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

Esophageal and paraesophageal varices are abnormally dilated veins of the esophagus. They are native veins that serve as collaterals to the central venous circulation when flow through the portal venous system or superior vena cava (SVC) is obstructed. Esophageal varices are collateral veins within the wall of the esophagus that project directly into the lumen. The veins are of clinical concern because they are prone to hemorrhage. Paraesophageal varices are collateral veins beyond the adventitial surface of the esophagus that parallel intramural esophageal veins. Paraesophageal varices are less prone to hemorrhage. Esophageal and paraesophageal varices are slightly different in venous origin, but they usually are found together.

Using a thin-barium technique, radiographic appearances of esophageal varices were described first by Wolf in his 1928 paper, "Erkennun von Osophaus-varizen im Rontgenbilde," or radiographic detection of esophageal varices. In 1931, Schatzki established the basis for the modern-day fluoroscopic detection of varices by refining positional and physiologic maneuvers to optimize visualization.

Today, more sophisticated imaging with CT, MRI, magnetic resonance angiography (MRA), and endoscopic ultrasonography (EUS) plays an important role in evaluating portal hypertension and varices. This article discusses the relevant anatomy, pathophysiology, and radiographic characteristics of esophageal varices with a focus on uphill varices secondary to portal hypertension.

Pathophysiology

Varices may be called uphill or downhill depending on the direction of venous flow to the central circulation. Uphill varices are more common and result from portal hypertension. Portal hypertension generates hepatofugal flow (reversal of flow), which diverts venous blood uphill in the cephalic direction through the left gastric vein to the venous plexus of the esophagus. The resulting varices are most prominent in the lower-to-mid thirds of the esophagus, especially at the gastroesophageal junction.

Solitary gastric varices identified with either endoscopy or barium techniques are also usually a result of portal hypertension. If isolated gastric varices are visualized during radiologic examination, one must critically look for associated esophageal varices. Only a minority of isolated gastric varices are a result of splenic vein obstruction.

The many etiologies of portal hypertension can be classified into 3 basic categories as follows:

• Presinusoidal, at the level of the portal vein
  • Periportal fibrosis (schistosomiasis)
  • Portal vein thrombosis
  • Umbilical vein infection (neonates)
  • Protein C deficiency
  • Trauma
  • Appendicitis
  • Hepatocellular carcinoma
  • Chronic active hepatitis
  • Congenital hepatic fibrosis
  • Early primary biliary cirrhosis
  • Sarcoid
  • Toxin
  • Arsenic
  • Polyvinyl chloride
• Sinusoidal, at the level of the liver parenchyma
  • Cirrhosis related to ethyl alcohol consumption
  • Hepatitis B, hepatitis C, and hepatitis D
  • Hemochromatosis
  • Wilson disease
  • Acute hepatitis related to ethyl alcohol consumption
  • Vitamin A toxicity
  • Drug-induced portal hypertension
  • Methotrexate use
  • Azathioprine use
  • Tropical splenomegaly syndrome (hepatic sinusoidal lymphocytosis or malaria in endemic areas)
• Postsinusoidal, at the level of the hepatic veins
  • Veno-occlusive disease (bone marrow transplant patients)
  • Budd-Chiari syndrome
  • Inferior vena cava obstruction
  • Thrombosis/thromboembolic disease
  • Tumor within the inferior vena cava (renal cell carcinoma)
  • Tumor-compressing inferior vena cava

Downhill varices are a result of obstruction of the SVC. Downhill varices have 2 presentations depending on the level of obstruction. When the SVC is obstructed superior to the azygous vein, venous blood is redirected downhill as it flows caudally from the head and upper extremities, through the esophageal veins, and into the azygous vein. Blood then enters the systemic circulation through the azygous vein. Resulting varices develop in the mid-to-upper thirds of the esophagus. When obstruction occurs at or inferior to the azygous vein, flow continues in the caudad direction through the venous plexus of the esophagus and cardiac veins and continues into the portal circulation.

Blood enters the central venous system through the inferior vena cava (IVC). In this setting, varices develop throughout the entire esophagus. The most common etiologies of downhill varices are lung carcinomas and large mediastinal tumors. Occasionally, obstruction may be a result of mediastinal fibrosis or substernal goiter. Prior central intravenous-line placement or intravenous-line infections are also in the differential diagnosis of SVC obstruction. Because malignancy is the most common etiology of SVC obstruction, few patients survive long enough to develop varices or variceal hemorrhage.

Case reports describe idiopathic varices or single idiopathic esophageal varix presenting as an esophageal mass on barium studies. These cases were confirmed either surgically or endoscopically, but no underlying etiologies were identified. A proposed explanation for their appearance is intrinsic congenital weakness of the venous channels of the esophagus; however, no scientific proof supports this proposal.

The hepatic venous-pressure gradient (HVPG) is an accurate estimate of portal venous pressure. The HVPG is determined angiographically by subtracting the free hepatic venous pressure from the hepatic venous wedge pressure. Hepatic venous wedge pressure is an indirect measurement of portal venous pressure and is analogous to the relationship of pulmonary wedge pressure to left atrial pressure in right heart catheterization.

Usually, the HVPG is less than 5 mm Hg. Portal hypertension is diagnosed when the HVPG exceeds 5 mm Hg. Clinical findings, such as splenomegaly and thrombocytopenia, may develop with HVPG readings of greater than 5 mm Hg. Development of esophageal varices is a late complication that develops when the HVPG rises above 12 mm Hg. As a result, the deep intrinsic veins of the esophagus become tortuous and dilated over time, with sustained elevated venous pressure.

The Laplace law applies, as it does in all other hollow, tubular structures under pressure in the body. Wall tension is directly correlated with the tendency for a single varix to bleed. Wall tension can be calculated by using the following equation, in which T is the wall tension, Q is the flow, L is the length of the vessel, h is the viscosity of the blood, r is the radius of the vessel, and x is the mural wall thickness:

T = QLhpr⁴(r/x)

Thus, a varix with a long, wide, and thin wall has high wall tension and an increased risk of bleeding.

In cirrhotic patients, an added factor of increased portal venous flow further adds to the problem. Patients with cirrhosis have an overall hyperdynamic circulation. As more collaterals develop, portal pressure decreases and triggers compensatory vasodilatation of the splanchnic circulation. The vasodilatory response is mediated at the cellular level primarily by the release of nitric oxide and prostacyclin, which result in increased volume and flow to portal circulation. Most patients with cirrhosis also develop hypoalbuminemia, which leads to ascites. The third-space effect of fluid creates relative hypovolemic hypotension that triggers a renin-angiotensin–mediated response to retain fluid. Retaining more fluid volume results in more third-space shifts, and a cycle is created.

Frequency

United States

Most esophageal varices are a result of portal hypertension resulting from cirrhosis. Cirrhosis of the liver is the third leading cause of death after cancer and cardiovascular disease in people aged 25-65 years. The leading cause of cirrhosis in the Western world is alcoholic liver disease, closely followed by viral hepatitis. In recent years, cirrhosis has become strikingly more prevalent as more cases of hepatitis C are discovered. The lifetime incidence of esophageal varices is approximately 50% for all patients with cirrhosis. The annual risk of developing varices is 5-15%.

International

The prevalence, incidence, and etiology of cirrhosis may differ depending on geographic location, but the international incidence and annual risk rates of esophageal varices are similar to those in the United States. Outside the Western world, the leading causes of cirrhosis are hepatitis B and hepatitis C. Periportal fibrosis secondary to schistosomiasis (mansoni and japonicum, not haematobium) infection is also a major cause of portal hypertension worldwide. Periportal fibrosis is a chronic granulomatous inflammatory reaction resulting in fibrosis of and around the portal vein and also is called pipe-stem fibrosis.

Mortality/Morbidity

Hemorrhage is a major complication in patients with esophageal varices, occurring in approximately one third of patients. The mortality rate for each bleeding episode is approximately 30%. If underlying etiology remains untreated, as many as 70% of patients who develop hemorrhage die within 1 year of the initial bleeding episode. The risk of bleeding is highest during the first year of diagnosis, and bleeding usually occurs near the gastroesophageal junction. Bleeding ceases spontaneously in one half of patients without intervention, but risk of rebleeding is high, especially in the first 48 hours. Diagnosing varices is critical so that treatment and close follow-up care may be started to prevent the first episode of hemorrhage.

Many studies have been conducted to determine the risk of variceal hemorrhage. In 1988, de Franchis studied the prediction of variceal hemorrhage on the basis of the patient's clinical status and the severity of varices at endoscopy. de Franchis used the endoscopic grade of the varices (see Preferred Examination), Child class, and identification of red wheals (dilated intraepithelial veins) to determine a patient's risk of hemorrhage. He found that the patient's Child classification was a major factor in predicting variceal hemorrhage; for example, the risk of hemorrhage in a patient with Child class A and grade 3/3 varices and no red wheals is only 15% compared with 42% in a patient with Child class C varices with identical endoscopic appearances.

In 1998, Nevens et al discussed the risk of hemorrhage in direct correlation with increasing portal venous pressure. The group determined that the risk of hemorrhage at portal venous pressures of 13 mm Hg is only 9% with an exponential increase to 72% if portal venous pressure rises to 17 mm Hg.

Therapy to prevent first variceal hemorrhage is usually pharmacologic. Nonselective beta-blockers, such as propranolol and nadolol, are used, as well as nitrates. Sclerotherapy and banding procedures may also be performed under endoscopic guidance.

The true risk of hemorrhage for downhill varices is unknown because most patients die as a result of the underlying etiology. See Intervention for a description of acute treatment of patients with esophageal varices.

Race

No specific racial predilection exists for developing uphill or downhill esophageal varices. Racial differences may vary depending on the etiology.

Sex

No specific sex predilection exists for developing uphill or downhill varices. Gender differences may vary depending on the underlying etiology.

Age

Patients' ages may vary depending on the underlying etiology of varices.

Anatomy

Venous drainage of the esophagus can be divided into 3 parts. The upper third of the esophagus to approximately the level of the aortic knob is drained primarily by the supreme intercostal, bronchial, and inferior thyroid veins. The middle third is drained by the azygous, hemiazygous, and accessory hemiazygous veins. Venous drainage from the upper two thirds of the esophagus enters the central venous circulation via the SVC. The lower third is drained by the periesophageal plexus, which comprises the intraepithelial channels, superficial venous plexus, and deep intrinsic veins coursing from the mucosa to the muscularis layers of the esophagus. This complex drains into the anterior branch of the left gastric vein (into the main left gastric [coronary] vein) and enters the portal circulation at the splenic vein or directly into the portal vein.

Paraesophageal varices are derived from the adventitial veins that drain into the posterior branch of the left gastric vein. Perforating veins run through the muscularis layer of the esophagus and connect the periesophageal plexus to the adventitial veins.

Clinical Details

Clinically, portal hypertension may be suggested in patients with cirrhosis. Clinical signs of cirrhosis include ascites, testicular atrophy, gynecomastia, and cutaneous spider angiomas. The last 3 signs are related to the inability of the liver to metabolize normal levels of estrogen in the body.

Abnormal laboratory test results, such as low albumin levels and a high international normalized ratio (INR), reflect hepatocellular failure. Hypoalbuminemia and coagulopathy develop because the liver is unable to synthesize important proteins, such as coagulation factors II, V, VII, IX, and X; albumin; and prealbumin. Elevated ammonia levels are due to impaired metabolism of amino acids. Clinically, such levels may result in hepatic encephalopathy.

Encephalopathy may be precipitated by changes in diet, dehydration, infection, and bleeding. Other liver function results, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), and bilirubin levels, may be within the reference range or only mildly elevated. In patients with hepatitis C, the only abnormal finding may be a mildly increased ALT level, which may be 1.5-2 times higher than the reference range.

In addition to esophageal varices, clues to developing portal hypertension in cirrhotic patients include splenomegaly, caput medusae, and internal hemorrhoids. Abnormal hematologic findings also may be identified in all 3 cell lines produced by the bone marrow (ie, WBCs, RBCs, platelets). Thrombocytopenia develops with increased platelet sequestration resulting from splenomegaly. Anemia resulting from extravascular hemolysis also develops as a result of splenomegaly. Leukopenia may develop in patients with advanced cirrhosis as a result of fibrosis of the space of Disse, in which reserves of white blood cells ordinarily reside. Therefore, cirrhotic patients are considered to be immunocompromised.

Hepatopulmonary syndrome is a complication in chronic liver disease that leads to idiopathic abnormalities of pulmonary blood flow and subsequent arterial hypoxemia. Transplantation has been the only successful treatment in patients with hepatopulmonary syndrome. Hepatorenal syndrome occurs before renal failure secondary to renal cortical vasoconstriction as a result of hemodynamic disturbance from cirrhosis, portal hypertension, and ascites.

In patients with downhill varices, swelling of the upper extremities, face, and neck is the most common clinical manifestation. Arm claudication may also be a rare clinical symptom.

Preferred Examination

Endoscopy is the criterion standard for evaluating esophageal varices and assessing the bleeding risk. This procedure is performed by a surgeon or a gastroenterologist with the patient under light sedation. The procedure involves using a flexible endoscope inserted into the patient's mouth and through the esophagus to inspect the mucosal surface. When esophageal varices are discovered, they are graded according to their size, as follows:

• Grade 1 - Small straight varices
• Grade 2 - Enlarged tortuous varices occupying less than one third of the lumen
• Grade 3 - Large coil-shaped varices occupying more than one third of the lumen

The varices also are inspected for red wheals, which are dilated intra-epithelial veins under tension and which carry a significant risk for bleeding. The grading of varices and identification of red wheals by endoscopy predict a patient's bleeding risk, on which treatment is based (see Morbidity/Mortality).

CT and MRI are identical in their usefulness in diagnosing and evaluating the extent of esophageal varices. These modalities have an advantage over endoscopy because CT and MRI can help in evaluating the surrounding anatomic structures, both above and below the diaphragm. CT and MRI are also valuable in evaluating the liver and the entire portal circulation.

These modalities are used in preparation for a transjugular intrahepatic portosystemic shunt (TIPS) procedure or liver transplantation and in evaluating for a specific etiology of esophageal varices. These modalities also have an advantage over both endoscopy and angiography because they are noninvasive. CT and MRI do not have strict criteria for evaluating the bleeding risk, and they are not as sensitive or specific as endoscopy. CT and MRI may be used be alternative methods in making the diagnosis if endoscopy is contraindicated (eg, in patient with a recent myocardial infarction or any contraindication to sedation).

In the past, angiography was considered the criterion standard for evaluation of the portal venous system. However, current CT and MRI procedures have become equally sensitive and specific in the detection of esophageal varices and other abnormalities of the portal venous system. Although the surrounding anatomy cannot be evaluated as they can be with CT or MRI, angiography is advantageous because its use may be therapeutic as well as diagnostic. Angiography may be performed if CT or MRI findings are inconclusive.

Ultrasonography, excluding EUS, and nuclear medicine studies are of minor significance in the evaluation of esophageal varices.

Limitations of Techniques

Although endoscopy is the criterion standard in diagnosing and grading esophageal varices, the anatomy outside of the esophageal mucosa cannot be evaluated with this technique. Therefore, imaging modalities such as CT, MRI, and EUS are also performed for a more complete evaluation.

Barium swallow examination is not a sensitive test, and it must be performed carefully with close attention to the amount of barium used and the degree of esophageal distension. Barium swallow images may help in detecting only 50% of varices.

On CT scans and MRIs, varices are difficult to see at times. However, in severe disease, varices may be prominent. CT and MRI are useful in evaluating other associated abnormalities and adjacent anatomic structures in the abdomen or thorax. On MRIs, surgical clips may create artifacts that obscure portions of the portal venous system. Disadvantages of CT include the possibility of adverse reactions to the contrast agent and an inability to quantitate portal venous flow, which is an advantage of MRI and ultrasonography.

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

Varicoid carcinoma of the esophagus

SVC obstruction - Downhill varices

Klippel-Trenaunay syndrome - Very rare, congenital venous malformations and varicosities usually involving only 1 limb, occasionally involves the venous system of the abdomen

Parkes-Weber syndrome - Very rare, similar to Klippel-Trenaunay syndrome but with angiographic appearances of a arteriovenous malformation

RADIOGRAPH

Section 4 of 12  

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

Findings

Plain radiography

Plain radiographic findings are insensitive and nonspecific in the evaluation of varices.

• Plain radiographic findings may suggest paraesophageal varices. Anatomically, paraesophageal varices are outside the esophageal wall and may create abnormal opacities. Esophageal varices are within the wall; therefore, they are concealed in the normal shadow of the esophagus.
• Ishikawa et al described chest radiographic findings in paraesophageal varices, as confirmed with CT scans, portal venography, or both, in 352 patients with portal hypertension. The most common finding on chest radiographs was obliteration of a short or long segment of the descending aorta without a definitive mass shadow. Other plain radiographic findings included a posterior mediastinal mass and an apparent intraparenchymal mass. On other images, the intraparenchymal masses were confirmed to be varices in the region of the pulmonary ligament.
• On plain radiographs, a downhill varix may be depicted as a dilated azygous vein that is out of proportion to pulmonary vasculature. In addition, a widened superior mediastinum may be shown. A widened superior mediastinum may result from dilated collateral veins or the obstructing mass.

Barium study

Endoscopy is the criterion standard method for diagnosing varices. Barium studies may be of benefit if the patient has a contraindication to endoscopy or if endoscopy is not available. Pay attention to technique to optimize detection of varices. The procedure should be performed with the patient in the supine or slight Trendelenburg position. These positions enhance gravity-dependent flow and engorge the vessels. The patient should be situated in an oblique projection and, therefore, in a right anterior oblique position to the image intensifier and a left posterior oblique position to the table. This positioning prevents overlap with the spine and further enhances venous flow.

A thick barium suspension or paste should be used to increase adherence to the mucosal surface. Ideally, single swallows of a small amount of barium should be ingested to minimize peristalsis and to prevent overdistension of the esophagus. If the ingested bolus is too large, the esophagus may be overdistended with dense barium, and the mucosal surface may be smoothed out, rendering varices invisible. In addition, a full column of dense barium may white out any findings of varices. Too many contiguous swallows create a powerful, repetitive, stripping wave of esophageal peristalsis that squeezes blood out of the varices as it progresses caudally.

Effervescent crystals may be used to provide air contrast, but crystals also may cause overdistension of the esophagus with gas and thereby hinder detection. In addition, crystals may create confusing artifacts in the form of gas bubbles, which may mimic small varices.

The Valsalva maneuver may be useful to further enhance radiographic detection. The patient is asked to "bear down as if you are having a bowel movement" or asked to "tighten your stomach muscles as if you were doing a sit-up." The Valsalva maneuver increases venous return and also prevents further peristaltic waves. The Valsalva maneuver also traps barium in the distal esophagus and allows retrograde flow for even coating.

Barium study findings are as follows:

• Esophageal varices appear as tortuous, serpiginous, longitudinal filling defects projecting into the lumen of the esophagus. These defects are seen best on relief projections of the esophagus.
• Esophageal varices may appear as thickened folds with rounded expansions etched in white because of barium trapped in the grooves of adjacent varices. This appearance may differentiate varices from thickened esophageal folds of esophagitis.
• In a filled esophagus, varices may be identified as a scalloped border, which is a more specific sign of esophageal varices, especially if found in conjunction with the aforementioned findings.
• In the differential diagnosis, varicoid carcinoma of the esophagus is important. Varicoid carcinoma demonstrates a similar appearance to esophageal varices but has a more-rigid appearance that does not change or become distended with positioning, repetitive swallows, or use of the Valsalva maneuver.

Degree of Confidence

Plain radiographic findings suggestive of paraesophageal varices are very nonspecific. Any plain radiographic findings suggesting a paraesophageal varices should be followed up with CT scanning or barium study to differentiate the findings from a hiatal hernia, posterior mediastinal mass, or other abnormality (eg, rounded atelectasis). Similarly, barium studies or CT findings suggestive of varices should be followed up with endoscopy. Endoscopic follow-up imaging can be used to evaluate the grade and appearance of varices to assess the bleeding risk. The results of this assessment directs treatment.

False Positives/Negatives

In review case studies, a single thrombosed varix may have been confused with an esophageal mass on barium studies. With endoscopy, the 2 entities can be differentiated easily.

The only normal variant is hiatal hernia. The rugal fold pattern of a hiatal hernia may be confused with esophageal varices; however, hiatal hernia can be identified easily by the presence of the B line marking the gastroesophageal junction.

CT SCAN

Section 5 of 12  

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

Findings

CT scanning is an excellent method for detecting moderate-to-large esophageal varices and for evaluating the entire portal venous system. CT is a minimally invasive imaging modality that involves the use of only a peripheral intravenous line; therefore, it is a more attractive method than angiography or endoscopy in the evaluation of the portal venous system.

Helical CT scanning and CT portal venography are becoming more important preprocedural tools before TIPS and transplant. A variety of techniques have been described for the CT evaluation of the portal venous system. Most involve a helical technique with a pitch of 1.5-1.7 and 5-mm collimation. For imaging, 100-150 mL of 60% iodinated contrast is administered into an 18-gauge (preferred) peripheral intravenous line with a 60- to 80-second delay. The images are reconstructed in 5-mm increments. The amount of contrast material and the delay time are slightly greater than those in conventional helical CT of the abdomen. The difference in technique ensures adequate opacification of both the portal venous and mesenteric arterial systems.

• On nonenhanced studies, esophageal varices may not be depicted well. Only a thickened esophageal wall may be found. Paraesophageal varices may appear as enlarged lymph nodes, posterior mediastinal masses, or a collapsed hiatal hernia.
• On contrast-enhanced images, esophageal varices appear as homogeneously enhancing tubular or serpentine structures projecting into the lumen of the esophagus. The appearance of paraesophageal is identical, but it is parallel to the esophagus instead of projecting into the lumen. Paraesophageal varices are easier to detect than esophageal varices because of the contrast of the surrounding lung and mediastinal fat.

On contrast-enhanced CT scans, downhill varices may have an appearance similar to that of uphill varices, varying only in location. Because the etiology of downhill varices is usually secondary to SVC obstruction, the physician must be aware of other potential collateral pathways that may suggest the diagnosis. Stanford et al had originally published data based on venography. They described 4 patterns of flow in the setting of SVC obstruction:

• Type 1 - Partial occlusion of the SVC with patency of the azygous vein
• Type 2 - Near-complete or complete obstruction of the SVC with patency and antegrade flow through the azygos vein and into the right atrium
• Type 3 - Near-complete or complete obstruction of the SVC with reversal of azygous blood flow
• Type 4 - Complete obstruction of the SVC and 1 or more major caval tributaries, including the azygos system

In a recent retrospective investigation, Cihangiroglu et al analyzed CT scans from 21 studies of patients with SVC obstruction. They describe as many as 15 different collateral pathways. Of their total cohorts, only 8 could be characterized by using the Stanford classification. In the setting of SVC obstruction, the most common collateral pathways were the following (in decreasing order of frequency): (1) azygous vein, (2) thoracoepigastric vein, (3) mediastinal vein, and (4) internal mammary vein. The azygous vein collateral is most likely to develop downhill varices; however, any collateral vessel identified in the chest wall or mediastinum in the setting of SVC obstruction should prompt the radiologist to look for esophageal varices.

Degree of Confidence

CT is a minimally invasive method used to detect moderate-to-large esophageal varices and to evaluate the entire portal venous system. CT scans also help in evaluating the liver, other venous collaterals, details of other surrounding anatomic structures, and the patency of the portal vein. In these situations, CT has a major advantage over endoscopy; however, unlike endoscopy, CT scans are not useful in predicting variceal hemorrhage.

Compared with angiography, CT is superior in detecting paraumbilical and retroperitoneal varices and at providing a more thorough examination of the portal venous system without the risk of intervention. In the detection of esophageal varices, CT is slightly better than angiography. As many as 25% of esophageal varices detected at endoscopy may be missed on angiograms. CT and angiography are approximately equal in the detection of varices smaller than 3 mm. If CT scans do not demonstrate small varices, they are unlikely to be seen on angiograms.

False Positives/Negatives

Contrast-enhanced CT is essential for evaluating esophageal varices. Contrast enhancement greatly increases the sensitivity and specificity of the examination and reduces the rate of false-positive or false-negative results. On nonenhanced CT scans, varices may mimic soft-tissue masses, enlarged lymph nodes, or other gastrointestinal (GI) tract abnormalities (eg, hiatal hernia).

MRI

Section 6 of 12  

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

Findings

MRI is an excellent noninvasive method for imaging the portal venous system and esophageal varices. Varices appear as flow voids on conventional T1- and T2-weighted images. This appearance makes them easily distinguishable from soft-tissue masses. Flow voids appear as well-defined circular structures outside of or within the wall of the esophagus on axial images or serpiginous on sagittal or coronal images. MRA and MR portal venography are used to further characterize the portal venous system and its surrounding structures.

Most imaging protocols are based on time-of-flight or phase-contrast methods. Improved images can be obtained by using a contrast-enhanced, breath-hold, fat-saturated, segmented, 3-dimensional (3D), gradient-echo technique. This approach involves imaging during 3 sequential breath holds, 6 seconds apart, after the injection of paramagnetic contrast material. Data from the 3 acquisitions are processed by using a maximum intensity projection (MIP) algorithm. The MIP technique provides imaging of the entire vascular anatomy at different phases, and it provides excellent resolution in a short time.

Esophageal varices and other portosystemic collaterals are demonstrated as serpiginous contrast-enhanced vessels in the portal venous phase. Downhill varices appear similar to uphill varices. The advantage of MRI over CT in evaluating downhill varices is its superior ability in evaluating soft tissues. Therefore, if SVC obstruction caused by a tumor is identified, the adjacent soft tissue structures of the mediastinum, thoracic inlet, and brachial plexus can be evaluated.

Degree of Confidence

Similar to CT, MRI is becoming a more common examination in pre-TIPS and pretransplantation evaluations. The only major disadvantages of MRI compared with CT are its limited availability and cost; otherwise, CT and MRI are equal in imaging the portal venous system and in detecting esophageal varices. An advantage of MRI over CT includes the ability to quantitate the peak velocity and to determine the direction of venous blood flow. As a result, MRI rivals ultrasonography when a bolus-tracking technique is used. Other advantages include better characterization of liver tumors and avoidance of iodinated contrast material.

False Positives/Negatives

In patients with severe portal hypertension, stagnant or to-and-fro flow may produce low or no signal intensity in a patent vessel, which may be mistaken for nonobstructive thrombus or occluded vessel. Surgical clips may create artifacts that obscure portions of the portal venous system. In imaging patients with portal hypertension, ascites may create significant motion artifact that degrades image quality and may result in a nondiagnostic study. Paracentesis is recommended prior to examination in patients with a large amount of ascites.

ULTRASOUND

Section 7 of 12  

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

Findings

Duplex Doppler ultrasonography is excellent for evaluating the velocity and direction of flow in the portal venous system. Duplex Doppler ultrasonography is good for evaluating portal vein patency. Sonography also provides an adequate evaluation of the size and echotexture of the liver. In the evaluation and detection of esophageal varices, conventional ultrasonography is limited and not clinically useful.

EUS is a procedure performed by gastroenterologists, sometimes in conjunction with radiologists, to evaluate the esophagus. The procedure is used primarily in the evaluation and staging of esophageal and pancreatic carcinomas, but it also has played a role in the evaluation and treatment of esophageal varices.

While the patient is under light sedation, a 13-mm side-view endoscope with a small ultrasound probe (7.5 or 12 MHz) at its tip is introduced into the esophagus. Once desired placement is confirmed endoscopically, a water-filled balloon is inflated around the probe in close contact with the mucosal surface of the esophagus. Occasionally, sodium chloride solution is also introduced into the lumen to eliminate any air artifact. Axial images in a 180° or 360° field of view are generated. The images demonstrate all 5 layers of the esophagus, in alternating echogenic and hypoechoic layers, starting with the echogenic mucosa.

Varices are identified as multiple, well-circumscribed, hypoechoic or anechoic structures that have a tubular or serpiginous appearance; they are located in the submucosal layer. Some EUS probes have color Doppler capability and permit the demonstration of flow. EUS has been used to guide sclerotherapy for precise injection of the sclerosing agent. EUS also has played a role in postsclerotherapy follow-up to predict the recurrence of varices. The prediction is made by identifying and measuring the size of the surrounding paraesophageal and perforating veins.

Degree of Confidence

Burtin et al evaluated 58 patients with cirrhosis and 16 control subjects by using endoscopy and EUS. Esophageal varices were detected more often with endoscopy than with EUS (88% vs 55%, respectively). In addition, Burtin et al reported that higher-grade varices, as determined endoscopically, were more readily detected by using EUS. Varices are graded 0-3 on the basis of their protrusion into the esophageal lumen. A significant increase in the rate of EUS detection was found between grade 1 varices and grade 2 varices (25% vs 73%, respectively). This increase is believed to be because grade 0 and 1 varices are easily compressed out by the inflated balloon and not as readily detectable.

Even with a water-filled esophagus, the overall detection rate for esophageal varices with EUS is only 60%. Endoscopic detection of varices alone remains the criterion standard, with EUS adding little more information to the evaluation.

False Positives/Negatives

With color Doppler ultrasonography, esophageal varices can be identified easily. However, in patients with a thrombosed varix due to either idiopathic causes or sclerotherapy, the appearance may resemble those of other submucosal masses, such as cystic duplications, leiomyomas, or leiomyosarcomas. These masses are more likely to be solitary or rounded, and they are not tubular or serpiginous as are varices. Case reports describe a solitary thrombosed idiopathic varix, but these are extremely rare. A clinical history of cirrhosis or other causes of portal hypertension is helpful in evaluating such masses.

NUCLEAR MEDICINE

Section 8 of 12  

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

Findings

Nuclear medicine does not play a clinically useful role in the evaluation or diagnosis of esophageal varices. In occasional case reports in the literature, variceal hemorrhage was identified as a source of upper GI tract bleeding seen on a tagged-RBC scan.

One group from Japan used abdominal blood pool single photon emission CT as a tool to evaluate success and predict recurrence of esophageal varices after sclerotherapy. More literature has been generated regarding the use of EUS imaging, with good results. To date, positron emission tomography has no role in the evaluation of portal hypertension or esophageal varices.

ANGIOGRAPHY

Section 9 of 12  

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

Findings

Prior to flexible endoscopy, angiography was the criterion standard in diagnosing esophageal varices.

• Angiographic findings of esophageal varices appear similar to those of serpiginous varicose veins in contiguity with the left gastric or azygous veins, depending on whether the course is uphill or downhill.
• Multiple small collateral vessels may be depicted in the upper chest, head, and extremities in the setting of downhill varices.
• Parasplenic, gastric, and umbilical varices may be seen in association with uphill varices.

Three major angiographic approaches to imaging and evaluation of the portal venous system and esophageal varices are used. The approach, advantages, and disadvantages of each are as follows:

• Indirect arterial portography
  • The procedure involves obtaining arterial access through the arm or groin and selectively cannulating the celiac or superior mesenteric arteries. A bolus of contrast agent is injected to obtain mesenteric angiograms and delayed images of the portal venous and splanchnic venous systems.
  • Intra-arterial injections of vasodilators, such as prostaglandin E or papaverine, may increase the amount of contrast agent that reaches the venous system to improve vessel opacification.
  • The technique is useful for defining the anatomy prior to shunt procedures and for evaluating the collateral circulation, including esophageal varices.
  • Major complications include bleeding at the arterial puncture site and dissection or pseudoaneurysm of any artery along the path of the procedure.
• Percutaneous transhepatic portography
  • The technique involves direct puncture of a main portal venous branch under ultrasonographic guidance, fluoroscopic guidance, or both.
  • The patient receives a local anesthesia at the midaxillary line and the 10th intercostal space.
  • A 22-gauge Chiba needle is inserted parallel to the table and slightly inferiorly. The needle is withdrawn while contrast material is injected until a portal branch is opacified.
  • Once the vessel is identified, a 5F catheter is inserted by using the Seldinger technique.
  • Venography may be performed through the catheter.
  • The procedure also may help in evaluating the venous anatomy and in identifying collaterals. It has the added benefit of better opacification of the main and intrahepatic portal venous system in the setting of hepatofugal flow.
  • Intervention, such as variceal embolization, may be performed by using this approach.
  • Although the risk is low with the procedure, morbidity rates are increased compared with those of indirect portography. Potential additional complications include subcapsular hematoma, hemobilia, biloma formation, and perforation of a hollow viscus.
• Hepatic phlebography
  • The technique involves venipuncture of the common femoral or common jugular vein and advancement of a catheter to the level of the hepatic veins through the IVC or SVC, respectively.
  • The primary purpose of the procedure is not to thoroughly evaluate the portal circulation but to evaluate hepatic venous anatomy and to search for postsinusoidal etiologies of portal hypertension.
  • Iodinated contrast material or carbon dioxide may be injected through a catheter wedged in a hepatic vein to obtain digital subtraction images of the hepatic venous system and, possibly, the portal venous system (in hepatofugal flow).
  • The liver parenchyma may be roughly evaluated for indirect signs of cirrhosis (pruned-tree venographic appearance), malignancy, and intrahepatic venous-to-venous anastomoses.
  • Indirect measurement of portal venous pressure may be obtained by measuring the difference between free hepatic venous pressure and hepatic venous wedge pressures.
  • Interventions, such as transvenous liver biopsy and the TIPS procedure, may be performed by using this approach.
  • Complications of the procedure are minimal, with a small possibility of infection and bleeding at the venipuncture site.

Degree of Confidence

Angiographic images may cause as many as 25% of esophageal varices to be missed, and the technique is inferior to endoscopy. Detection is slightly better with a percutaneous technique, but it potentially creates more morbidity than the indirect method. Hepatic phlebography is not a technique designed for the detection of esophageal varices.

False Positives/Negatives

The major disadvantage of angiography is incomplete opacification of the portal venous system, either because of extreme hepatofugal flow, to-and-fro flow, or the dilution of contrast medium. Incomplete opacification may create problems in evaluating for portal vein thrombosis or in detecting collateral pathways, including esophageal varices. Incomplete opacification is more of a problem with the indirect portography technique.

INTERVENTION

Section 10 of 12  

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

On detection of esophageal varices prior to first hemorrhage, medical therapy with propranolol or other nonselective beta-blockers is attempted as the initial treatment method. If varices are of higher endoscopic grade, sclerotherapy or variceal ligation may be performed. In the setting of acute esophageal variceal hemorrhage, control of bleeding can be accomplished endoscopically in 80-90% of patients. Radiologic interventions in the treatment and management of esophageal varices include placement of a TIPS, embolization of esophageal varices, or both.

TIPS is a minimally invasive procedure performed through the jugular vein (preferably the right), in which a shunt between the hepatic and portal veins is created to provide decompression of the portal venous system. The procedure is performed in the setting of acute or recurrent variceal bleeding that cannot be controlled medically or endoscopically.

Other indications for TIPS, other than control of variceal hemorrhage, include refractory ascites, cirrhotic hydrothorax, or portal gastropathy. TIPS can be performed as a bridge to eventual liver transplantation. To date, no significant data have demonstrated a benefit of TIPS in the prevention of refractory or recurrent hemorrhage in patients with Child class A varices or in the prevention of initial variceal hemorrhage.

Contraindications to TIPS include right- or left-sided heart failure, cardiac valve insufficiency, fulminate hepatic failure, unrelieved biliary obstruction, polycystic liver disease, hepatic malignancy, and portal vein thrombosis.

TIPS entails venous access through the right jugular vein with a micropuncture catheter set. The left internal jugular vein or right external jugular vein may be used if the right internal jugular vein is occluded.

• A long 10-12F catheter is advanced down the SVC and into the right hepatic vein. The right hepatic vein is preferred because of its size and proximity to the portal vein.
• A TIPS needle (16-gauge Colapinto, 21-gauge Angiodynamics, or 14-gauge Rosch-Uschida needle) is directed caudally and anteriorly toward the right portal vein. The right portal vein is approximately 0.5-1.5 vertebral body widths to the right of the lateral margin of the spine between the 10th and 12th ribs.
• A small amount of contrast material may be injected into the periportal region to further aid localization.
• Once the portal vein is accessed, a floppy tip guidewire is advanced into the splenic or superior mesenteric vein, over which a 5F catheter is inserted into the main portal vein.
• The portosystemic gradient can be measured at this time by retrieving the sheath to the level of the right atrium. The central venous pressure can be measured in relation to portal venous pressure.
• Portal venogram may be performed at this time.
• Then, the catheter can be exchanged for an 8-mm balloon for angioplasty of the parenchymal segment.
• A wall stent is deployed over the balloon. Commonly used stents include the self-expanding nitinol, Smart, and Symphony stents, which have minimal or no shortening once deployed and can create high amounts of radial force.

The goal of the TIPS procedure is to reduce the portosystemic gradient to less than 12 mm Hg. TIPS is successful in controlling variceal hemorrhage in approximately 97% of patients; however, a significant rebleeding rate of 5-32% is seen at 2 years. Most recurrence is within the first 6 months; this observation is comparable to recurrence after endoscopic therapy. Early complications include stent migration, thrombosis, or shunt dysfunction demonstrated by slow flow secondary to a competing shunt. Later complications include hepatic vein stenosis and pseudointimal hyperplasia within the stent lumen. The criterion standard method for detecting shunt stenosis is venography.

Stenosis is defined as a reduction of diameter of greater than 50%. The preferred method for follow-up imaging after a TIPS procedure is Doppler sonography. Doppler sonography is an excellent noninvasive method for evaluating TIPS patency and flow. A baseline study should be performed the day after the procedure and then at 1 month, 3 months, 6 months, and then every 6 months.

TIPS patency is evaluated by measuring the shunt velocity in the proximal, distal, and middle portions. Direction of portal venous flow should be evaluated. The 1-year patency rate of TIPS is 20-66%. TIPS are associated with a morbidity rate of 10-20%, with a mortality rate of 1-2% immediately after the procedure. Major morbidities include portosystemic encephalopathy (17-36%), right- or left-sided heart failure, and intraperitoneal bleeding secondary to transcapsular puncture (£30%). Most morbidity is related to changing postprocedural flow dynamics and to bypassing the liver to clear metabolic toxins.

The role of embolization in acute esophageal variceal hemorrhage is controversial. Variceal embolization may be performed at the time of TIPS procedure or may be performed by percutaneous/transhepatic procedure to control bleeding. Embolization materials include ethanol, stainless steel coils, or bucrylate. Embolic agents are deployed or injected after selective catheterization of the left gastric vein.

In a study by L'Hermine et al involving 400 patients with variceal embolization, bleeding was controlled in 83%. Recurrence occurred in almost 60% of patients in the first 6 months and 80% in 2 years. The study was performed before the TIPS procedure; therefore, data are from patients with uncorrected underlying portal hypertension. Theoretically, performing the TIPS procedure prior to embolization therapy may decrease the risk of rebleeding; however, no strong clinical data suggest that TIPS and embolization versus TIPS alone is better in preventing recurrent hemorrhage.

Medical/Legal Pitfalls

• Misdiagnosis and failure to diagnose esophageal varices are the only major medical-legal issues.
• Russo et al compared the cost effectiveness of TIPS procedure versus endoscopic therapy for recurrent variceal hemorrhage. The group analyzed costs of the procedure and hospitalizations of patients undergoing TIPS, sclerotherapy, or ligation at 2 medical centers. The authors concluded that, in patients with recurrent hemorrhage, the TIPS procedure has lower recurrent variceal bleeding rates and is more cost-effective in the short-term than endoscopic therapy.

See also the Medscape topic Medical Malpractice and Legal Issues.

Special Concerns

• In children, varices are a consequence of extrahepatic obstruction of the portal vein rather than parenchymal liver disease.
• • Portal venous thrombosis may result from dehydration, sepsis, umbilical vein catheterization, and abdominal infection.
  • The diagnosis is difficult because all clinical laboratory, physical examination, and biopsy results may be normal.
  • Varices may be seen on images such as barium studies, CT scans, or MRIs.
• Detection is important because varices are a major cause of upper GI bleeding in children.
• • After detection, sclerotherapy and variceal ligation have been shown to be superior treatment modalities.
  • TIPS and surgical shunts may also be considered, although success rates are not as promising.

MULTIMEDIA

Section 11 of 12  

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

Media file 1:  Normal venous flow through the portal and systemic circulation.
	View Full Size Image
Media type:  Image

Media file 2:  Redirection of flow through the left gastric vein secondary to portal hypertension or portal venous occlusion. Uphill varices develop in the distal one third of the esophagus.
	View Full Size Image
Media type:  Image

Media file 3:  Direction of venous flow with superior vena cava obstruction proximal to the azygous vein. Flow is redirected through the azygous vein into the systemic circulation. Downhill varices develop in the upper one third of the esophagus.
	View Full Size Image
Media type:  Image

Media file 4:  Direction of flow with superior vena cava obstruction involving or distal to the azygous vein. Flow is redirected through the azygous vein, the esophageal veins, and into the portal circulation. Flow enters the systemic circulation through the inferior vena cava. Downhill varices develop the entire length of the esophagus.
	View Full Size Image
Media type:  Image

Media file 5:  Uphill esophageal varices. Barium swallow demonstrates multiple serpiginous filling defects primarily involving the lower one third of the esophagus with striking prominence around the gastroesophageal junction. The patient had cirrhosis secondary to alcohol abuse.
	View Full Size Image
Media type:  X-RAY

Media file 6:  Uphill esophageal varices on mucosal relief barium swallow.
	View Full Size Image
Media type:  X-RAY

Media file 7:  Uphill esophageal varices on barium swallow.
	View Full Size Image
Media type:  X-RAY

Media file 8:  Downhill esophageal varices. Mucosal relief view shows the serpiginous varicoid filling defects in the proximal esophagus, with normal distal mucosa in this patient with superior vena cava obstruction.
	View Full Size Image
Media type:  X-RAY

Media file 9:  Downhill esophageal varices on barium swallow examination. Notice the serpiginous filling defects proximally with normal appearing esophagus distally.
	View Full Size Image
Media type:  X-RAY

Media file 10:  Barium swallow demonstrating esophageal varices involving the entire length of the esophagus. This appearance may be seen in advanced uphill varices or downhill varices secondary superior vena cava obstruction at or below the level of the azygous vein.
	View Full Size Image
Media type:  X-RAY

Media file 11:  Varices involving the entire esophagus on barium swallow examination. Note the thickened folds with rounded expansions at the level of the gastroesophageal junction that are characteristic of esophageal varices findings on barium studies.
	View Full Size Image
Media type:  X-RAY

Media file 12:  Full-column image of the esophagus with varices throughout its entire length. Note scalloping of the borders of the filled esophagus. This sign, in conjunction with thickened folds with rounded expansions and some degree of distensibility, is pathognomonic for esophageal varices.
	View Full Size Image
Media type:  X-RAY

Media file 13:  CT appearance of esophageal varices. Arrow points to enhancing vascular structures within the wall of the esophagus projecting into the lumen.
	View Full Size Image
Media type:  CT

Media file 14:  CT scan shows large, enhancing paraesophageal varices just to the left of the esophagus. Note the ascites and cirrhosis.
	View Full Size Image
Media type:  CT

Media file 15:  CT sections near the gastroesophageal junction demonstrate esophageal varices protruding into the lumen, as well as paraesophageal varices.
	View Full Size Image
Media type:  CT

Media file 16:  CT scan showing esophageal varices. Note the extensive collateralization within the abdomen adjacent to the spleen as a result of severe portal hypertension (same patient as in Image 12).
	View Full Size Image
Media type:  CT

Media file 17:  Maximum intensity projection MRI of the normal portal venous system. Courtesy of Ali Shirkhoda, MD, William Beaumont Hospital, Royal Oak, Mich.
	View Full Size Image
Media type:  MRI

Media file 18:  Maximum intensity projection MRI (arrow). Courtesy of Ali Shirkhoda, MD, William Beaumont Hospital, Royal Oak, Mich.
	View Full Size Image
Media type:  MRI

Media file 19:  Maximum intensity projection MRI of the portal venous system demonstrates extensive esophageal varices (arrows) in conjunction with splenic and gastric varices. Courtesy of Ali Shirkhoda, MD, William Beaumont Hospital, Royal Oak, Mich.
	View Full Size Image
Media type:  MRI

REFERENCES

Section 12 of 12

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

• Azuma M, Kashiwagi T, Nagasawa M, et al. Evaluation of portosystemic collaterals by SPECT imaging after endoscopic variceal sclerotherapy: usefulness for predicting recurrence. J Nucl Med. Apr 2000;41(4):600-4. [Medline].
• Baum S, Pentecost MJ. Abrams Angiography and Interventional Radiology. 4th ed. Little, Brown & Co;1997:397-404, 525-8, 1027-9.
• Burkart DJ, Johnson CD, Ehman RL. Correlation of arterial and venous blood flow in the mesenteric system based on MR findings. 1993 ARRS Executive Council Award. AJR Am J Roentgenol. Dec 1993;161(6):1279-82. [Medline].
• Burtin P, Cales P, Oberti F, et al. Endoscopic ultrasonographic signs of portal hypertension in cirrhosis. Gastrointest Endosc. Sep 1996;44(3):257-61. [Medline].
• Butler H. The veins of the esophagus. Thorax. 1951;6:276.
• Chedid A, Mendenhall CL, Gartside P, et al. Prognostic factors in alcoholic liver disease. VA Cooperative Study Group. Am J Gastroenterol. Feb 1991;86(2):210-6. [Medline].
• Cho KC, Patel YD, Wachsberg RH, Seeff J. Varices in portal hypertension: evaluation with CT. Radiographics. May 1995;15(3):609-22. [Medline].
• Cihangiroglu M, Lin BH, Dachman AH. Collateral pathways in superior vena caval obstruction as seen on CT. J Comput Assist Tomogr. Jan-Feb 2001;25(1):1-8. [Medline].
• Cotran RS, Kumar V, Collins T. Robbins Pathologic Basis of Disease. 6th ed. WB Saunders Co;1999:845-901.
• Escorsell A, Garcia-Pagan JC, Bosch J. Assessment of portal hypertension in humans. Clin Liver Dis. Aug 2001;5(3):575-89. [Medline].
• Felson B, Lessure AP. "Downhill" varices of the esophagus. Dis Chest. 1964;46:740-6.
• Fevery J, Nevens F. Oesophageal varices: assessment of the risk of bleeding and mortality. J Gastroenterol Hepatol. Aug 2000;15(8):842-8. [Medline].
• Gazelle GS, Saini S, Mueller PR. Hepatobiliary and Pancreatic Radiology: Imaging and Intervention. Thieme Medical Pub;1998:294-317.
• Gore RM, Livine MS. Textbook of Gastrointestinal Radiology. 2nd ed. WB Saunders Co;2000:454-63, 2082.
• Grace ND. Prevention of initial variceal hemorrhage. Gastroenterol Clin North Am. Mar 1992;21(1):149-61. [Medline].
• Hegab AM, Luketic VA. Bleeding esophageal varices. how to treat this dreaded complication of portal hypertension. Postgrad Med. 2001;109:75-89. [Medline].
• Hughes LA, Hartnell GG, Finn JP, et al. Time-of-flight MR angiography of the portal venous system: value compared with other imaging procedures. AJR Am J Roentgenol. Feb 1996;166(2):375-8. [Medline].
• Irisawa A, Saito A, Obara K. Endoscopic recurrence of esoophageal varices is associated with specific EUS abnormalities: severe periesophageal collateral veins and large perforating veins. Gastrointest Endosc. 2001;53:77-84. [Medline].
• Ishikawa T, Saeki M, Yoshihiko T. Detection of paraesophageal varices by plain films. Am J Roentgenol. 1985;144:701-4.
• Kirsh IE, Blackwell CC, Bennett HD. Roentgen diagnosis of esophageal varices: comparison of roentgen and esophagoscopic findings in 502 cases. AJR Am J Roentgenol. 1955;74:477-85.
• L''Hermine C, Chastanet P, Bonniere P, Gauthier P. [Embolization treatment of hemorrhages due to intestinal and umbilical varices in portal hypertension]. Ann Radiol (Paris). 1987;30(2):161-4. [Medline].
• Lahoti S, Catalano MF, Alcocer E. Obliteration of esophageal varices using EUS-guided sclerotherapy with color doppler. Gastrointest Endosc. 2000;51:331-3. [Medline].
• Lee JK, Sagel SS, Stanley RJ. Computed Body Tomography with MRI Correlation. Lippincott Williams & Wilkins;1998:645-6.
• Lefkovitz Z, Cappell MS, Kaplan M, et al. Radiology in the diagnosis and therapy of gastrointestinal bleeding. Gastroenterol Clin North Am. Jun 2000;29(2):489-512. [Medline].
• Lowe RC, Grace ND. Pharmacologic therapy for portal hypertension. Curr Gastroenterol Rep. Feb 2001;3(1):24-9. [Medline].
• Luketic VA, Sanyal AJ. Esophageal varices. I. Clinical presentation, medical therapy, and endoscopic therapy. Gastroenterol Clin North Am. Jun 2000;29(2):337-85. [Medline].
• Merkel C, Bolognesi M, Angeli P, et al. Prognostic indicators of survival in patients with cirrhosis and esophageal varices, without previous bleeding. Am J Gastroenterol. Jul 1989;84(7):717-22. [Medline].
• Mikkelsen WJ. Varices of the upper esophagus in superior vena caval obstruction. Radiology. 1963;81:945-8.
• Nelson SW. The roentgenologic diagnosis of esophageal varices. AJR Am J Roentgenol. 1957;77:599-611.