Non–small cell lung cancer is the number one cause of cancer deaths worldwide. Surgical resection, which is offered for early-stage lung cancer, can be curative but is often associated with morbidity. Pneumonectomy, however, confers significantly greater morbidity and mortality rates and is also associated with a poorer quality of life. When possible, thoracic surgeons should perform lobectomy with sleeve resection of the bronchus or of the pulmonary artery (PA), or both, to avoid pneumonectomy. Knowledge of the anatomy of the tracheobronchial tree is essential to this technique.
Step 1
Surgical Anatomy
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The trachea originates below the cricoid cartilage and extends from front to back to the carina. The trachea then bifurcates into left and right mainstem bronchi, with length, depending on gender, ranging from 10 to 14 cm. The trachea and main bronchi have an anterior horseshoe-shaped cartilaginous portion comprised of 16 to 20 tracheal rings and a posterior membranous portion apposed against the upper esophagus and vertebral column. The membranous portion is more elastic and extensible in younger people and with age becomes more rigid, which is important to consider in deciding between sleeve lobectomy and pneumonectomy.
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The right main bronchus is in direct line with the trachea. The primary bronchus is distal to the right upper lobe bronchus and becomes the bronchus intermedius, about 2 cm long. Anterior to the bronchus intermedius is the middle lobe bronchus in direct line with the origin of the superior segmental bronchus of the lower lobe, arising from the posterior wall of the bronchus intermedius.
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The left main bronchus arises more obliquely from the carina than the right main bronchus and is longer, 4 to 6 cm long versus about 1.5 cm. It passes under the aortic arch posterior to the left hilum, where it bifurcates to form the upper and lower lobe bronchi. There is no bronchus intermedius on the left side, making sleeve resection on the left side more difficult.
Step 2
Preoperative Considerations
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If safe dissection of the pulmonary arterial branches cannot be performed but lobectomy can yield complete resection of all of the cancer, PA resection can be used. Indications for PA resection include localized tumors, strictures, impacted broncholiths, and traumatic damage to the mainstem bronchus. Whenever it is possible to achieve a margin-negative resection and yet preserve noncancerous, functioning pulmonary tissue, sleeve resection of the bronchus or of the PA should be employed, avoiding pneumonectomy. Compared with pneumonectomy, PA resection is associated with lower rates of morbidity and mortality, blood flow is unimpeded, and recurrence rate is uncompromised.
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Careful patient selection for this procedure is crucial. Preoperative tests should include a chest radiograph and conventional or computed tomography. Preoperative pulmonary function tests are of limited value. The main consideration in deciding to resect the mainstem bronchus should be based on the patient’s overall cardiopulmonary status.
Step 3
Operative Steps
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The surgical approach is through a posterolateral thoracotomy, allowing access to the trachea, the mainstem bronchi, and the lung. Proximal control of the main PA is obtained extrapericardially. On the right side, proximal control is obtained posterior to the superior vena cava, and on the left side it is obtained just distal to the ligamentum arteriosum. Care is taken to avoid the left recurrent laryngeal nerve.
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The pulmonary vein of the lobe to be removed is encircled and then divided. A vascular stapler is used. Then about 500 units (we have not based the dose of heparin on the patient’s weight) of intravenous (IV) heparin is given. Recently (i.e., in our last 15 procedures), we have not used any heparin. Approximately 1 minute later, a Satinsky clamp is placed on the proximal PA. It is positioned so that its handle is facing in the opposite direction of the Satinsky to be placed on the vein ( Fig. 9-1 ). This allows more room for the operating surgeon. A Satinsky clamp is then placed on the remaining pulmonary vein(s). (See Figure 9-1 , which shows a left upper lobectomy and a partial PA resection.) This clamp is positioned so that its handle faces opposite from the handle of the Satinsky on the artery as shown in Figure 9-1 . A knife is used to cut out the part of the PA that has cancer invading its surface, and then the bronchus is cut as well. The lobe with the cancer is removed from the operative field. This opens up the entire surgical field and affords more room for the surgeon to work.
