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This is one of a series of statements discussing the use of gastrointestinal endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts.

Guidelines for appropriate use of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

INTRODUCTION

The purpose of this updated guideline is to provide practical recommendations regarding the indications and techniques for the use of esophageal dilation. Esophageal dilation (EGD) is performed for treatment of documented anatomic, and sometimes functional, narrowing of the esophagus caused by a variety of benign and malignant conditions.The formation of benign strictures of the esophagus is believed to be caused by the production of fibrous tissue and deposition of collagen stimulated by deep esophageal ulceration or chronic inflammation. The most common form of an esophageal stricture, a peptic stricture, is a sequela of reflux esophagitis. In the recent past, nearly 80% of strictures were due to gastro-esophageal reflux,although this may be decreasing with the widespread use of proton pump inhibitors (PPIs). Other common benign causes include Schatzki's ring, radiation therapy, congenital strictures, caustic ingestion, and anastomotic strictures. Less common causes of benign esophageal strictures include those following endoscopic therapy of varices, photodynamic therapy (PDT),reaction to a foreign body or pill, infectious esophagitis, and eosinophilic esophagitis (Table 1). Narrowing of the esophagus from malignancy may result either from intrinsic luminal tumor growth or from extrinsic esophageal compression. During the endoscopic evaluation of an esophageal stricture, biopsy specimens should be taken to exclude malignancy when this diagnosis is suspected on the basis of clinical presentation or endoscopic appearance. In young patients with dysphagia with or without endoscopic abnormalities, especially with a history of food impaction, midesophageal biopsy specimens should be obtained to exclude eosinophilic esophagitis.Endoscopic esophageal biopsy samples can be safely obtained before esophageal dilation.

Patients with an esophageal stricture characteristically have dysphagia to solids and generally have no difficulty swallowing liquids, in contrast to those with an esopha-geal motility disorder in which liquid and solid dysphagia occurs.Symptoms in the latter group of patients are generally not improved with esophageal dilation, with achalasia being the most notable exception.

EOSINOPHILIC ESOPHAGITIS

Eosinophilic esophagitis deserves special mention because it is becoming increasingly common,there is available therapy in addition to dilation,there are recognizable endoscopic and histologic features,and there appears to be an increased risk for mucosal tearing during endoscopy.The latter may translate into an increased risk perfo-ration during dilation.Eosinophilic esophagitis is common in young patients with otherwise unexplained dysphagia. A clinical presentation of food impaction is not uncommon.

INDICATIONS FOR DILATION

The primary indication for esophageal dilation is to relieve dysphagia. Cost analysis evaluations have suggested that initial EGD with therapeutic intent is less costly than a barium swallow in patients with a history suggesting esophageal obstruction.Additionally, early endoscopy should be the initial diagnostic test performed in patients with dysphagia who are R40 years old and those with concomitant heartburn, odynophagia, or weight loss because of the high yield of finding significant pathology in these patients.

TABLE 1. Common causes of esophageal strictures/obstruction

Gastroesophageal reflux disease (peptic)
Schatzki's ring
Esophageal cancer
Radiation therapy
Esophageal surgery
Eosinophilic esophagitis
Sclerotherapy
Caustic injury
PDT


Esophageal strictures can be structurally categorized into two groups: simple and complex.Simple strictures are symmetric or concentric with a diameter of R12 mm or easily allow passage of a diagnostic upper endoscope. Complex strictures have one or more of the following features: asymmetry, diameter 12 mm or inability to pass an endoscope. Regardless of the cause, dysphagia is an indication for dilation of benign strictures. Although some endoscopists suggest that large-bore dilators be passed empirically if the endoscopy has normal results, results from two of three studies17-19 have shown that empiric dilation does not improve dysphagia scores. Thus, because of the potential risk of perforation with use of large-bore dilators, particularly in patients with unrecognized eosinophilic esophagitis,empiric dilation cannot be routinely recommended if no structural abnormalities are seen at endoscopy.

Most data regarding management of esophageal strictures have been gathered in the adult population. The safety and efficacy of esophageal dilation in children has also been confirmed.

Endoscopic dilation of malignant strictures can be done to assist the completion of endoscopic procedures such as endoscopic ultrasonographic tumor staging or to aid the placement of an esophageal stent to achieve temporary palliation.Most malignant strictures respond to dilation, but relief of dysphagia is transient and more definitive treatment is usually needed. The dysphagia caused by malignant extrinsic compression of the esophagus responds poorly to esophageal dilation.

DILATOR TYPES

Three general types of dilators are currently in use.These are mercury or tungsten-filled bougies (Maloney or Hurst), (2) wire-guided polyvinyl dilators (Savary-Gilliard or American), and (3) TTS ("through-the-scope") balloon dilators. The Maloney type bougies have a tapered tip and can be passed either blindly or under fluoroscopic control. Fluoroscopy may lead to better functional results and fewer adverse events.This type of dilator is used for simple strictures with a diameter of 12 to 14mm. The risk of esophageal perforation may be higher with blind passage of Maloney dilators than with Savary or TTS balloons, particularly in patients with a large hiatal hernia, a tortuous esophagus, or those with complex strictures.Savary and American dilators are passed over a guidewire that has been positioned with the tip in the gastric antrum, with or without fluoroscopic guidance.There are a variety of available TTS balloon dilators available in either single or multiple diameters that may be passed with or without wire guidance. A new endoscopically guided bougie has recently become available (InScope) but clinical experience with it is limited.

PREPARATION

Anticoagulants should be discontinued.Routine antibiotic coverage is not recommended; endocarditis prophylaxis guidelines should be followed.During the informed consent process, patients should be informed about the risk of perforation and the possible need for surgery should it occur. Esophageal dilation is routinely performed in an outpatient setting. Patients should fast for 4 to 6 hours before the procedure. Patients with achalasia are susceptible to esophageal stasis and a prolonged fast or esophageal lavage may be required to empty the esophagus. Although some patients may tolerate dilation with use of only topical anesthesia, conscious sedation is generally used.30When bougie dilators are used, neck extension may facilitate passage of the dilator.