How Shunt Obliteration Helps in Recurrent Encephalopathy with Lienorenal Shunt
Shunt obliteration redirects nutrient-rich portal blood back to the liver, eliminating the bypass that causes recurrent hepatic encephalopathy, with approximately 60% of patients achieving freedom from encephalopathy at 100 days and 50% maintaining this benefit at 2 years. 1
Mechanism of Benefit
Shunt obliteration works by reversing the pathophysiology that causes recurrent encephalopathy:
Restores hepatopetal portal flow: Large portosystemic shunts like lienorenal shunts deprive the liver of nutrient-rich portal blood, and obliterating these shunts redirects this blood back through the liver 2
Reduces systemic ammonia levels: After shunt embolization, serum ammonia levels drop dramatically (from 181±86 μg/dL to 107±45 μg/dL in one study, and from 127±35 to 31±17 in another) 3, 2
Improves liver volume and function: Shunt occlusion increases mean liver volume by 8.8% and improves serum albumin levels (from 2.92±0.40 g/dL to 3.30±0.49 g/dL), demonstrating restoration of hepatic synthetic function 2
Patient Selection Criteria
The most critical factor is MELD score <11, which is the strongest predictor of successful intervention without complications. 1
Key selection criteria include:
- MELD score <11: This threshold separates patients who benefit from those at high risk of complications 1
- Child-Pugh class A or B: Avoid attempting shunt obliteration in Child C cirrhosis 3
- Confirmed single large portosystemic shunt on imaging: Essential for appropriate patient selection 1
- Failed medical therapy: Patients should have inadequate response to optimized lactulose (2-3 soft bowel movements daily) plus rifaximin 550 mg twice daily 1, 4
- Absence of large ascites or large varices: These are relative contraindications 3
Procedural Approaches
Coil-assisted retrograde transvenous obliteration (CARTO) via jugular vein approach has shown promising results with limited side effects for splenorenal shunts 1
Balloon-occluded retrograde transvenous obliteration (BRTO) or plug-assisted retrograde transvenous obliteration (PARTO) are effective techniques using sclerosants (sodium tetradecyl sulphate, lipiodol) and/or endovascular occlusion plugs 3, 5
Embolization of minor outflow veins using coils and glue may be needed to allow stable deposition of sclerosants in the dominant shunt 3
Expected Outcomes
Complete resolution of encephalopathy occurs in the majority of appropriately selected patients:
No recurrence of encephalopathy was observed in all patients in one series during follow-up periods ranging from 6 months to 2 years 3
94.4% achieved non-recurrence of HE when complete shunt occlusion was accomplished 2
60% remain free of hepatic encephalopathy at 100 days, with nearly 50% maintaining freedom from encephalopathy for 2 years 1
Improvement in MELD-Na score and bone density compared to medical management alone 2
Post-Procedure Monitoring
Critical surveillance after shunt obliteration includes:
Assess for recurrence of varices, portal hypertensive gastropathy, or ascites following shunt obliteration, as redirecting portal flow increases portal pressure 1
Continue maintenance lactulose and rifaximin even after successful shunt obliteration unless precipitating factors are completely controlled 1
Monitor for hepatic myelopathy, a rare complication presenting as spastic paraparesis, which requires urgent transplant evaluation if it develops 1
Follow-up imaging to confirm complete shunt obliteration 3
Critical Pitfalls to Avoid
Do not attempt shunt obliteration if MELD ≥11, as the risk of complications outweighs benefits 1
Avoid in patients with Child C cirrhosis or large ascites, as these predict poor outcomes 3
Do not discontinue medical therapy immediately post-procedure—continue lactulose and rifaximin during the initial recovery period 1
Comparison to Other Therapies
While surgical shunt procedures and TIPS are very effective in preventing variceal rebleeding, they markedly increase the risk of hepatic encephalopathy and have no effect on survival 6. In contrast, shunt obliteration specifically addresses the problem of encephalopathy caused by existing shunts, making it the appropriate intervention for patients with recurrent encephalopathy rather than those needing prevention of variceal bleeding 1.
When Shunt Obliteration Fails
If recurrent or persistent hepatic encephalopathy continues despite shunt obliteration, or if MELD score >15 with history of recurrent hospitalizations for overt encephalopathy, transplant evaluation is indicated 1, 4