Rigid bronchoscopy is mostly used for therapeutic airway interventions such as airway dilation, laser debridement, tumor debulking, placement of airway stents, or foreign body retrieval (Figure 74-1). The use of the rigid bronchoscope continues to be an important diagnostic tool in special circumstances, such as those requiring a better tactile sense when assessing for possible extrinsic tumor invasion of the airway, or when larger biopsies are sought. It is also indispensable when airway control is in question because of hemoptysis or tumor invasion.

Figure 74-1 Rigid bronchoscopy equipment. Top to bottom, Bronchoscope with light cable, straight and right-angled surgical telescopes, biopsy forceps, suction cannula.

Rigid bronchoscopy requires general anesthesia with a muscle relaxant and specific ventilatory strategies. The options most often used include jet ventilation and continuous or intermittent insufflation. In patients with airway control as an overwhelming concern because of an obstructing airway lesion, muscle relaxants are avoided to maintain spontaneous breathing.

Technique

In general, the size of the rigid bronchoscope used for adult men is 8 or 9 mm (outer diameter) and 7 or 8 mm for adult women. Smaller sizes are available for children or smaller adults.

After induction of anesthesia, the patient is positioned supine with the neck extended into the “sniffing” position. Right-handed surgeons use their left thumb to further protect the upper teeth and lips from injury and to serve as the fulcrum in positioning and supporting the bronchoscope throughout the procedure. Protection is also supplemented by use of a rubber tooth guard or saline-soaked gauze sponge. The patient’s eyes are also shielded from inadvertent injury with padded covers for the duration of the procedure.

The bronchoscope is inserted through the right side of the patient’s mouth with the bevel down (Figure 74-2). It is advanced toward the base of the tongue in the posterior oropharynx. The tip of the epiglottis is then identified by carefully elevating the tongue as the scope is brought more into a horizontal position. The scope is then advanced a short distance past the tip of the epiglottis. The protruding superior lip of the bronchoscope is then used to lift gently the tip of the epiglottis, allowing visualization of the vocal cords and laryngeal inlet. The surgeon will then rotate the bronchoscope 90 degrees along its long axis, placing the bevel in the anteroposterior plane to allow easy passage through the vocal cords. The bronchoscope can then be carefully advanced into the trachea under direct vision. To facilitate passage of the bronchoscope into the left or right main stem bronchus, the patient’s head is turned to the contralateral side. Visualization of the segmental and subsegmental airways can be facilitated by insertion of a flexible bronchoscope through the lumen of the rigid bronchoscope.

Figure 74-2 Positioning and insertion of rigid bronchoscope. The rigid bronchoscope is inserted with the bevel down while the patient is positioned supine with the neck extended.

Cervical, Scalene, and Supraclavicular Lymph Node Biopsy

Both bronchogenic and esophageal carcinoma may involve the lymph nodes in the cervical, scalene, and supraclavicular areas. Open biopsy of nonpalpable scalene lymph nodes is no longer a routine preoperative staging, and in fact, this procedure has become rare. Clinically positive or palpable nodes in this area are now accessed by fine-needle aspiration (FNA) directed by either CT or ultrasound imaging, if necessary. Patients who are thought to have lymphoma may require an open surgical biopsy to obtain a sample size adequate to assess for histologic architecture and sufficient tissue quantities for flow cytometry or additional studies required for a complete diagnosis.

A 3 to 4–cm–long skin crease incision is made at the level just above the insertion of the sternocleidomastoid muscle into the medial clavicle. Dissection can proceed between the clavicular and sternal heads of this muscle, or both can be retracted medially. The scalene fat pad lies on the anterior scalene muscle, lateral to the internal jugular vein, and usually receives its blood supply from the transverse cervical artery entering the fat pad inferiorly. This artery should be identified, ligated, and divided. Injury to the phrenic nerve is possible because of its location along the anterior surface of the anterior scalene muscle, deep to the fat pad. Other, rare but significant complications of open surgical lymph node biopsy include pneumothorax and thoracic duct injury with subsequent chylous fistula.

Cervical Mediastinoscopy

Cervical mediastinoscopy is a mainstay of lung cancer staging and was popularized in Europe by Carlens and in North America by Pearson in the 1960s. It is used not only for lung cancer staging but also to assess any lymphadenopathy in the pretracheal, paratracheal, and subcarinal areas. Lymph nodes that are accessible by the standard cervical approach are the highest: the upper and lower paratracheal and subcarinal levels as well as upper lymph nodes of the pulmonary hilum, or stations 1, 2, 4, 7, and 10 in the American Joint Committee on Cancer (AJCC) nomenclature. The “extended” cervical mediastinoscopy, introduced by Ginsberg, allows access to the aortopulmonary window and paraaortic lymph nodes (stations 5 and 6, respectively). More recently, level 5 and 6 lymph node stations are more often biopsied under direct vision by use of left thoracoscopy or anterior mediastinotomy.

Repeat mediastinoscopy, although technically possible, carries a higher risk of complications because of the loss of normal tissue planes to guide the usual dissection. Cervical mediastinoscopy can usually be performed as an outpatient procedure when done as an individual procedure. In many situations, mediastinoscopy is performed as a staged procedure that precedes a pulmonary resection. In experienced hands, mediastinoscopy provides substantial lymph node specimens, which are evaluated immediately by pathologists, who rule out lymph node metastases before the patient proceeds to an anatomic resection of the lung cancer.

Recently in Europe, more extensive procedures, referred to as transcervical extended mediastinal lymphadenectomy (TEMLA) and video-assisted mediastinal lymphadenectomy (VAMLA), have been proposed as alternatives to conventional cervical mediastinoscopy. These techniques are significantly more involved, with larger lymph node harvests accompanied by significant increases in the length of surgery (2-5 hours). Unfortunately, a recent trial of cervical mediastinoscopy versus TEMLA was prematurely halted before enough cases could be accrued for an adequately powered comparison of morbidity between these two staging procedures. Thus, we cannot accurately assess the risk of morbidity associated with the more invasive staging procedure.

Despite improvements in imaging of the mediastinum with CT imaging and positron emission tomography (PET), cervical mediastinoscopy remains the “gold standard” for preoperative staging of the mediastinum in lung cancer. Of special note is the low positive predictive value (PPV) of PET scans for staging the mediastinum in lung cancer. It is therefore imperative that a tissue diagnosis be obtained to document mediastinal metastases before surgical resection is denied. Cervical mediastinoscopy has a diagnostic accuracy of more than 98% in experienced centers and thus remains the mainstay of prethoracotomy mediastinal staging.

Technique

With the patient intubated and under general anesthesia, a bolster is placed under the shoulders to provide adequate neck extension for the procedure. A 2.5-cm transverse incision is made approximately 1 cm above the sternal notch. The pretracheal fascia is exposed by splitting the strap muscles in the midline, with right-angle retractors used to retract the thyroid gland superiorly if necessary. The pretracheal fascia is incised transversely and bluntly dissected off the anterior surface of the trachea with the index finger. This allows direct palpation of the vascular structures, including the aortic arch and innominate vessels, as well as any prominent lymphadenopathy. The mediastinoscope is introduced beneath the pretracheal fascia (Figure 74-3). Further blunt dissection can be done under direct vision using the tip of the mediastinoscopy sucker. Systematic dissection and biopsy of the different lymph node levels are then possible.

Figure 74-3 Path of cervical mediastinoscope.

A spinal needle attached to a syringe can be used to aspirate and thus differentiate in equivocal circumstances between solid masses that can be biopsied and vascular structures that should be avoided. Most small bleeding can be controlled by judicious use of electrocautery or temporary gauze packing. Because of the risk of significant hemorrhage from injury to the many nearby vascular structures, the surgical staff should always be prepared for possible conversion to sternotomy or thoracotomy for definitive control of bleeding. Special care should also be taken when obtaining biopsy samples of lymph nodes in the left paratracheal area, because the left recurrent laryngeal nerve courses nearby and can be injured by aggressive biopsies or injudicious use of electrocautery.

Anterior Mediastinotomy

Anterior mediastinotomy, also known as the Chamberlain procedure, is a technique that provides access to the anterior mediastinum. It is typically used to sample lymph nodes in the aortopulmonary window and paraaortic lymph nodes (stations 5 and 6, respectively, in AJCC nomenclature). These nodal stations can also be accessed by extended cervical mediastinoscopy or left thoracoscopy. Although anterior mediastinotomy is somewhat more invasive than cervical mediastinoscopy, patients are usually discharged the day of surgery.

Although this technique is still performed, anterior mediastinotomy is being replaced by video-assisted thoracoscopic surgery (VATS; see next section) in many other centers. The advantage of an anterior mediastinotomy is that if the pleural space is not violated, the patient may go home the day of the procedure. However, the pleural space is often opened, and patient discomfort frequently leads to a brief hospital stay. VATS is becoming increasingly popular as a diagnostic procedure to assess the level 5 and level 6 mediastinal lymph nodes because of the superior visualization this technique provides and the additional ability to visualize the entire thoracic cavity.

Technique

A 3 to 4–cm transverse incision is usually made in the second interspace, just lateral to the lateral sternal border for anterior mediastinotomy. The pectoral muscle can usually be split in the line of its fibers without cutting through muscle. The intercostal muscle is then incised along the upper edge of the second costal cartilage. The internal mammary vessels, located medially, can usually be avoided and preserved. The mediastinal pleura are bluntly pushed laterally to avoid entry into the pleural space. The mediastinoscope is introduced to permit optimal lighting and visualization and obtain appropriate biopsies.

Occasionally, the mediastinal pleura are breached. A chest tube is generally not required if the lung parenchyma has not been damaged. At the end of the procedure, a small catheter can be inserted into the pleural space through the mediastinotomy. The tube is pulled out once the overlying muscular tissues have been almost closed, with the anesthesiologist providing sustained positive-pressure ventilation to evacuate any residual intrapleural air.

Video-Assisted Thoracoscopic Surgery

Minimally invasive access to the lung, pleural space, and mediastinum can be obtained by video-assisted thoracoscopic (thoracic) surgery. VATS is useful in the diagnosis of pleural pathology such as diffuse or focal thickening because of mesothelioma, pleural metastases, asbestos-related plaques, or benign inflammatory pleuritis. Thoracoscopy can also assist in the diagnosis and treatment of pleural fluid collections. In the staging of lung and esophageal cancer, thoracoscopy can provide access, in a minimally invasive way, to the paratracheal, prevascular, aortopulmonary window, paraaortic, subcarinal, paraesophageal, and inferior pulmonary ligament lymph node groups (stations 2 to 9, respectively, in AJCC nomenclature). Tumor invasion of local structures and overall resectability can also be assessed. Thoracoscopy is also used to obtain biopsies of lung tissue to assess discrete nodules or diffuse lung disease.

Thoracoscopy is most effectively done with single-lung ventilation of the contralateral side using a double-lumen endotracheal tube or bronchial blocker. This allows collapse of the lung on the operated side, permitting adequate visualization and maneuverability within the pleural space. Dense pleural adhesions are therefore a contraindication for effective thoracoscopy, as is the inability to tolerate single-lung ventilation.

Although thoracoscopy is a form of minimally invasive surgery, it remains a high-risk procedure when performed in high-risk patients. Of particular note are patients with interstitial lung disease (ILD) requiring lung biopsy to tailor treatment options. These patients usually have severe respiratory compromise before VATS and may already be receiving mechanical ventilation, with a significant proportion having elevated pulmonary artery pressure. Patients with pulmonary hypertension do not tolerate single-lung ventilation well because of their inability to perfuse the ventilated lung preferentially. Therefore, a significant amount of blood is shunted through the nonventilated lung, and the patient experiences significant hypoxemia while attempting single-lung ventilation. In the Mayo Clinic experience, patients with ILD undergoing thoracoscopic lung biopsy had an operative mortality of just under 6%.

Technique

Thoracoscopy is performed by use of single-lung ventilation of the contralateral side. The patient is positioned in the lateral position similar to the positioning used for a posterolateral thoracotomy. When VATS is done for drainage and evaluation of a pleural effusion, a single 1-cm port is usually sufficient. It is placed in the sixth or seventh interspace in the anterior axillary line. Through this port, the camera and a thin suction tip or biopsy forceps can be introduced and maneuvered. For most other applications, one or two additional 1-cm ports are required, usually positioned separately along the fourth or fifth interspace, in the line of a potential posterolateral thoracotomy (Figure 74-4). In this way, conversion to thoracotomy simply requires extending the incision between these two upper port sites. The anterior port can be converted to a 5-cm to 7-cm “access” port for removal of a lobectomy specimen, if the procedure requires conversion to a VATS lobectomy, in the case of a biopsied lung nodule found to be an invasive primary lung cancer.

Figure 74-4 Location of thoracoscopic port sites. One port is placed at the seventh interspace in the anterior axillary line. Further ports may be required and are usually placed along the line of a potential posterolateral thoracotomy incision at the level of the fifth interspace.

Whereas biopsy for diagnosis of ILD requires only defining several areas of representative pathology, wedge resection of an indeterminate pulmonary nodule first necessitates precise localization of the lesion. This is usually done with the surgeon’s finger introduced through one of the thoracoscopy incisions (Figure 74-5). It is clearly easier to locate larger and peripherally located lesions. Smaller or deeper lesions may not be accessible and may require conversion to open thoracotomy. In general, a pulmonary nodule can be palpated during a VATS exploration if the diameter of the lesion is greater than the depth of lung tissue through which it is felt. Recent experience has been initially promising with radiotracer guidance (technetium 99m) to locate small pulmonary lesions not otherwise discernible thoracoscopically.

Figure 74-5 Palpation of intrapulmonary nodule during thoracoscopic surgery.

Once the area to be biopsied has been located, an endoscopic stapling device can be inserted through a thoracoport and used to perform a wedge resection (Figure 74-6). Once the specimen has been resected, it should be removed from the pleural cavity within an endoscopic specimen retrieval bag to avoid port site contamination. A more economical alternative is to use a surgical glove introduced through one of the port sites and held open with two Kelly clamps.