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Who Needs a Transplant?

• Waiting List Statistics:

  • Nearly 107,000 people in the US on waiting list for organ transplants (as of 8/12/21).

• Wait Times:

  • Patients aged 50 and over face the longest average wait, ranging from 6 months to 4 years depending on organ type (e.g., kidneys, kidney-pancreas).

  • Kidneys have the longest wait list, followed by livers.

  • Lungs are identified as the hardest organ to transplant.

Transplant Team

• Composition:

  • Includes clinical transplant coordinators, transplant physicians, surgeons, financial coordinators, and social workers.

• UNOS (United Network for Organ Sharing):

  • Maintains a centralized networking system for organ procurement organizations and transplant centers, ensuring fairness in candidate selection.

History and Criteria for Liver Transplantation

• Liver Disease Requirements:

  • Severe liver disease necessitates a transplant for survival.

• Types of Liver Failure:

  • Acute liver failure: Sudden onset often due to drug-induced injury (notably acetaminophen overdose).

  • Chronic liver failure: Progressive condition developing over months to years.

Other Liver Diseases

• Diseases Leading to Liver Failure:

  • Chronic Hepatitis B and Autoimmune Hepatitis.

  • Nonalcoholic Steatohepatitis (NASH): Fat and inflammation of the liver.

  • Hemochromatosis: Iron accumulation in the liver.

  • Wilson Disease: Copper accumulation in the liver.

  • Budd-Chiari Syndrome: blockage of hepatic veins.

  • Various biliary diseases and liver cancer.

• Transplant Procedure:

  • Patients typically receive a portion of a liver, often the right hepatic lobe.

MELD and PELD Scales

• Purpose:

  • MELD (Model for End-Stage Liver Disease) for adults and PELD (Pediatric End-Stage Liver Disease) for children under 12.

  • Both scales help predict prognosis and prioritize transplant recipients.

  • Higher scores indicate greater urgency for transplant.

Milan Criteria

• Indications for Liver Transplant:

  • Applicable to cirrhotic patients with Hepatocellular Carcinoma (HCC):

    • Candidates may have one tumor <5 cm or up to three tumors each <3 cm, with no vascular invasion or extrahepatic involvement.

Common Reasons for Liver Transplant

• Primary Causes:

  • Alcoholic cirrhosis, chronic hepatitis C (leading cause), alcohol abuse, and other chronic liver diseases.

Allograft Definition

• Allograft:

  • Refers to the transplant of an organ or tissue from one individual to another of the same species but different genotype. (not twins)

Cadaveric Liver Donation

• Definition:

  • Involves the transplantation of a liver from a deceased donor.

Living Donor Liver Donation ‘

• Benefits:

  • Offers an alternative for patients waiting for transplants and increases organ supply.

• Process Comparison:

  • Surgical technique similar to cadaveric transplants with generally quicker organ function due to reduced preservation time.

  • Approximately 60% of the donor's liver is utilized for the transplant.

Evaluation of the Liver Allograft

• Assessment Criteria:

  • Evaluate transplant size, echotexture, contour, biliary tree, vasculature, and search for masses or ascites.

  • Follow-up ultrasounds typically conducted every 6 months to 1 year if no complications arise.

  • Look for urgent complications including thrombosis (formation of blood clot in vessel)or active bleeding.

Normal Sonographic Findings of the Liver Transplant

• Imaging Results:

  • Normal liver parenchyma should appear smooth, homogeneous, and isoechoic relative to the right renal cortex.

  • Vessels and biliary ducts should appear anechoic with no distinct walls in hepatic veins and inferior vena cava.

Pathology of the Liver Transplant

• Rejection:

  • Most common cause of transplant failure, with acute rejection possible within the first 10 days and chronic rejection occurring gradually.

• Infection and Abscesses:

  • Abscess appearance includes thick walls, hypoechoic characteristics, and complex structures with poorly defined borders.

Additional Complications

• Hepatic Artery Stenosis:

  • Can be visualized with superselective angiograms showing stenosis and altered Doppler waveforms.

  • Stenosis- abnormal narrowing of passage or opening in the body

• Thrombus Development:

  • Thrombosis can occur at the anastomosis sites of hepatic veins and portal veins, requiring careful ultrasound evaluation for detection.

  • Anastomosis- connection or joining of two structures