| | Surgery | Anesthetic concerns |
| Dissection/pre-anhepatic phase | - Incision
- Drainage of ascites if present
- Dissection and isolation of recipient liver structures
- Ligation of:
- Bile duct
- Hepatic artery
- Portal vein
- Institution of venovenous bypass if used
| - Drainage of ascites causes hypovolemia
- Vasodilatory state requires vasopressors
- Potential for excessive bleeding due to dissection, portal hypertension, and coagulopathy
- Avoid volume overload to prevent worsening venous bleeding while maintaining organ perfusion
|
| Anhepatic phase | Anastomosis of vena cava and portal vein after removal of the native liver techniques employed include: - Caval clamping
- Piggyback technique with or without temporary porto-caval bypass
- Venovenous bypass
- Combinations of these techniques
| - Loss of preload (caval clamp > piggyback > venovenous bypass) and possibility of profound hypotension
- Hyperkalemia needs aggressive treatment to prevent hyperkalemic arrest during reperfusion
- Worsening acidemia due to absent hepatic lactate clearance and organ hypoperfusion
- Preparation for reperfusion
- Ensure potassium level <4.0 to 4.5 mEq/L
- Administer magnesium sulfate 2 g over 10 to 25 minutes
|
| Reperfusion | Release of: - Vena caval clamp
- Portal vein clamp
| Initially (with caval clamp release): return of preload and blood pressure unless caval anastomosis is kinked Portal reperfusion syndrome (decrease of MAP >30% for >1 minute within 5 minutes of reperfusion[1]): - Hyperkalemia
- Hypotension
- Pulmonary hypertension
- Right ventricular failure
- Cardiovascular collapse
- Thromboembolic complications
If not rapidly stabilized the surgeon can reclamp the portal vein to prevent cardiac arrest |
| Neohepatic phase | - Hepatic artery anastomosis
- Biliary anastomosis (possibly with Roux-en Y hepaticojejunostomy)
- Surgical hemostasis
- Wound closure
| Adequate graft function requires hepatic artery blood flow Signs of graft dysfunction: - Persistent or increasing vasopressors requirements
- Increasing arterial lactate
- Decreased urine output
- Worsening or persistent coagulopathy
Rule out reversible causes: inadequate hepatic arterial flow, technical complications |
