Gastrointestinal varices overview

# Overview
Gastrointestinal varices were initially described as dilated veins that bulge into the lumen, producing uneven worm like surface of the inside of esophagus. Varices in the gastrointestinal tract are thought to arise due to increased pressure in the portal venous system, leading to establishment of porto-systemic shunts. In the 20th century, sclerotherapy became an important treatment option in the management of variceal haemorrhage, especially with the advent of fibre-optic endoscopy. In 1950, The Sengstaken-Blakemore tubes use was first described by Sengstaken and Blakemore and later used as a treatment option. Gastrointestinal varices may be further classified into esophageal and gastric varices. Esophageal varices may be further divided according to various classification systems such as the Dagradi classification, Conn's classification, Pachquet classification, Westaby classification, Soehendra classification and Cales classification. Gastric varices may be classified according to Hoskins and Johnsons classification, Mathurs classification, Hashizume classification and Sarin's classification system. Varices arise from hemodynamic disturbance between the systemic and portal venous system. The majority of venous drainage of the gastrointestinal system occurs via the portal venous system. Whenever there is an interruption of drainage through the portal system (for example due to cirrhosis), the vessels contributing to the porto-caval shunts become more prominent due to increased pressure gradient. The interruption in blood flow leads to the creation collateral vessels that involve veins of the esophagus, stomach, pelvis (hemorrhoids), retroperitoneum, liver, abdominal wall, and other areas. Causes of gastointestinal varices include all the causes of increased portal venous pressure, which may be divided into cirrhotic and non-cirrhotic causes. Non-bleeding varices are asymptomatic. Ruptured esophageal and gastric varices may lead to upper gastrointestinal bleeding and present with hematemesis. They must be differentiated from other causes of upper gastrointestinal bleeding such as peptic ulcer disease, esophagitis, gastritis, angiodysplasia, Dieulafoy's lesion, vascular ectasia, Mallory-Weiss tears, aorto-enteric fistulas and upper gastrointestinal tumors. Gastroesophageal varices are present in approximately 50,000 per 100,000 patients with cirrhosis, depending upon the clinical stage of the disease. The annual incidence of gastrointestinal varices ranges from a low of 7,000 per 100,000 individuals to a high of 8,000 per 100,000 individuals. Variceal hemorrhage occurs at a rate of around 10%-15% per year. If left untreated, recurrent variceal hemorrhage occurs in 60% of patients, usually within 1-2 years of the initial hemorrhage. Complications include, transient dysphagia, chest pain, esophageal ulceration, ulcerogenic bleeding, post-therapeutic hemorrhage, esophageal strictures, pleural effusions, pericarditis and portal vein thrombosis. Factors associated with a poor prognosis of presence of bacterial infections, HVPG >20 mm Hg, alcohol intake and obesity. The AIMS65 score is the best predictor of mortality in patients with variceal bleeding. Esophagogastroduodenoscopy (EGD) is the gold standard test for the diagnosis of gastrointestinal varices. EGD should be performed once the diagnosis of cirrhosis is established. Physical examination of patients with gastrointestinal varices is usually remarkable for ascites, pallor, jaundice, tachycardia, low blood pressure in case of shock, hepatomegaly or shrunken liver (in case of cirrhosis), splenomegaly, altered mental status, palmar erythema, cyanosis and clubbing. X-ray taken after a barium swallow in cases of gastrointestinal varices may show multiple radiolucent filling defects. On CT scan gastrointestinal varices may appear as well-defined, tubular structures that have a smooth appearance with homogeneous attenuation. Upper endoscopy may be helpful in the diagnosis of gasteroesophageal varices. Findings on an upper endoscopy diagnostic of esophageal varices include visible submucosal tortuous veins, congested veins without compression during air insufflation, and grape-like varicose veins that may occlude the lumen. Medical therapy in cases of gastrointestinal varices includes goal-directed management of the cause of portal hypertension along with specific management of varices after their development. The treatment is aimed at optimizing portal venous inflow, portal pressure and portal resistance. The pharmacological therapy includes vasoconstrictors (beta blockers) and venodilators (nitrates). These therapies may be employed alone or in combination with endoscopic variceal ligation/sclerotherapy and transjugular intrahepatic shunt (TIPS) therapy depending upon the condition of the patient.

# Historical Perspective
In 1850s, Sappey for the first time, described esophageal varices. In 1877, well before the role of portal hypertension in the development of variceal disease was understood, Nikolai Eck had already established the role of port-caval shunts to relieve animals from ascites. Popularly known as the Eck fistula, these shunts were employed in the treatment of eight dogs, seven of which died post-operatively and one escaped the laboratory. In 1906 Gilbert and Villaret coined the term portal hypertension. In 1928, Wolf first showed esophageal varices on thin barium roentgenograms as small dilated structures with a lumen. In 1931, Schatzki published the first findings of gastric varices on roentgenograms of five patients, followed by 45 further patients with esophageal and gastric varices in 1933. Varices were initially described as dilated veins that bulge into the lumen, producing uneven worm like surface of the inside of esophagus. In 1939, Crafoord and Freckner discovered sclerotherapy with the help of quinine for the management of esophageal varices. In the 20th century, sclerotherapy became an important treatment option in the management of variceal haemorrhage, especially with the advent of fibre-optic endoscopy. In 1950, The Sengstaken-Blakemore tubes use was first described by Sengstaken and Blakemore and later used as a treatment option. Ethanolamine oleate, sodium tetradecyl sulphate, polidocanol, sodium morrhuate and ethanol have been used as treatment options in sclerotherapy. In 1988, endoscopic variceal band ligation (EVBL) was first used for the treatment of esophageal varices, based on the concept of banding haemorrhoids with elastic O-rings. EVBL became a treatment option for the treatment of esophageal varices in 1990s. Antibiotics were recently used for the first time during the management of varices. Antibiotics were found to decrease the rate of bacterial infections, recurrent bleeding and improve mortality in patients bleeding from esophageal varices.

# Classification
Gastrointestinal varices may be further classified into esophageal and gastric varices. Esophageal varices may be further divided according to various classification systems such as the Dagradi classification, Conn's classification, Pachquet classification, Westaby classification, Soehendra classification and Cales classification. Gastric varices may be classified according to Hoskins and Johnsons classification, Mathurs classification, Hashizume classification and Sarin's classification system. These classificatication systems are based on morphological features, anatomical location, size and color of the varices.

# Pathophysiology
Varices arise from hemodynamic disturbance between the systemic and portal venous system. The majority of venous drainage of the gastrointestinal system occurs via the portal venous system. Whenever there is an interruption of drainage through the portal system (for example due to cirrhosis), the vessels contributing to the porto-caval shunts become more prominent due to increased pressure gradient. The interruption in blood flow leads to the creation of collateral vessels that involve veins of the esophagus, stomach, pelvis (hemorrhoids), retroperitoneum, liver, abdominal wall, and other areas.

# Causes
Causes of gastointestinal varices include all the causes of increased portal venous pressure, which may be divided into cirrhotic and non-cirrhotic causes.

# Differentiating Gastrointestinal Varices From Other Diseases
Non-bleeding varices are asymptomatic. Ruptured esophageal and gastric varices may lead to upper gastrointestinal bleeding and present with hematemesis. They must be differentiated from other causes of upper gastrointestinal bleeding such as peptic ulcer disease, esophagitis, gastritis, angiodysplasia, Dieulafoy's lesion, vascular ectasia, Mallory-Weiss tears, aorto-enteric fistulas and upper gastrointestinal tumors.

# Epidemiology and Demographics
Gastroesophageal varices are present in approximately 50,000 per 100,000 patients with cirrhosis, depending upon the clinical stage of the disease. The annual incidence of gastrointestinal varices ranges from a low of 7,000 per 100,000 individuals to a high of 8,000 per 100,000 individuals. Variceal hemorrhage occurs at a rate of around 10%-15% per year and depends on the severity of liver disease, size of varices, and presence of red wale marks (areas of thinning of the variceal wall).

# Risk Fators
The most potent risk factor for the development of gastrointestinal varices is increased portal venous pressure. Conditions that predispose an individual to development of increased portal venous pressure and consequently leading to varices can be divided into those leading to development of varices, those involved in progression of varices from small to large size and those leading to variceal hemorrhage.

# Screening
Screening esophagogastroduodenoscopy (EGD) for the diagnosis of esophageal and gastric varices is recommended after the diagnosis of cirrhosis is made.

# Natural History, Complications and Prognosis
If left untreated, recurrent variceal hemorrhage occurs in 60% of patients, usually within 1-2 years of the initial hemorrhage. Gastrointestinal varices are an indication of increased portal venous pressure, especially in cirrhotic patients. The progressive increase in portal pressure leads to a progressive increase in size of the varices and an increased vascular wall tension. Variceal hemorrhage resulting from rupture occurs when the expanding force exceeds the maximal wall tension. Complications include, transient dysphagia, chest pain, esophageal ulceration, ulcerogenic bleeding, post-therapeutic hemorrhage, esophageal strictures, pleural effusions, pericarditis and portal vein thrombosis. Factors associated with a poor prognosis of presence of bacterial infections, HVPG >20 mm Hg, alcohol intake and obesity. The AIMS65 score is the best predictor of mortality in patients with variceal bleeding.

# Diagnosis

## Diagnostic study of choice
Esophagogastroduodenoscopy (EGD) is the gold standard test for the diagnosis of gastrointestinal varices. EGD should be performed once the diagnosis of cirrhosis is established.

## History and symptoms
Patients suffering from gastrointestinal varices may present with other co-morbid conditions which lead to portal hypertension. Chronic liver disease and portal vein thrombosis commonly lead to the development of gastrointestinal varices. Patients with a family history of venous abnormalities, hypercoaguable states, autosomal recessive polycystic kidney disease (may lead to hepatic fibrosis), nephronophthisis 1, Joubert syndrome and related disorders 5, cranioectodermal dysplasia (Sensenbrenner syndrome), Ellis-van Creveld syndrome, Jeune asphyxiating thoracic dystrophy, renal-hepatic-pancreatic dysplasia, autosomal dominant polycystic kidney disease have an increased risk of developing gastrointestinal varices. Non-bleeding gastrointestinal varices do not produce any symptoms, however bleeding gastrointestinal varices may lead to hematemesis, abdominal pain, lightheadedness, loss of consciousness, melena, bloody stools (in severe cases), shock (in case of loss of a large volume of blood).

## Physical examination
Physical examination of patients with gastrointestinal varices is usually remarkable for ascites, pallor, jaundice, tachycardia, low blood pressure in case of shock, hepatomegaly or shrunken liver (in case of cirrhosis), spleenomegaly, altered mental status, palmar erythema, cyanosis and clubbing.

## Laboratory findings
Cirrhosis of the liver is the most common cause of portal hypertension worldwide. A range of laboratory values may be obtained in the evaluation of cirrhosis, in order to determine disease severity and causation. Liver function tests, complete blood count, basic metabolic panel and coagulation factors are standard in the evaluation of cirrhosis. More specific testing for markers and serum enzymes may be performed when certain etiologies are suspected.

## Electrocardiogram
Electrocardiogram (EKG) in case of variceal bleeding after rupture may show sinus tachycardia.

## Echocardiography/Ultrasound
Echo-Doppler may be helpful in the diagnosis of portal hypertension. Findings on an echo-doppler suggestive of portal hypertension include lack of increase in portal vein diameter in response to meals, increased portal blood flow velocity, and decreased portal vein cross-sectional area. Color-Doppler ultrasound may be helpful in the diagnosis of portal hypertension. Findings on a color-doppler ultrasound suggestive of portal hypertension include increased diameter of left gastric vein, increased diameter of portal vein, and increased flow velocity in left gastric vein. Biphasic and reverse flow in portal vein along with re-canalization of umbilical vein are pathognomonic for portal hypertension.

## X-Ray
X-ray taken after a barium swallow in cases of gastrointestinal varices may show multiple radiolucent filling defects.

## CT scan
On CT scan gastrointestinal varices may appear as well-defined, tubular structures that have a smooth appearance with homogeneous attenuation.

## MRI
There are no abnormal MRI findings associated with gastrointestinal varices.

## Other imaging findings
Upper endoscopy may be helpful in the diagnosis of gasteroesophageal varices. Findings on an upper endoscopy diagnostic of esophageal varices include visible submucosaltortuous veins, congested veins without compression during air insufflation, and grape-like varicose veins that may occlude the lumen. Three dimensional portal venography may be helpful in the diagnosis of gasteroesophageal varices. Findings on a portal venography diagnostic of esophageal varices include reverse flow in porto-systemic shunts, collateral veins draining into inferior vena cava (IVC), and other collateral veins.

## Other diagnostic studies
Hepatic venous pressure gradient (HVPG) is the difference between hepatic venous wedge pressure (HVWP) and free hepatic venous pressure (FHVP). HVPG reflects the intra-sinusoidal pressure. HVPG is measured through insertion of a catheter in right internal jugular vein.

# Treatment

## Medical therapy
Medical therapy in cases of gastrointestinal varices includes goal-directed management of the cause of portal hypertension along with specific management of varices after their development. The treatment is aimed at optimizing portal venous inflow, portal pressure and portal resistance. The pharmacological therapy includes vasoconstrictors (beta blockers) and venodilators (nitrates). These therapies may be employed alone or in combination with endoscopic variceal ligation/sclerotherapy and transjugular intrahepatic shunt (TIPS) therapy depending upon the condition of the patient.

## Surgery
Endoscopic procedures along with pharmacotherapy is the first line management of gastrointestinal varices. During endoscopic procedures the rate of hemostasis failure is almost 10%-20%, and mortality is approximately 60% if a second unsuccessful endoscopic treatment is performed without further intervention. In such situation surgical intervention may be required to achieve hemostasis and to stop the bleeding. Surgical shunts used for the management of bleeding gastrointestinal varices include pericardial devascularization plus proximal splenorenal shunt, Warren shunt, interposition shunts, caval-mesenteric shunts, end-to-end portacaval shunts with hepatic arterialization, left gastric vena-caval shunt and conventional splenorenal shunt. Non-shunting surgical procedures include ligation of varices and esophageal transection, splenic artery ligation and splenectomy.

# Prevention

## Primary prevention
Primary prevention of variceal bleeding may be achieved via rigorous surveillance of varices after their development and via the use non-selective beta blockers and/or endoscopic band ligation (EBL). Liver disease is the most common cause of portal hypertension and effective measures for the primary prevention of liver diseases includehepatitis B vaccination, avoidance from unprotected sexual intercourse, precise screening of the blood products before infusion, reducing alcohol consumption, obesityprevention, and diabetes mellitus prevention.

## Secondary prevention
Secondary prevention of gastrointestinal varices involves prevention of rebleeding. The choice of method chosen for secondary prevention of gastrointestinal varices depends upon the condition of the patient, medication history and response to treatment. Methods used for secondary prevention include the use of beta blockers, band ligation, TIPS and liver transplantation.