgical Technologist 15 Instruments, supplies and medications in Springfield, Mass. She is married and has three children, all of whom are in college. CME instrument set Supplies mediastinoscope drapes Acknowledgments light carrier basins I would like to thank professor Kathleen Flynn, light cord pack who is not only a dedicated educator but also a 1 Mayo scissors prep set good friend, and Springfield Technical Commu­ 1 Metzenbaum scissors double lumen endotrachael tube nity College for having such an outstanding pro­ 2 curved mosquito bolster for positioning gram for Surgical Technology. My sincere thanks 4 Coller 22 gauge needle (to remove speci­ to the surgical technologists, doctors, and nurs­ 2 Kelly men from biopsy punch) es at Baystate Medical Center and Mercy Medical 2 Allis litigating clips Center of Springfield, Mass. 2 regular right angle Lukens traps 2 short needleholder ties (Vicryl 3-0) References 2 French-eye needleholder aspirating needle (spinal) 1. Kaplan JA. Thoracic Anesthesia. 2nd edition. 2 short alligator forceps Surgicel New York, Edinburgh, London, Melbourne, 2 medium DeBakey tissue forceps Gelfoam Tokyo: Churchill Livingstone; 1991: 337-340. 2 short single toothed forceps Formalin/specimen containers 2. Deslauriers J, Ginsberg RJ, Hiebert CA, McK­ 2 Adson with teeth dressings neally MF, and Urschel HC. Thoracic Surgery. 2 Army-Navy light source New York, Edinburgh, London, Melbourne, 2 Weitlaner suction apparatus Tokyo: Churchill Livingstone; 1995: 837-840. 1 small and large straight biopsy electrosurgical unit 3. Shields TW. Mediastinal Surgery. Philadel­ punch phia, London: Lea & Febiger; 1991: 77-80. 1 small and large, angled upward Medications 4. CA A Cancer Journal for Clinicians. Jan/Feb biopsy punch Marcaine 0.5% with epinephrine 2002, Vol. 52/No.1-27. 1 biopsy punch, angled left 5. George RB, Light RW, Matthay MA, Matthay 1 biopsy punch, angled right RA. Chest Medicine—Essentials of Pulmonary 2 mediastinal clip applier and Critical Care Medicine. 2nd edition. New 2 short medium litigating clip York: Churchill Livingstone; 1990 155-156, applier 368-369. 2 small clip applier 6. The Staging of Cancer. www.bmsconcology.com 2 Schnid Accessed 3/25/02 1 metal suction catheter (Frazier) 7. Texas Cancer Online. www.jasper-web.com/texas canceronline/staging.htm Accessed 4/14/02

Editor’s note Interested readers may wish to consult the March 1999 Surgical Technologist for a related article, “Bronchoscopy: Diagnosis of Tumors in the Lung.”

The Surgical Technologist DECEMBER 2002 16