Portal Vein Reconstruction during Liver Transplantation

Joseph F. Magliocca

DEFINITION

After the reconstruction of the hepatic venous outflow is complete, the next step in graft implantation is the restoration of portal venous and hepatic arterial inflow to the donor liver. Although the sequence of the vascular anastomoses has been reported in varying orders, the implantation generally proceeds as follows: reconstruction of venous outflow, reconstruction of portal venous inflow, reperfusion, reconstruction of hepatic arterial inflow, and reconstruction of biliary outflow.

TECHNIQUES

PREPARING THE RECIPIENT PORTAL VEIN FOR ANASTOMOSIS

Clamp the recipient portal vein with a vascular clamp near the head of the pancreas. If more length is needed on the portal vein, carefully dissect back to the head of the pancreas by dividing the loose areolar tissue around the vein. If the portal vein was transected using a vascular stapler during the recipient hepatectomy, the staple line is excised at this time.
Trim the open end of the portal vein back to healthy-appearing tissue, if safely possible. It is imperative to leave a suitable vein cuff for sewing.

Assessment of Portal Inflow

Firmly grasp both corners of the cut edge of the recipient portal vein to prevent vein retraction. Briefly open the vascular clamp to remove any clot that may have formed in the portal vein and to ensure brisk portal venous inflow.

Flushing Preservation Solution from the Donor Liver

If the donor liver was preserved with University of Wisconsin (UW) preservation solution, the organ must be flushed to remove the preservation solution prior to reperfusion. This is due to the fact that UW solution has a potassium concentration of 125 mEq/L. If released directly into the systemic circulation, it can cause cardiac arrest.
Adequate flushing can be achieved in one of two ways.
- The liver can be flushed via the donor portal vein with 1 L of an admixture containing 0.9% normal saline per 5% human albumin. Albumin is felt to prevent any further hepatocyte swelling. The flush is drained from the liver via the donor infrahepatic inferior vena cava (IVC). If the piggyback technique of caval reconstruction was used, then the flush is drained freely, followed by ligation of the donor infrahepatic caval cuff. If the bicaval technique was used, then the infrahepatic anastomosis must be left loose to allow the flush to drain freely. The infrahepatic caval suture is subsequently secured.
- Alternatively, the liver can be flushed with blood. This flush is performed after completion of the portal venous anastomoses and immediately prior to reperfusion and will be described at the appropriate point in the text.

Preparing the Donor Portal Vein for Anastomosis

Cut the donor portal vein to the appropriate length for the best possible anastomosis. If the vein is cut too short, the anastomosis will be under tension and may tear. If left too long, vein redundancy can cause significant angulation and/or kinking. The goal is to achieve a straight, near-anatomic anastomosis. It is important to configure the liver in a normal, anatomic position before deciding on the portal vein length. This is achieved by slightly relaxing the pull on the retractors. During the transplant procedure, the retractors are pulling firmly upward on the costal margin and downward on the intestines. This configuration allows the liver to “fall away” from the recipient porta hepatis. After abdominal closure, the liver will be pushed into close proximity with the pancreatic head and portal structures.
Place icy laparotomy pads above and behind the liver to push it out of the hepatic recess and into a more anatomic position. The donor portal vein is then transected to a final length, which allows it to lay adjacent to the recipient portal vein under no tension.

Performing the Venovenous Anastomosis

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