Bioartificial Liver And Extracorporeal Liver Assist Devices
Rationale For Extracorporeal Support
Pathophysiology Of Liver Failure
- Necrosed hepatocytes release toxins and inflammatory mediators.
- Initiates cascade leading to multiorgan failure.
- Elicits vicious cycle of autointoxication.
Purpose Of Liver Assist Devices
- Interrupts autointoxication cycle via toxin removal.
- Provides opportunity for native liver regeneration.
- Evaluated as temporary bridge to liver transplantation or spontaneous regeneration.
Ideal Extracorporeal Liver Support System
Required Functional Capabilities
- Requires performance of complex synthetic functions.
- Demands detoxifying capabilities.
- Necessitates biotransformatory functions mimicking hepatocytes and Kupffer cells.
Classification Of Liver Support Devices
- Broadly classified into cell-free cleansing devices and bioartificial liver support systems.
Comparative Analysis Of Liver Support Systems
| System Feature | Cell-Free Cleansing Devices | Bioartificial Liver Support Systems |
|---|---|---|
| System Type | Non-biologic system | Biologic liver support system |
| Primary Mechanism | Liver dialysis | Perfusion of blood through cellular cartridge |
| Core Components | Albumin-containing dialysate | Human liver cells, liver cell lines, porcine hepatocytes |
| Liver Functions Provided | Detoxifying function only | Synthetic, detoxifying, and biotransformatory functions |
| Theoretical Advantage | Basic toxin filtration | Mimics complex hepatocyte and Kupffer cell properties |
Clinical Outcomes And Efficacy
Biochemical And Neurological Impact
- Removes circulating toxins effectively.
- Decreases serum ammonia, bilirubin, and inflammatory cytokines.
- Improves serum biochemical abnormalities.
- Improves neurologic function in select cases.
Mortality And Survival
- Demonstrates no significant effect on overall mortality.
- Yields little evidence of improved survival rates.
- Remains elusive for successful use as reliable bridge therapy.
Limitations In Pediatric Practice
Clinical Constraints
- Remains strictly experimental.
- Not recommended outside formal research settings.
- High cost prohibits widespread clinical application.
Pediatric-Specific Challenges
- Suffers from nonavailability of small filters appropriate for children.
- Lacks robust safety data in pediatric populations.
- Few children have received this specific treatment modality.