Liver Transplantation Basics

Indications & Scores - Who Gets a Liver?

• Acute Liver Failure (ALF):
  • King's College Criteria (KCC):
    • Acetaminophen: pH < 7.3 OR (INR > 6.5, Cr > 3.4 mg/dL, HE III/IV).
    • Non-acetaminophen: INR > 6.5 OR 3/5: (Age <10/>40, Jaundice >7d pre-enceph, INR > 3.5, Bili > 17 mg/dL, Unfavorable etiology).
• Chronic Liver Disease (CLD):
  • MELD Score > 15. Uses Bilirubin, INR, Creatinine. (MELD-Na adds Sodium). $MELD = 3.78 \times \ln(\text{Serum Bilirubin mg/dL}) + 11.2 \times \ln(\text{INR}) + 9.57 \times \ln(\text{Serum Creatinine mg/dL}) + 6.43$
  • PELD Score for children < 12 yrs.
  • Complications: Refractory ascites, variceal bleeds, SBP, HE.
• Contraindications:
  • Absolute: Sepsis, extrahepatic malignancy, severe cardiopulmonary disease, active substance abuse.
  • Relative: Age >70, BMI >40, controlled HIV, psychosocial issues.

⭐ MELD score incorporates objective parameters: serum bilirubin, serum creatinine, and INR for prothrombin time.

Donors & Allocation - The Gift Source

• Deceased Donors (DD):
  • Donation after Brainstem Death (DBD): Preferred, heart-beating donor.
  • Donation after Circulatory Death (DCD): Non-heart-beating donor, e.g., Maastricht category III.
• Living Donors (LD):
  • Strict Criteria: Age 18-55 years, BMI <30-35 kg/m², voluntary consent, psychological stability, adequate future liver remnant (>30% for donor, GRWR >0.8% for recipient), no significant comorbidities.
• Essential Donor Evaluation:
  • Comprehensive medical, surgical, social history.
  • Serology: HIV, HBV, HCV, CMV, EBV.
  • Imaging: CT/MRI for liver anatomy, steatosis, volumetrics.
  • Liver biopsy: If steatosis or fibrosis suspected.
• Allocation & Matching:
  • ABO Compatibility: Identical (e.g., A to A) or compatible (e.g., O to A/B/AB). ABO-incompatible (ABOi) is high-risk, requires desensitization.
  • MELD/PELD Score: Prioritizes sickest patients. MELD (Model for End-Stage Liver Disease) for adults; PELD (Pediatric ELD) for children <12 years. 📌 MELD: "BIC" (Bilirubin, INR, Creatinine).

  ⭐ The MELD score, ranging from 6 to 40, predicts 3-month mortality on the waiting list; higher scores indicate greater urgency.

The Operation - Swap & Stitch

• Techniques:
  • Conventional: IVC cross-clamping, Veno-Venous Bypass (VVB).
  • Piggyback: Preserves recipient IVC, no VVB. ↓Hemodynamic instability.
• Key Phases & Anastomoses:

• Post-op Monitoring:
  • Hemodynamics: BP, HR, CVP.
  • Graft function: LFTs, INR, glucose.
  • Urine output: >0.5 ml/kg/hr.

⭐ Post-Reperfusion Syndrome (PRS): Mean Arterial Pressure (MAP) ↓ >30% for >1 min within 5 min of graft reperfusion.

Post-Op Path - Guarding the Graft

Immunosuppression Strategy:

• Phases:
  • Induction: Basiliximab, ATG. Prevents early rejection.
  • Maintenance: Lifelong. CNI (Tacrolimus) + Antimetabolite (MMF) ± Steroids. mTORi (Sirolimus) option.
  • Rejection Tx: Pulse steroids; ATG if steroid-resistant.
• Key Drug Side Effects (📌):
  • CNIs: Nephro/Neurotoxic, HTN, DM. Cyclo: Gingival hyperplasia, Hirsutism.
  • MMF: GI distress, myelosuppression.
  • Steroids: Cushingoid, DM, osteoporosis.

Graft Rejection Types:

• Hyperacute: Pre-formed Ab (ABO/HLA); mins-hrs.
• Acute Cellular (ACR): T-cell; days-wks. Biopsy: Endotheliitis, portal inflammation, bile duct injury.
• Antibody-Mediated (AMR): DSA; C4d+.
• Chronic: Months-yrs; fibrosis, Vanishing Bile Duct Syndrome (VBDS).

Common Complications:

• Vascular: Hepatic Artery Thrombosis (HAT) (early), PVT.
• Biliary: Strictures, leaks.
• Infections: CMV, fungal. Prophylaxis vital.
• PTLD (EBV-driven).
• Disease recurrence (HCV, HCC).

⭐ Hepatic Artery Thrombosis (HAT) is the most common early vascular complication, often leading to graft failure if not promptly addressed.

High‑Yield Points - ⚡ Biggest Takeaways

• MELD score is crucial for adult recipient prioritization, reflecting disease severity.
• PELD score is used for pediatric recipients (<12 years), including growth factors.
• Milan criteria (e.g., single HCC ≤5 cm) guide HCC transplant eligibility.
• ABO blood group compatibility is mandatory; Rh matching is not a primary concern.
• Commonest indication: Decompensated cirrhosis (e.g., viral hepatitis, alcoholic liver disease).
• Standard immunosuppression: Tacrolimus (CNI), Mycophenolate Mofetil (antimetabolite), and steroids.
• Biliary complications (strictures, leaks) are common technical issues post-transplant.