DEFINITION
Cervical mediastinoscopy is a surgical procedure that allows exploration of the superior mediastinum and allows for biopsy of level 2, 4, 7, and 10 lymph nodes or masses.
Extended cervical mediastinoscopy is a cervical mediastinoscopy during which the surgeon passes the mediastinoscope around the innominate artery to gain access to the aortopulmonary window to biopsy the level 6 and 5 nodes.
Video mediastinoscopy is the use of a video mediastinoscope to perform mediastinoscopy. For traditional mediastinoscopy, the surgeon looked directly through the mediastinoscope to perform the procedure. The video mediastinoscope allows better visualization of the structures in the mediastinum so that a better operation is performed.
INTRODUCTION
Pathologic staging of the mediastinum is a crucial step in the evaluation and treatment of non–small cell lung cancer. The extent of lymph node involvement guides the therapeutic plan toward resection, neoadjuvant therapy, or nonsurgical treatment. Accurate staging of the mediastinum is, therefore, essential ( Fig. 5-1 ).
Radiographic assessment of the mediastinum is not as accurate as pathologic staging. The size of mediastinal lymph nodes on computed tomography (CT) cannot be relied on in the staging of non–small cell lung cancer. Up to 40% of positive mediastinal nodes are less than 1 cm, and only 60% of nodes greater than 2 cm contain metastases. Therefore, both the sensitivity and specificity for the CT evaluation of the mediastinum are 60%. The positron emission tomography (PET) scan has a higher sensitivity, but the false-positive rate is as high as 35%. Pathologic assessment of the mediastinum via mediastinoscopy is the preferred method of staging the mediastinum.
CERVICAL MEDIASTINOSCOPY
Carlens developed cervical mediastinoscopy to enable the passage of a mediastinoscope into the mediastinum for biopsy of nodes from the paratracheal and subcarinal regions. Cervical mediastinoscopy is one of the most important procedures used in the staging and diagnosis of non–small cell lung cancer. It also aids in the pathologic evaluation of mediastinal adenopathy not associated with lung cancer and some mediastinal masses.
Recently, other techniques have been used to biopsy mediastinal nodes. Esophagoscopy with endoscopic ultrasound–guided biopsies has been shown to diagnose level 2, 4, 7, 8, and 9 nodes; level 6 nodes may possibly also be biopsied with this technique. Endobronchial ultrasound can help biopsy level 2, 4, 7, and 10 nodes. The advantage of these techniques is that they do not necessarily require general anesthesia as mediastinoscopy does. However, mediastinoscopy remains the gold standard to which all new techniques are compared.
- ▪
Lymph node stations accessible to cervical mediastinoscopy.
- ○
High paratracheal, left and right (stations 2L, 2R).
- ○
Pretracheal (stations 1, 3).
- ○
Tracheobronchial angle, left and right (stations 4L, 4R).
- ○
Subcarinal (station 7).
- ○
Level 10 nodes on the main stem bronchi.
- ○
- ▪
Lymph node stations not accessible to conventional cervical mediastinoscopy.
- ○
Para-aortic and aortopulmonary window (station 6 and 5) (see later section on extended cervical mediastinoscopy).
- ○
Paraesophageal (station 8).
- ○
Inferior pulmonary ligament (station 9).
- ○
Level 11, 12, and 13 nodes.
- ○
INDICATIONS
- ▪
Mediastinal staging in patients with greater than stage 1A (T1N0) non–small cell lung cancer, and patients with
- ○
Central tumors
- ○
Adenocarcinoma
- ○
Need for pneumonectomy
- ○
Superior sulcus tumors
- ○
Adenopathy or suggested invasion on CT scan
- ○
Patients with synchronous primary lung cancers
- ○
Patients with poor performance status
- ○
- ▪
Undiagnosed mediastinal adenopath.
- ▪
Lymphoma
- ▪
Inflammatory disease
- ○
Sarcoidosis
- ○
Histoplasmosis
- ○
Drainage of abscess or lymphocele
- ○
Tuberculosis
- ○
- •
Pneumoconioses
- ▪
Mediastinal tumors and cysts
- ○
Parathyroid adenoma
- ○
Thymoma
- ○
Cystic hygromas, bronchogenic cysts
- ○
Mediastinal goiter
- ○
TECHNIQUE
- ▪
General anesthesia with a single lumen endotracheal tube.
- ▪
Patient positioned supine with neck extended via a roll or pillow under the shoulders.
- ▪
Transverse 2-cm incision approximately 2 cm above the sternal notch ( Fig. 5-2 ).
Figure 5-2
Transverse skin incision 2 cm above sternal notch. Patient’s head is toward the bottom of the picture.
- ▪
Divide platysma transversely.
- ▪
Dissect in midline to retract the strap muscles, exposing the pretracheal fascia.
- ▪
Open the fascia, bluntly dissect on anterior surface of trachea.
- ▪
Identify and partially dissect adenopathy or mass by palpation using the index finger; this also opens the plane for introduction of the mediastinoscope.
- ▪
The right paratracheal nodes lie anterior and lateral to the trachea and inferior to the innominate artery, whereas the left paratracheal nodes lie lateral and posterior to the trachea.
- ▪
Introduce the mediastinoscope along the anterior surface of the trachea ( Fig. 5-3 ).
Figure 5-3
View of mediastinum, anterior to the trachea. Metal suction catheter along left side of trachea.
- ▪
Use a metal suction catheter to mobilize nodes at the various stations ( Fig. 5-4 ).
Figure 5-4
Metal suction catheter is used to mobilize nodes at various stations.
- ▪
Grasp and biopsy nodes with a cupped biopsy forceps ( Fig. 5-5 ).
Figure 5-5
Cupped biopsy forceps are used to grasp and biopsy lymph nodes or a mass in the mediastinum.
- ▪
If any doubt regarding the vascular nature of a structure, a 22-gauge spinal needle can be used to aspirate; however, this is rarely necessary because nodes are dissected well enough that there should be no doubt that they are nodes, not vessels.
- ▪
Small bleeding vessels can be cauterized or clipped.
- ▪
If no clear bleeding vessel is identified, then can pack with oxidized cellulose, Surgicel (Johnson & Johnson, Langhorne, PA), or long, 1-inch packing and re-evaluate after a few minutes; almost all minor bleeding will stop with packing and time.
- ▪
After adequate hemostasis, the strap muscles are reapproximated in the midline.
- ▪
The platysma is closed with interrupted stitches, followed by closure of the skin with subcuticular stitches.
Note: See video of procedure on accompanying DVD.
LIMITATIONS
- ▪
Conditions that increase difficulty but are not absolute contraindications.
- ○
Superior vena cava (SVC) obstruction because collateral veins increase the risk of bleeding with the procedure.
- ○
Previous radiation or chemotherapy because it usually causes significant scarring that may make the dissection dangerous
- ○
- ▪
Contraindications
- ○
Large goiter that physically precludes access to the trachea and the mediastinal nodes.
- ○
Severe calcification or aneurysm of the innominate artery. Stroke is a well known, albeit rare, complication of mediastinoscopy because the mediastinoscope may compress the innominate artery during the procedure. Severe calcifications may break loose and travel to the brain and cause an embolism.
- ○
End tracheostomy after laryngectomy. A permanent tracheostomy is in the surgical field and very close to the incision for mediastinoscopy so that sterility for the operation is compromised.
- ○
Severe cervical arthritis and kyphosis preclude extension of the neck, which is necessary for the mediastinoscope to gain access to the mediastinum.
- ○
Prior paratracheal lymph node dissection because all the tissue from the trachea to the superior vena cava is resected so that attempted dissection in that area is likely to damage either the trachea or the superior vena cava.
- ○
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
