Portal hypertension Usually caused by increased resistance to portal venous blood flow The obstruction is prehepatic, hepatic or posthepatic The normal pressure in the portal vein varies from 5 to 15 cmH2O. When the portal venous pressure is consistently raised above 25 cmH2O may → serious clinical consequences Portal hypertension

Portal hypertension

Anatomy of the portal venous system

Causes of portal hypertension Obstruction to portal flow Increased blood flow (rare) Prehepatic Congenital atresia of the portal vein Portal vein thrombosis Neonatal sepsis Pyelophlebitis Trauma, Tumour Extrinsic compression of the portal vein Pancreatic disease Lymphadenopathy Biliary tract tumours Intrahepatic Cirrhosis Schistosomiasis Posthepatic Budd-Chiari syndrome Constrictive pericarditis Arteriovenous fistula Increased splenic blood flow in hypersplenism Table 19.1 Causes of portal hypertension

Portal hypertension Prehepatic Portal vein thrombosis Rare cause Commonly due to neonatal umbilical sepsis, though the effects may manifest after many years Portal hypertension

Portal hypertension Hepatic - Liver cirrhosis Cirrhosis of the liver The commonest cause Results from chronic liver disease Characterized by liver cell damage, fibrosis & nodular regeneration Micronodular cirrhosis even distribution of nodules a few millimeters in diameter Macronodular cirrhosis the nodules vary in size usual in end-stage cirrhosis The fibrosis obstructs portal venous return & → portal hypertension Portal hypertension

Portal hypertension Hepatic - Liver cirrhosis Alcohol The commonest etiological factor in western countries Abnormal resistance is predominantly postsinusoidal (increase in wedge hepatic venous pressure) The hepatic veins become distorted by regenerative nodules, there is narrowing of the central veins by centrilobular collagen deposition, and swelling of the hepatocytes encroaches on the sinusoidal lumen Schistosomiasis Due to Bilharzia mansonii is a common cause in North Africa, Middle East Granulomas from parasitic involvement are seen in the portal triads Hypertension is presinusoidal Portal hypertension

Portal hypertension Hepatic - Liver cirrhosis Other causes Chronic active hepatitis Primary & secondary biliary cirrhosis Cryptogenic cirrhosis (obscure cause) Portal hypertension

Portal hypertension Posthepatic Rare Due to spontaneous thrombosis of the hepatic veins Associated with Neoplasia Oral contraceptive agents Polycythaemia Presence of abnormal coagulants in the blood The resulting Budd-Chiari syndrome is characterized by portal hypertension, liver failure & gross ascites Portal hypertension

Abdominal radiograph demonstrating calcified & thrombosed portal & splenic veins

Effects of portal hypertension Gradual chronic occlusion of the portal venous system → Collateral develop between the portal & systemic venous circulations The most important consequence of shunting is the development of varices in the submucosal plexus of veins in lower esophagus & gastric fundus. The esophageal varices may then rupture → acute massive gastrointestinal bleeding (occurs in 40% of patients with cirrhosis). Initial episode of variceal hemorrhage is fatal in ⅓ of patients. Bleeding from retroperitoneal & periumbilical collaterals. Collaterals may develop & → bleeding at site of stomas. Anorectal varices are found at proctoscopy but rarely cause bleeding. Progressive enlargement of the spleen due to vascular engorgement & associated hypertrophy Portal hypertension

Sites of portosystemic shunting Fig. 19.7 The portal venous system. Sites of portosystemic shunting are marked 1-3. Retroperitoneal communications also exist.

Effects of portal hypertension Hematological consequences Anemia, thrombocytopenia & leukopenia (hypersplenism) Ascites Increased formation of hepatic & splanchnic lymph Hypoalbuminaemia Retention of salt & water Increased aldosterone & antidiuretic hormone Portosystemic encephalopathy due to Increased level of toxins (ammonia) in systemic circulation Develop where there are large spontaneous or surgically created portosystemic shunts Gastrointestinal hemorrhage increases absorption of nitrogenous products → encephalopathy Portal hypertension

Clinical presentation Patients with cirrhosis Anorexia Generalized malaise Weight loss Clinical manifestations of liver disease Hepatosplenomegaly Ascites Jaundice Spider naevi Serum bilirubin may ↑ Serum albumin ↓ Anaemia Leukocyte count ↑ or ↓ (hypersplenism) Prothrombin time & other indices of clotting may be abnormal Portal hypertension

Gross splenomegaly secondary to portal hypertension Abdominal radiograph demonstrating gross splenomegaly secondary to portal hypertension.

Modified Child's grading system (Clinical & biochemical parameters) Points scored Criterion 1 2 3 Encephalopathy Ascites Bilirubin (µmol/L) Albumin (g/L) Prothrombin ratio None < 35 > 35 < 1.4 Minimal Slight 35-50 28-35 1.4-2.0 Marked Moderate > 50 <28 > 2.0 Table 19.2 Assessment of patients with portal hypertension by a modification of Child's grading system Grade A = 5-6 points; grade 6 = 7-8 points; grade C =10-15 points.

Portal hypertension Acute variceal bleeding Patients presenting with acute upper gastrointestinal bleeding are carefully examined for evidence of chronic liver disease. Distended collateral veins around the umbilicus ('caput medusae‘). Slurring of speech, a flapping tremor or dysarthria may point to encephalopathy may be precipitated or intensified by accumulation of blood in gastrointestinal tract The key investigation during an episode of active bleeding is endoscopy Allows detection of varices & defines whether they are or have been site of bleeding. Peptic ulcer & gastritis are common complaints (in 20% of patients with varices). Portal hypertension

Management of bleeding esophageal varices Active resuscitation Group & cross-match blood Assessment of coagulation status Prothrombin time Platelet count Establish i.v. infusion line(s) Monitor pulse , blood pressure hourly urine output , central venous pressure Urgent endoscopy

Management of bleeding esophageal varices Control of bleeding Tamponade (Minnesota tube) or injection sclerotherapy Pharmacological measures (e.g. vasopressin/somatostatin) Treatment of hepatocellular decompensation Treatment/prevention of portosystemic encephalopathy Portal hypertension

Management of bleeding esophageal varices Prevention of further bleeding from varices Injection sclerotherapy Stapled esophagogastric junction Portosystemic shunting/TIPSS Liver transplantation Portal hypertension

Active resuscitation Large volumes of blood may be lost rapidly and the aim is to replace blood loss quickly. Fresh blood is preferred for transfusion purposes Fresh-frozen plasma (FFP) Platelet transfusion Portal hypertension

Rarely, bleeding occurs from varices in gastric fundus. Endoscopy Performed at the earliest opportunity, and in patients threatened by massive bleeding, active resuscitation is instituted and continued in the endoscopy suite. The tortuous varices are usually in three columns & most prominent in the lower third of the esophagus. If varices are the source of blood loss, this usually occurs from the lowest few centimeters of esophagus. Rarely, bleeding occurs from varices in gastric fundus. Portal hypertension

Medical agents to lower portal venous pressure & arrest bleeding Control of bleeding Medical agents to lower portal venous pressure & arrest bleeding synthetic form of somatostatin, octreotide If variceal hemorrhage is apparent at the endoscopy injection of a sclerosant (ethanolamine) application of bands If hemorrhage is torrential & prevents direct injection, balloon tamponade may be used to stop the bleeding. Minnesota tube (four-lumen) Sengstaken-Blakemore tube (three-lumen) Portal hypertension

Control of bleeding Minnesota tube (four lumen) Aspiration of gastric contents Inflation of a gastric balloon with 150 ml of water with radio-opaque dye (Hypaque) to be checked radiologically compresses the gastric fundus & EGJ → reducing flow of blood into esophageal varices Inflation of esophageal balloon with air to a pressure of 40 mmHg (direct pressure to the esophageal varices) Aspiration of esophagus & pharynx above esophageal balloon, reducing the risk of aspiration pneumonitis Traction is applied to the Minnesota tube by pulling the gastric balloon up against EGJ & taping the tube as it emerges from the angle of the mouth. Pharynx & stomach are aspirated every 15-30 minute. Arrests bleeding from varices in over 90% of patients The tube is not left in place for more than 24-36 hours for fear of causing esophageal necrosis.

Esophageal tamponade using a Minnesota tube

Tamponade should be regarded as a holding measure Control of bleeding Tamponade should be regarded as a holding measure Further resuscitation & treatment of hepatic decompensation. More definitive measures are used to prevent further variceal bleeding two-thirds rebleed while still in hospital 90% rebleed within a year Portal hypertension

Resuscitation & treatment of hepatocellular decompensation Control of variceal bleeding allows blood loss to be made good & permits a full assessment of coagulopathy. Blood may be evacuated from the gut by a bowel washout to reduce the risk of portosystemic encephalopathy. Lactulose (15-30 ml tid) to reduce bacterial degradation of blood in the gut lumen & further reduce risk of encephalopathy. Esophageal varices due to liver disease frequently have major defects in intrinsic & extrinsic clotting systems. Vitamin K to aid restoration of the extrinsic system FFP, factor concentrates & platelet transfusion may all be required to cover specific procedures such as sclerotherapy. Transfusion measures have transient effects on blood coagulation Ultimate coagulation status depends upon restoration of hepatic function. Portal hypertension

Prevention of further bleeding Injection sclerotherapy Carried out by fibreoptic endoscopy. Injection is repeated at weekly or fortnightly intervals until the varices are completely sclerosed. Following complete ablation, fibreoptic examination is repeated periodically & any recurrent varices are injected. Excessive or too frequent injection may be complicated by ulceration & necrosis, sometimes with a fatal result. Sclerosant can be injected directly into the varix or into the surrounding mucosa. Reduced the number of patients undergoing surgery Most successful in patients with well-preserved liver function. Improves long-term survival?. Portal hypertension

Prevention of further bleeding Endoscopic banding Used to occlude varices at esophagogastric junction. The reduced risk of esophageal ulceration & perforation has resulted in this technique being favoured in many centres. Portal hypertension

Prevention of further bleeding Surgical disconnection Rarely used in management of variceal hemorrhage. The gastric veins & short gastric veins are ligated and the distal esophagus is transected & reanastomosed just above the cardia using a stapling gun. Stapled esophageal transection occludes flow into varices. Technically difficult in patients who have been submitted to repeated injection sclerotherapy. Considerable morbidity & mortality when employed as a last resort in the emergency situation.

Esophageal stapling Esophageal stapling The gun is inserted through an anterior gastrostomy. A ligature is tied just above the cardia, invaginating a flange of esophageal wall between the two parts of the gun. Inset: the gun has been fired, simultaneously resecting a full-thickness ring of esophageal wall and anastomosing the cut ends with staples.

Prevention of further bleeding Emergency portosystemic shunting High mortality. Elective portosystemic shunting is still used to decompress portal system & reduce risk of further variceal hemorrhage, but portosystemic encephalopathy can be troublesome. Operation is rarely considered in patients whose condition is complicated by jaundice, ascites or encephalopathy, and where there is a clear indication for liver transplantation. Portal hypertension

Types of shunt procedure The distal splenorenal (Warren) shunt Selectively decompresses lower esophagus & upper stomach Maintains liver blood flow The incidence of encephalopathy is lower than after other shunt procedures Portal hypertension

Relatively safe (no GA & no laparotomy). Types of shunt procedure Transjugular intra hepatic portosystemic stent shunting (TIPSS) In this procedure a metal stent is inserted via the transjugular route using a guide-wire passed through the hepatic vein to the intrahepatic branches of the portal vein. Relatively safe (no GA & no laparotomy). The risk of encephalopathy is similar to that of a surgical portosystemic shunt. Now considered routinely before surgical intervention in both the acute and the elective setting. Portal hypertension

Types of portosystemic shunt Portal vein IVC Superior mesenteric vein Normal End-to-side portocaval shunt Mesocaval shunt (Dacron graft interposition) Distal splenorenal shunt Fig. 19.10 Types of portosystemic shunt.

Ascites Ascites can be controlled by bed rest, salt & water restriction & a diuretic such as the aldosterone-inhibitor spironolactone. If refractory, ascites can be treated by inserting a peritoneojugular (LeVeen) shunt, which allows one-way flow between the peritoneum & jugular vein. Portal hypertension

Peritoneovenous (Le Veen) shunt to relieve ascites