test 7 liver transplants and assist

Question 1

Veno-Venous Bypass for liver transplants

Answer 1

 During liver removal, IVC and portal vein occluded
 Decreased venous return results in ~50% drop in CO, ↑ SVR
 Portal HTN, bowel congestion and hemorrhaging from high pressure venous collaterals
 Stabilizes blood inflow to heart
 Safer extension of anhepatic phase

Question 2

No V-V Bypass for liver transplants

Answer 2

 Complicates procedure
 Risk of air embolism
 Potential of thrombi cannulated vessels
 Hypothermia risk

Question 3

Liver transplants

Answer 3

 Patients are often hemodynamically tested by “trial” clamping the IVC
 V-V bypass allows maintenance of filling pressures and CO
 Degree of support depends on health of patient
 Benefits also include:
 increased renal perfusion
 ↓ renal failure
 decreased transfusion requirements
 safer extension of anhepatic phase

Question 4

Liver Transplant Equipment

Answer 4

 Heparin coated cannulae and tubing connected to centrifugal pump (No Heparin Leaching)
 Portal vein and IVC (iliac veins) cannulae placed and drained to centrifugal pump.
 Return flow empties into axillary or IJ vein
 Flows are maintained >1L/min to avoid stasis and potential thrombus formation

Question 5

Extracorporeal Liver Assist Device (LAD®)

Answer 5

 Key to the performance of ELAD® System is the proprietary C3A human hepatocyte cell line
 An immortal cell line that is grown in ELAD® cartridges
 Provides liver support up to ten days or more
o compromised liver function
o stabilize the patient until transplantation.

Question 6

Extracorporeal Liver Assist Device (LAD®) functionality

Answer 6

 Separates cell from plasma thru ultragenerator
 Cellular portion returned to patient
 Plasma perfuses thru 3 ELAD C3A cell cartridges
 C3A cells pass into plasma
 Flows thru 3 filters recombining with the cellular portion