14: Esophagoscopy

Esophagoscopy is an endoscopic procedure that permits visualization of the internal lumen of the esophagus. It is usually accomplished as a part of a more extended procedure called esophagogastroduodenoscopy (EGD), which includes the stomach and duodenum. This visual examination is performed by using a specially designed endoscope (flexible or rigid). Since its invention by Philip Bozzini in 1806, the endoscope, which at that time consisted of a rigid tube, external light source, and a viewer, has evolved to become smaller, flexible, and more versatile. Currently, flexible endoscopes are equipped with video imaging systems that generate magnified, clear images that can be viewed by the entire operating room staff. Although flexible esophagoscopy can be performed with topical anesthesia, conscious sedation, or general anesthesia, rigid esophagoscopy is usually performed with the patient under general anesthesia.

Esophagoscopy is the primary diagnostic tool for any disease suspected to involve the esophagus. It also can be used for many different therapeutic applications, including delivery of ablative energy (cautery and photodynamic or laser therapy) for tumors, banding of varices, cauterization or injection for bleeding, deployment of stents, removal of foreign objects, and other surgical manipulations. Expertise in esophagoscopy is a requisite for all esophageal and general thoracic surgeons, and guidelines for skill attainment have been established and published by a number of surgical societies.^1-5

The modern endoscopic system consists of an endoscope, light source, optical system, and working port. A basic understanding of these components, outlined in Table 14-1, is essential. For most applications, a flexible videoendoscope is sufficient and preferred. Flexible endoscopes come in many sizes. The larger sizes allow for wider suction and working ports while providing excellent images. The smaller sizes are more comfortable for the patient and allow sufficient room for additional devices to be placed through the lumen of the esophagus at the same time. Rigid esophagoscopes are large, inflexible metal cylinders that come in different widths and lengths. These are used only for work that requires a very wide lumen, such as removing a foreign object or repositioning a stent.

EGD is indicated when there is a clinical suspicion of pathology of the upper gastrointestinal tract, before surgery of the esophagus or stomach, and for specific therapy of known disorders. This procedure enables the surgeon to visualize the endoluminal anatomy in great detail, as well as structural anomalies, disorders, and defects of the gastrointestinal tract. In addition, endoscopy is an excellent way to obtain tissue biopsy for histologic diagnosis or to examine the mediastinum or the rest of the layers of the esophagus with ultrasound.

Endoscopy should be performed in a controlled, well-equipped setting staffed and monitored by experienced personnel. Such locations usually include freestanding endoscopy suites and operating rooms. In emergent cases, the equipment and personnel can be moved to the bedside in the ICU or emergency ward, obviating the need to move a critically ill patient. As for any other procedure, the endoscopist should be well trained and have proper credentials to perform the procedure. Clear indications and expectations for any procedure should be discussed with the patient before endoscopy. It is also important for the surgeon to be familiar with the potential complications of endoscopy and to take proactive measures to reduce overall morbidity (Table 14-2). Several good practices are (1) to avoid applying undue force when maneuvering the instrument through the patient's oropharynx or esophagus because this may lead to perforation or unsafe instrumentation, (2) to remove all tubes that are in place (e.g., nasogastric tube) before starting the procedure, and (3) to not compromise patient care by lack of the equipment required to perform the proposed procedure, a particular concern in the office setting.

The risk of endoscopy arises from the patient's medical condition, anesthetic management, and, the actual procedure. A careful and thorough preprocedural assessment of the patient, including evaluation, selection, and preparation, is the first step for any surgical procedure. Particular attention should be focused on history of coagulopathy (primary or secondary to medication) because this can increase the procedural risk significantly. Patients deemed high risk secondary to other comorbid disease or procedures that may require technology not readily available in the outpatient setting should be treated in a hospital setting. All patients are assessed for their relative risk of undergoing anesthesia using standard American Society of Anesthesiologists' (ASA) guidelines.⁶ Anesthesia-related risks include aspiration, intravenous conscious sedation or general anesthesia, and anaphylaxis. Patients with an ASA score of 4, defined as a “patient with severe systemic disease that is a constant threat to life,” should not undergo endoscopy in the office setting. Patients with an ASA score of 3 (a “patient with severe systemic disease”) should undergo additional preoperative assessment to determine the appropriateness of office endoscopy. Before the endoscopic procedure, patients must be given clear instructions that stress the importance of fasting for at least 6 to 8 hours before the procedure. Aspiration can be a catastrophic complication. Procedural complications are reduced in the hands of an experienced endoscopist.

Preoperative Setup

Before performing esophagoscopy, all equipment (endoscopic, monitoring, and resuscitative) must be assembled and examined for proper function (Table 14-3). The endoscope should be examined for sterility and external integrity (e.g., the plastic coating must be completely intact without visible fractures). All knobs and buttons should be fit snugly in place and should be tested for proper function, including axial motion, air insufflation, water instillation, and suction. The video monitor should be turned on, the patient data should be entered in the electronic record, and the scope should be balanced for image clarity. The monitor should be placed directly in front of the endoscopist, and the room lights should be dimmed to maximize the quality of the image on the video monitor.

Anesthesia

The patient's status with respect to oral intake is confirmed (NPO for at least 6 hours). Anesthesia has already been selected on the basis of surgeon preference and the goals of the procedure. Standard procedures for anesthesia or conscious sedation are instituted. For general anesthesia, the patient is placed in the supine position on the operating table, induced, and intubated. The conscious patient is placed in left lateral decubitus position, and a mouth guard is placed both to enable passage of the scope into the mouth and to prevent the patient from biting the scope.

Equipment

Two types of flexible endoscopes are available: videoscopic and those that utilize eye pieces. The standard endoscope is 140 cm long. It has a diameter of 5 to 11 mm and a working port that is 2.8 mm wide. Adult endoscopes typically have two dials that enable four directional control (left and right as well as up and down), whereas pediatric endoscopes have only one dial. In anesthetized adults we typically use a 9- to 12-mm scope, while 5-mm endoscopes are reserved for awake patients and those with tight strictures. All equipment should be examined for proper function prior to the procedure. This includes checking for maneuverability, light, insufflation, suction, and irrigation. Flexible endoscopic equipment is expensive. Proper maintenance (cleaning and storage) of the endoscope, including all its detachable parts, must be maintained to assure long-term function.

Esophagoscopy

After the patient has been inducted with general anesthesia, the endoscope is placed into the oropharynx and esophagus by extending the lower jaw anteriorly and placing the endoscope behind the endotracheal tube (Fig. 14-1). Alternatively, endoscopy can be performed under intravenous conscious sedation or with the patient fully awake. A bite blocker is placed between the teeth to prevent damage to the scope. The conscious patient is positioned on his or her side, usually the left. Monitored sedation is then administered using short-acting intravenous medications, after which the endoscope is carefully introduced. Alternatively, in a cooperative patient, awake endoscopy can be performed with a small scope inserted via the nose or regular endoscope after aerosolized analgesia of the oropharynx. The awake patient can aid the endoscopist by active “swallowing.”

The endoscope is maneuvered by rotation in the hands of the operator, who at all times should be attempting to center the lumen on the video monitor, which decreases the chance of perforation, and by using insufflation as needed before advancing the endoscope farther along. The scope should be in the unlocked position. The scope should be advanced with minimal force. During endoscopy, the majority of the maneuvering is done by the dominant hand on the scope while the fine tuning is done by the nondominant hand on the dials. Typically, in the anesthetized patient, the scope can be passed directly into the mid-esophagus with the nondominant hand. The mouth and chin are elevated and the scope is gently advanced. If resistance is encountered, the endoscopist should draw back 1 to 2 cm, center the scope, and only then gently advance. After the scope is beyond the first narrowing of the upper esophageal sphincter at the cricopharyngeus, the esophagus is insufflated with air and the mucosa examined as the scope is advanced (Fig. 14-2).

A second narrowing occurs in the area of the aortic arch and carina, approximately 24 to 25 cm from the incisors. The final anatomic narrowing occurs at the lower esophageal sphincter (LES), which is about 40 cm from the incisors. The esophageal, gastric, and duodenal mucosae are examined visually for lesions, strictures, webs, ulcers, dilatations, diverticula, and other pathology (Fig. 14-3). The Z-line is identified, and the length is measured (incisors to Z-line) and documented.

The stomach is entered, insufflated, and examined in its entirety. Retroflexion is performed by advancing the scope into the greater curvature and then angling it to achieve maximal retroflexion. The scope is pulled back toward the gastroesophageal junction and turned 360 degrees, providing good visualization of the esophagogastric junction and its relation to the hiatus from within the stomach. The greater and lesser curvatures of the stomach, as well as the antrum and pylorus, are insufflated and examined. The scope is then passed into the second part of the duodenum to exclude the presence of additional pathology and determine how tight the pylorus may be. In our practice, endoscopy routinely includes visualization up to and including the second part of the duodenum. Before withdrawing the scope from the duodenum, air is removed by suction.

Depending on the indication for esophagoscopy, after visual examination, diagnostic procedures such as biopsy using flexible biopsy forceps or therapeutic procedures can be performed. Visual examination of the mucosa is typically performed using white light. Attention is paid to the regularity of the mucosa, in addition to color and presence of nodularity, ulceration, or masses. Newer scopes may have customized features such as a narrow band imaging (NBI) mode that accentuates the microvasculature and can help the endoscopist identify subtle changes. Additional diagnostic endoscopic modalities include life-scope and confocal technologies. Currently, these are not widely used. Biopsy should be performed when suspected pathology is encountered. This can be accomplished with regular or jumbo forceps. Endoscopic mucosal resection (EMR) may provide diagnostic as well as therapeutic benefit (see Chapter 173). In the event of stricture, a guidewire may be inserted to cross the stricture before (if the stricture is very tight) or after the scope has traversed it. The scope is withdrawn, and serial dilations are carried out using Savary dilators. Alternatively, a pneumatic dilator can be placed over the guidewire and the stricture dilated using preset pressure and diameter. Completion endoscopy is then carried out to evaluate the results of the dilation and to rule out procedure-related injury. In cases where stenting is indicated a guidewire can be placed beyond the target lesion, and a stent placed under direct endoscopic vision or using fluoroscopy.

Prevention is key to avoiding the complications of endoscopy, namely, oversedation, aspiration, bleeding, perforation, systemic processes, and injury incidental to recovery (Table 14-4). Oversedation can be avoided by judicious use of sedatives, but when it occurs, it is best managed by postprocedural monitoring or intubation and monitoring in an intensive care unit setting. The major risks of oversedation are central respiratory suppression and loss of gag reflex. The risk of aspiration is minimized with proper patient preparation (i.e., NPO for at least 6 hours), by avoiding excessive insufflation, and through judicious use of sedation and monitoring. Bleeding can be minimized by gentle maneuvering of the endoscope, cessation of anticoagulant medication preoperatively, and if encountered, cauterization of bleeding sites as soon as they are identified. Parenthetically, some of the flexible biopsy forceps also have the capability of functioning as electrocautery. Perforation can be avoided largely by careful maneuvering of the endoscope without forcing it through tight spots. Perforations usually occur at the site of one of the three narrow points described earlier or next to the diseased portion. It is important to recognize perforation early because immediate therapy reduces mortality. A high index of suspicion is important. Patients with perforation usually complain of pain and may have tachycardia and/or subcutaneous emphysema. A chest x-ray may demonstrate a pneumothorax or air tracking in the mediastinum. A contrast study such as an upper gastrointestinal series or CT scan may be helpful to identify a perforation before the repair.

Finally, systemic complications are extremely rare except in critically ill patients. These can be secondary to medications (i.e., hypotension, arrhythmias, and rarely, anaphylaxis). Instrumentation insufflation can lead to a vasovagal reflex, and rarely, translocation of bacteria has been reported to precipitate sepsis, as has the use of instruments not sterilized properly.

Esophagoscopy is an evolving and important diagnostic and therapeutic operation. Hybrid procedures are emerging that combine the advantages of multiple therapeutic and technologically advanced platforms. Reports of initial experiences with long-distance endoscopy are encouraging and in future could facilitate improved medical care to remote and underserved regions. The experimental field of natural orifice transluminal endoscopic surgery (NOTES) one day may expand the indications for use of this important technology.⁷ Endoscopes with sewing ports are currently used for plication of the gastroesophageal junction. The longevity and efficacy of these procedures, however, have yet to be proved. In addition, early reports of using natural orifices for organ removal, with intentional internal perforation of the stomach for cholecystectomy and appendectomy, are unproved in terms of safety and long-term benefit. Intriguing emerging technologies that one day may replace diagnostic endoscopy, thus reducing the procedural risks associated with sedation and instrumentation, are also being developed. Examples include the wireless capsule endoscopy and virtual endoscopy with three-dimensional computed tomographic reconstruction. Despite the aforementioned advances, acquiring the skills for conventional endoscopy is paramount to the surgeon interested in foregut practice and will be needed for some time to come.

This concise and clearly written chapter describes the indications for and the technique of endoscopy of the esophagus. Taking great care with patient preparation and having appropriate backup monitoring as well as OR capability are key to performing this procedure safely. Although not all esophageal surgeons do their own esophagoscopy, there is a trend for more surgeons to do this at the time of resection. EGD with biopsy is the first confirmatory diagnostic test to prove the presence of esophageal cancer. Safe dilation in skilled hands can allow EUS to be performed to further assess the depth of wall invasion as well as judge the presence of regional lymph nodes. It also permits a palliative therapy, such as stent or laser procedures, to be undertaken at the same time, allowing neoadjuvant or definitive chemoradiation to be undertaken without the loss of GI alimentation.