Portal hypertension refers to abnormally high pressure in the hepatic portal vein. It is defined as a portal pressure of 12 mm Hg or more (compared with the normal 5-10 mm Hg).¹

See related articles dealing with ascites, cirrhosis, hepatic encephalopathy, hepatorenal syndrome, liver failure and oesophageal varices, listed below under 'Complications'.

Aetiology²

Causes can be divided into: prehepatic, hepatic and posthepatic. Cirrhosis is a common cause.

Pathophysiology^5,6

Portal hypertension develops due to:

• Increased vascular resistance in the portal venous system - from various mechanical causes (above), and also as an active process in which liver damage activates stellate cells and myofibroblasts, contributing to the abnormal blood flow patterns.
• Increased blood flow in the portal veins - from splanchnic arteriolar vasodilatation, caused by an excessive release of endogenous vasodilators.

The raised portal pressure opens up venous collaterals, connecting the portal and systemic venous systems. These occur in various sites:

• Gastro-oesophageal junction - producing varices which are superficial and easily bleed.
• Anterior abdominal wall:
  • Via the umbilical vein - visible as caput medusae radiating from the umbilicus.
  • May also occur where adhesions exist between abdominal viscera and the parietal peritoneum, or at sites of stomas or previous surgery.
• Anorectal junction - rarely cause bleeding.
• Veins from retroperitoneal viscera - communicate with systemic veins on the posterior abdominal wall.

Other patterns of blood flow:

• If individual tributaries of the portal vein are thrombosed, this causes local venous hypertension. With splenic vein block, oesophageal and gastric varices may result.
• In Budd-Chiari syndrome (hepatic vein occlusion), collaterals open up within the liver; blood tends to be diverted through the caudate lobe whose short hepatic veins drain directly into the inferior vena cava.

Portosystemic venous anastomoses can cause encephalopathy, possibly due to various 'toxins' bypassing the liver's 'detoxification' process.

Circulatory disturbances:

• Portal hypertension and cirrhosis produce a hyperdynamic circulation, with splanchnic vasodilatation, increased cardiac output, arterial hypotension, and hypervolaemia.
• There is salt and water retention, ascites and hyponatraemia.

Presentation

History

For causes of liver disease:

• History of jaundice.
• Alcohol consumption.
• Blood transfusion, especially abroad; lifestyles that predispose to hepatitis B or hepatitis C.
• Family history, e.g. Wilson's disease or hereditary haemochromatosis.

For complications of portal hypertension:

• Haematemesis or melaena - suggest bleeding varices.
• Lethargy, irritability and changes in sleep pattern - suggest encephalopathy.
• Increased abdominal girth, weight gain - suggest ascites.
• Abdominal pain and fever - suggest spontaneous bacterial peritonitis.

Examination¹

Signs of portal hypertension:

• Dilated veins in the anterior abdominal wall and caput medusae (tortuous collaterals around the umbilicus). A venous hum, loudest during inspiration, is sometimes heard over large upper abdominal collaterals.
• Splenomegaly.
• Ascites.

Signs of liver disease:

• Jaundice, spider naevi, palmar erythema.
• Confusion, liver flap and fetor hepaticus are signs of encephalopathy.
• Signs of hyperdynamic circulation: bounding pulse, low blood pressure, warm peripheries.
• Enlarged or small liver.
• Gynaecomastia and testicular atrophy.

Investigations¹

• Blood tests:
  • LFTs, U&Es, glucose, FBC, clotting screen.
  • Investigations for liver disease if the cause not known, e.g ferritin (for haemochromatosis), hepatitis serology, autoantibodies, alpha-1-antitrypsin (for alpha-1-antitrypsin deficiency), ceruloplasmin (for Wilson's disease).
• Scans:
  • Abdominal ultrasound - for liver and spleen size, ascites, portal blood flow and thrombosis of the portal or splenic veins.
  • Doppler ultrasound - can show direction of flow in blood vessels.
  • CT scan, especially spiral CT, may show portal vasculature - can be useful if ultrasound was inconclusive.
  • MRI scan - gives similar information to CT.
  • Elasticity measurement (FibroScan®) - a new technique based on the velocity of an elastic wave via an intercostally placed transmitter. Results correlate with liver stiffness and so with fibrosis.⁷
• Endoscopy - for oesophageal varices - essential for those with suspected portal hypertension. Varices indicate portal hypertension, but their absence does not exclude it.
• Portal hypertension measurement:⁸
  • Portal pressure is indirectly measured in clinical practice by the hepatic venous pressure gradient (HVPG).
  • Normal HVPG values are <5 mm Hg. HVPG >10 mm Hg predicts the development of oesophageal varices.
  • However, HVPG is moderately invasive and its clinical role is uncertain.
• Liver biopsy - if indicated, may help diagnose the underlying cause.
• Vascular imaging:
  • The site of the portal venous block can be demonstrated by examining the venous phase of a coeliac or superior mesenteric arteriogram, by splenic portography following injection of dye into the splenic pulp, or by retrograde portography via a hepatic vein.
  • Hepatic venography is helpful when hepatic vein block or idiopathic portal hypertension is suspected.

Management

The portal hypertension itself is difficult to treat effectively, except by:

• Treating the underlying cause, where possible.
• Liver transplantation, if indicated and feasible.

Portal venous pressure can be reduced by:

• Betablockers ± nitrates.
• Shunt procedures - create an anastomosis between the portal and hepatic veins (below).

Complications⁷

Complications of portal hypertension ± cirrhosis are:

• Bleeding from oesophageal or gastric varices - the most common complication of portal hypertension.
• Ascites and its complications:
  • Spontaneous bacterial peritonitis.
  • Hepatorenal syndrome (a complication of cirrhosis with ascites).
  • Hepatic hydrothorax.⁹
• Pulmonary complications:⁹
  • Portopulmonary hypertension (pulmonary arterial hypertension complicating portal hypertension in patients with liver disease).
  • Hepatopulmonary syndrome (a triad of hepatic dysfunction, hypoxemia and extreme vasodilation in the form of intrapulmonary vascular dilations).
• Liver failure.
• Hepatic encephalopathy.
• Cirrhotic cardiomyopathy.¹⁰

For specific management, see separate articles Ascites, Cirrhosis, Hepatic Encephalopathy, Hepatorenal Syndrome, Liver Failure and Oesophageal Varices.

The following gives an overview of treatments used on the portal vascular system:

Drug treatments⁸

Betablockers:

• Nonselective betablockers reduce portal pressure in many patients.
  • They reduce rates of bleeding and rebleeding in patients with oesophageal varices.
  • They may also protect against spontaneous bacterial peritonitis (perhaps through increasing intestinal transit).
• Carvedilol (a nonselective betablocker with anti-alpha1-adrenergic effects) showed promising results in a recent study, and may have a role in preventing variceal bleeds.

Nitrates:

• Added to betablocker therapy, they contribute to reducing portal pressure and may reduce rates of variceal rebleeding.

Vasoactive drugs:

• Terlipressin and octreotide are used to assist the control of acute variceal bleeding.¹¹

Endoscopic procedures⁸

• Endoscopy - to detect and monitor oesophageal varices.
• Endoscopic vein ligation - to prevent bleeding of oesophageal varices.
• For gastric varices with acute bleeding, endoscopic variceal obturation with tissue adhesives (e.g. cyanoacrylate) is effective - but there are recognised complications (mucosal ulceration and thromboembolism).

Transjugular intrahepatic portosystemic shunt (TIPS)^12,13

This is a radiological procedure, connecting the portal and hepatic veins using a stent. The purpose of a TIPS is to decompress the portal venous system, to prevent rebleeding from varices or to reduce the formation of ascites.

However, there are potential complications - hepatic encephalopathy and deteriorating liver function. The stent may stenose; it requires follow-up and may require repeat procedures. There are various contra-indications, detailed in recent guidelines⁸.

TIPS is an established treatment option for:

• Ascites - for patients requiring repeated and frequent paracentesis.
• Oesophageal variceal bleeding refractory to medical treatment (acute bleeding or secondary prevention).
• Bleeding from non-oesophageal varices, e.g. gastric varices.

TIPS may also have a role in treating:

• Hepatorenal syndrome.
• Hepatic hydrothorax.
• Hepatopulmonary syndrome.
• Budd-Chiari syndrome.

Surgical procedures⁵

Surgical portosystemic shunts:⁶

• These require major surgery and an experienced surgeon. They are less likely to stenose than TIPS and can be used where TIPS is not feasible.
• Shunts may be total, partial or selective.

Devascularisation procedures:

• Include gastro-oesophageal devascularisation, splenectomy and oesophageal transection.
• Generally used where other therapies are unsuitable.

Management of rectal varices

• These are common in patients with portal hypertension but don't usually bleed. They are located at the anorectal junction.
• If they bleed, suggested treatment is similar to that used for upper gastrointestinal varices - using drugs to reduce portal pressure, endoscopic banding and TIPS if bleeding persists.¹⁴

Prognosis

This depends on the prognosis of the underlying disease, and on the outcome of any complications such as variceal bleeding.

The Child-Pugh classification system indicates prognosis in some types of liver disease such as cirrhosis.

Survival rates according to Child-Pugh class are: one-year survival in class A is 100%; class B 81%; class C 45%.

Other scoring systems have been developed, including:

• Model for End Stage Liver Disease (MELD).⁷
• Additions to MELD such as MELD-Na (incorporates serum sodium)¹⁵ and MELD-ICG (incorporates indocyanine green clearance).¹⁵

Variceal haemorrhage, especially from oesophageal varices, is the most common complication associated with portal hypertension. Almost 90% of patients with cirrhosis develop varices, but only 30% of varices bleed. The first episode of variceal haemorrhage is estimated to carry a mortality rate of 30-50%.¹⁶

Document references

1. McIntyre N and Burroughs AK. Cirrhosis, portal hypertension, and ascites. In: Concise Oxford Textbook of Medicine, chapter 5.36.
2. Krige JE, Beckingham IJ; ABC of diseases of liver, pancreas, and biliary system. Portal hypertension-1: varices. BMJ. 2001 Feb 10;322(7282):348-51.
3. Harmanci O, Bayraktar Y; Clinical characteristics of idiopathic portal hypertension. World J Gastroenterol. 2007 Apr 7;13(13):1906-11. [abstract]
4. Thompson RJ, Taylor MA, McKie LD, et al; Sinistral portal hypertension. Ulster Med J. 2006 Sep;75(3):175-7. [abstract]
5. Carale J; Portal Hypertension, eMedicine, Jun 2010
6. Dib N, Oberti F, Cales P; Current management of the complications of portal hypertension: variceal bleeding and ascites. CMAJ. 2006 May 9;174(10):1433-43. [abstract]
7. Schuppan D, Afdhal NH; Liver cirrhosis. Lancet. 2008 Mar 8;371(9615):838-51. [abstract]
8. Mehta G, Abraldes JG, Bosch J; Developments and controversies in the management of oesophageal and gastric Gut. 2010 Jun;59(6):701-5.
9. Huffmyer JL, Nemergut EC; Respiratory dysfunction and pulmonary disease in cirrhosis and other hepatic Respir Care. 2007 Aug;52(8):1030-6. [abstract]
10. Moller S, Henriksen JH; Cardiovascular complications of cirrhosis. Gut. 2008 Feb;57(2):268-78. [abstract]
11. Management of acute upper and lower gastrointestinal bleeding, SIGN Clinical Guideline (September 2008)
12. Rossle M, Gerbes AL; TIPS for the treatment of refractory ascites, hepatorenal syndrome and hepatic Gut. 2010 Jul;59(7):988-1000. [abstract]
13. Boyer TD, Haskal ZJ; The Role of Transjugular Intrahepatic Portosystemic Shunt (TIPS) in the Hepatology. 2010 Jan;51(1):306.
14. Cahill RA, Norris S, Stephens RB; Hematochezia in a patient with liver cirrhosis. World J Emerg Surg. 2007 Dec 4;2:32. [abstract]
15. Zipprich A, Kuss O, Rogowski S, et al; Incorporating indocyanin green clearance into the Model for End Stage Liver Gut. 2010 Jul;59(7):963-8. [abstract]
16. Jalan R, Hayes PC; UK guidelines on the management of variceal haemorrhage in cirrhotic patients. British Society of Gastroenterology. Gut. 2000 Jun;46 Suppl 3-4:III1-III15.

Internet and further reading

• Harmanci O, Bayraktar Y; Portal hypertension due to portal venous thrombosis: etiology, clinical outcomes. World J Gastroenterol. 2007 May 14;13(18):2535-40. [abstract]
• Tandon P, Moncrief K, Madsen K, et al; Effects of probiotic therapy on portal pressure in patients with cirrhosis: a Liver Int. 2009 Aug;29(7):1110-5. Epub 2009 Apr 20. [abstract]
• Ponziani FR, Zocco MA, Campanale C, et al; Portal vein thrombosis: insight into physiopathology, diagnosis, and treatment. World J Gastroenterol. 2010 Jan 14;16(2):143-55. [abstract]
• Cichoz-Lach H, Celinski K, Slomka M, et al; Pathophysiology of portal hypertension. J Physiol Pharmacol. 2008 Aug;59 Suppl 2:231-8. [abstract]
• Garcia-Tsao G, Lim JK; Management and treatment of patients with cirrhosis and portal hypertension: Am J Gastroenterol. 2009 Jul;104(7):1802-29. Epub 2009 May 19. [abstract]

Acknowledgements