CHAPTER 5 Endoscopic Diagnosis of Thoracic Disease
Endoscopy, especially fiberoptic endoscopy, has revolutionized nearly all theaters of medicine in terms of diagnosis and therapeutic intervention.1 This is particularly true for thoracic surgery, where bronchoscopy and esophagoscopy are essential modalities in the diagnosis, approach, and treatment of tracheal, bronchial, and alimentary tract pathology. As the technology of optics, endoscope instrumentation, and appurtenances such as endoscopic ultrasound and yttrium-aluminum-garnet (YAG) laser have evolved, so have the indications and capabilities of the skilled endoscopist. Although many clinicians may perform endoscopy, thoracic surgeons in particular should be adept and pioneering with these procedures, because new endoscopic technology will continue to enable all aspects of minimally invasive thoracic surgery.
ESOPHAGOSCOPY
In 1868, Kussmaul intubated a sword swallower’s stomach via the esophagus with a 13-mm hollow metal tube. This maneuver proved that the oral cavity, esophagus, and stomach could be simultaneously intubated with one rigid instrument. Mikulicz added one crucial aspect to the tube—a distal light to illuminate the esophagus and stomach—and he was able to visualize gastric motility and view probable malignancies. The fiberoptic endoscope was introduced in 1958. This instrument allowed more patient comfort as well as greater therapeutic possibilities in the distal stomach and proximal small intestine. Although the scope itself has not changed greatly, the adjunctive instruments have dramatically changed the way many disease states can be treated.2
Indications
For the thoracic surgeon, dysphasia and odynophagia are two of the most common indications for esophageal endoscopy (Box 5-1). Others include reflux, an abnormal esophagogram, trauma, screening, or staging of gastrointestinal (GI) or adjacent masses including tracheoesophageal fistulas. Upper GI bleeding is another very common indication for endoscopy, which has become the first line in management of this clinical scenario.
Box 5–1 Indications for Upper Endoscopy∗
According to the American Society for Gastrointestinal Endoscopy. Appropriate use of gastrointestinal endoscopy. Gastrointest Endosc 2000; 52:831-37.
The most common reason for a thoracic surgeon to perform upper endoscopy is to visualize and biopsy esophageal and proximal stomach masses. Biopsy has a sensitivity of 66% to 96% in esophageal cancers.3,4 Seven to 10 biopsies are usually taken throughout the area of the lesion, or randomly in the setting of Barrett’s esophagitis. For lesions with a tight stricture, the surgeon can use a small-diameter scope, and brushings have been shown to increase the yield of tissue in such cases.4,5 The role of endoscopic ultrasound in the diagnosis and staging of esophageal disease will be discussed later.
Corrosive ingestion is another indication for early (within 36 hours) endoscopic inspection,6 which can help identify transmural involvement and subsequent development of strictures.
ENDOSCOPIC ULTRASOUND
Endoscopic ultrasound (EUS), for which a small ultrasonic transducer is attached to the end of the endoscope, is a relatively new adjunctive procedure that has expanded the examination of the esophagus and the periesophageal tissues. It is never an initial procedure but is indicated when a previous esophagoscopy has been performed and pathology has been located and evaluated. Indications for esophageal ultrasound range from benign to malignant esophageal disease and include evaluation of periesophageal pathology, usually bronchogenic carcinoma (Box 5-2). The most common indication for EUS is the evaluation of esophageal malignancy. The stage of the lesion, as defined by the depth of invasion and nodal involvement, is the best predictor of surgical resection and therefore possible cure.