You are in: eMedicine Specialties > Radiology > GASTROINTESTINAL Gastroesophageal RefluxArticle Last Updated: Mar 6, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Michael AJ Sawyer, MD, Director, Videoendoscopic Surgical Institute of Oklahoma, Consulting Staff, Department of Surgery, Comanche County Memorial Hospital; Consulting Staff, Great Plains Surgical Clinic, Lawton, Oklahoma Michael AJ Sawyer is a member of the following medical societies: American College of Surgeons, Society for Surgery of the Alimentary Tract, Society of American Gastrointestinal and Endoscopic Surgeons, and Society of Laparoendoscopic Surgeons Coauthor(s): Manish K Varma, MD, Chief of Interventional Radiology, Department of Radiology, Tripler Army Medical Center; Thomas F Murphy, MD, Chief of Abdominal Imaging Section, Department of Radiology, Tripler Army Medical Center Editors: Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Abraham H Dachman, MD, FACR, Professor, Department of Radiology, The University of Chicago School of Medicine; Director of CT, Department of Radiology, The University of Chicago Hospitals; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; Eugene C Lin, MD, Consulting Staff, Department of Radiology, Virginia Mason Medical Center Author and Editor Disclosure Synonyms and related keywords: hiatal hernia, heartburn, reflux regurgitation, GERD, gastric reflux, gastroesophageal reflux disease, acid reflux, bile reflux, esophageal clearance, pyrosis, esophagitis, esophageal strictures, Barrett esophagus, dysphagia INTRODUCTIONSection 2 of 12
  BackgroundExcessive retrograde movement of acid-containing gastric secretions or bile and acid-containing secretions from the duodenum and stomach into the esophagus is the etiologic effector of gastroesophageal reflux disease (GERD). Reflux of these secretions to some degree into the esophagus is prevalent in the United States. A study by Richter and a Gallup Organization National Survey estimated that 25-40% of healthy adult Americans experience symptomatic GERD, most commonly manifested clinically by pyrosis (heartburn), at least once a month (Richter, 1992; Gallup, 1988). Furthermore, approximately 7-10% of the adult population in the United States experiences such symptoms on a daily basis. In most of these people, endogenous defense mechanisms either limit the amount of noxious material that is introduced into the esophagus or rapidly clear the material from the esophagus so that symptoms and esophageal mucosal irritation are minimized. Examples of the defense mechanisms include actions of the lower esophageal sphincter (LES) and normal esophageal motility. When the defense mechanisms are defective or become overwhelmed so that the esophagus is bathed in acid or bile and acid-containing fluid for prolonged periods, GERD can be said to exist. Patients typically have numerous daily episodes of symptomatic reflux, including pyrosis, water brash or sour taste in the mouth, nighttime coughing or aspiration, pneumonia or pneumonitis, bronchospasm, and laryngitis and voice changes including hoarseness. In addition, objective evidence of esophageal damage can be seen on esophagogastroduodenoscopy as manifested by the incremental grades of esophagitis discussed below. For excellent patient education resources, visit eMedicine's Heartburn/GERD/Reflux Center. Also, see eMedicine's patient education articles Reflux Disease (GERD), Gastroesophageal Reflux Disease (GERD) FAQs, and Understanding Heartburn/GERD Medications. PathophysiologySchematically, the esophagus, LES, and stomach can be envisioned as a simple plumbing circuit as described by Stein and coworkers (Stein, 1992). The esophagus functions as an antegrade pump, the LES as a valve, and the stomach as a reservoir. The abnormalities that contribute to GERD can stem from any component of the system. Poor esophageal motility decreases clearance of acidic material. A dysfunctional LES allows reflux of large amounts of gastric juice, and delayed gastric emptying can increase volume and pressure in the reservoir until the valve mechanism is defeated, leading to GERD. From a medical or surgical standpoint, it is extremely important to identify which of these components is defective so that effective therapy can be applied. Esophageal defense mechanisms can be broken down into 2 categories, ie, esophageal clearance and mucosal resistance. Proper esophageal clearance is an extremely important factor in preventing mucosal injury. Normal clearance limits the amount of time the esophagus is exposed to refluxed acid or bile and gastric acid mixtures. Abnormal peristalsis can cause inefficient and delayed acid clearance. Whether peristaltic dysfunction is secondary to esophageal exposure to acids or a primary defect is not understood clearly. In a review by Kahrilas et al, peristaltic dysfunction was progressively more common in patients with greater degrees of esophagitis (Kahrilas, 1986). Abnormal peristalsis was identified in 25% of patients with mild esophagitis and 48% of patients with severe esophagitis. Buttar and associates described the importance of esophageal mucosal resistance as a protective mechanism (Buttar, 2001). They classified the factors into pre-epithelial, epithelial, and postepithelial defenses. When the defenses fail, esophagitis and other complications of reflux disease arise. Proper LES function is the most important factor in preventing or limiting GERD. The LES is defined by manometry as a zone of elevated intraluminal pressure at the esophagogastric junction. LES dysfunction is the most common etiology of GERD. Dysfunction of the LES occurs via one of several mechanisms. There can be transient relaxation of the LES (most common mechanism), permanent LES relaxation, and transient increase of intra-abdominal pressure that overcomes the LES pressure. Transient relaxation of the LES can be caused by foods (coffee, alcohol, chocolate, fatty meals), medications (beta-blockers, nitrates, calcium channel blockers, anticholinergics), and nicotine. Delayed gastric emptying may cause GERD. The postulated mechanism is an increase in gastric contents resulting in increased intragastric pressure and, ultimately, increased pressure against the LES. This pressure eventually defeats the LES and leads to reflux. However, objective studies have produced conflicting data regarding the role of delayed gastric emptying in the pathogenesis of GERD. When discussing mechanisms for GERD, the issue of hiatal hernia must be addressed. It has been well proven that not all patients with hiatal hernias have symptomatic reflux. Buttar and coworkers state that a hiatal hernia may contribute to reflux via a variety of mechanisms. The LES may migrate proximally into the chest and lose its abdominal HPZ, or the length of the HPZ may decrease. The diaphragmatic hiatus may be widened by a large hernia, which impairs the ability of the crura to function as an external sphincter. Finally, gastric contents may be trapped in the hernial sac and reflux proximally into the esophagus during relaxation of the LES. To summarize, GERD can be caused by malfunction of 1 or more defense mechanisms involving the esophagus (pump), the LES (valve), and the stomach (reservoir). FrequencyUnited StatesWestern dietary habits have made GERD a common disease. Richter and associates reported that 25-40% of Americans experience symptomatic GERD at some point. Approximately 7-10% of Americans experience symptoms of GERD on a daily basis. The actual number of individuals with GERD is probably higher, since most people control the symptoms with over-the-counter medications. InternationalThe prevalence of GERD internationally appears to be less than in Western society. This appears to be related to the high fat diet typically consumed by Westerners. Mortality/MorbidityComplications of GERD include the development of esophagitis, strictures, and Barrett esophagus. Most of the mortality associated with this disease is not due to reflux but to the sequelae of these complications.
RaceCompared with other groups, white men are at higher risk for the development of Barrett esophagus and esophageal adenocarcinoma. Otherwise, no race is more predisposed than another to developing GERD. SexNo sex predilection appears to exist for the development of symptomatic GERD. AgeGERD is present in all age groups; typically, prevalence increases in individuals older than 40 years. AnatomyA thorough discussion of the anatomy of the esophagus and stomach is beyond the scope of this article. This discussion focuses on the pertinent anatomy involved in GERD. The distal thoracic esophagus is located to the left side of midline. The abdominal esophagus begins as the esophagus enters the abdomen through the esophageal hiatus in the diaphragm. At this point, the esophagus is surrounded by fibroelastic tissue termed the phrenoesophageal membrane or ligament. This membrane arises from the subdiaphragmatic fascia. A prominent fat pad located on the anterior surface of the esophagus marks the lower limit of the phrenoesophageal membrane. This lower limit corresponds to the gastroesophageal junction. The LES, or more accurately, the distal esophageal high-pressure zone (HPZ) is located in the distal intra-abdominal esophagus. In adults, this HPZ can be anywhere from 2-5 cm in length. Maintenance of an adequate intra-abdominal HPZ is crucial in preventing GERD. This HPZ does not correspond to any visible anatomic structure. It is a zone created by a complex architecture of smooth muscle fibers, and it typically is identified during manometry. In addition to the esophagus and stomach, an understanding of the esophageal hiatus is mandatory. The hiatus is formed by the right and left diaphragmatic crura. These crura form a sling around the distal esophagus. Both crura originate from the right crus of the diaphragm. The actual contribution the crura provide in maintaining an adequate length of intra-abdominal esophagus is not understood clearly; however, careful identification and closure of the crura during surgical treatment is crucial for preventing reflux disease. Hiatal hernias can be encountered frequently in patients with reflux disease. Reduction of the hernias and crural closure is key to restoring an adequate intra-abdominal length of esophagus and recreating the HPZ. Usually, GERD is caused by a malfunction of one or more of these anatomic features. Proper surgical treatment requires complete preoperative and intraoperative evaluation and correction of all defective features. Clinical DetailsPatients with GERD can exhibit a variety of symptoms, both typical and atypical. Typical symptoms include heartburn, regurgitation, and dysphagia. Atypical symptoms include noncardiac chest pain, asthma, pneumonia, hoarseness, and aspiration. Heartburn is the most common symptom. A clear positional relationship can be demonstrated with exacerbations while the patient is lying supine or bending over. History of nausea, vomiting, or regurgitation should alert the physician to evaluate for delayed gastric emptying. Dysphagia can be an advanced symptom and can be due to a primary underlying esophageal motility disorder, a motility disorder secondary to esophagitis, or stricture formation. The diagnosis of GERD in patients with atypical symptoms can be difficult. When patients present with atypical complaints, the diagnosis of GERD must be kept in mind. Patients with recurrent aspiration can have asthma, history of pneumonias, and progressive pulmonary fibrosis. Additionally, hoarseness can be present due to chronic laryngeal irritation. Chest pain is another presenting symptom that can be difficult to evaluate. In these patients, excluding cardiac etiology is important prior to labeling the pain as noncardiac chest pain secondary to GERD. Preferred ExaminationThe assessment of patients who present with complaints consistent with GERD begins with a thorough history and physical examination. In obtaining a history, the physician must concentrate on the clinical details mentioned above. A thorough history helps the clinician make or highly suspect the diagnosis prior to performance of any tests. If a patient presents with a classic history for reflux disease, medical treatment may be initiated without further testing. If the patient has persistent symptoms despite medical treatment or is considering surgical intervention, further testing is indicated. Several tests can be obtained to confirm the diagnosis and ascertain the etiology of GERD, including the following:
Not all of these tests are ordered during the workup in a patient with GERD. Mandatory studies include upper GI endoscopy and manometry. Endoscopy can help confirm the diagnosis of reflux by demonstrating complications of reflux (esophagitis, strictures, Barrett esophagus) and can help in evaluating the anatomy (eg, hiatal hernia, masses, strictures). Manometry helps surgical planning by determining the LES pressure and identifying any esophageal motility disorders. Esophageal amplitudes and propagation of esophageal swallows also are evaluated. Optional studies include 24-hour pH probe test and upper GI series. Use of 24-hour pH testing helps confirm the diagnosis in patients in whom the history is not clear, atypical symptoms dominate the clinical picture, or endoscopy shows no complications of reflux disease. Upper GI series can be ordered to further delineate the anatomy. Hiatal hernias can be evaluated (size) and reflux can be demonstrated. In addition, gastric emptying can be evaluated to a limited. If a question exists regarding inadequate gastric emptying or if the patient has a history of nausea and vomiting, a nuclear medicine gastric emptying study can be obtained. At the authors' institution, endoscopy, manometry, and 24-hour pH studies are obtained routinely. Upper GI series and nuclear medicine gastric emptying studies are ordered only if clinically indicated. Presently, no role exists for CT, MRI, or ultrasonography in the routine evaluation of patients with reflux disease. Limitations of TechniquesA conclusive diagnosis of reflux disease cannot be made by using barium esophagography. This technique is not sensitive for detection of motility disorders. Endoscopy cannot help make a diagnosis of motility disorders. The 24-hour pH probe test does not help evaluate either anatomy or motility abnormalities. Manometry does not help evaluate anatomy. Nuclear medicine gastric-emptying study does not help in assessing the anatomy and cannot help in the diagnosing reflux disease. Each type of study has attendant strengths and weaknesses. The studies must be viewed as complementary. In combination, their use increases sensitivities and limits weaknesses. DIFFERENTIALSSection 3 of 12
Barrett Esophagus Brain, Colloid Cyst Esophagus, Carcinoma Gastric Ulcer Hiatal Hernia Other Problems to Be ConsideredGastroparesis
RADIOGRAPHSection 4 of 12
FindingsPlain radiography Plain radiographic findings are not useful in evaluating patients for GERD, but they are helpful in evaluating pulmonary status and basic anatomy. Chest images may demonstrate a large hiatal hernia, but small hernias can be missed easily. In patients with pulmonary symptoms, an infiltrate due to aspiration pneumonia may be seen. The standard radiologic workup of a patient with reflux disease does not require chest radiography. Upper GI series Upper GI contrast-enhanced studies are the initial radiologic procedure of choice in the workup of the patient in whom GERD is suggested. The primary use of an upper GI in suspected reflux is to evaluate anatomy and not detect reflux as sensitivity is limited in patients with known esophagitis and normal controls can have visualized reflux. Drinking 15-30 mL of iced water can improve the sensitivity and specificity for reflux. Barium esophagograms or swallows are helpful for identifying structural abnormalities of the esophagus and esophageal hiatus, which include esophageal rings, strictures and ulcers, and hiatal hernias. Various techniques are used, and each has relative strengths and weaknesses in the ability to detect specific abnormalities or disease processes. A typical barium esophagram is performed in multiple steps or phases. A high-density barium suspension is administered, and double-contrast views are used for images taken with the patient in the upright position. Prone-positioned images are typically obtained with single contrast and a lower-density barium suspension. Mucosal relief images can be made to complement these techniques. Esophageal inflammatory and neoplastic diseases are better detected with double-contrast techniques. Conversely, single-contrast techniques are more sensitive for structural defects such as hiatal hernias and strictures or esophageal rings (Levine, 2005). The presence of Barrett esophagus occasionally is detected as a reticular mucosal pattern. As may be expected, the more advanced the esophageal disease, the more sensitive is barium swallow at detecting it. Early esophagitis is not well demonstrated and decreases the overall sensitivity of barium swallows, especially compared to tests such as 24-hour pH monitoring. This is why many clinicians reserve barium swallow for the evaluation of patients with GERD and symptoms that include dysphagia. Barium swallow is not sensitive in the detection of actual reflux, except in the occasional patient who has a wide-open LES and free reflux. Barium swallow is a very important study in the investigation and detection of postoperative complications following fundoplication. Recurrent hiatal hernia, disruption or slippage of the fundoplication, and other structural abnormalities can be identified (Mattioli, 2004). Late postoperative dysphagia can be investigated by a combination of manometry and esophageal fluoroscopic examination. Increases in esophagogastric transit time of liquid barium and solid boluses correlate positively with the presence of postoperative dysphagia (Scheffer, 2005). Degree of ConfidenceThe degree of confidence offered by plain films for the diagnosis of GERD is low. A suggested diagnosis of GERD must always be confirmed by other more sensitive and specific tests. False Positives/NegativesNo well-described normal variants of GERD are seen on plain radiographs. CT SCANSection 5 of 12
FindingsCT scanning, similar to chest radiography, is not a part of the standard radiologic workup of patients with GERD. CT scans can provide information regarding the anatomy (ie, presence and size of a hiatal hernia) but do not provide information regarding the presence or absence of reflux. CT does not need to be performed in most of patients with reflux disease. Degree of ConfidenceCT scanning offers excellent anatomic detail and is sensitive for the detection of a hiatal hernia; however, it cannot help make a diagnosis of GERD. False Positives/NegativesNo well-described normal variants of GERD can be detected by using CT scans. MRISection 6 of 12
FindingsCurrently, MRI has no role in the evaluation or diagnosis of GERD in patients with reflux disease. Degree of ConfidenceNo role exists for MRI in the workup of this disease process. False Positives/NegativesNo variants of GERD have been found on MRIs. ULTRASOUNDSection 7 of 12
FindingsUltrasonography is not used in the diagnosis of GERD. False Positives/NegativesThere are no normal ultrasonographic variants of GERD. NUCLEAR MEDICINESection 8 of 12
FindingsGastric-emptying studies may be worthwhile in the evaluation of patients in whom delayed gastric emptying is believed to contribute to the manifestation of GERD symptoms. Gastroesophageal reflux scintigraphy can be performed with acidified orange juice labeled with technetium-99m sulfur colloid. Compared with fluoroscopy, this allows for a longer time of evaluation, a decreased radiation dose, and the ability to semiquantitate the amount of reflux. However, gastroesophageal reflux scintigraphy has little role in the adult patient due to limited sensitivity and the availability of other methods of evaluation. Gastroesophageal reflux scintigraphy is much more commonly used in infants and children due to the noninvasive nature of the study and relatively low radiation dose. In infants and children the study is often performed with labeled milk. In addition to evaluating the degree of reflux, pulmonary aspiration can be detected by imaging over the lungs. Degree of ConfidenceScintigraphic studies are neither sensitive nor specific for the diagnosis of GERD. The results should always be confirmed with another study, preferably upper GI endoscopy or 24-hour pH monitoring. False Positives/NegativesNo normal scintigraphic variants for GERD have been described. ANGIOGRAPHYSection 9 of 12
FindingsAngiography has no role in the diagnosis of GERD. INTERVENTIONSection 10 of 12
Therapeutic radiologic interventions are not described for GERD. Treatment is either medical with antacids or proton pump inhibitors or surgical with corrective antireflux surgery. Medical/Legal Pitfalls
See also the Medscape topic Medical Malpractice and Legal Issues. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Gastroesophageal Reflux excerpt Article Last Updated: Mar 6, 2008 | |||||||||||||||||||||||||||||||||||
