Portal Hypertension &
PH is elevated pressure within the portal venous system.
Normal portal pressure is ~<10mmHg
Portal hypertension typically >12mmHg
A portal system is a venous system with 2 sets of capillaries joined
by a vein.
Hepatic venous portal system is valveless venous system
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Varies by cause
Or more practically, as pre-sinusoidal or post-sinusoidal.
- Pre-sinusoidal normally has normal hepatocellular function (hence,
eg, pts won't develop liver failure in context of variceal bleeding)
- hepatic or sinusoidal is by far the most common cause of PH
Can be differentiated based on wedge pressure measured by a catheter
introduced into superior or inferior cava.
(Liver function usually maintained unless inflammation extends
beyond portal tracts)
Congenital absence of portal vein or abnormality
Portal vein thrombosis and causes
- eg. sepsis, splenectomy, pancreatitis, hypercoagulable states.
Splenic or SMA thrombosis also
Idiopathic Portal Hypertension
- common worldwide; causes obstruction to portal venules
Nodular regenerative hyperplasia
Primary biliary cirrhosis (prior to cirrhosis)
Non-cirrhotic portal fibrosis
Cirrhosis and causes
- worldwide, viral hepatitis is a key cause.
[Any disease that distorts the sinusoids can lead to PH e.g.
scarring of liver]
Pressure is transmitted upstream and throughout the portal system.
- viral hepatitis is the most common cause worldwide.
Hepatic vein thrombosis
Trucuspid valve incompetence; chronic venous congestion
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70% of liver blood
comes from vein; 30% from artery
Portal venous pressure should be compared to the vena cava; the
'portal pressure gradient'.
- can be measured by liver vein catheterization with wedging of the
catheter in a hepatic vein.
Gradient <10 normal; >10 = PH
- at >10 often ascites will develop
- at >12, varices may develop.
- at >20, high mortality associated with bleeding.
Portal pressure distributed throughout portal system and collateral
i) changes in portal pressure
ii) autonomic effects
iii) liver metabolism effects.
iv) release of cytokines affecting circulation
1. There is an active contraction of myofibroblasts and vascular
smooth muscle cells in portal veins to compensate
--> this is counterproductive attempt to increase liver flow).
- vascular tone is a result of balance between endogenous
vasoconstrictors (endothelin, leukotrienes, angiotensin II) and
vasodilators (NO, prostacyclin).
--> due to low liver blood flow, mediators released favor
vasoconstrictor imbalance, worsening PH.
2. In splanchnic circ, NO is plentifully released as a response to
PH, leading to splanchnic vasodilation, further increasing portal
- meanwhile, peripheral vasodilation causes water and salt
retention; accumulation of salt and water further increases
splanchnic circulation and ascites
Increased circulating blood volume manifested by hyperdynamic CO
- despite this compensation, renal compromise may occur secondary to
low effective perfusion pressure; hepatorenal syndrome.
Complications / Manifestations
Usually PH made in the context of its complications
- most serious complication.
- mortality of 20% mortality, and 60% rebleed rate within 2y if
- PH implicated; associated with blood pooling in splanchnic
- retention of water
- sodium and fluid accumulation in peritoneal cavity
- and trapping of platelets and WCs
--> thrombocytopaenia in a pt with liver disease strongly
Liver Failure (follows variceal bleeds)
Hepatorenal syndrome (follows variceal bleeds)
Associated with high mortality from cirrhosis.
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Patients without complications have few if any symptoms.
Diagnosis usually made in context of one of the above complications.
Need to Assess
1. Underlying liver disease
- clinical history and findings.
- e.g. jaundice, ascites, muscle wasting
- lab tests for grading.
2. Imaging studies
- liver uss, augmented by CT, MRI
- shape and size of liver, focal lesions suspicious for HCC
- assessment of venous and arterial liver anatomy
- portal vein patency and tributaries
Varices and gastropathy.
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See also ascites
Low platelets in cirrhotics is strongly suggestive
Imaging focuses on liver morphology and vasculature.
USS +/- CT and MRI.
Focused on varices and portal hypertensive gastropathy.
Size, extent and risk factor of varices are considered carefully in
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Assess underlying disease, imaging and endoscopy.
Grade severity of liver disease, as with Child-Turcotte-Pugh or MELD score.
Treat underlying cause.
Total Serum Bilirubin
Bilirubin <35 mg/dl: 1 point
Bilirubin 35-52 mg/dl: 2 points
Bilirubin >52 mg/dl: 3 points
Albumin >3.5 g/dl: 1 point
Albumin 2.8 to 3.5 g/dl: 2 point
Albumin <2.8 g/dl: 3 point
INR <1.70: 1 point
INR 1.71 to 2.20: 2 point
INR >2.20: 3 point
No Ascites: 1 point
Ascites controlled medically: 2 point
Ascites poorly controlled: 3 point
No Encephalopathy: 1 point
Encephalopathy controlled medically: 2 point
Encephalopathy poorly controlled: 3 point
PH alone does not constitute reason for transplant.
See management of complications.
Role of Transplant
Often is the ultimate treatment (depending on cause)
- but PH alone is not an indication for transplant
--> only done in
context of liver decompensation or HCC. (limited supply and
need for immunosuppression).
Calculates a score based on creatinine, bilirubin, INR
- validated; indicates how likely a pt with end-stage liver disease
is to die with transplantation.
- highest MELD score = highest priority
Risk of bleeding relates to coagulopathy.
Bleeding may be harzardous for transplant in this context
- coagulopathy and varices in retroperitoneum
- ocreotide may help to reduce splanchnic hypertension.
Venovenous bypass may be needed to reduce anhepatic phase.
Graft function may be impaired by high flow through portal system
- decrease portal pressure gradient with pharcologic therapy
Generally successful, though many have varices they don't usually
Persistent hypersplenism may continue
Need to watch graft for problems from recurrent liver disease or
- will reincite PH.
Medical Management of Varices
See also Varices notes
- beta blockers; reduce portal pressures
- banding if large or beta-blocker intolerant.
- only with advanced end stage disease ie other indications for
Acute variceal bleeding
- 10% of people = not controlled or recurs, then TIPS may be
Prevention of recurrent bleeding
- beta blockers
--> these two steps control bleeding in 80%
4. Liver Transplant
5. Shunts = ~legacy.
Ascites and SBP
Ascites common sequela of PHTN
Rx fluid restriction and diuretics
Frusemide and spironolactone advised
If SBP suspected, tap and culture peritoneal fluid.
- some use prophylactic antibiotics.
No longer a significant part of the management repertoire in portal
Now better management with radiology, endoscopic, and liver
Effective across spectrum of causes of PH
1. Variceal bleeding; as per algorithm
2. Recurrent ascites
- TIPS is very effective in control, but risks generally outweigh
benefits; highly selective.
3. Hepatic hydrothorax
- 500ml+ of pleural fluid accumulation with ascites
- in <10% of cirrhotics, due to peritoneal fluid entering chest
- same points as for TIPS, not routine; highly selective
4. Hepatorenal syndrome
- a bad prognostic sign; late stages of haemodynamic change
resulting from cirrhosis
- alterations in vasoactive hormones cause renal arterial
vasoconstriction and intrarenal arteriovenous communications
--> renal hypoperfusion and renal failure.
- TIPS is possible but not very safe due to contrast load and
5. Hepatopulmonary Syndrome
- intrapulmonary vasodilation and multiple right to left shunts;
impaired gas exchange
- TIPS cannot be recommended as little evidence; but possible in
highly selected cases as bridge to surgery
- hepatic venous ouflow obstruction, results in cirrhosis and PH
- treated with hepatic balloon angioplasty, liver transplant if
fulminant; then TIPS can be a bridge to surgery
- may permenantly stabilize liver in some pts, obviating need for
7. Portal Gastropathy
- diffuse dilatation of gastric veins; inflamed and fragile gastric
mucosa can bleed.
- TIPS may normalize portal pressure, reducing this risk.
- only if not responsive to more conservative therapies.
1. Proper pt work up reduces complications
- Imaging of patent portal vein and relative orientation of hepatic
--> plan efficient access
- Hydrate for renal function
- Prophylactic ABs +/- lactulose
Be cognizant of risks, esp 30d mortality, which ranges from <5%
to 50% for emergent procedures in pts with advanced liver disease.
2. Access through R Int Jug with vascular sheath
3. Assessment of Pressures
- must ensure R atrial pressure not elevated else blood shunted to
an already overburdened heart.
- 20mmHg R pressure dangerous. 16 mmHg borderline; don't do
unless variceal bleeding and needs life saving therapy.
- delineate portal venous system by injection of CO2 via hepatic
vein catheter; not nephrotoxic
4. Place Shunt
- cannulate R portal vein from R hepatic vein
- sheath advanced across tract over needle; contrast injected to
ensure correct location.
- balloon used to predilate tract.
- portal pressure checked and shunt only placed if benefit suggested
- (then bail out and instead embolize varices
5. Evaluate shunt
- us. 8-10mm stent to allow sufficient flow but prevent
- final portal venogram documents flow and lack of variceal filling
TIPS: Special Issues
challenging due to thrombosis; classic spider vein appearance.
- may necessetate IVC placement
Parallel TIPS: if symptoms
not alleviated from a previous TIPs
- can place a second parallel
Transumbilical or Direct Portal
-When access to portal vein challenging due to anatomy can use these
methods to conduit into L portal vein.
- opacified portal system, providing a TIPS target
TIPS Reversal: occasionally
- when overzealous shunting causes liver failure or encephalopathy
- options are decrease shunting or shut down the TIPS
- reduce by second stent inside first, e.g. hourglass shape.
Most effective option for treating varices
- rebleeding rate is low; 4%
- cessation of bleeding almost immediate after TIPS
Very effective for ascites when used; reduces risk 50-80%
Improves survival and transplant free survival compared to other
Improves renal function in 62% of hepatorenal syndrome pts.
Liver failure 2%
Encephalopathy 10% (unless already decompensated; then 50%)
Sepsis 4%, (use prophylactic ABs)
Renal failure (contrast, dehydration).
Mortality 10-30%, mainly in advanced liver disease patients.
Recurrent variceal bleeding suggests TIPS occlusion.
10% reintervention rate
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Tjandra, Clunie, Thomas