Portal Hypertension

Question 1

Variceal hemorrhage, hepatic encephalopathy, and ascites—the major complications of cirrhosis of the liver

Answer 1

result from portal hypertension, defined as an increase in hepatic sinusoidal pressure to 6 mm Hg or greater

Question 2

The portal vein is formed by the confluence

Answer 2

of the splenic vein and the superior mesenteric vein behind the neck of the pancreas

Question 3

The portal vein

Answer 3

is approximately 7.5 cm in length and runs dorsal to the hepatic artery and bile duct into the hilum of the liver.

Question 4

In the hilum of the liver,

Answer 4

the portal vein divides into the left and right portal vein branches, which supply the left and right sides of the liver

Question 5

The umbilical vein

Answer 5

drains into the left portal vein, and the cystic vein from the gallbladder drains into the right portal vein.

Question 6

The liver receives a dual blood supply from the

Answer 6

portal vein and the hepatic artery that constitutes nearly 30% of total cardiac output.

Question 7

Portal venous blood derived from the

Answer 7

mesenteric venous circulation constitutes approximately 75% of total hepatic blood flow, whereas the remainder of blood to the liver is derived from the hepatic artery, which provides highly oxygenated blood directly from the celiac trunk of the aorta.

Question 8

Other unique aspects of the hepatic sinusoids are

Answer 8

the space of Disse, a virtual space located extraluminal to the endothelial cell and adjacent to the hepatocyte, and its cellular constituents, the hepatic stellate cell (HSC) and the Kupffer cell

Question 9

Four distinct zones of venous drainage at the gastroesophageal junction are particularly relevant to the formation of esophageal varices

Answer 9

The gastric zone, which extends for 2 to 3 cm below the gastroesophageal junction, comprises veins that are longitudinal and located in the submucosa and lamina propria. They come together at the upper end of the cardia of the stomach and drain into short gastric and left gastric veins.

Question 10

Four distinct zones of venous drainage at the gastroesophageal junction are particularly relevant to the formation of esophageal varices

Answer 10

The palisade zone extends 2 to 3 cm proximal to the gastric zone into the lower esophagus.

The palisade zone is the dominant watershed area between the portal and systemic circulations.

Question 11

Four distinct zones of venous drainage at the gastroesophageal junction are particularly relevant to the formation of esophageal varices

Answer 11

More proximal to the palisade zone in the esophagus is the perforating zone, where there is a network of veins. These veins are less likely to be longitudinal and are termed perforating veins because they connect the veins in the esophageal submucosa and the external veins.

Question 12

Four distinct zones of venous drainage at the gastroesophageal junction are particularly relevant to the formation of esophageal varices

Answer 12

The truncal zone, the longest zone, is approximately 10 cm in length, located proximal to the perforating zone in the esophagus, and usually characterized by 4 longitudinal veins in the lamina propria.

Question 13

The fundus of the stomach drains

Answer 13

through short gastric veins into the splenic vein.

Question 14

progression of portal hypertension results from

Answer 14

1) the prominent obstructive resistance in the liver; (2) resistance within the collaterals themselves; and (3) continued increase in portal vein inflow.

Question 15

Hepatic Vein Pressure Gradient

Answer 15

The HVPG is the difference between the wedged hepatic venous pressure (WHVP) and free hepatic vein pressure (FHVP).

Question 16

Measurement of the HVPG has been proposed for the following indications:

Answer 16

1) to monitor portal pressure in patients
taking drugs used to prevent variceal bleeding; (2) as a prognostic marker (3) as an end point in trials using pharmacologic
agents for the treatment of portal hypertension; (4) to assess
the risk of hepatic resection in patients with cirrhosis; and (5) to
delineate the cause of portal hypertension (i.e., presinusoidal,
sinusoidal, or postsinusoidal usually in combination with venography, right-sided heart pressure measurements, and transjugular liver biopsy.

Question 17

DETECTION OF VARICES

Answer 17

EGD is the most commonly used method to detect esophageal varices

Question 18

If small varices are detected on the initial examination,

Answer 18

endoscopy should be repeated in 1 to 2 years.

Question 19

In patients in whom no varices are detected on initial evaluation,

Answer 19

endoscopy to screen for varices should be repeated in 2 to 3 years.

Question 20

a platelet count less than 110,000/mm3 and liver stiffness measurement by transient elastography greater than 25 kPa

Answer 20

may identify with a high degree of confidence the patients who may need therapy to prevent variceal bleeding.

Question 21

The best known criteria are those compiled by the Japanese Research Society for Portal Hypertension

Answer 21

descriptors include red color signs, color of the varix, form (size) of the varix, and location of the varix.
Red color signs include red “wale” markings, which are longitudinal whip-like marks on the varix;
cherry-red spots, which usually are 2 to 3 mm or less in diameter;
hematocystic spots, which are blood-filled blisters 4 mm or greater in diameter; and diffuse redness.
The color of the varix can be white or blue.

Question 22

Esophageal varices may be small and straight

Answer 22

Grade 1

Question 23

tortuous and occupying less than one third of the esophageal lumen

Answer 23

Grade 2

Question 24

or large and occupying more than one third of the esophageal lumen

Answer 24

Grade 3

Question 25

US

Answer 25

portal vein diameter greater
than 13 mm and the absence of respiratory variations in the
splenic and mesenteric veins are sensitive but nonspecific markers of portal hypertension

Question 26

Causes of Portal Hypertension

Answer 26

COMMON
Cirrhosis
Schistosomiasis
Extrahepatic portal vein thrombosis Idiopathic portal hypertension Cardiac fibrosis

Question 27

Schistosomiasis

Answer 27

Portal hypertension results from presinusoidal obstruction caused by deposition of eggs of Schistosoma mansoni or Schistosoma japonicum in the presinusoidal portal venules.

Question 28

he host reaction results in granulomatous inflammation, which causes presinusoidal and peri- portal fibrosis.
The fibrosis that results is sometimes called “clay pipestem” or simply “pipestem” fibrosis and is associated with sustained heavy infection.

Answer 28

Schistosomiasis

Question 29

the agents that decrease splanchnic blood flow acutely

Answer 29

vasopressin and its analogs and somatostatin and its analogs.

Question 30

DRUGS THAT DECREASE PORTAL BLOOD FLOW

Answer 30

Nonselective β-adrenergic blocking agents (e.g., propranolol, nadolol) Somatostatin and its analogs
Vasopressin and terlipressin

Question 31

DRUGS THAT DECREASE INTRAHEPATIC RESISTANCE

Answer 31

α1-Adrenergic blocking agents (e.g., prazosin) Angiotensin receptor blocking agents
Nitrates

Question 32

Diuretics,

Answer 32

ecreasing plasma volume, may reduce portal pressure but are not recommended if the patient does not have ascites.

Question 33

Vasopressin

Answer 33

is an endogenous peptide hormone that causes splanchnic vasoconstriction, reduces portal venous inflow, and decreases portal pressure.

Question 34

Nonselective beta blockers such as pro-

pranolol or nadolol are preferred.

Answer 34

Blockade of β1-adrenergic
receptors in the heart decreases cardiac output.
Blockade of
β2-adrenergic receptors, which cause vasodilatation in the mesenteric circulation, allows unopposed action of α1-adrenergic
receptors and results in decreased portal flow.

Question 35

Carvedilol

Answer 35

is a drug that has both nonselective beta blocker and weak α-receptor blockade activity.

known to have antioxidant as well as antiproliferative actions and may be superior to endoscopic variceal ligation in the prevention of a first variceal bleed.

Carvedilol is started at a dose of 3.125 mg twice daily, and the dose is increased stepwise to a maximum of 25 mg daily

Question 36

Nitrates

Answer 36

short-acting (nitroglycerin) or long-acting (isosorbide mononitrate) nitrates result in vasodilatation.

Question 37

Endoscopic variceal ligation

Answer 37

eferred endoscopic modality for control of acute esophageal variceal bleeding and prevention of rebleeding

Question 38

Control of Acute Bleeding

Answer 38

The approach to treating esophageal variceal hemorrhage also applies to acute gastric variceal hemorrhage and includes volume resuscitation, avoidance of overtransfusion, and antibiotic prophylaxis with norfloxacin, 400 mg twice daily, or ciprofloxacin, 500 mg twice daily, for 7 days.

Question 39

A diagnosis of gastric variceal hemorrhage should be considered if bleeding is noted from a gastric varix

Answer 39

blood is found to appear at the gastro- esophageal junction or the gastric fundus; blood is found in the stomach and gastric varices with a “white nipple sign” (indicating a fibrin-platelet plug) are seen in the absence of other causes of bleeding;

Question 40

The preferred endoscopic therapy for fundal gastric variceal bleeding

Answer 40

injection of polymers of cyanoacrylate, usually N-butyl-2-cyanoacrylate,

The mucosa overlying the varix injected eventually sloughs, and the hardened polymer is extruded.

Question 41

Prevention of Rebleeding

Answer 41

Cyanoacrylate glue injection may be superior to nonselective beta blockers in preventing gastric variceal rebleeding.

Question 42

Ectopic Varices

Answer 42

They also may manifest with hemobilia, hematuria, hemoperitoneum, or retroperitoneal bleeding.

The duodenum is a common site of ectopic varices, and varices typically are associated with portal vein obstruction, but in the West, the usual cause of duodenal varices is cirrhosis.

Question 43

Anorectal varices

Answer 43

reported in 10% to 40% of cirrhotic patients who undergo colonoscopy

Rectal varices are dilated superior and middle hemorrhoidal veins, whereas hemorrhoids are dilated vascular channels above the dentate line.
Rectal varices collapse with digital pressure, but hemorrhoids do not.

Question 44

Endoscopic glue injection or band ligation is the

Answer 44

preferred approach for bleeding duodenal varices.

Question 45

The diagnosis of PHG

Answer 45

mosaic-like pattern of the gastric mucosa on endoscopic examination.
This pattern is characterized by small polygonal areas with a depressed border. Superimposed on this mosaic- like pattern may be red point lesions that are usually greater than 2 mm in diameter.
PHG is considered mild when only a mosaic-like pattern is present and severe when superimposed discrete red spots are also seen.

Question 46

In GVE

Answer 46

aggregates of ectatic vessels can be seen on endoscopic examination as red spots without a mosaic background.

GVE appears histologically as dilated mucosal capillaries with focal areas of fibrin thrombi or ectasia in combination with proliferation of spindle cells.

Question 47

Treatment GVE

Answer 47

The more common presentation is one of chronic, slow bleeding and anemia.
Pharmacologic therapy to prevent bleeding (primary prophylaxis) in patients with severe PHG is not currently recommended.

Question 48

For GVE: If lesions are localized, the platelet count is greater than approximately 45,000/mm3, and the INR is less than 1.4,

Answer 48

thermoablative therapy, as with argon plasma coagulation, may be helpful

Question 49

When the vascular ectasias are diffuse and extensive in the stomach,

Answer 49

cryotherapy using liquid nitrogen or CO2 may be tried.

If endoscopic treatment fails, therapy with an oral estrogen-progesterone combination (estradiol 35 μg plus norethindrone 1 mg daily) may help reduce transfusion requirements.