What are the steps involved in performing a split liver transplant?

Split Liver Transplantation: Technical Steps

Split liver transplantation involves dividing a deceased donor liver into two functional grafts—typically a left lateral segment (segments II-III) for a pediatric recipient and an extended right lobe (segments I, IV-VIII) for an adult recipient, or alternatively splitting along the line of Cantlie into full right and full left lobes for two recipients. 1

Pre-Splitting Assessment and Planning

Donor Selection Criteria

• Evaluate donor liver anatomy, parenchymal quality, and volumetric adequacy to ensure both grafts will meet minimum size requirements 1
• The graft-to-recipient weight ratio must be at least 0.8% (e.g., a minimum graft weight of 640g for an 80kg recipient) 1
• Careful preoperative interrogation of aberrant hepatic arterial anatomy is essential to prevent vascular complications 2
• Assess hepatic vein patency and anatomical relations, particularly middle hepatic vein tributaries 2

Recipient Matching

• For adult-child splits: the left lateral lobe (segments II-III, approximately 450g) is suitable for small children, while the extended right lobe goes to adults 1, 3
• For adult-adult splits: division along Cantlie's line creates right lobe (segments V-VIII) and left lobe (segments I-IV) 1
• The left lobe typically weighs approximately 450g, limiting its use to recipients weighing 50-55kg 1, 3

Surgical Technique: Splitting Procedure

In Situ vs Ex Situ Splitting

• Splitting can be performed either in situ (in the donor) or ex situ (on the back table after procurement) 4, 5
• Both approaches are viable, with selection based on local expertise and donor stability 4

Parenchymal Division Steps

• For adult-child splits: Divide the liver to create a left lateral segment (II-III) and extended right lobe (I, IV-VIII) 1
• For adult-adult splits: Divide along the line of Cantlie, creating anatomically complete right and left lobes 1, 6
• The falciform ligament marks the division between medial and lateral segments of the left lobe 3

Vascular Reconstruction

• Complete parenchymal division before ligating and transecting the right hepatic artery to minimize vascular complications 2
• Arterial anastomoses are particularly challenging due to small vessel diameter (3-4mm), requiring precise microsurgical technique 2
• Each graft requires separate reconstruction of hepatic artery, portal vein, and hepatic veins 1
• The left lateral graft typically has three separate suprahepatic veins requiring bench surgery reconstruction 1

Biliary Reconstruction

• Liberal use of cholangiograms and bile leak tests is critical, as bile duct complications represent the most common donor complication 2
• Each graft requires separate biliary reconstruction, typically with duct-to-duct anastomosis 1

Implantation Technique

Recipient Hepatectomy

• The piggy-back technique (preserving recipient IVC) is most commonly used in Europe 1
• Anastomosis of donor suprahepatic IVC to recipient's three hepatic veins is performed 1
• Selective use of temporary portocaval shunt or veno-venous bypass may be considered 1

Vascular Anastomoses

• Reconstruct portal vein with end-to-end anastomosis 1
• Hepatic artery reconstruction requires meticulous technique given small vessel caliber 2
• Hepatic vein anastomosis connects donor suprahepatic IVC to recipient hepatic vein confluence 1

Biliary Anastomosis

• Duct-to-duct anastomosis between donor and recipient bile ducts is standard 1
• In recipients with diseased ducts, Roux-en-Y hepaticojejunostomy is performed 1

Critical Technical Considerations

Avoiding Small-for-Size Syndrome

• Ensure minimum graft-to-recipient weight ratio of 0.8% to prevent graft dysfunction 1
• For adult recipients, right lobe grafts are typically required to meet volume requirements 1

Complication Prevention

• Approximately one-third of living donors experience complications, with right lobe donors having significantly higher rates than left lobe donors 2
• Biliary complications and hepatic artery thrombosis are more common in split grafts compared to whole organs 7
• Despite increased short-term complications, long-term graft and patient survival are comparable to whole organ transplantation when performed at experienced centers 4, 5, 7

Center Experience Requirements

• Split liver transplantation is technically demanding and should be concentrated in high-volume centers with sufficient training and experience 1
• Careful donor and recipient selection is essential to optimize outcomes 4, 5