Endoscopic Diagnosis of Thoracic Disease

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 or adjacent masses including tracheoesophageal fistulas. Upper gastrointestinal bleeding is another common indication for endoscopy, which has become the first line in management of this clinical scenario. Likewise, esophagoscopy can be a useful tool in evaluating and treating patients with known or suspected complications following surgery of the foregut.

Dysphagia can arise from a number of pathologic processes. Many causes can be distinguished with a careful history that records the duration and persistence of symptoms and accompanying constitutional complaints. Endoscopy allows the surgeon to distinguish between malignant and benign causes of dysphagia with direct endoscopic visualization and pathologic sampling, thereby guiding therapy.

Reflux is another indication for upper endoscopy. The thoracic surgeon searches for any long-term sequelae associated with chronic gastroesophageal reflux disease, such as Barrett esophagus. Esophagoscopy is crucial in the surveillance of known Barrett esophagus because of the link with the development of adenocarcinoma. Many support recommendations for surveillance at 3- to 5-year intervals, but its efficacy in reducing death from esophageal cancer has not been firmly established.

Upper gastrointestinal bleeding is another indication for endoscopy, and the procedure is often used therapeutically, as with bleeding esophageal varices—a difficult problem that can be palliated endoscopically with banding or sclerotherapy.

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. Seven to 10 biopsies are usually taken throughout the area of the lesion, or randomly in the setting of Barrett 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. After foregut surgery, endoscopy is also useful in the management of postoperative complications for both therapeutic and diagnostic purposes. The role of endoscopic ultrasound in the diagnosis and staging of esophageal disease will be discussed later.

Upper endoscopy can also play a role in the assessment of other mediastinal masses and malignancies that cause esophageal obstructive symptoms. Endoscopy can reveal whether the lesion is causing mass effect or actual erosion through the wall of the esophagus, possibly resulting in a fistula.

Upper endoscopy is also important for investigating trauma—blunt, penetrating, or caustic—and for foreign body retrieval. When using endoscopy to remove foreign bodies lodged in the esophagus, the surgeon should be alert to the potential for intraesophageal lesions, which may be responsible for the failure of material to pass through. The thoracic surgeon is frequently asked to document and manage iatrogenic trauma to the esophagus via instrumentation. Although the esophagogram is the mainstay for the diagnosis of perforation, the usefulness of endoscopy for the diagnosis and documentation of the extent of injury should not be underestimated. Cases of esophageal perforation have been reportedly managed with endoscopic techniques—primarily stenting. Most experience comes from extreme cases when patients either are too acutely ill for attempts at repair or have minimal systemic derangement. In these highly select cases, outcomes have been favorable.

Corrosive ingestion is another indication for early (within 36 hours) endoscopic inspection, which can help to identify transmural involvement and subsequent development of strictures.

Preprocedure

Most endoscopies can be performed on an outpatient basis with conscious sedation. Patients should receive nothing by mouth (NPO) after midnight for a morning examination, and those with obstructive symptoms should be administered a clear liquid diet for 24 to 48 hours before the examination. When the patient arrives, a peripheral intravenous line and electrocardiograph (ECG) leads should be placed. Because the sedatives can cause respiratory depression, continuous ECG and pulse oximetry monitoring is performed, and blood pressure measurements are obtained frequently during the procedure. Once the monitors are in place, sedation is given to ensure that the patient is comfortable and cooperative. Local anesthesia minimizes the degree of conscious sedation required.

Flexible Esophagoscopy

Rigid Esophagoscopy

Rigid esophagoscopy is a rarely used modality, usually reserved for three instances: trauma, removal of impacted food, and removal of foreign bodies. Rigid esophagoscopes can accommodate larger graspers than the working channel of a standard flexible esophagoscope and do not require insufflation. The scope is held in the examiner's right hand while the left hand keeps the mouth open with the left thumb protecting the upper dentition. During the insertion of the scope, the head is initially held forward, in the “sniffing position” used for tracheal intubation. Once the cricopharyngeus is passed, the head is extended to eliminate the angle of the mouth and the pharynx. The scope can then be advanced carefully throughout the length of the esophagus and proximal stomach. Manipulating the head and cervical spine at the areas of narrowing allows less traumatic passage.