AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Background

Embryologic development of the diaphragm is complex, and a number of defects allow a variety of congenital hernias through the diaphragm. A hernia may occur through a congenitally large esophageal hiatus; however, acquired hernias through the esophageal hiatus are more common. These hernias are classified either as sliding or paraesophageal. Approximately 99% of hiatal hernias are sliding, and the remaining 1% are paraesophageal.

Although paraesophageal hernias are uncommon, they are potentially life threatening because of the risk of volvulus and incarceration. Incidence of a hiatal hernia increases with age. When the lower esophageal sphincter is located within the thorax, its reinforcement of the diaphragmatic crus is loosened and allows gastroesophageal reflux of acid contents; such reflux may be symptomatic in one quarter of patients because of reflux esophagitis.

For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center. Also, see eMedicine's patient education article Hiatal Hernia.

Pathophysiology

The phrenicoesophageal membrane normally surrounds the lower esophagus and fixes it to the diaphragm, thereby preventing gastric herniation through the esophageal hiatus into the thorax. When the phrenicoesophageal membrane is deficient, an axial gastric herniation may develop in the thoracic cavity.

The stomach may be totally intrathoracic. This condition is usually related to a defect in the central tendon of the diaphragm rather than to herniation through the esophageal hiatus. The stomach acquires a position behind the heart as a result of a slight volvulus in its transverse axis. The cardia of the stomach is usually within the thorax, but occasionally, it may lie below the diaphragm. The gastric curvature may lie on the right or the left.

With a paraesophageal hernia, part of the stomach herniates through a defect in the phrenicoesophageal membrane into the thorax, while the gastric cardia remains in the normal intra-abdominal position. The herniated portion of the stomach is usually anterior to the esophagus; the hernia is frequently nonreducible. In such cases, epigastric discomfort and, occasionally, dysphagia may occur; however, no reflux symptoms are evident because the cardiac mechanism is not disturbed. Occasionally, a gastric ulcer on the lesser curve may be associated at the level of the diaphragmatic hiatus.

A distinct subgroup of paraesophageal hernias occurs in a younger age group and appears to be secondary to a congenital defect. These hernias are characteristically situated to the right of the lower thoracic esophagus where a part of the gastric fundus herniates into the thorax. A congenitally short esophagus, which is not a true hernia and is exceptionally rare, may mimic a hiatal hernia. Gastric ectopy is responsible for this condition, in which the esophagus is short and straight and a segment of the stomach is intrathoracic; the segment may be round or cylindrical with large sinuous folds. The gastric intrathoracic segment is nonreducible and remains in the thorax with the patient in both the erect and the supine positions. Often, a circular narrowing occurs at the intrathoracic junction; this finding is commonly associated with gastroesophageal ulcer.

When the lower esophageal sphincter is located within the thorax, its reinforcement of the diaphragmatic crus is loosened. On its own, the lower esophageal sphincter is not sufficiently strong to prevent the reflux of gastric contents into the lower esophagus. Gastroesophageal reflux disease is a common finding in patients with hiatal hernia; however, most patients with hiatal hernia do not have gastroesophageal disease. Occasionally, differentiating a normal ampulla of the distal esophagus from a small hiatal hernia may be difficult. The most ideal way of localizing the lower esophageal sphincter is by manometry, which is performed by monitoring pressure changes between the abdominal and thoracic cavities during breathing.

Hiatal hernia is associated with esophagitis in 20% of patients; duodenal ulcer, in another 20%; diverticulosis, in 25%; and gallstones, in 18%. In a small series, an association between asplenia syndrome and a hiatal hernia has been described.

Symptoms in patients with hiatal hernia may be multifactorial. Barrett esophagus consists of columnar epithelium lining the esophagus. It is an acquired condition related to chronic gastroesophageal reflux. These patients can develop an ulcer, stricture, or malignancy. An associated hiatal hernia is common. Adenocarcinoma represents the most serious complication of Barrett esophagus. In patients with Barrett esophagus, the risk of esophageal carcinoma is 30-40 times higher than that of the general population.

Frequency

United States

The incidence of hiatal hernia increases significantly with age, and it occurs in 10% of the adult population. Sliding hiatal hernias are common. Paraesophageal hernias are rare.

International

The international frequency is the same as found in the United States.

Mortality/Morbidity

• Paraesophageal hernias are rare but can be potentially life threatening because of the risk of volvulus and incarceration.
• Morbidity also can occur as a result of diagnostic procedures, such as endoscopy, in which the mucosa may be lacerated close to the gastroesophageal junction (generally in the setting of hiatal hernia). Such Mallory-Weiss tears can result in massive gastrointestinal (GI) tract hemorrhage. An upper GI barium series may result in aspiration of barium into the lungs.
• Some of the treatments offered for a hiatal hernia, such as fundal plication, may have risks of morbidity and mortality.

Race

No racial predilection is recognized.

Sex

Women are affected more frequently than men.

Age

Most hiatal hernias occur in patients older than 40 years. The incidence increases with age.

Anatomy

The diaphragm is a dome-shaped septum dividing the thoracic from the abdominal cavity. The diaphragm is composed of 2 parts: a peripheral muscular part and the central fibrous tendinous aponeurosis to which it attaches. The central aponeurosis is trefoil shaped and is partially attached to the undersurface of the pericardium. The peripheral muscular part is arranged into 3 groups of muscle fibers: (1) the vertebral fibers arising from the crura and arcuate ligaments, (2) the costal fibers arising from the inner aspects of the lower 6 ribs and the costal cartilages, and (3) the sternal fibers arising from the deep surface of the sternum.

The right crus of the diaphragm arises from the anterior aspects of the bodies of the first 3 lumbar vertebral bodies and the associated intervertebral discs. The left crus is attached to the first 2 lumbar vertebral bodies and the intervertebral disks. The arcuate ligaments comprise a series of fibrous arches. The medial arch is formed by thickening of the fascia covering the major psoas muscle, while the lateral arch represents the fascia covering the quadratus lumborum muscle. The median arcuate ligament is formed by the medial fibrous borders of the 2 crura and is placed on the anterior surface of the aorta.

In the diaphragm, 3 main openings are identified as follows: The aortic opening transmits the aorta, the thoracic duct and, often, the azygos vein. The esophageal opening is located between the muscular fibers of the right diaphragmatic crus and transmits the esophagus, the vagi, and branches of the left gastric artery and vein. The opening of the inferior vena cava (IVC) is located within the central aponeurosis, which transmits the IVC and the right phrenic nerve.

Embryologic development of the diaphragm is complex, and as a result, several defects may occur, giving rise to a variety of congenital hernias. These hernias include the following: (1) herniation of upper abdominal contents through the canal of Morgagni, which is positioned anteriorly between the xiphoid and the costal margins; (2) herniation through the posteriorly located pleuroperitoneal canal (Bochdalek foramen); (3) herniation through a deficient central tendon; and (4) herniation through a congenitally large esophageal hiatus. Herniation through the central tendon may occasionally be traumatic. In particular, it may be caused by steering-column injuries sustained in motor vehicle accidents.

Clinical Details

Most hiatal hernias are found incidentally and usually are discovered on routine chest radiographs or CT scans performed for unrelated symptoms. When symptomatic, patients may experience heartburn, dyspepsia, or epigastric pain. Rarely, the patient may present with recurrent chest infections due to aspiration of gastric contents. A paraesophageal or, rarely, a sliding hiatal hernia may present acutely due to a volvulus or strangulation. Paraesophageal hernias are particularly likely to incarcerate and cause symptoms of intermittent epigastric pain. Barrett esophagus is commonly associated with hiatal hernia and may present with reflux symptoms or dysphagia.

Sliding hiatal hernias are common. The clinical significance of a sliding hiatal hernia is uncertain. Most patients with a sliding hiatal hernia do not have gastroesophageal reflux, but reflux esophagitis is found more commonly in patients who have a hiatal hernia than in those who do not.

Paraesophageal hernias are rare but can be potentially life threatening because of the risk of volvulus and incarceration. Strangulation of the stomach may occur but is rare. Symptoms associated with a hiatal hernia may be multifactorial and may be related to gallstone disease; peptic ulcer disease; esophagitis; or, rarely, a carcinoma developing within a hiatal hernia. Recurrent chest infections may be due to aspiration of gastric contents from esophageal reflux; this rarely occurs in elderly patients.

Preferred Examination

Plain chest radiographs may demonstrate a retrocardiac gas-filled structure. An upper GI barium series is the preferred examination in the investigation of suggested hiatal hernia and its sequelae. CT scans are useful when more precise cross-sectional anatomic localization is desired. The use of MRI and radionuclide studies is anecdotal. Ultrasonography is a sensitive means of diagnosis of gastroesophageal reflux and is particularly attractive in young patients because it is noninvasive and does not require the use of ionizing radiation.

Limitations of Techniques

Findings in an upper GI barium series may be specific, although images may fail to demonstrate a small sliding hiatal hernia. Since gastroesophageal reflux may be intermittent, its presence may be overlooked. When no gas is present within the hernia, differentiating hernias from other retrocardiac masses may be difficult at times.

Diagnosis of a hiatal hernia is not always straightforward by using sonography, and an intermittent hernia is likely to be missed, although some regard sonography as the examination of choice in infants because the findings may differentiate duodenal causes of vomiting from esophageal causes.

DIFFERENTIALS

Section 3 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Other Problems to be Considered

Diaphragmatic hernia
Morgagni hernia
Bochdalek hernia
Duplication cysts
Neuroenteric cysts
Neurogenic tumors

RADIOGRAPH

Section 4 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Plain radiography

Most hiatal hernias are found incidentally on routine chest radiographs. The hernia may be seen as a retrocardiac mass with or without an air-fluid level. When air is seen within the hernia, the stomach air bubble found below the diaphragm tends to be absent. The hernia usually is positioned to the left of the spine; however, larger hernias (particularly incarcerated hernias) may extend beyond the cardiac confines and even mimic cardiomegaly. Most of these large hernias contain an air-fluid level and gastric contents.

An air-fluid level may be absent in the hernia on supine radiographs; occasionally, differentiation from other retrocardiac masses may be difficult by using supine radiographs.

Upper GI barium series

An upper GI barium series is the definitive method of diagnosing hiatal hernias. A single-contrast barium swallow performed with the patient in the prone position is more likely to demonstrate a sliding hiatal hernia than an upright double-contrast examination. On double-contrast examination, areae gastricae can be recognized within the intrathoracic stomach.

If the mucosal B ring is more than 1-2 cm above the diaphragmatic impression, a sliding hiatal hernia is present. A sliding hiatal hernia also may be diagnosed by recognizing 5 or more mucosal folds that are more than 1-2 cm above the diaphragm on single-contrast barium examination. A sliding hiatal hernia is reducible with the patient in an erect position.

The hernia can often be recognized by the demonstration of mucosal gastric folds within the hernia. A hiatal hernia may cause deformity of the esophagus and/or fundus of the stomach. A tortuous esophagus may have an eccentric junction with the hernia.

On a dynamic study, the esophageal peristaltic wave ceases above the hiatus; thus, the end of a peristaltic wave delineates the esophagogastric junction.

An incarcerated hiatal hernia is believed to be present when a hernia remains fixed within the thorax and becomes irreducible.

With a paraesophageal or rolling hernia, part of the stomach rolls into the thorax; usually, this occurs anterior to the esophagus. The hernia is frequently irreducible. A paraesophageal hiatal hernia is diagnosed by the position of the gastroesophageal junction. The cardia of the stomach-esophagogastric junction usually remains in the normal position below the diaphragmatic hiatus, and only the stomach herniates into the thorax, adjacent to the normally placed gastroesophageal junction. A double-contrast examination occasionally depicts an ulcer on the lesser curve of the stomach. Paraesophageal hernia is usually not associated with gastroesophageal reflux.

A totally intrathoracic stomach is not a true hiatal hernia because herniation occurs through a defect in the central tendon of the diaphragm. The hernia is readily apparent on a single- or double-contrast barium swallow. The cardia is usually intrathoracic, but occasionally, it may be subdiaphragmatic. The greater curve of the stomach may lie either on the right or on the left.

Gastroesophageal reflux or esophagitis often accompanies a hiatal hernia and may be depicted effectively on barium swallow scans.

Degree of Confidence

An upper GI barium series or barium swallow study is the examination of choice for depicting a hiatal hernia, gastroesophageal reflux, and any associated complications.

False Positives/Negatives

A small sliding hiatal hernia may be missed by using a barium swallow or meal study. Mimics of a hiatal hernia on plain radiographs include other types of acquired or congenital diaphragmatic hernias, duplication cysts, neuroenteric cysts, neurogenic tumors, and causes of paraspinal widening of soft tissues around the lower dorsal spine.

CT SCAN

Section 5 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Hiatal hernias often are seen incidentally on CT scans obtained for other indications. A hiatal hernia appears as a retrocardiac mass with or without an air-fluid level. The mass usually can be traced into the esophageal hiatus on sequential cuts. Herniation of omentum through the esophageal hiatus may result in an increase in the fat surrounding the lower esophagus.

CT scanning is particularly useful in the accurate anatomic depiction of a totally intrathoracic stomach, especially in patients in whom volvulus of the stomach is suspected. CT scanning is also useful for staging purposes in patients in whom a carcinoma complicates a hiatal hernia. Dehiscence of diaphragmatic crura of more than 15 mm may be seen.

Degree of Confidence

CT scanning is not routinely used in the diagnosis of a hiatal hernia, but it may be a useful for specific indications (see CT Findings above).

False Positives/Negatives

Mimics of hiatal hernia include a normal temporary cephalad motion of the esophagogastric junction by 1-2 cm into the thorax due to contraction of longitudinal muscles during esophageal peristalsis, lower-esophageal duplication cysts, lower-thoracic aortic aneurysms, and neuroenteric cysts.

MRI

Section 6 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

MRI has helped achieve a diagnosis of a paraesophageal omental hernia in which a retrocardiac mass was shown as a fatty tumor with contiguous blood vessels extending from the abdominal portion into the thoracic portion.

Degree of Confidence

MRI is not routinely used in the diagnosis of a hiatal hernia, and it offers no advantages over the dynamic capability of an upper GI barium series.

False Positives/Negatives

Theoretically, conditions mimicking hiatal hernia on CT scans can mimic hiatal hernia on MRIs.

ULTRASOUND

Section 7 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

In individuals without hiatal hernia, the gastroesophageal junction can almost always be depicted with a cross-sectional diameter of 7.1-10.0 mm at the diaphragmatic hiatus level. The gastroesophageal junction is not depicted in a hiatal hernia, and the bowel diameter measured at the diaphragmatic hiatus is 16.0-21.0 mm. Each of the aforementioned signs has a predictive value of 100%. The negative predictive value of the bowel diameter is 90%, and failure to depict the gastroesophageal junction has a negative predictive value of 94.7%.

Sliding hiatal hernia in children

Signs of a sliding hiatal hernia in infants and young children include the following: intra-abdominal esophagus measuring less than 2 cm, rounding of the gastroesophageal angle, and the presence of a beak at the gastroesophageal junction.

Gastroesophageal reflux

Gastroesophageal reflux may be sonographically diagnosed with 95% sensitivity, but reflux is an intermittent phenomenon, and prolonged scanning times may be required, and these may not always be practical. To detect reflux, the patient must also be positioned so that fluid is lying over the gastroesophageal junction. The examination may start with the patient lying in the supine position, but raising the left side or even placing the patient in a head-down position may be necessary to allow reflux to occur.

On sonograms, fluid refluxing into the lumen of the esophagus is seen sonographically as an anechoic column. With slight reflux, the column is small, transient, and easily missed. In more severe reflux, the column of fluid is long and may persist for some time. The fluid often contains small echogenic air bubbles caused by turbulent flow. With care, the accuracy of sonography in the diagnosis of gastroesophageal reflux is similar to accuracy of a barium meal examination.

Persistent vomiting in infants

Ultrasonography of the abdomen is an accurate and rapid screening method that can be used to differentiate the causes of persistent vomiting in infants. Findings can reliably help differentiate esophageal from duodenal causes. A test feeding is usually given, followed by sonography. The examination is focused on the duodenum to document or exclude pyloric stenosis. Once pyloric stenosis has been excluded, attention is paid to the gastroesophageal junction to detect reflux, hiatal hernia, or both.

Degree of Confidence

Sonography is a noninvasive technique that may be useful in the diagnosis of a hiatal hernia and gastroesophageal reflux. The use of ultrasonography is an attractive option in infants and young children in whom the images can help in differentiating esophageal causes of vomiting from duodenal causes.

False Positives/Negatives

The predictive value of the criteria used in the evaluation of a sliding hiatal hernia in infants and young children is quite good; however, the criteria cannot be applied if the gastric fundus distal to the esophagus and gastroesophageal junction no longer lies within the abdominal cavity. One of the disadvantages of using ultrasonography for evaluating reflux is that sonograms poorly depict the severity of reflux, and sonograms are not sensitive for depicting esophagitis. However, associated hiatal hernia can be detected reliably.

NUCLEAR MEDICINE

Section 8 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Radionuclides are not routinely used for the diagnosis of a hiatal hernia, but hiatal hernias may be incidentally found on whole-body radioiodine surveys performed in patients with thyroid cancer in whom hernias may mimic metastatic cancer. Similarly, technetium Tc 99m pertechnetate and other ^99mTc-labeled isotopes may depict a hiatal hernia incidentally. Oral ^99mTc sulfur colloid scans and single photon emission computed tomography (SPECT) images may help in differentiating a hiatal hernia from metastatic thyroid cancer.

Degree of Confidence

The use of radionuclides rarely is indicated in the diagnosis of a hiatal hernia.

False Positives/Negatives

Theoretically, a duplication cyst or a neuroenteric cyst containing gastric mucosa may take up radioiodine or ^99mTc compounds.

ANGIOGRAPHY

Section 9 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Hiatal hernia and esophagitis rarely produce massive GI tract hemorrhage; however, if this occurs, angiography may be able to depict the site of GI tract hemorrhage and the feeding blood vessels.

Degree of Confidence

Experience with angiography in hemorrhage from a hiatal hernia is limited, and the degree of confidence with which diagnosis can be made is unknown.

False Positives/Negatives

False-negative diagnosis may occur if the gastric hemorrhage has temporarily stopped at the time of angiography (intermittent bleed) or the rate of hemorrhage is slow. False-positive diagnosis may occur when using digital subtraction angiography when bowel movement can be erroneously interpreted as hemorrhage.

INTERVENTION

Section 10 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

If a bleeding point is identified within the hiatal hernia or lower esophagus, selective arterial infusion of vasopressin almost always controls the bleeding. Similarly, Mallory-Weiss tears respond to vasopressin readily. Some of the treatments offered for a hiatal hernia, such as fundal plication, may have risks of morbidity and mortality.

Medical/Legal Pitfalls

• On an upper GI barium series, a hiatal hernia may cause deformity of the esophagus and/or fundus of the stomach. These appearances may lead to unnecessary endoscopic procedures.

See also the Medscape topic Medical Malpractice and Legal Issues.

Special Concerns

• Recurrent and unexplained chest infections in young or elderly patients should raise the possibility of gastroesophageal reflux or a hiatal hernia.

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Media file 1:  Diagram shows the 3 major orifices at the inferior aspect of the diaphragm (inferior vena cava [IVC], esophagus, aorta).
	View Full Size Image
Media type:  Image

Media file 2:  Diagram shows a sliding hiatal hernia. The gastroesophageal junction (Jn) is located above the diaphragmatic hiatus.
	View Full Size Image
Media type:  Image

Media file 3:  Diagram of a paraesophageal hiatal hernia shows the normal infradiaphragmatic location of the gastroesophageal junction.
	View Full Size Image
Media type:  Image

Media file 4:  Plain chest radiograph shows a well-defined, rounded, soft-tissue mass in the retrocardiac region consistent with a sliding hiatal hernia.
	View Full Size Image
Media type:  Image

Media file 5:  Frontal chest radiograph in a patient with a large hiatal hernia demonstrates a retrocardiac opacity with radiolucent gas, which shifts the mediastinum to the right.
	View Full Size Image
Media type:  X-RAY

Media file 6:  Lateral chest radiograph shows a hiatal hernia (same patient as in Image 5). Note the absence of fundal gas below the left hemidiaphragm.
	View Full Size Image
Media type:  X-RAY

Media file 7:  Barium-meal examination in a patient with a sliding hiatal hernia demonstrates the supradiaphragmatic location of the gastroesophageal junction.
	View Full Size Image
Media type:  X-RAY

Media file 8:  Frontal chest radiograph in a 75-year-old woman with a hiatal hernia demonstrates an air-fluid level.
	View Full Size Image
Media type:  X-RAY

Media file 9:  Axial CT scan of the thorax in a 75-year-old woman shows a retrocardiac mediastinal mass with a fluid level due to a hiatal hernia (same patient as in Image 8).
	View Full Size Image
Media type:  CT

Media file 10:  Chest radiograph in a patient with a huge air-filled hiatal hernia, which appears as a mediastinal mass.
	View Full Size Image
Media type:  X-RAY

Media file 11:  Abdominal radiograph in a patient with a huge air-filled hiatal hernia (same patient as in Image 10). Radiograph obtained on the day after Image 10 was obtained shows acute gastric dilatation due to incarcerated hiatal hernia.
	View Full Size Image
Media type:  X-RAY

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• MRI
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

• Avidan B, Sonnenberg A, Schnell TG, Sontag SJ. Hiatal hernia and acid reflux frequency predict presence and length of Barrett''s esophagus. Dig Dis Sci. Feb 2002;47(2):256-64. [Medline].
• Bisset RAL, Khan AN. Differential Diagnosis in Abdominal Ultrasound. 2nd ed. London: W. B. Saunders;1992:235-7.
• Csendes A, Smok G, Quiroz J, et al. Clinical, endoscopic, and functional studies in 408 patients with Barrett''s esophagus, compared to 174 cases of intestinal metaplasia of the cardia. Am J Gastroenterol. Mar 2002;97(3):554-60. [Medline].
• Gurgun C, Yavuzgil O, Akin M. Images in cardiology. Paraoesophageal hiatal hernia as a rare cause of dyspnoea. Heart. Mar 2002;87(3):275. [Medline].
• Halkiewicz F, Kasner J, Karczewska K, Rusek-Zychma M. Ultrasound picture of gastroesophageal junction in children with reflux disease. Med Sci Monit. Jan-Feb 2000;6(1):96-9. [Medline].
• Huang X, Zhu HM, Deng CZ, et al. Gastroesophageal reflux: the features in elderly patients. World J Gastroenterol. Oct 1999;5(5):421-423. [Medline].
• Ogunyemi D. Serial sonographic findings in a fetus with congenital hiatal hernia. Ultrasound Obstet Gynecol. Apr 2001;17(4):350-3. [Medline].
• Ouatu-Lascar R, Lin OS, Fitzgerald RC, Triadafilopoulos G. Upright versus supine reflux in gastroesophageal reflux disease. J Gastroenterol Hepatol. Nov 2001;16(11):1184-90. [Medline].
• Scheidler MG, Keenan RJ, Maley RH, et al. "True" parahiatal hernia: a rare entity radiologic presentation and clinical management. Ann Thorac Surg. Feb 2002;73(2):416-9. [Medline].
• Spechler SJ, Goyal RK. Barrett''s esophagus. N Engl J Med. Aug 7 1986;315(6):362-71. [Medline].
• Yamashita K, Tsunoda T. Three-dimensional computer images of stomach diseases. Am J Surg. Jan 2002;183(1):87-8. [Medline].

Article Last Updated: Sep 8, 2005