Portal Hypertension Flashcards
What is the definition of portal hypertension?
- portal vein pressure > 12mmHg
- portal vein to hepatic vein pressure gradient greater than 5
What does the portal vein drain?
- lower esophagus
- stomach
- small & large intestines
- spleen
- pancreas
- gallbladder
Which veins form the portal vein?
Superior mesenteric vein & splenic vein
Which veins cause the varices in portal hypertension?
- umbilical & paraumbilical veins enlarge -> form umbilical varices
- coronary vein receives distal esophageal veins -> form esophago-gastric varices
What is the pathophysiology of portal hypertension?
- increase in vascular resistance: in cirrhosis -> mechanical consequence of hepatic architectural disorder
- > deposition of collagen in spaces of Disse
- > contraction of myofibroblasts
- increase in portal blood flow
Splanchnic arteriolar vasodilatation -> portosystemic collaterals
What are the prehepatic causes of increased vascular resistance?
- portal vein thrombosis
- splenic vein thrombosis
- congenital atresia or stenosis of portal vein
- extrinsic compression
- umbilical vein sepsis in children
What are the hepatic causes of increased resistance to flow?
- hepatic cirrhosis
- congenital hepatic fibrosis
- bilharzial peri-portal fibrosis
- lymphoma
- acute & fulminant hepatitis
- veno-occlusive disease
What are the post hepatic causes of increased resistance to flow?
- IVC obstruction
- right side heart failure
- constrictive pericarditis
- tricuspid regurgitation
- budd-chiari syndrome
What are the causes of increased blood volume of portal blood flow?
- Porto-hepatic fistula
- increased splenic flow (splenomegaly)
What are the consequences of portal HTN?
- enlargement of liver then shrinks with failure
- spleen enlarged with RES hyperplasia
- portosystemic shunt
- ascitis
- congestive gastropathy
How to determine the presence of complications?
- upper GI bleeding
- mental status change: lethargy, increased irritability, altered sleep patterns (portosystemic encephalopathy)
- increased abdominal girth (ascites formation)
- hematochezia & melena (bleeding from portal colopathy)
What are the signs of porto-systemic collateral formation?
- dilated veins in the anterior abdominal wall (umbilical epigastric shunts)
- caput medusa
- rectal varices
What will be seen on physical examination of person with portal hypertension?
- signs of porto systemic collaterals
- ascites (dullness in flanks with +ve shifting dullness & fluid thrill)
- splenomegaly
- paraumbilical hernia
- inguinal hernia or hydrocele
What are the signs of liver cell dysfunction?
- ascites
- jaundice
- spider angiomas
- palmar erythema
- testicular atrophy
- gynecomastia
- muscle wasting
What is the cause for morbidity & mortality in portal hypertension?
- variceal hemorrhage: most common
first episode has mortality of 30-50%
second episode has mortality of 80%
90% of patients with cirrhosis develop varices
What are the factors that lead to rupture and bleeding in esophageal varices?
food, reflux, & PHT causing ulcerations & erosions
Which varices are considered risky?
- > 15mm (1.5cm)
- unhealthy mucosa
- cherry red spots
What is the cause of splenomegaly in portal HTN?
EARLY -> toxins -> RE hyperplasia
LATE due to congestive splenomegaly -> 2ndry hypersplenism -> splenic infarction
What are the signs of GIT congestion?
- anorexia
- dyspepsia
- malabsorption
- gastric gastropathy
Whats the reason for ascities in portal HTN?
- increased aldosterone & ADH leads to salt & water retention
- increased hepatic transudation (WEEPING LIVER)
- hypo-albuminemia
- PHT is a localizing factor of the fluid into the peritoneal cavity
How should ascities be treated?
- best rest
- sodium restriction
- fluid restriction
- diuretics
- large volume paracentesis with 6-10g albumin/1L fluid
- TIPS
- LeVeen shunt & Denver shunt (peritoneovenous shunt)
- side to side portocaval shunt
What are the investigations done for portal HTN?
- assessment of liver function
- detection of varices (endoscope, barium swallow, Duplex)
- detection of hypersplenism (radioactive isotope, CBC, BM exam)
- liver biopsy, ultrasound
- pre-op measurement of portal HTN
What is the most effective method for screening for portal HTN & helps in diagnosing the cause?
DUPLEX ULTRASONOGRAPHY
- can demonstrate volume & direction of portal flow
- diagnoses the cause (PV thrombosis or splenic vein thrombosis)
How is portal pressure measured?
- hepatic venous pressure gradient (HVPG)
- wedge hepatic venous pressure WDVP - free hepatic venous pressure (FHVP)