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

Portal hypertensionPrehepatic

Portal vein thrombosis Rare cause

Commonly due to neonatal umbilical sepsis, though the effects may manifest after many years

Portal hypertension

Portal hypertensionHepatic - 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 hypertensionHepatic - Liver cirrhosis

Other causes Chronic active hepatitis

Primary & secondary biliary cirrhosis

Cryptogenic cirrhosis (obscure cause)

Portal hypertension

Portal hypertensionPosthepatic

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

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

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

None

< 35

> 35

< 1.4

Minimal

Slight

35-50

28-35

1.4-2.0

Marked

Moderate

> 50

<28

> 2.0

Portal hypertensionAcute 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

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

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 bleedingMinnesota 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

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 bleedingInjection 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 bleedingEndoscopic 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 bleedingSurgical 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

Prevention of further bleedingEmergency 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 procedureThe 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

Types of shunt procedureTransjugular 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

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