Portal Hypertension
Overview
Normal portal vein pressure is 5–10mmHg. Portal hypertension develops when the portal pressure is greater than 12mmHg.
Mechanism of disease
Increased Intrahepatic resistance of blood flow through the liver due to cirrhosis
Increased splanchnic blood flow secondary to vasodilation leading to increased portal flow through liver
Cirrhosis is the most common cause of portal hypertension.
Portal Vein Anatomy
The portal vein drains blood from the GIT so that nutrition absorbed can first enter the liver
Portal vein is formed from the superior mesenteric vein and splenic vein
Portal vein ← Superior mesenteric vein + Splenic vein
Splenic vein ← inferior mesenteric vein
CAUSES OF PORTAL HYPERTENSION Prehepatic Hepatic Posthepatic Portal Vein thrombosis Cirrhosis Budd-Chiari Syndrome Splenic Vein thrombosis Acute hepatitis Constrictive pericarditis Massive splenomegaly Parasitic – Schistomosis Tricuspid Regurgitation
Complications of Portal Hypertension
Gastroesophageal varices
Portal Hypertensive gastropathy
Splenomegaly
Ascites
Management
Treat complications above
Tranjugular Intrahepatic portosystemic shunt (TIPS)
Liver transplantation (definitive)
Oesophageal-gastric varices
Overview
>75% of patients with cirrhosis will eventually develop varices. Risk of variceal haemorrhage is 5-15% per year, and is related to variceal size. Risk amplified in progressive CPS and presence of red wale marks. Without secondary prophylaxis , re-bleeding occurs in 60-70%, usually within the first 2 years of index bleed. Screening is important.
Mechanism of disease
Varceal haemorrhage results from rupture of the variceal wall due to excessive wall tension. Tension opposes the variceal transmural pressure, which depends upon portal pressure and vessel size . Once variceal wall rupture occurs, the amount of bleeding is mainly related portal pressure.
Major complication of cirrhosis and portal hypertension is gastroesophageal varices with haemorrhage.
Investigations
Gastroscopy
CT abdo
MRI abdo
Management of varices
Prevention – Screening those at risk with gastroscopy
yearly – small varices
2nd yearly – no varices
If high risk bleeding (Medium and large varices, Any size with red wale markings):
Betablockers – Propranolol (to reduce portal venous pressure) OR
Endoscopic variceal band ligation
Pharmacology
Non-selective BetaBlocker (propranolol) – mechanism of action – Reduction in cardiac output and splanchnic blood flow. It allows unopposed alpha-1 adrenergic receptor activity which results in splanchnic vasoconstriction and reduction in portal pressure.
Acute management of variceal bleed – emergency
Resuscitation
Bloods – cross match (aim Hb >70)
Monitor
Fluid resuscitation
Contact gastroenterological/surgical team for emergency gastroscopy
IV Proton pump inhibitors
IV Somatostatin OR octreotide
Consider giving vitamin K and fresh frozen plasma to correct clotting problems
Antibiotics – oral norfloxacin OR IV ciprofloxacin
Balloon tamponade – for those who can not get endoscopy immediately
Endoscopy – first line
Repeated sclerotherapy injection
Endoscopic variceal band ligation
Tranjugular Intrahepatic portosystemic shunt (TIPS)
Pharmacology
Octreotide is synthesised somatostatin used to treat acromegaly, portal hypertension and reduces side effects of chemotherapy. It is used in acute oesophageal bleed because it is through to cause vasoconstriction of splanchnic circulation.
Ascites
Overview
Ascites is accumulation of fluid within the peritoneal cavity. Usually 1-2L of fluid in abdomen before patient is aware of abdominal distention.
Clinical features
Abdominal distention
Shortness of breath
Hepatic hydrothorax
Malnourished
Muscle wasting
Fatigue and weakness
Investigation
Ultrasound
CT abdomen
Paracentesis
Bloods – LFT , FBC, EUC
Serum to albumin gradient (SAAG)
>11 – portal hypertension
<11 – malignant or infectious
Management
Complication
Spontaneous bacterial peritonitis
Spironolactone associated hyperkalaemia
Paracentesis with high neutrophil count >250 is highly suspicious of spontaneous bacterial peritonitis.
Spontaneous Bacterial Peritonitis (SBP)
Common complication of ascites
Usually asymptomatic
25% mortality
E-coli main causative agent
Paracentesis with high neutrophil count highly suggestive of SBP
Treatment : cephalosporin or Pip/taz
Primary prophylaxis in those with low protein (<10g/L) ascites or bilirubin >50 with impaired renal function
Splenomegaly
Clinical features
Enlarged spleen
Thrombocytopaenia and leukopaenia
Complications
Click here for more information on splenomegaly
Hepatorenal syndrome
Overview
Renal failure without renal pathology due to renal vasoconstriction
Renal vasoconstriction leads to RAAS activation which further causes systemic vasoconstriction
Vasodilatation in splanchnic system
Diagnosis
Large Ascites
High creatinine
Types of Hepatorenal syndrome
Type I – decrease eGFR and increase in creatinine within 1-2 weeks of presentation
Type II – decrease eGFR with increase in creatinine level but stable
Management
Midodrine
α-agonist
Octreotide
IV albumin
Liver transplantation
Pharmacology
Midrodrine is a α 1 -receptor agonist and exerts its actions via activation of the alpha-adrenergic receptors of the arteriolar and venous vasculature, producing an increase in vascular tone and elevation of blood pressure .
Hepatic encephalopathy
Overview
Alteration in mental status and cognitive function due to liver failure
Clinical diagnosis
Precipitating events
Hypokalaemia
Infection
Increased dietary protein load
Electrolyte disturbances
Clinical features
Personality change within weeks to months
Violent OR
Sleepy
Ascites
Asterixis
Mechanism of condition
Gut-derived neurotoxins bypass liver
Neurotoxins reach the brain
Investigations
Ammonia (does not correlate with severity)
Management
Identify precipitating factor and correct it
Lactulose OR antibiotics (for those where lactulose is no good) – to promote 2-3 soft stools a day and minimise ammonia production by gut bacteria
Zinc supplementation
Coagulopathy
Other complications
Bone disease due to Vitamin D deficiency
The liver plays a role in the conversion of cholecalciferol to calcidiol
Calicidiol then goes to kidneys to become calcitriol the active form of vitamin D
Liver failure means the conversion from cholecalciferol to calcidiol does not occur so there is vitmain D deficiency
Vitamin D deficiency leads to hypercalcaemia
Liver Transplantation
Indications for chronic liver disease
Life threatening complications
2 year mortality of 50% without transplant
Diuretic resistant ascites
Recurrent hepatin encephalopathy
Recurrent CBP
Recurrent or persistent gastrointestinal haemorrhage
Intractable cholnagitis
Hepatorenal syndrome
MELD SCORE Stratifies severity of end-stage liver disease, for transplant planning.Factors: Dialysis, bilirubin, INR , SodiumMELD SCORE Mortality rate (3-month) <9 3% 10-19 15% 20-29 30% 30-39 60% >40 >70%
Stratifies severity of end-stage liver disease, for transplant planning.
Acute liver disease (King’s College Hospital Criteria)
Paracetamol induced liver failure
arterial pH <7.3 OR
all three of the following: INR >6.5, Serum creatinine >300 and Grade III/IV encepalopathy
Non-paracetamol induced acute liver failure
INR >6.5 OR
Three of the following five: age <11 or >40, serum bilirubin >300, jaundice to coma time of >7 days, INR >3.5 and drug toxicity
Liver Transplantation of hepatocellular carcinoma (Milan Mazzaferro criteria)
A single nodule <5cm OR
3 nodules the largest of which is <3cm
no evidence of gross vascular invasion
No metastasis
4 year survival of 75%
Discussion