The portal vein and its tributaries
|Classification and external resources|
Portal hypertension is hypertension (high blood pressure) in the hepatic portal system, which is composed of the portal vein and its branches and tributaries. Portal hypertension is defined as elevation of hepatic venous pressure gradient. In clinical practice the pressure is not measured directly until the decision to place a transjugular intrahepatic portosystemic shunt has been made. Part of the procedure, a hepatic vein wedge pressure is measured with the assumption of no pressure drop across the liver yielding portal vein pressure.[medical citation needed]
Signs and symptoms
Signs and symptoms of portal hypertension include:
- Ascites (free fluid in the peritoneal cavity).
- Dilated veins in the anterior abdominal wall 
- Abdominal tenderness (Spontaneous bacterial peritonitis. presents as complication)
- Jaundice (Hepatorenal syndrome. presents as complication)
- Portal hypertension does not increase the risk of hemorrhoids
°oesophageal varices & haematemesis
- Prehepatic causes include portal vein thrombosis or congenital atresia.
- Intrahepatic causes include liver cirrhosis, hepatic fibrosis, and less commonly noncirrhotic causes such as schistosomiasis, massive fatty change and diffuse granulomatous diseases (e.g. sarcoidosis, miliary tuberculosis).
- Posthepatic obstruction occurs at any level between liver and right heart, including hepatic vein thrombosis, and constrictive pericarditis.
The pathophysiology of portal hypertension is indicated by increasing vascular resistance via different etiologies,additionally stellate cells and myofibroblasts are activated.Increased endogenous vasodilators in turn promote more blood flow in the portal veins.
Nitric oxide is an endogenous vasodilator and it regulates intrahepatic vascular tone(it is produced from L-arginine) According to Maruyama, et al., in laboratory studies nitric oxide inhibition increases portal hypertension and hepatic response to norepinephrine is increased.
The diagnosis of portal hypertension can be done via HVPG (hepatic venous pressure gradient) measurement has been accepted as the gold standard for assessing the severity of portal hypertension.Portal hypertension is defined as HVPG greater than or equal to 5mm Hg and is considered to be clinically significant when HVPG exceeds 10 to 12 mm Hg.
The treatment of portal hypertension is divided into:
Selective shunts select non-intestinal flow to be shunted to the systemic venous drainage while leaving the intestinal venous drainage to continue to pass through the liver. The most well known of this type is the splenorenal. This connects the splenic vein to the left renal vein thus reducing portal system pressure while minimizing any encephalopathy. In an H-shunt, which could be mesocaval (from the superior mesenteric vein to the inferior vena cava) or could be, portocaval (from the portal vein to the inferior vena cava) a graft, either synthetic or the preferred vein harvested from somewhere else on the patient's body, is connected between the superior mesenteric vein and the inferior vena cava. The size of this shunt will determine how selective it is.
It should be noted that with the advent of transjugular intrahepatic portosystemic shunting (TIPS), portosystemic shunts are less performed. TIPS has the advantage of being easier to perform and doesn't disrupt the liver's vascularity.
Prevention of bleeding
Both pharmacological (non-specific ß-blockers, nitrate isosorbide mononitrate, vasopressin such as terlipressin) and endoscopic (banding ligation) treatment have similar results. TIPS (transjugular intrahepatic portosystemic shunting) is effective at reducing the rate of rebleeding.
The management of active variceal bleeding includes administering vasoactive drugs (somatostatin, octreotide), endoscopic banding ligation, balloon tamponade and TIPS(Transjugular intrahepatic portocaval shunt)
This should be gradual to avoid sudden changes in systemic volume status which can precipitate hepatic encephalopathy, renal failure and death. The management includes salt restriction, diuretics (spironolactone), paracentesis, and transjugular intrahepatic portosystemic shunt
A treatment plan may involve lactulose, enemas, and use of antibiotics such as rifaximin, neomycin, vancomycin, and the quinolones. Restriction of dietary protein was recommended but this is now refuted by a clinical trial which shows no benefit. Instead, the maintenance of adequate nutrition is now advocated.
- "Portal hypertension | Disease | Overview | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program". rarediseases.info.nih.gov. Retrieved 2016-01-08.
- "Portal Hypertension. Learn about Portal Hypertension | Patient". Patient. Retrieved 2016-01-08.
- "Spontaneous Bacterial Peritonitis". www.karger.com. Retrieved 2016-01-08.
- Al-Busafi, Said A.; McNabb-Baltar, Julia; Farag, Amanda; Hilzenrat, Nir (2012). "Clinical Manifestations of Portal Hypertension". International Journal of Hepatology. 2012: 1–10. doi:10.1155/2012/203794.
- "Hepatorenal syndrome: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-01-08.
- Sun, Z; Migaly, J (March 2016). "Review of Hemorrhoid Disease: Presentation and Management.". Clinics in colon and rectal surgery. 29 (1): 22–9. doi:10.1055/s-0035-1568144. PMID 26929748.
- Bloom, S.; Kemp, W.; Lubel, J. (2015-01-01). "Portal hypertension: pathophysiology, diagnosis and management". Internal Medicine Journal. 45 (1): 16–26. doi:10.1111/imj.12590. ISSN 1445-5994.
- Perkins, [edited by] Vinay Kumar, Abul K. Abbas, Jon C. Aster ; artist, James A. Robbins basic pathology (9th ed.). Philadelphia, PA: Elsevier/Saunders. p. 608. ISBN 978-1-4377-1781-5.2013
- "Portal Hypertension: Practice Essentials, Background, Anatomy".
- Maruyama, Hitoshi; Yokosuka, Osamu (2012). "Pathophysiology of Portal Hypertension and Esophageal Varices". International Journal of Hepatology. 2012: 1–7. doi:10.1155/2012/895787.
- Al-Busafi SA, McNabb-Baltar J, Farag A, Hilzenrat N (2012). "Clinical manifestations of portal hypertension". Int J Hepatol. 2012: 203794. doi:10.1155/2012/203794. PMC . PMID 23024865.
- Shah, Omar Javed; Robbani, Irfan (2005-01-01). "A Simplified Technique of Performing Splenorenal Shunt (Omar's Technique)". Texas Heart Institute Journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital. 32 (4): 549–554. ISSN 0730-2347. PMC . PMID 16429901.
- Moore, Wesley S. (2012-11-23). Vascular and Endovascular Surgery: A Comprehensive Review. Elsevier Health Sciences. p. 851. ISBN 1455753866.
- Yin, Lanning; Liu, Haipeng; Zhang, Youcheng; Rong, Wen (2013). "The Surgical Treatment for Portal Hypertension: A Systematic Review and Meta-Analysis". ISRN Gastroenterology. 2013: 1–10. doi:10.1155/2013/464053.
- Pomier-Layrargues, Gilles; Bouchard, Louis; Lafortune, Michel; Bissonnette, Julien; Guérette, Dave; Perreault, Pierre (2012). "The Transjugular Intrahepatic Portosystemic Shunt in the Treatment of Portal Hypertension: Current Status". International Journal of Hepatology. 2012: 1–12. doi:10.1155/2012/167868.
- Bari, Khurram; Garcia-Tsao, Guadalupe (2012-03-21). "Treatment of portal hypertension". World Journal of Gastroenterology : WJG. 18 (11): 1166–1175. doi:10.3748/wjg.v18.i11.1166. ISSN 1007-9327. PMC . PMID 22468079.
- "Portal Hypertension Medication: Somatostatin Analogs, Beta-Blockers, Nonselective, Vasopressin-Related, Vasodilators". emedicine.medscape.com. Retrieved 2016-01-08.
- Dib, Nina; Oberti, Frédéric; Calès, Paul (2006-05-09). "Current management of the complications of portal hypertension: variceal bleeding and ascites". Canadian Medical Association Journal. 174 (10): 1433–1443. doi:10.1503/cmaj.051700. ISSN 0820-3946. PMC . PMID 16682712.
- Garbuzenko D.V., Arefyev N.O., Belov D.V. Mechanisms of adaptation of the hepatic vasculature to the deteriorating conditions of blood circulation in liver cirrhosis. World J. Hepatol. 2016; 8 (16): 665-672.
- Garbuzenko D.V. Current approaches to the management of patients with liver cirrhosis who have acute esophageal variceal bleeding. Curr. Med. Res. Opin. 2016; 32 (3): 467-475.
- Garbuzenko D.V. Contemporary concepts of the medical therapy of portal hypertension under liver cirrhosis. World J. Gastroenterol. 2015; 21 (20): 6117-6126.
- "Functional aspects on the pathophysiology of portal hypertension in cirrhosis – Journal of Hepatology". www.journal-of-hepatology.eu. Retrieved 2016-01-08.
- Rossi, Plinio (2012-12-06). Portal Hypertension: Diagnostic Imaging and Imaging-Guided Therapy. Springer Science & Business Media. ISBN 9783642571169.
- Imanieh, Mohammad Hadi; Dehghani, Seyed Mohsen; Khoshkhui, Maryam; Malekpour, Abdorrasoul (2012-10-01). "Etiology of Portal Hypertension in Children:A Single Center's Experiences". Middle East Journal of Digestive Diseases. 4 (4): 206–210. ISSN 2008-5230. PMC . PMID 24829658.