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Introduction

Portal Hypertension

The liver receives approximately 25% of cardiac output through a dual blood supply:

1. Hepatic Arteries – supply oxygenated blood from the aorta via the celiac axis.
2. Portal Vein – carries nutrient-rich blood from the gastrointestinal tract to the liver for processing. The portal vein forms from the union of the superior mesenteric and splenic veins behind the pancreas. It branches into right and left divisions that enter respective liver lobes, with venous drainage via hepatic veins into the inferior vena cava.

Portal hypertension results from increased resistance to portal blood flow, primarily due to structural liver disruption (most commonly cirrhosis in Western populations). Other causes exist, involving both fixed and dynamic components (e.g., stellate cell contraction triggered by acute events like sepsis or high alcohol intake).

Diagnosis

Portal hypertension diagnosis may be suggested by:

• Clinical signs of cirrhosis
• Hematologic indicators like thrombocytopenia
• Radiologic findings such as splenomegaly, recanalization of the umbilical vein, or reversed portal vein flow.

The hepatic venous pressure gradient (HVPG) measurement is the gold standard for diagnosis and prognosis. HVPG, calculated during hepatic venous catheterization, is the difference between balloon-wedged hepatic venous pressure and free hepatic venous pressure. Normal HVPG is up to 5 mm Hg; portal hypertension is defined as HVPG ≥6 mm Hg, with complications like variceal hemorrhage typically occurring at ≥10 mm Hg due to collateral circulation development.

Clinical manifestations of portal hypertension include:

• Ascites
• Hydrothorax (transudative pleural effusion, often right-sided)
• Varices (esophageal, gastric, periumbilical, rectal)
• Portal hypertensive gastropathy
• Hepatorenal and hepatopulmonary syndromes

Treatment Options

The goal of treating portal hypertension is to reduce HVPG, either pharmacologically or through TIPS, while managing complications. Addressing the underlying cause (e.g., alcohol abstinence, antiviral treatment) can mitigate or reverse complications.

Management strategies include:

• Ascites and hepatic hydrothorax: Sodium-restricted diet and diuretics (spironolactone, furosemide); for diuretic-resistant cases, large-volume paracentesis with intravenous albumin replacement is used.
• Endoscopic surveillance for varices in cirrhotic patients every 2–3 years, with primary prophylaxis using non-selective beta-blockers (e.g., carvedilol, propranolol) or variceal band ligation.

When medical or endoscopic therapies fail, and portal pressures remain high, TIPS can provide symptomatic relief and improve survival in select cases.

TIPS Selection Criteria

TIPS offers symptomatic relief and survival benefit, notably in:

• Diuretic-resistant ascites
• Variceal bleeding, where it helps control hemorrhage from esophageal or gastric varices and prevents recurrence.

Additional indications, with limited supportive evidence, include:

• Portal hypertensive gastropathy
• Gastric antral vascular ectasia
• Refractory hepatic hydrothorax
• Hepatorenal syndrome
• Budd–Chiari syndrome
• Hepatic veno-occlusive disease
• Hepatopulmonary syndrome

Outcome Prediction: Clinical outcomes post-TIPS, including mortality, can be predicted using liver disease severity scores like the Model for End-Stage Liver Disease (MELD) or Child–Pugh score.

Contraindications to TIPS Insertion

1. Absolute Contraindications:

   • Heart failure
   • Severe tricuspid regurgitation
   • Severe pulmonary hypertension (mean pulmonary pressure >45 mm Hg)
   • Multiple hepatic cysts
   • Sepsis
   • Biliary obstruction

2. Relative Contraindications:

   • Hepatocellular carcinoma
   • Obstruction of all hepatic veins
   • Portal vein thrombosis
   • Severe coagulopathy
   • Thrombocytopenia (platelet count <20×10^9/L)
   • Prior encephalopathy
   • Moderate pulmonary hypertension

Where feasible, clinical assessment by a hepatologist, echocardiography, and triple-phase CT imaging should be conducted before TIPS placement.

Procedure and Complications of TIPS Insertion

Procedure Overview

TIPS insertion requires specialized skills in interventional radiology and is typically performed in an angiography suite. The process involves the following steps:

1. Internal Jugular Vein Cannulation:

   • A catheter is introduced via the internal jugular vein and navigated to the hepatic vein.
   • Hepatic venous wedge pressure is measured, and HVPG is calculated.

2. Hepatic Venography:

   • Using contrast or carbon dioxide, hepatic venography helps outline the liver’s vascular anatomy.
   • This step is often ultrasound-assisted to enhance visualization.

3. Creation of a Hepatic-Portal Communication:

   • Under fluoroscopic guidance, a branch of the hepatic vein is connected to the portal vein using a catheter with a cutting tip.
   • A balloon catheter is then used to dilate the tract, creating a pathway between the two circulations.

4. Stent Deployment:

   • A polytetrafluoroethylene (PTFE)-covered nitinol stent (e.g., Gore Viatorr®; typically 10 mm × 80 mm) is placed within the tract to keep it open.
   • The stent’s goal is to reduce the HVPG to near-normal levels, ideally <12 mm Hg to alleviate portal hypertension symptoms.

Procedure Duration and Challenges:

• The procedure time may vary depending on individual anatomical and technical challenges, such as accurate guidewire positioning and achieving sufficient HVPG reduction with stent placement.

Complications

Early Complications:

• Internal Jugular Vein Access Complications:

  • Carotid or tracheal puncture
  • Pneumothorax or hemothorax
  • Thoracic duct injury or brachial plexus injury

• Catheter Passage through Right Atrium:

  • Arrhythmias may occur due to atrial irritation.
  • Rare cases of myocardial injury.

• Portal Vein Puncture Difficulties:

  • Misguided puncture can result in liver capsule puncture and potentially fatal hemorrhage into the peritoneal cavity.

• Other Risks:

  • Portal vein rupture
  • Inadvertent puncture of hepatic arteries, biliary structures, or the right kidney.

Late Complications:

• Stent Complications:
  • Stent occlusion or thrombosis
  • Stent dislodgement

Overall Complication Rates:

• Major complications occur in approximately 3–5% of TIPS procedures.
• Mortality rates are variable and typically higher for emergency TIPS placements.

Anaesthesia for TIPS Insertion

Patient Complexity

Patients undergoing TIPS are generally complex, with significant physiological disruptions due to chronic liver disease. Preoperative assessment and optimization involve a multidisciplinary approach.

For patients who are potential or confirmed transplant candidates, there is a risk of precipitating acute hepatic failure post-TIPS. These cases should be discussed with a transplant center, with transfer considered if appropriate.

Pre-procedure Work-up and Optimization

1. Cardiovascular Evaluation:

   • Patients with liver disease often have hyperdynamic circulation (increased cardiac output and reduced systemic vascular resistance).
   • Heart failure and tricuspid regurgitation should be assessed with transthoracic echocardiography.
   • Echocardiography is also essential to evaluate left ventricular function and screen for severe pulmonary hypertension, which is a contraindication for TIPS due to increased right heart pressures after shunt placement.

2. Respiratory Assessment:

   • Patients may have reduced functional residual capacity from ascites and hepatic hydrothorax, further compromised in the supine position.
   • Chest radiography can help assess hydrothorax, and drainage of intrathoracic or intraperitoneal fluid may be indicated preoperatively. If severe respiratory impairment is present, drainage should occur the day before TIPS, with albumin replacement (8 g per 2.5 L drained) to prevent post-paracentesis circulatory dysfunction.

3. Coagulation and Hematology:

   • Thrombocytopenia and coagulopathy are common in cirrhosis and should be corrected preoperatively.
   • Target platelet count >50×10^9/L and INR <1.5 are recommended, especially in cases of variceal bleeding.
   • Cross-matched blood may be necessary due to prior transfusions, often requiring extended cross-matching for atypical antibodies.

4. Renal Function:

   • Baseline renal impairment could represent intrinsic damage or hepatorenal syndrome. TIPS involves a contrast load that can further impair renal function.
   • Prophylactic measures, like correcting hyponatremia, volume expansion with albumin, and acetylcysteine for 48 hours, may mitigate risks, although clinical evidence is limited.

5. Hepatic Encephalopathy:

   • Preexisting hepatic encephalopathy should be assessed and graded, as shunt insertion can worsen symptoms by allowing unprocessed portal blood into systemic circulation. Overt encephalopathy may contraindicate elective TIPS.

6. Laboratory Testing and Stabilization:

   • Perform baseline testing of hemoglobin, platelet count, coagulation, and renal and hepatic function to guide optimization and post-procedure planning.
   • In cases of variceal bleeding, IV fluids and blood products may be required to stabilize the patient, along with vasopressors (e.g., terlipressin) and broad-spectrum antibiotics (e.g., piperacillin-tazobactam) as part of medical therapy.

Anaesthetic Technique

Remote site anaesthesia complexities arise due to limited proximity to standard OR resources. The choice between sedation and general anaesthesia (GA) is influenced by patient factors and institutional protocols.

1. Sedation:

   • Sedation with short-acting agents like midazolam, propofol, and remifentanil may be feasible.
   • Challenges include patient discomfort in the supine position, compromised airway protection, potential agitation from encephalopathy, and severe discomfort during balloon dilatation.
   • If sedation is chosen, personnel and equipment for rapid conversion to GA should be immediately available.

2. General Anaesthesia (GA):

   • GA is often preferred due to enhanced safety, particularly during complications.
   • Avoid sedative premedication to prevent prolonged effects and potential encephalopathy exacerbation.
   • Premedication may include H2-receptor antagonists or proton pump inhibitors.

3. Logistics and Monitoring:

   • Anaesthesia induction requires a tilting table for regurgitation management; often necessitating a separate induction area outside the angiography suite.
   • IV access can be challenging in cirrhotic patients; central venous access may be required, with options including femoral or left internal jugular veins as coordinated with the radiologist.
   • Use of invasive arterial pressure monitoring is advised due to frequent hemodynamic instability, with a double pressure transducer setup for arterial and venous pressures.

4. Pharmacologic Considerations:

   • Choose induction agents (e.g., propofol or thiopental) carefully, considering altered pharmacokinetics in liver disease. Muscle relaxation can be achieved with succinylcholine followed by renally excreted non-depolarizing agents like atracurium.
   • Short-acting opioids (e.g., alfentanil or fentanyl) should be titrated to tolerate intubation and provide analgesia.
   • Maintenance options include volatile agents or total IV anaesthesia, aiming for quick recovery post-procedure.

5. Airway and Aspiration Management:

   • Tracheal intubation is often necessary to manage increased regurgitation risk from ascites.
   • Rapid sequence induction with cricoid pressure and controlled ventilation helps ensure a motionless patient and allows breath-holding for optimal shunt positioning.

6. Additional Supportive Measures:

   • Administer a broad-spectrum antibiotic (e.g., piperacillin-tazobactam or a third-generation cephalosporin) preoperatively, and continue for 24 hours post-procedure.
   • Patient warming and urinary catheterization are also recommended, as the procedure can be prolonged.

Emergency TIPS for Acute Variceal Hemorrhage

In emergencies, rapid stabilization is essential:

• Airway protection via rapid sequence intubation and large-bore IV access.
• Invasive arterial monitoring, correction of coagulopathy, and judicious transfusion are critical, with activation of a major hemorrhage protocol as needed.
• When TIPS follows failed endoscopic therapy in high-risk re-bleeding cases, management aligns with elective protocols, though preoperative work-up may be limited.

Post-procedure Care for TIPS Patients

Haemodynamic Monitoring and Stabilization

Hemodynamic instability is common post-TIPS, especially in patients with significant blood loss. Management includes:

• Hemodynamic monitoring: Continuous monitoring is crucial to assess and address fluctuations in blood pressure and heart rate.
• Correction of anaemia and coagulopathy: Blood transfusions and coagulation factor replacement should be administered as needed to address blood loss and correct coagulation deficits.

The increased venous return to the heart following TIPS can precipitate heart failure, particularly in patients with compromised cardiac function. Management steps include:

• Medical stabilization with initial pharmacologic therapy to control heart failure symptoms.
• Diuretic therapy to manage fluid overload.
• Continuous positive airway pressure (CPAP) may be used to treat pulmonary edema secondary to heart failure.

Management of Hemolytic Anaemia

Some patients may develop hemolytic anaemia within 7–14 days post-procedure. This is due to mechanical shear stress on red blood cells as they pass through the TIPS shunt, causing cell damage and hemolysis. Management involves:

• Monitoring of hemoglobin levels and red blood cell indices.
• Providing supportive care as necessary, with transfusion if anemia becomes severe.

Hepatic Encephalopathy

Hepatic encephalopathy occurs in up to 20% of patients post-TIPS. This condition arises from shunting of blood containing neurotoxic substances (e.g., ammonia and benzodiazepine-like compounds) directly into the systemic circulation, potentially increasing cerebral GABAergic tone.

Management strategies for encephalopathy include:

1. Pharmacologic treatment:

   • Lactulose to reduce ammonia levels by promoting its excretion.
   • Non-absorbable antibiotics (e.g., rifaximin) to decrease ammonia-producing gut bacteria.

2. TIPS Modifications:

   • Shunt size reduction to limit the amount of shunted blood.
   • TIPS occlusion may be considered for intractable cases.

Renal Monitoring and Management

The use of iodine-based contrast agents during TIPS may cause contrast-induced nephropathy or worsen pre-existing hepatorenal syndrome, even if subclinical prior to the procedure.

1. Fluid management is essential, with a cautious approach to prevent fluid overload in these patients.
2. Renal replacement therapy (e.g., hemodialysis) may be required for significant renal dysfunction and should involve consultation with critical care and nephrology teams.

Prevention and Management of Post-procedure Sepsis

Post-procedural sepsis is a risk, typically caused by gram-negative bacteria (e.g., Escherichia coli, Klebsiella, Enterococcus species).

1. Antibiotic prophylaxis and early treatment: Administer broad-spectrum antibiotics, such as piperacillin-tazobactam or a third-generation cephalosporin. Prompt administration is essential to prevent further organ function deterioration.
2. Fluid and vasopressor support: Maintain circulatory stability in septic patients with judicious fluid management and vasopressors as needed.

Post-procedure Monitoring and Care Setting

Patients are generally monitored in critical care, hepatology, or gastroenterology units, with:

• Early warning scoring and frequent medical review to promptly detect any signs of decompensation.
• Critical care outreach and high dependency care for prompt intervention if systemic decompensation occurs.

Given the guarded prognosis in many patients with severe liver disease, ceiling of care discussions are essential. These should be set in a multidisciplinary environment, ideally pre-procedure, to ensure that care goals align with patient outcomes and family wishes.

Links

ICU and liver disease

Liver physiology and pathology

Liver transplant

References

1. Chana, A., James, M., & Veale, P. (2016). Anaesthesia for transjugular intrahepatic portosystemic shunt insertion. BJA Education, 16(12), 405-409. https://doi.org/10.1093/bjaed/mkw022

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© 2025 Francois Uys. All Rights Reserved.

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