What is right hepatic artery embolization (RHA) or ligation?

Right Hepatic Artery Divestment: Embolization and Ligation

Right hepatic artery (RHA) divestment refers to the intentional interruption of blood flow to the right hepatic lobe through either embolization or ligation of the right hepatic artery, typically performed in trauma settings or as part of planned surgical procedures.

Indications and Procedures

Trauma Management

In liver trauma, selective hepatic artery ligation may be necessary when:

• Persistent arterial bleeding occurs despite initial maneuvers (hepatic packing, Pringle maneuver) 1
• Direct repair of the injured vessel is not possible or effective 1
• The patient is hemodynamically unstable due to ongoing hemorrhage 1

Procedural Options

1. Selective Hepatic Artery Ligation:

   • Surgical ligation of the right hepatic artery branch when repair is not possible
   • Performed during exploratory laparotomy for trauma or planned procedures
   • Must be accompanied by cholecystectomy when right or common hepatic artery is ligated to prevent gallbladder necrosis 1

2. Angioembolization:

   • Less invasive alternative to surgical ligation
   • Can be performed pre-operatively or post-operatively
   • Useful for persistent arterial bleeding after non-hemostatic procedures 1
   • Allows hemorrhage control while potentially reducing complications 1

Risks and Complications

The interruption of right hepatic arterial flow carries several significant risks:

• Hepatic necrosis: Areas of liver tissue may become devitalized 1
• Biloma formation: Collection of bile due to ischemic injury to bile ducts 1
• Abscess formation: Secondary to tissue necrosis 1
• Biliary complications: Including anastomotic failure in cases involving biliary reconstruction 2

Clinical Decision Algorithm

1. Assess hemodynamic status:

   • If unstable with active bleeding from RHA → consider immediate intervention
   • If stable → consider less invasive options first (angioembolization)

2. Evaluate arterial injury:

   • Attempt direct repair of RHA if technically feasible
   • If repair not possible → proceed with divestment

3. Choose divestment method:

   • For trauma patients requiring immediate control → surgical ligation
   • For stable patients with persistent bleeding → angioembolization
   • For planned procedures → consider preoperative embolization to allow collateral formation 3

4. Mandatory additional procedures:

   • Perform cholecystectomy when ligating right or common hepatic artery 1
   • Consider post-operative monitoring of liver function

Special Considerations

• Collateral Circulation: The liver has dual blood supply (portal vein and hepatic artery), which may allow for adequate perfusion after RHA divestment in some cases 2

• Preoperative Planning: In elective cases where RHA sacrifice is anticipated (e.g., pancreaticoduodenectomy with RHA involvement), preoperative embolization may allow for sufficient collateralization before definitive surgery 3

• Anatomic Variations: Aberrant right hepatic artery anatomy is common (present in approximately 15-20% of patients) and must be carefully identified before any intervention 4, 5

Post-Procedure Management

• Close monitoring of liver function tests
• Surveillance for signs of hepatic ischemia or necrosis
• Early detection and management of potential biliary complications
• Consideration of post-operative angiography if concerns for inadequate perfusion arise

RHA divestment, while sometimes necessary, should be approached with caution and performed by experienced surgeons or interventional radiologists with a thorough understanding of hepatic vascular anatomy and potential complications.